Which sight records are reportable?

Recently I spent a few days on Java and saw a bunch of mammals, including two sightings of what I IDed as being very rare and little-know species (more on this below). Before submitting the trip reports, I discussed the sightings with a bunch of people, and one of them, also a mammalwatcher (let’s name him X), got kind of angry at me, saying that I should never make these sightings public. We got into a lengthy discussion, and since the subject is probably of interest to many people here, I’m going to repeat my arguments and add some thoughts in this post. I hope you’ll not find this text too boring (if you do, better stop reading soon because it is VERY long).

So X’s reasoning (if I understood him correctly) was that extraordinary claims require extraordinary proof, which a sighting without a photo or a specimen can’t be. And since I didn’t meet this criterion, I should keep silent about the sightings.

I was surprised by this argument because proving anything was the last thing on my mind. I wasn’t applying for a conservation grant based on these sightings or counting them towards the total of some Big Year competition. I simply wanted to get the information out because I assumed it would be of interest to people conducting research in the area; they themselves should decide if the evidence is good enough to be taken seriously. But was the evidence any good at all?

A century ago, ornithologists considered bird records valid only if they were supported by specimens. Very gradually they began to trust records with photos, and then sight records. It wasn’t because their criteria became laxer. It was because countless people spent decades developing the techniques for identifying birds without shooting them, discussed their findings, and published them. Did it make sight records of birds 100% reliable? Of course not. But it got to the point when they were reliable enough to do more good than harm when used in research.

Mammalogy is decades behind. Contrary to popular belief, it’s not because mammals are so much more difficult to ID by sight. In Europe, for example, there are very few species pairs that can’t be told apart by external appearance – a situation not that uncommon in birds, where some species can be reliably told apart only by song, or by nesting season/location, or only in certain plumages. It’s because until recently, few people even tried to ID small mammals by sight, and even fewer got good at it. There are still very few books listing useful field marks, and scientists studying and using those field marks seldom bother sharing their knowledge.

Just as with birds, it takes practice and learning, and the better you get, the more reliable are your records. But there is no objective way for other people to know how good you are (having a Ph.D vs. having 2 years of village school is not a reliable indicator, contrary to another popular belief). And once you get really good, it actually becomes difficult for others to believe you can be that good. My late father never believed that I could ID most birds in flight, even though he himself could ID in flight most butterflies of the former Soviet Union – a much more difficult task.

And the skeptics do have a point. Unless you are on an island with just one species of everything, sight records of small mammals are almost never 100% certain, particularly brief ones. Your brain’s image recognition software can play stupid jokes on you and make you make stupid mistakes.

But records with “hard evidence” aren’t always 100% certain, either. Photos and videos can distort shapes and colorations, or not show critical features, and people analyzing them make stupid mistakes, too (I made one just last month). Even museum specimens are routinely misidentified. Often the only way to be 100% certain is to get a good nuclear DNA sample, and even that would work only if there are reference data from all possible species.

So should you publish your sight record? Well, before you answer this question, there’s another one: can you? For scientific publications, the answer is usually no. At least one of your reviewers will always be an old-school mammologist who will demand a specimen. I gave up trying long ago. Last year I made an exception for one rat record from Iraq because it was the purpose of a whole trip, my friend and I saw the animal very well, and it was a species not recorded with certainty for a long time and thought possibly extinct, so I thought the sighting was important. Turned out, we didn’t have to bother: a month after our paper came out, another one was published by Iranian zoologists who obtained a specimen just a few kilometers from our site (but across the border) on the same week. Well, at least our sight record got “confirmed”.

That means that the only possible place to make your sight records public is this site or social networks. If you decide not to do it, you save yourself from criticism, but the information you possibly obtained goes to waste. If you do make it public, it might still go to waste, but it might also be picked up by someone and prove useful. Will it do more harm or good?

Personally, I don’t see much possible harm, even if you misidentified the species. Your record is unlikely to be cited in scientific literature and distort some study. Nobody is going to create a new national park in a crappy area or dole out funding to a wrong person based on a sight record (if you are thinking “wait, what about the ivory-billed woodpecker?”, remember that there were sound recordings believed by experts to be strong evidence).

But is there any good, assuming you are correct? There is some hope. Perhaps someone will read it and decide to check out your site when he happens to be working in the area. Or someone will keep the probability of encountering the species in mind when doing a survey. Or simply get another sight record in the same place, but get more credibility because two independent records are better than one (well, this sometimes backfires, and chains of wrong IDs are created, but such situations are rare).

Let’s talk about my two records that started this.

1. A large freetail bat flying over a river is seen at dusk, silhouetted against the sky; the only ID feature I can see is long ears protruding over the nose. I come back on another evening, see it again (but not so well) and get a detector recording (click on the green image in this post to see part of the sonogram). I can’t even attempt to get a photo because my camera broke down earlier.

Now, there are four species of freetails known from the area; three of them have short ears (and two of those three species are not large). My recording doesn’t match any of these three species, but freetail vocalizations are notoriously variable so it doesn’t mean much; besides, the quality of the recording sucks because the bat was flying a bit high and I had a tiny handheld detector. The fourth species has huge ears, it is also the only one known to roost in trees, and there are no caves or houses nearby. (That is not terribly meaningful, either, because freetails are fast flyers and some are long-distance foragers, but I saw it at dusk so it’s likely that the roost wasn’t too far.) That fourth species is known only from two records, one of them made many decades ago. There are no call recordings; calls of a related species look a bit like the one I obtained but not identical. So if I saw it, it’s an extraordinary claim, and I certainly don’t have an extraordinary proof – I don’t have any proof! And I myself have no way of knowing if I really saw what I thought I saw: what if my brain played a trick on me, or the bat had a large moth in its mouth that made its silhouette look long-eared? Why bother making this record public?

Well, first of all, the claim is not as extraordinary as it seems. Most freetails are high-altitude foragers, so they can be extremely difficult to catch unless you find a roost or happen to be mistnetting in a place where they come to drink (but large species tend to drink from larger bodies of water where it’s difficult to set up a mistnet). So a lot of species, particularly tree-roosting ones, are almost never collected and are generally poorly known; it doesn’t mean they are truly rare.

Second, if I somehow make this record public, the only harm is to me: a lot of people will tell me that I made it up. But maybe (a big maybe) local zoologists who perhaps all but forgot about this bat will now keep in mind that it might occur in the area where I reported it, and that will increase the chances of them noticing/recognizing it when they see it. I decided to make it public. What would you do?

2. My friend and I are walking along a forest trail just 5 min from a busy campground, and a rat runs across the trail along a hanging branch. I’ve been training myself to ID rodents running across roads and trails for a long time, so the first thing I look at is the tail to body length ratio; my friend is relatively new to this so he doesn’t pay attention to the tail. The tail is very long and it isn’t black. There is only one rat-sized rodent on Java with such a tail. It is known only from the type series collected decades ago, at locations not far from our trail. One of these sites was in bamboo so the rat is believed to be a bamboo specialist. The whole area is just outside Jakarta and a lot of zoologists have done research there. Of course, there is a chance that my brain played a trick on me, or that the rat had an abnormally long tail (it does happen, although much, much less often than abnormally short tails – I’ve only seen one such rodent in my life, and I’ve handled and measured thousands), or that I’m not as good at estimating relative tail length as I think. Again, an extraordinary claim without any proof?

And again, it’s not actually that extraordinary. Arboreal rodents are difficult to trap and thus relatively poorly known. It was always believed that Sri Lanka had none, but a few years ago a tree mouse was photographed there by a mammalwatching tour group, and it was from a genus known only from very far away; if not for the photo, it would probably remain unknown. I don’t think many people capable of IDing rodents on sight have been spotlighting on that trail – perhaps nobody, because there is much more pristine habitat a short walk away. And I’m almost sure nobody searched the trail for that particular species, because there’s very little bamboo there.

So should I make this record public? Again, I would be risking my credibility. Again, there is a chance that somebody will try looking for the rat along that trail, and a much smaller chance that a specimen will be obtained. I thought about this and decided not to publish the record – although I’ll not keep it a secret, I am a scientist and shouldn’t withhold information (yes, I know, a murky line). I’ll just try to carve out a week at some point and spend it living at that campground. If you’d like to try yourself, ask me for details personally.

Note: of course, everything I said only works if you are not into competitive mammalwatching. Once it becomes a competition, there should be strict pre-agreed criteria on what is countable and what isn’t. No idea what they should be (requiring photo evidence would turn the whole thing into a camera quality competition). But I’ve never been into competitive twitching, Big Days etc., so I don’t think I should discuss that subject.

Comments very welcome.


  • Peregrine Rowse

    Interesting philospohical debate. It reminds me of an incident yesterday. I came home and told my wife I had seen an old friend on the other side of the street. Incredibly she believed me. I didn’t kill him and collect a specimen, I didnt take a photograph of him and I didn’t rush up to him and cut of lock of his hair for DNA analysis. Any sight record can never be 100% proven but in capable hands (and eyes) with a supporting decription of circumsatnces, light, duration, distance etc should be acceptable and readers can make their own judgement. Some will doubt, many others will not. Peregrine Rowse

    • Vladimir Dinets

      Oh, I think all sight records should be doubted a bit; the probability of error is always there. The questions are, how can you improve the reliability of your sightings and how can people decide if your sighting is reliable enough for their particular purposes: keeping your eyes open for a reported rarity when you walk the same trail is one thing, embarking on an expensive expedition to chase a sight record is another. It’s a good idea to describe in detail how you identified the species, but doing it for all species in all trip reports is probably impractical… perhaps only for rare, difficult to ID, or otherwise problematic species?

  • JanEbr

    I really don’t get where people like Mr. X are coming from, but I have strong suspicion that it’s just a misguided sense of “this is how things have been done always and thus it must continue and I know this and by perpetuating this knowledge of mine, acquired by hearing it from people I deem wise, I am thus also wise!” – a condition that occurs quite commonly woth all kinds of people.

    There are only two valid reasons to withholding information: 1. releasing it would cause harm to a living being, 2. you can’t be bothered. Since you clearly can be bothered and there doesn’t seem to be any harm, there is no reason left. I don’t think you personally need to worry about your reputation in any means imaginable – I think everyone who cares enough to have an opinion on you already does 🙂

    • Vladimir Dinets

      I don’t think that was Mr. X’s logic. To me it seemed like he applied the same approach to informal reports as to scientific papers – but in my personal opinion it shouldn’t be that way. Or maybe he was just thinking in terms of competitive listing, where a false claim is often assumed to be cheating rather than an honest error.

      • Jurek

        Of course, the same care should be applied to a trip report and a scientific paper. Because in case of birds, scientific reports often include visual sightings from trip reports. 99,9% of bird records are trip reports and bird lists. If an ornithologist would apply lax criteria to his hobbyist observations, nobody would believe visual observations in his scientific papers.

  • mikehoit

    Couldn’t agree more. I don’t see what possible harm can come of reporting sightings informally, and like you think raising awareness that a species might be present is likely to have positive result. Personally I’d always take this approach: when I’ve managed to produce trip reports, I would rather list a species as “probably X” with caveats that eg rodent/shrew/microbat field ID is not certain, than ignore the sighting entirely.

    One point on this might be that no one can be sure of how much restraint other observers show. I’m sure we’ve all encountered people who tend to get, let’s say, a bit overexcited over a brief wildlife encounter… As someone who spends a lot of time in the field, I like to think I’m a fairly cautious observer: aware of the limits of both what you can reasonably see, aware of the pitfalls of eyes & brain playing tricks, and happy to be corrected if I’ve made a mistake. However, there’s no way of anyone else knowing this (and others could have a different opinion!).


  • Rob

    Fully agree to publish in mammal trip reports etc. As long as you describe (like you do) how you saw it and why you came to that ID, I don’t see the problem. It might even help people that are less experienced to learn from the reasoning, but also be alert for those features if they are in that same region. Even mammalwatchers not so much into rodent (like me) might take a picture if I see an animal I think I read about being rare;) There is still so much unknown, even birds get (re)discovered, and as you say mammalwatching is far behind still. Best citizen science in my opinion:)

  • Ian Howarth

    One issue that’s not explicitly addressed here is the well-being of the animal/site. Locations — or just observations — of rare plants are often withheld because of the danger that they’ll be “overtouristed”, or even dug up (sadly, a very real risk for scarce orchids, even in the UK). I guess that’s not so much of a problem for things that move (birds, mammals); could they even benefit from publicity? Or am I overestimating the tourism potential of a rat running along a branch…?

    • Vladimir Dinets

      That’s seldom an issue for small mammals (although bat colonies in caves not often visited by people can be sensitive to disturbance). Once you get to pangolin size, things change dramatically.

  • Morgan Churchill

    Unless the species is sensitive and revealing information might endanger it, I don’t see a reason not to report it via websites like this or in trip reports or what have you. Let the reader decide. I think this is true for observations even made in a “competitive” sense. If you feel comfortable counting/reporting something, do so. At the end of the day, we are really only in competition with ourselves, and I think most people aren’t so willy nilly on counting things, because we want our lifelist to have some degree of integrity.

    For actual publications, I do think there should be a higher degree of evidence, especially for a sighting which may be unusual in any way (rarity, habitat, location, etc). Identification by sight is still something that for many groups is not real well worked out, and I would say as a birder detection and ID of mammals IS far more difficult. It might be more appropriate to first really get the ID criteria out there in the literature first. Bird Identification in part has become easier because it builds off of innumerable articles on the subject published in scientific and quasi-scientific sources. Birds are pretty much the only major group where there are lots of really good and usable field guides to allow field ID by even beginners. Even in the US, the body of reference material for non-bird groups is dissapointingly small, and much of it is keyed for in-hand identification.

  • JanEbr

    I am yet to meet a mammalwatcher in the wild 🙂 I think this report is of interest to like 10 people in the world… this may change, but for now, there isn’t a horde of people going after small nocturnal animals.

    • tomeslice

      I’ve actually met mammal watchers in the wild!

      It’s the coolest thing, to be in a remote middle of nowhere, run into someone you’ve never met before (sometimes the only other westerner you’ve seen in days), say “Hi, I’m Tomer” and then have them respond with “Oh, we’ve spoken before” or “I tried e-mailing you”
      There are some very good people in this community ☺️

  • Jon Hall

    I can’t speak for Mr X but I do know the wider conversation about the Java report, and some of these sightings. For me at least the point is not that sight records cannot be trusted. It is that when sight records are inconclusive they ought to be reported as inconclusive together with a range of qualifications and other’s opinions too if they have been given (this is even covered in the Code of Conduct which warns against “cavalier sightings”).

    Of course one person’s inconclusive is another person’s 100%, but I think most of the reports on this sight do a thorough job of considering what can and cannot be claimed (I know personally it keeps me up at night). Some of you might remember the valiant effort Jan Ebr went to to try to figure out some voles he photographed in Turkey recently but left those in the end as “microtus sp”.

    I decided to temporarily remove the Java trip report from the site until it can be given some more clarifications for two reasons.

    1. There was not enough nuance or background in the report about those sightings that did not seem conclusive to others, especially some of the significant ones. Many were just reported as “We saw X”.

    2. There was no mention that others disagreed (including others who were actually there) about some of the sightings, which was frustrating for them and for me to hear.

    Here are three examples

    Reporting an extremely rare bat based on animals moving too high for the basic detector to get a good reading, and presumably quickly, and then estimating size in low light does feel like it might be a bit “cavalier”. And somehow seeing its ears too. I am pretty sure I have never seen a bat’s ears in flight no matter how big they are. What did the rest of the group who saw them think? This might be a Giant Mastiff Bat. But it might also be a number of others things and in this case I think the report ought to set out those qualifications so that readers get more information to make their own assessment.

    The report talks about a Leopard seen through a thermal scope. I think it would have been more objective to have noted that at least one person in the group is adamant the leopard was a macaque.

    The report reports seeing warty pigs, an extremely rare species. But this ID apparently was based on what the guides told you. I have had Javan guides show me warty pigs at closer range and I took photos. I too believed them. The pigs were wild boar. The females of the two species are almost impossible to separate in any case.

    Of course your group may have seen all three species. But you may have seen none.

    This is hopefully blindingly obvious to everyone but we all have a responsibility to be objective, rather than selective, when we report sightings that might catch the interest of scientists (and this site is used by scientists so there is a risk in devaluing its usefulness ). I hope everyone agrees – or have I totally misunderstood?

    On the second point – about noting dissenting voices – then I heard from at least 3 people who were frustrated that they felt their opinions were not being listened to when the report was being written. People who have expertise in the area, or the species in question.

    A chance to get expert advice on what we see is invaluable and so I hope we can always show respect to others opinions or they will stop offering them. Again I think this community seems do “respect” very well. But maybe this needs to be talked about more….

    For me the bottom line is that it is fine to disagree with an expert – after all the observer was there and the expert was not – but at least include their comments in the report on whether they think the picture/bat recording etc is solid enough evidence. They took the time to offer them so we should take the time to report what they felt.

    In short sight records are fine if reported objectively and – when they are particularly notable – come with added detail on the evidence for and against the ID. Records with photos are far better for sure but of course they are not always possible. We might all distrust a sight record of a thylacine, but it is much harder to know how much scepticism is healthy when it comes to records of smaller species.

    And yes it does matter. When we share a report with others we do so in the hope it will help them successfully mammalwatch. A poor report can hurt rather than help the hobby. Reports with exaggerated claims can lead people on wild (mon)goose chases that will waste their time, money and mammalwatching enthusiasm. Long lists of species from a trip, which seem sometimes based more on wishful thinking than evidence, can mean those who come next will feel disappointed when they don’t see half as much. And poor reports can also damage the website and community’s credibiity among scientists, which would be a great pity now more and more of them are getting involved.

    But as always happy to hear what others think. How do the birding community police reporting accuracy without getting into a huge fight?



    • Vladimir Dinets

      Well, as you know, I normally incorporate IDing info into trip reports, but in this case I had to fit it into the template used by the tour company. Once you said it should be done anyway, the company owner and me had to spend a lot of time fighting with Acrobat to do this; the expanded version is now ready and you should receive it shortly.

      The most frustrating thing about this was that I circulated the draft report among all participants, specifically asking for input, but only one person ever responded. I personally think it’s better for everyone if disagreements about IDs are settled by the participants before the report is submitted.

      So I wasn’t even aware of the macaque theory. The problem with it is that long-tailed macaques living in forests always spend night in trees. Spotting one roaming the forest floor at night would be a much more extraordinary sighting than a leopard. Leopards are common in Ujung Kulon: there are tons of camera trap photos, all park guys told us they’ve seen them, and we found fresh tracks both times we walked on riverbanks away from camps. Not to mention that finding a nocturnal macaque with rosettes would be the zoological discovery of the century… pity I’m not that lucky.

      I would be extremely interested to know which experts contacted you: as far as I know, no living person can call himself an expert on either the rat or the bat being discussed.

  • JanEbr

    @Jon you made it bow really clear that you are not and never have been a birder, because you think that the birding community can do *anything* without getting into a huge fight :))

  • Tom Clode

    I can relate to several of the points made here, both as a client on the Java trip in question, but also as an operator who has had to rely on sight records in reports I’ve made on this very site.

    On the latter point, I’m hugely proud to have been able to record sightings of species such as Jentink’s duiker, zebra duiker and Liberian mongoose in Cote d’Ivoire earlier this year, but these were sight records only. Getting a photo, let alone even harder proof, would have been impossible. And that bothers me a little, because I’m sure there will be people who doubt these records, and there’s not much to be done about it. We corroborate the sightings with others who were there with us, but besides that I can only share the sightings with as much accurate info as I can. As such, I certainly understand the frustration if and when sight records are disregarded as useless or fallacious out of hand.

    But I think there is little doubt that we should always strive to produce as accurate a report as we reasonably can. Mistakes happen, of course, and I certainly make my fair share of them in the field. But what is missing from the Java report, in my opinion, are the shades of grey that Jon alludes to – the sightings that require context, expert input and, even then, sometimes a response of ‘I haven’t actually got a bloody clue what that was’. As I sometimes say, the sign of an expert is often how frequently they say ‘I don’t know’. And that, for me, is absent in this report, and several others that spring to mind. As Jon says, there should have been less ‘we saw X’ and more ‘we saw something that might have been X, but we can’t be sure’.

    What is more frustrating is that, in any case where there was any doubt, the ID shared is (almost without fail) the rarest of the possible species that it might have been. What we end up with is an aspirational mammal list attached to the report, given a misleading impression of the success of the tour. The report was not representative of my experience in Java, which is of course problematic. Had I written the report, and I do understand this is a matter of opinion, I would not have included confirmed sightings of leopard or warty pig. I’m sure you had, Vladimir, conversations with experts regarding the bat IDs, so I can’t speak to the veracity of the ID made, but I think I’m right in saying it wasn’t made on sight.

    The question, I suppose, still remains though: what’s the harm? The main point I would make is that the discussion so far is dominated by the red herring of whether sight records should be reported. Of course they should – if not, we would have barely any records of some species and we would be all the poorer for it. But I would argue that records are only valuable when adequately contextualised. Vladimir, you talk about the point being made that extraordinary claims require extraordinary proof (I would refute your point that making an ID based on a quick glance at a rodent’s tail in low-light conditions is not an extraordinary claim, but that seems like a conversation for another time). I think there is more nuance than this – extraordinary claims require accurate and reasonable characterisation and context. Without this:

    1. We end up in this bizarre situation where reports are at odds with the experience of those who were on the tour, and mammal-lists end up being inflated.

    2. Inflated mammal-lists, as Jon says, may skew how and when people choose to spend their hard-earned money. But, more than this, I’ve noted that some people have come away disappointed from trips because they haven’t seen the number of mammals they expected based on past reports – reports which suffer from having unreasonable mammal-lists. If someone were to plan to visit Ujung Kulon based on this report giving the impression that leopard, warty pig etc might reasonably be expected, they would end up being disappointed. Of course, everyone needs to manage their expectations, do their research and not just rely on a single report – but the existence of such a report can only muddy the waters and make it more difficult for mammal-watchers to set their expectations appropriately.

    3. Linked to the above point, I am concerned that reports will become less reliable if we see these ‘aspirational’ mammal lists on the site. Particularly in a very small number of younger mammal-watchers, I am seeing an increasing tendency to exaggerate or overstate records, which I suspect is driven by wanting to compete with reports like this report from Java, which mis-state the certainty of records.

    To be clear, I am not laying the blame for all of the above on you Vladimir, or any other author of any other report. I only want to point out that, whilst there may be very limited harms to reporting sight-only records, there are more pertinent issues associated with the claims made in the report. My understanding is that these are being addressed.

    TL;DR – IMO, sight records can and should be reported, but use common sense and do it responsibly. Mammal-watching is a hobby that fundamentally relies on a level of trust between all who partake, so an extra few lines of context in a report such as this is a small price to pay to ensure that that trust can remain intact.

    • Vladimir Dinets

      There are only two or three locally rare species in the trip report; of these, the flying squirrel wasn’t supposed to be there at all and I am eternally thankful to Alex for managing to get good photos (as you know, I am particularly interested in giant flying squirrels, and having such a cool sighting without photos would be pure torture for me). Leopard is not rare in Ujung Kulon at all since the extinction of tiger, and how rare is the warty pig is an open question: in the last two months I’ve read and heard all possible answers, from “long extinct” to “Eurasian boars are only in the hills and on small islands”.

      An interesting side note: during my conversation with Mr. X I couldn’t resist the temptation and looked into his own trip reports to see what he considers “extraordinary proof” – DNA sequences? close-up photos of teeth? complete lists of measurements? But what I found was lots of sight records of difficult to ID species with no corroborating info whatsoever. When I asked about this, Mr. X first said “I actually captured or photographed them all”, then “that bat I reported as flying around was actually hanging from a tree”, and then cut the conversation short.

      I have no reason to think any of his sightings are false claims or errors; he appears to be a knowledgeable person with a healthy dose of skepticism 😉 I’m just making the point that very few authors of trip reports actually bother to discuss potentially uncertain sightings in much detail. Everybody is busy, writing trip reports takes a lot of time even in simpler form, etc., etc.

      I expanded the Ujung Kulon trip report (in my reply to Jon above I explain why the first version was so brief), and I very much hope you’ll like the second edition better. I’ve tried to provide my reasoning behind IDs in the past and will do it in the future. But I think a more practical approach is to simply contact the author if you need more detail on a particular sighting. Most people here (not all, unfortunately) readily respond to RFIs.

      • Tom Clode

        Apologies Vladimir, only just getting back around to this, but thanks for your thoughtful response.

        We obviously have more in common on this issue (and, indeed, most other issues) than on which we differ, and I agree with much of what you have said. But I do think you’ve elucidated very clearly the key difference between the TR you initially penned, and that which I would have written – for me, the burden of proof for a sighting is on the author of the TR, whereas for you it sounds like (and please correct me if I am misrepresenting your point) readers of the TR should reach out should they feel like they need more info than we saw/did not see a certain species. I would certainly argue that it is the author’s responsibility to provide as much context as they can to all sightings, particularly when leading a tour for any commercial enterprise (I can see Martin’s response later in this thread covered all the nuances of this very neatly). But I suspect we could both argue this until the banteng come home without being moved from our points of view. Nevertheless, I appreciate your input and contribution to what was, in spite of all this, an enjoyable (if damp) tour.

  • tomeslice

    So I wasn’t on the trip, and Vladimir – you know I have very high appreciation of you, your experience, your abilities and your knowledge!

    But as far as this question goes, I agree more with you, Jon, and I’ll explain:
    Vladimir’s descriptions of the encounters as detailed above are great! But that’s not how they were portrayed in the report. If they were specified as “most likely” or “almost positively” Species X, with a reference to an appendix which details the encounters as they’re detailed in this post, then I think the discussion would be more about the identification, rather than about the legitimacy of the report.

    I also completely agree that spending more time in the field enables you to get better at identifications. But I have personally seen Mike Gordon (who I think is the absolute top, when it comes to wildlife guides) briefly mistake a malay civet for a clouded leopard, after 10 long, sleepless nights of spotlighting, as we initially saw it from afar and only from the back. Of course he almost immediately corrected himself, especially as we got closer to the animal. But if this can happen to Mike, it can literally happen to anyone. I don’t have to elaborate on how good Mike is, at ID’ing anything from the rarest snake or rat to the most common cat.

    It’s just that tiredness, adrenaline, low light conditions, etc. all can lead to misidentifications, even by the top experts.

    A picture is always more helpful, of course, because even years down the line somebody can have a look at it, maybe play around with the light and dark balances and say “nope, it’s another a leopard cat”.
    Of course a picture isn’t always possible, and yes, you can see a very very rare species and not have a chance to photograph it. It does happen on rare occasion. But I do think the more “humble” approach is to say “I know it sounds impossible, but I truly believe I saw XXXXX” than to say “it was a XXXXX” . Otherwise it’s a tiny-bit reminiscent of these people on National Geographic searching for bigfoot in Minnesota – they are very sure they have seen one, but many others don’t believe them.

    Should it be published though?
    Absolutely – just with the stipulations we have all agreed upon. In reality – I don’t think there is actually a disagreement about that by either side. I only think that there wasn’t room in the report, the details and the supporting claims were missing, and we were left with the “we saw X”. But I think both sides agree that for such a rare encounter, the story behind it, along with the supporting claims, are much more interesting than the mammal name appearing on the list.

    But I also agree (from personal experience) that if I plan a trip based on previous people’s lists, and they all supposedly see 10 “very rare” species all on one trip, and then I go there and see none – it makes me feel that:
    1. I did something wrong
    2. My choice of guide or operator was wrong
    3. I had bad luck
    and 4. general disappointment for spending my vacation time and money on a trip that I feel was unsuccessful.

    Then It would make me more reluctant to post a trip report, because who wants to be the “loser” who spent 3 weeks in X and saw none of the rare species? And then by not posting a report, I’m passively misinforming people who may want to go there… etc.

    But all-in-all I do think everyone is mostly in agreement…
    I think the more relevant question here is “who cares about a damn bat?” (Just kidddinggg!!!)

    • Vladimir Dinets

      There is a scientific journal (in medical science) titled “Journal of Negative Results”, created specifically to counter the bias against publishing such results by both authors and editors. Yes, I also think that misses and near-misses (especially unexpected ones) should be reported. For example, a few years ago I learned the hard way that a certain sengi becomes nearly impossible to find in summer at a site where in spring many people had reported them being more common than neo-Nazis at a Trump rally. Certainly helpful information for anyone planning to look for them.

  • Morgan Churchill

    Thanks Jon for the additional information on the report

    A few random thoughts.

    As far as people reporting things, I would agree that people should give the full context if there might be a question of ID. I mean a list of just species seen is not that informative anyway. Overall, again I am not that concerned of what individual people count for there lists. Nor am I concerned that someone goes some place and becomes disappointed that the didn’t see X. You need to go into every trip with realistic expectations. Even if the intel is backed up with great photos, there is still NEVER a guarantee you will see anything. I’ve twitched enough rare birds over the years to accept this.

    The biggest potential issue is that when you have people misidentifying smaller, hard to identify mammals. Because I HAVE noticed that future people who visit that site will just go and assume its that species without further consideration of what might be present. So then you get a bunch of erroneous reports at a sight. I’ve personally seen this in play with certain species of chipmunk and rabbits where all to often people will not use morphology but assumptions of range to identify the critter in question. and once that chipmunk is recorded there by one person, every future visitor assumes it is that same thing.

    From a birder perspective (I identify as a birder before a mammalwatcher), dubious records or people prone to making less certain claims are simply filtered out. There are probably more serious birders just in my state of Wisconsin then there are serious hobbyist mammalwatchers in the world. So if something weird or rare is seen, it’s almost certainly going to be chased down by others, including people with more experience. Repeat offenders are just dismissed out of hand and ignored. So bad ID’s and outright hoaxes occur, but I don’t’ think they really impact birding experience overall. For major aggregators of bird sightings such as in ebird, there are also local reviewers who will flag anything suspect, or ask for further evidence before accepting it.

    • Vladimir Dinets

      Yes, that’s what I meant by “chains of wrong IDs” in the post. There is a hill in Cuba that was a good place for rare Bahama mockingbird ten years ago; they are long gone but a lot of people visiting the place still report very common northern mockingbirds as Bahamas, despite the fact that the difference is very obvious.

  • Jason Waine

    It all seems very simple to my simplistic brain – the Mammal Watching site caters for a wide spectrum of experience from beginners to professionals with vast experience and a published sighting labelled “possible” or “probable” will be treated as just that. Beginners may visit the site but without any realistic hope of proving they have repeated this sighting whilst more knowledgable and experienced watchers visiting the area will keep a special lookout for repeat sightings. Further, when examining photos of difficult species later, the previous, possible, sighting will be kept in mind. People should include probables and possibles, suitably annotated, in a trip report. I can see no reason not to.

    • Jon Hall

      Thanks Jason for your simplicity of explanation. That is exactly right, though you said what I wanted to say in about 5% of the time it took me. I don’t think anyone thinks anything different to what you say here to be honest. At least not that I have seen or heard.

  • Bud Lensing

    I’ve been a wildlife enthusiast for over 30 years, mostly birds because they are easier. Diurnal mammals and herps as well.

    If it is “possible” or “probable” and I don’t have a photo or a clear view of a distinguishing feature to separate it, I don’t “tick it off”. I wouldn’t report it either. If i get a picture of a vole and its range conflicts with two or three other voles I make a best judgment decision and tick it off. I would also submit the photo for any input.

    With so many mammals being rodents and bats and most of them being nocturnal and you may only get a glimpse of the mouse running across the road. Or the bat flying high near dark when the Echo meter gives you a “most likely possibility” and a “less likely possibility”.

    Make a judgement exercise your freedom of speech.

  • Venkat Sankar

    Late to the discussion here, but I want to emphasize a few key points that really stood out to me:

    1) Use your discretion. I think this applies both for the person writing the report (who saw the animal), and for the person at the other end reading the report. Sight records are just that – there’s no way to confirm or deny them. So it’s up to you to decide whether you have enough evidence to report something, and also up to you to decide whether someone else provides enough evidence for you to believe them. We’re not writing scientific papers here so I think sight records shouldn’t be removed altogether, but I do think users should be more liberal about using “possible”, “probable” etc. if there are real uncertainties. Not a bad thing – a lot of small mammals can’t be confidently identified unless in the hand (and still more without a skull or nuclear DNA). It’s just the nature of our hobby.

    2) Jon’s point that cavalier sight records waste other mammal watcher’s time and money & skew expectations, which somewhat relates to my point 1). With one qualification that I don’t think this responsibility lies solely in the hands of the person writing the report. I agree it is the responsibility of the reporter – especially if they are reporting something rare and small – to provide as much supporting information as possible about the sighting. Photos, physical descriptions, sonograms/call frequency (if you’re IDing a bat by detector), expert commentary, references to publications on a species, database records at a particular locality are all really helpful and will bolster your credibility. But it’s also in the hands of the reader to judge for themselves. If it’s something rare, use it as an opportunity to learn about a new species – read about the animal, and come to your own conclusions. Don’t just look for or assume you saw species X in a particularly locality because some mammal watchers before you did.
    2a) As a subset to point 2, I encourage mammal watchers traveling on guided trips to ask guides how they came to a certain ID, especially for small mammals. I’ve seen cascades of misidentifications because a guide told a mammal watcher some mammal was rare species X, and it was believed without further questioning. Besides, it will help you and the guide learn the species better and have a more enjoyable experience.

    3) Tom’s point on aspirational lists creating a cascade of less reliable reports. I’m not sure who he’s referring to here – but as a “younger mammal watcher” who just reported a very long species list from Kenya – my thoughts are likely relevant. I do think exaggerated/overstated reports can be problematic for people who aren’t yet interacting with more experienced mammal watchers.

    So this brings me to something that will either destroy my credibility here permanently, or earn me a bit of respect – I say all this from personal experience. When you’re a kid, you’re naive and optimistic and – especially with no one else to ask for advice – it’s easy to fall into the trap of turning that mouse or bat you briefly saw into something rare and special. In fact, it’s extra easy when other reports you see claim multiple sightings of such species over a short time span. I’ll be the first to admit that I’ve been guilty of this – over the last couple of years, I’ve gone back through my old records and removed sketchy stuff I reported before (e.g. some mammals in an East Africa TR from 2013, Arizona Myotis in southern CA, etc.) where in hindsight, the evidence just didn’t meet the mark. Now, I’m going to edit & resubmit those pre-2017 reports so I don’t unintentionally mislead anyone else.

    As a young mammal watcher, an important moment for me was meeting more members of this community starting 2017. Interacting with other mammal watchers taught me an important lesson – mammal watching is hard. Mammals are hard to find, and often harder to ID. I learned that it’s ok (and more respectable!) to have doubts, leave things, unidentified, and not count marginal sightings (looking at you, possible Zorilla in Kenya) than to try to ID & count everything you see.

    4) Still, this all doesn’t mean we should discard or censor all reports featuring large species lists with a lot of small mammals just because we automatically assume they’re inflated/exaggerated. With a lot of effort, knowledge, and importantly – pre and post-trip research – such lists are definitely possible. For example, on my Kenya trip, I put in nearly-inhuman hours in the field, literally hundreds of hours scouring specimen databases pre-trip, and got a lot of help with bats from local experts. Mammal watching is getting more and more efficient these days, and the goalposts for a successful trip have changed a lot over the last 5 years!

    Correspondingly, I do think mammal watchers posting “impressive” results ought to be held to a higher standard for supporting evidence, as it’s extra easy to give false impressions to others in these cases. For example, in my Kenya report, I’ve tried to include plenty of photos or supporting info for the smaller stuff to improve credibility (I knew there would be doubts from some over 120+ species in 3 weeks – which is perfectly understandable). Those are things I try to put into all my trips reports now, and I stand by the accuracy of my reports posted over the last 4-5 years as a result. My email is always on my reports, and I’m always happy to answer questions/clarifications. 6-7 other mammal watchers have contacted me since September regarding my Kenya trip, and I’m happy to see that most of them enjoyed similar results. That speaks for itself.

    5) For 95+% of viewers on this site, this is just a hobby. Let’s not forget that. Yes, we contribute to science from time to time but I’ve always figured that researchers, while they use this info, are usually (rightly) skeptical about some of it without e.g. photos, measurements, etc. We’re writing reports of our holidays, not peer reviewed publications from surveys. It’s ok for IDs to be wrong sometimes and we shouldn’t get into fights over it, but I think the most important thing is just to make sure we’re not inadvertently misleading anyone in the process, or conveying certainty in writing that’s not there in real life.

    • Tom Clode

      Oh dear, Venkat – you have me worried that I’ve alienated every mammal-watcher under 30 now!

      By and large, I agree with what you’ve said. We need to be careful not be conflate ‘inflated’ with ‘big’ – just because an excellent mammal-watcher, such as yourself or Vladimir or anyone else for that matter, returns a long list from mammal-watching trips, that should not itself warrant any significant degree of scepticism. I do think, though, there is a huge difference between the Java report at hand and your Kenya report, and that is one you have already highlighted – I think the context (photos, additional detail etc) you offered in your report was deeper and more accurate than the initial Java report. But, I need to be aware also that I know the areas you visited very well, and that may skew my impression of what is and isn’t possible in each area, whereas this was my first visit to Java and was very much getting to grips with the ecosystem and its inhabitants.

      In short, I totally agree that this is a hobby – let’s have fun enjoying mammal-watching because, for some reason, the other 99.9% of humanity hasn’t cottoned on to it yet. But let’s do it in a way that is unlikely to make someone feel like a dung beetle for ‘only’ returning 20 species on a TR. Off the back of this thread, I will certainly be submitting a few TRs that were less successful, as I think to do otherwise would undermine the very point I’m making.

      • Venkat Sankar

        Thanks for your response, Tom – no offense taken on my end and I hope from no one else’s. My apologies if my tone may have suggested otherwise, just got a bit carried away in discussion here.

        Certainly agree with your note on big lists. I need to be better about reporting my less successful trips, too (I just failed to find a rare mouse last week in CA!). Of course, one other consideration here is not just the number of species you see, but also the quality of sightings. And I think this is worth discussion both with regards to smaller species as well as larger ones. I think one thing birding has done really well is giving the smaller, less conspicuous species often a similar spotlight to the large, flashier ones. And I wish this mentality were more pervasive in mammal watching. For me, a proper sighting of a charismatic small mammal (e.g. a Large-eared Flying Mouse or Spotted Bat) can be just as exciting as a Margay or Hirola… And like you where I have a problem with reports that just list small species without further context, is that it reinforces the myth that small mammals are just “list padding” that all look/sound/behave the same. This just takes away what is unique about them – whether beauty, weirdness, or just a fun ID challenge! Personally that’s why I tend to shy away from reporting lots of bat detector ID’d stuff because it doesn’t showcase these species as well as, say a single photo of Myotis muricola roosting in a rolled up banana leaf!

        • Lennartv

          Personally what stops me from really spending time on the small mammals is how difficult they are to ID. With birds, no matter how plain they may seem, it’s usually very well possible to ID them in the field mostly based on appearance alone and otherwise on call (which one can actually hear as being distinctive, without using a special device). And although bird guiding books in many places across the globe leave much to be desired at least for many places there are pretty decent ones. Also there are quite a few birders that can offer expert opinions on pretty much all the places in the world.

          With smaller mammals definitive identification often requires having them in hand. The main reason I watch animals is the thrill of seeing them in the field. In hand is a completely different experience for me. I think many birders think this way, because birds in hand are often counted separatly from birds in the field. Mammalwatchers on the other hand don’t make this distinction at all. For me the fun ends when a bat can only be identified by it’s specific teeth which can only be seen by having the bat in hand. I do understand the scientific value of recording them, but it doesn’t give me much excitement. A small rodent that I find in a trap, might as well be a zoo animal for me. I have tried to conclusively ID the smaller rodents that I have seen in the field, but I have rarely been able to do so, even with the help of the forum here. I also find that there is a much smaller number of experts that can confidently ID smaller rodents, for birds it’s much more easy to find a person that can help you. Also there are only so many things you can bother other people with. With birds I am usually able to ID everything but a handful of species myself. For mammals this would require me to have knowledge of many scientific papers that I don’t have access to (to be fair I could probably get it), but more importantly that I don’t have the time for it since I am not a professional biologist. I am barely able to properly process my trips as it is.

          Birding is also much more accessible to many people. If you can afford a pair of binoculars and a guiding book, nothing is stopping you from filling up your life list and competing with the top. With mammals you need access to the right people that can help you catch things. I think this will also prevent the watching of smaller mammals ever becoming as popular as the watching of smaller birds. In some popular birding places you can meet quite a few different birding groups on a day. Imagine all of them setting traps. It would be the same as every birder carrying their own mist net.

          For me an ID is only conclusive if it 100% excludes all the other species (within range). Since I don’t like to see things that I can’t ID I don’t look for them any more. When I find a rodent in my thermal I usually don’t even take pictures anymore because it takes up valuable time at night and I will probably not be able to ID it anyways. On bats I spend a bit more effort though, because (with help) I have been able to identify most of my sightings. I must say I am starting to like bats more so who knows :). I can also very well understand the appeal of jerboa’s or cool hedgehogs, since it’s possible to enjoy and ID them in the field.

          In the end I suppose it’s all part of the fun with mammalwatching since mammals are such a diverse group of animals. And especially with the smaller mammals I believe there are many things to be discovered since the group of people that specifically looks for them is so relatively small. Even with birds there are still new (and sometimes pretty distinctive) species discovered or rediscoverd, we’ve probably not even scratched the surface with small mammals. Just take a picture when you do see that extraordinary mammal ;).

  • Jurek


    Small mammals are not usually subject of illegal catching and mobile, so there is no problem of secrecy for conservation reasons.

    Some naturalists consider some places or groups as their own, and claim a totally unjustified authority. One should not care about it.

    Important is how you describe your observation without a photo or unidentifiable photo. This is familiar to bird watchers, who since decades have been submitting descriptions of observations of vagrant birds. You should describe what you saw, especially visual characters used to determine the species and excluding others. You should understand that others cannot know what you saw. There is lots of literature about it. If an experienced birdwatcher reads this, he is surely familiar with the task of describing and believing e.g. a brief sighting of a seabird passing a headland, or a vagrant warbler, which are just as similar to related species as rodents or bats.

    However, in this particular case, I am missing the length and distance of the bat observation, and how reliable it is that you saw the bats long ears, plus the description why it was a freetail bat.
    In the second case, again – length of the observation, plus details of the rodent other than its tail. Plus how sure one can be that a terrestrial rodent cannot occassionally climb trees.
    And in both cases, damning thing is that if local bats and rodents are so poorly known, how can you be certain of variability of similar species, or even an unexpected species?
    You have vastly more field experience that I do, but if it was a rare bird, and an experienced birdwatcher, one would not claim such sightings.

    Just to be sure: I am all for establishing field identification of small mammals visually, not only by trapping them and collecting specimens. Just as it is done with birds.

    • Vladimir Dinets

      Well, here’s how it went with the bat. The sun had set, the bats started flying, I was telling the team how bats can be IDed in flight, and said something like “freetails are particularly easy to recognize in flight, they look almost like swifts, I’ll show you if we see one.” A few minutes later a freetail appeared, flying across the river 20-30 m high, I said “And there’s a freetail! Long, narrow wings… and long ears, too – there is a very rare species here that might be it.” The bat made a second pass (or maybe it was a different individual) and I said “I’ll sure bring the bat detector next time!” But next time we got to the place a bit later and it was darker; a freetail flew over again and I got a sonogram but I could barely see it. Every time I could only see it for a few seconds.

    • Vladimir Dinets

      And yes, terrestrial rodents climb trees all the time. I didn’t really appreciate how often it happens until I got a thermal scope. White-footed mice around here are supposed to be mostly terrestrial, yet I see them in shrubs and low trees more often than on the ground, and sometimes in big trees up to maybe 10 m. But no terrestrial rodent on Java has such a long tail.

  • Judy

    1> I am unfamiliar with the definition of “reportable”, so cannot speak to the criteria here.
    2> There is a lot to be said for field experience. Respectfully suggest that such great sightings be starred with appropriate annotation as you provide in this submission, that: 1) while there is no physical record, 2) what follows will present the logic behind this ID…. “Just the facts” ought to be respected by anyone, who would be free to make their own determination based on their own unique definition of what is “reportable”.
    3> I would be keenly saddened, in this day and age, to find that we needed a carcass (aka “specimen”) to prove identification. IMHO we need to get past the old-school concept that killing the last of a lingering mammal species is the right way to go. With digital cameras, that proof ought to be considered state of the zoology art.

  • Carlos Bocos

    This is incredible, this is not about Sight records and you know that so i dont know why are you transforming the original discussion into this.

    You asked for directions to get some bats, i helped you.
    You asked for help to identify some bat photos and recordings, i gave you my opinión. So others did. I dont understand why you didnt Accept our opinion.

    This has nothing to do with sight records. There is no problem at all. I neither photograph every roe deer i see in Spain or every Northern Common Cuscus i see here but what you are doing is claim two extremely rare species, Lost for science since decades ago, without throwing any evidence.

    And honestly, you get wrong loads of common things, like your Cynopterus that you said they were Rousettus. But thats not the point at all

    The point is that mammalwatching can actually be as good as birdwatching if we provide good evidence and information about our sightings.
    If you are that confident about your sightings, i recommend you to Contact BRIN, the department of zoology. They will visit your locations with high-end bat detectors and proper equipment for arboreal rodents and lets see what they get.

    But turns out that not even your clients are so sure about your sightings or id skills so please, Accept that others disagree on some of your sightings and move forward.


    Mr X

    • Vladimir Dinets

      If you read the comments to the post you’d notice that I consider you a knowledgeable and trustworthy person and take your opinions seriously. For example, I accepted your opinion that the sound recording is nearly useless for ID. And thanks for the advice on the caves, too!
      But then it all boiled down to just two questions. (1) Is there only one possible freetail bat on Java with ears long enough to be visibly protruding forward in flight? and (2) Is there only one possible rat-size murid on Java with non-black tail longer than 3/2 head+body and white belly? I think the answer to both questions is yes. You never actually argued with this, but instead said that I should never publish these records because they “don’t prove anything”. The only way I could interpret this was that you think either that I’m making this all up or that sight records are unreliable because they lack solid proof. Did you mean something else?
      And please note that the point of this post is not to argue with you. As you noted, there’s nothing left to argue about. I’m just discussing a broader question.
      P.S. Yes, I didn’t ID those Cynopterus on sight – the stupid mistake I mention in one of the comments. I just assumed that fruit bats found deep in a cave would be Rousettus and didn’t pay further attention because I had a lot of more interesting stuff to focus on. But I would certainly catch this during final checks of the trip report.

  • Carlos Bocos

    Honestly, i dont know if you even saw a freetail. Apparently no one is confident about that freetail but you alone. With a good recording or some photos we could discuss about it but there is no evidence at all.
    Same thing applies for the rats. I know you consider yourself a Sort of Spetsnaz of the rodents but really, with such a poor view and no evidence at all again (just as usual in your trip reports) i would never ever claim such a thing. One can be fooled by so many things in the middle of the night. And i dont think either this is about knowledge at all. I consider yourself a knowledgeable, experienced guy. But your trip report is full dodgy sightings. Im not even talking about that ghost leopard or the warty pigs…
    Looking forward to read the new report after all your corrections
    Best wishes

  • Vladimir Dinets

    OK, now I am totally confused. First you say “this is not about sight records” and then you say the problem is that “there is no evidence at all”. But isn’t a sight record precisely that – a record with no evidence? (I also don’t understand why you think a rat running along a branch five feet in front of your face is a “poor view”, but let’s not go there.)
    And again, you talk about “claiming” as if I was a trophy hunter. I don’t care about claiming stuff: I saw an animal and I identified it to the best of my ability. Perhaps I can’t tell a freetail from a flying fish, or perhaps I can tell if the bat was a virgin from 300 m away – nobody knows, and I myself might be wrong about my skills, but that’s also a problem with all sight records, isn’t it?

  • Martin Royle

    Sorry for entering this discussion late, I spent most of the last 2.5 days travelling back to the UK from Gabon. For people who didn’t see the first edit of the report that was briefly up, the Java report in question is a Royle Safaris’s one.

    Vladimir was our guide for this trip and so undertook the job of compiling the trip report. I know that after the first draft was given to me to edit (into the template for my trip reports) it was given to the trip participants for their input. I was not on the trip (and I am also not Mr. X – in case anyone was wondering); so cannot qualify any of the sightings myself. But after hearing about the leopard sighting I contacted the group to offer my congratulations.

    I received replies to my congratulations on a leopard sighting from 2 of the 3 people on the trip and their comments were (1) “we didn’t see a leopard, it was a macaque” and (2) “…was his Leopard sighting while he was next to us in the boat. I have no doubt that he genuinely believes he saw a Leopard. And there is a chance he may have done, and it was just his poor communication of the sighting to us that caused our doubts. But he reminds me of some birders I know who push their perceptions of brief/poor sightings to the limit to make a ‘confirmed’ ID.”

    After receiving strong views like those from 2 of the 4 people there, I was a little concerned. I was also out of the country and unsure how much quick contact I would be able to have with Vladimir to discuss this all, so I contacted Jon to mention that there was some disagreement with some sightings on the trip report. In case the report was uploaded when I was out of contact, he would have some ‘quality control’ to do. Unbeknownst to me at around the same time, Jon was being contacted by some bat experts with expertise in SE Asian species to tell him that they had seen the recordings and evidence from some claims from this trip and that they were categorically false and not that species. So Jon was already preparing himself for a little push-back regarding the trip report.

    A further point which I was a little ‘concerned’ about was the number of species recorded being so much higher than any trip to Ujung Kulon ever, I have personal and second hand experience from people I trust 100% with regards to over 10 trips to Ujung Kulon, covering nearly all habitats and mammal focused and the average number of species is around 25, so to double that number was a little odd in my opinion. In fact another client on this same trip has a confirmed mammal list of just 28 species which he is including for himself – which seems to me ‘reasonable’ and in line with past experiences.

    So this body of evidence (first hand reports from the trip disputing sightings, experts who were asked for help being ignored (seemingly) and so many species being seen) began to grow and it quickly became apparent that something would have be done about the report when it was published.

    After it was published, it was taken down by Jon; myself, Vladimir and Jon went into good and long detail about each sighting and the controversy they had caused. Vladimir went to great lengths to provide evidence and explain the nuance behind some of the ID’s. So the trip report was edited to include full explanations on each sighting and now it is a more accurate report in terms of all views on the trip are alluded to and people reading the report can make their own minds up as to whether such and such a sighting be reliable, 100% confirmed or ‘best guess’. Explaining fully potentially dubious sightings is important and is what has been done in the new edit.

    The new report will be uploaded in the next couple of days and this may be a little bit of a watershed moment in the mammalwatching community, this hobby is growing and growing fast. I have several thousand people in my database and the majority are what they would coin themselves ‘hardcore mammalwatchers’, this forum has a lot of members and so something like this occurring and forcing people to relook and refresh themselves of the code of conduct is a good thing.

    One thing that Jon and I are in compete agreement on – which was discussed in our email thread with Vladimir too – is that when any sighting occur and the ID cannot be 100% confirmed there are 2 things that should happen:

    1. The whole sighting, thought process behind an ID, evidence for backing up the ID (over other possibilities) and asserting other view points from at the time of the sighting – needs to be reported in the trip report – so that full transparency be provided for future people visiting the area. In a similar vein to what Venkat speaks about in his post in this discussion – I may have been lax on that myself in the past – using the caveat at the end of my sightings log (Some bats identified 100% at roosts or with good views. Others identified with spectrograms in combination with sightings (no spectrograms without visual confirmation are recorded), behaviour and habitat – so not 100% but best educated guesses. For more information please email me.); is probably not sufficient and where bat ID’s are used using the above methodology and are very much ‘best guesses’ I will make that clearer in future. For other sightings we are not 100% sure on or could be one of two options this is explained in the body of the text on my reports, but i will go into more detail for bats in future.

    2. When looking at a sighting that is not 100% you should look first for the most likely animal. A common animal doing a rare thing is much more likely than a rare animal doing a common thing (in nearly all cases). Ruling out the most likely outcomes first seems to be the most logical way of approaching this and it appeared that with this report the immediate thought was to go to the most unusual or rare sighting.

    Of course all of this is circumstantial as I (and Jon and the other people (Mr. X included) who offered help in IDing animals for the report), where not there in field. Which is why only after I heard from people who were there about the disagreements on sightings, I decided to flag this.

    Having a Royle Safaris trip report boast a large total of species is of course fantastic on the face of it, but not if they are not all substantiated as creating false expectation levels for future visitors to the area is painful for the visitor, misleading from the tour operator and can lead to disillusionment for the local guides. All of which goes against the overall aim of creating small scale responsible eco tourism projects around mammals so that we (as mammalwatchers) can continue to enjoy them and their habitats for decades to come.

    Whilst the full email threads and various message exchanges between the clients, Vladimir, Jon, Mr X, other experts etc will not be disclosed to the wider audience, I would like people on the forum to know that we all take this matter seriously and all of this is aimed at producing the most honest and transparent reports possible. I am thankful for the discussion this has caused as I think it has been needed and I am certain for anyone coming to Spain in September for the mammalwatching get together, this will be discussed further.

  • Vladimir Dinets

    Thanks, Martin. I think the only thing to be added at this point is a sonogram of that poor freetail that could also be a flying fish. The recording has 21 calls but this is a fragment with some of the best-recorded ones. As you can see, Carlos is right and it’s not terribly good quality. I can’t put a photo in a comment so I added it to the original post. Click on the little green image to see it.

  • Charles Foley

    Hi all, an interesting discussion with lots of good points. A couple of people mentioned that scientists are using the site, and how these types of records might affect their opinion, so I thought I’d elucidate on how we tackled sighting records submitted to a country database. Some colleagues and I ran the Tanzania Mammal Atlas database for many years, where we collated and kept all records of large mammal species reported in the country. We had a system of gathering records from individuals, which could be submitted as hard copies or online. The bottom line is that we were very, very conservative about what records we would accept as valid. We produced a ranking system for contributors and were fairly brutal with giving people a low rank based on any errors in their submissions (we never shared the rankings with anyone outside our team so we managed to retain a few friends by the end of the enterprise). If someone reported seeing a rare species or a species out of its range, we would first check the persons ranking to determine whether we would pursue it further, and, if they made the grade, we would then subject them to a rendition of the Spanish inquisition to determine if they could provide further details that could validate the sighting. Unless they were unequivocal about the sighting, we would not record it. Why? Because our goal was to ‘do no harm’. Many years ago someone published a very short paper where they reported seeing a Giant Forest hog in the Ngorongoro highlands. Despite TWO subsequent papers refuting the sighting, plus the author rescinding the article (they had mistaken it with a male Bushpig), people still continue to talk about Giant Forest hogs in Ngorongoro. While we were not recording rodents and bats for the atlas, had these records been entered with the same sighting descriptions for a larger species, they would not have been accepted. I suspect what we would have done with such data is flagged it and said ‘there are possible records of interesting X or Ys in this area, so bear this in mind if a future survey is carried out in that area’; assuming of course those people had a high sighting grade.

    Of course, as many of you have pointed out, trip reports are different to publications, and are often rapidly compiled and not subject to any peer review process; ergo, people submitting them might be a bit more relaxed with their identifications, and people reading them may be a bit more discerning about what they read. Well maybe. I once spent two nights sitting up looking for a rare species of mammal that a mammalwatcher who I considered to have a fairly robust reputation had reported seeing at a particular location in central Africa. I didn’t see the animal. A few years later the same mammalwatcher mentioned in some forum comments that he ‘might have seen’ said mammal in that area. As you can imagine I was not best pleased. Had those three words of clarification been included in the original report, I would not have put so much stock in the sighting and would have focused my efforts on finding other species instead. So yes, I think it does matter what we put in trip reports and how the information is presented, particularly for rarer species.

    For what it’s worth, my general creed is that I’m pretty conservative with what I record – and what I regard as an acceptable sighting record by others. For instance, I would rarely accept any records of bats seen on the wing in the tropics. The only exceptions would be for a handful of highly distinctive species, or if the recorder had a strong record of bat work in the area and thus knew the local species well, or if the record was accompanied by excellent sighting notes together with an unequivocal sonogram. Yet even sonograms can be tricky. Bats often have regional accents to their calls, so the sonogram of a pipistrelle in South Africa can be totally different to that of the same species in East Africa. Frankly it’s a ruddy nightmare. I tend to give more leeway to rodent records, but only if they are seen well. Otherwise in my experience the eyes – and memory – and desire – play too many tricks on you. I won’t divulge how many African wild cats I’ve tried to turn into Golden cats over the years in Tanzania. And if I can do that with a mid-sized cat sitting in a meadow, heaven help me with a fast-flying bat zooming around at night. As Martin points out, the logical answer invariably points to the animal being the more common species.

  • Vladimir Dinets

    Excellent points, Charles. A few comments if I may.

    1. Worth noting that you could save yourself those two nights in Central Africa if you contacted the said mammalwatcher in advance and asked him how sure he was about the sighting. Good chances he would warn you that it wasn’t a certain one (or maybe not, hard to say without knowing who you are talking about, but certainly worth trying).

    2. The thing is, nobody knows which freetails are more common in Ujung Kulon Peninsula. High-elevation nets have been used a lot in Africa but not so much in Asia, and probably never on Java. In Ujung Kulon there’s been no bat survey at all (unless I’ve missed something). Tree roosters feeding high above ground tend to be severely underrepresented in collections, and the peninsula has neither caves nor houses, so it is possible and even likely that O. formosus is the most common (if not the only one) species of freetail there.

    3. Since the subject of identifying bats in flight keeps coming up, let me share some personal experience. I once lived on Okinawa for two years. The island has 5 regularly occurring species of microbats, all of them very small insectivores, all with distinctive calls (in sonograms, I mean), all from different genera and representing 3 families. Two of them, a Rhinlophus and a Miniopterus, were common around my house. So I spent a lot of time trying to learn to ID them in flight: looking at a bat, guessing the species and checking the answer with a bat detector. Minis had longer wings and more direct flight. At first I only got it right half the time, but by the end of the two years I could get the ID right 6 to 9+ times out of 10, depending on sighting conditions; the easiest sightings were of bats flying overhead at dusk in the open. There was a small population of Pipistrelles in a nearby town where Minis and Rhinos also occurred; since I always saw Pips in the open they were easy to tell from Minis but the best I could do telling them from Rhinos was maybe 6-7 times out of 10, which is only slightly better than simply guessing (I don’t have good stats on this because all three species weren’t particularly common there).
    But there was also a species of Murina in the north of the island, and it was a very different story. I once saw it being released, and after that could always recognize it in flight, even if it was seen for a second while it was flying in dense tangles. It has a highly distinctive, moth-like flight with deep, slow wingbeats; gets a bit faster if disturbed at roost and escaping, but still instantly recognizable. I later checked and it works for all Murina species.
    The 5th species, a Myotis, was extremely rare and local; I only saw it in flight once and it was also recognizable because it was black and hunting low over water at dusk, but I don’t think I’d be able to ID it if I saw it in the forest at night.

    What I am trying to say is that the question “can you ID bats in flight?” has no simple answer. Even in high-diversity areas there are usually bats that you can ID to genus or even species, like spectral and ghost bats in the Neotropics, or black-hawk bat in Africa, or some Myotis and Kerivoula in Asia, etc. Their proportion increases as diversity decreases, and there’s a lot of regional variation: you can recognize more bats in flight in southwestern USA than in Europe or China (although I can’t predict how far you can advance if you practice for, like, twenty years in those places).

    The problem with all this is, of course, that you have no idea what your reliability is unless you do a lot of testing, and you can only do the testing with common species in a place where you spend enough time. But at least with bats you can often test yourself with a detector; with other mammals you’d have to use a gun. There are, of course, situations when you see a mammal run across the road and then jump out of the car and catch it, or see it far ahead, make a guess and then sneak up closer, but normally it doesn’t happen often enough to get any statistics (well, unless you are chasing jerboas in some place like Mongolia…). So IDing bats in flight is not inherently worse than other sight IDs.

  • Eran Tomer

    Apologetically late in this excellent discussion, but brief points:

    * Reporting a sighting as a possibility does not damage one’s credibility and respect. Quite the contrary. Having profound knowledge, an expert recognizes complexities and pitfalls amateurs don’t.

    One may state, “I saw a possible / probable XYZ”, provide the details & logic, and let readers decide by themselves. That’s truthful, honorable, and enables an observer to rescind a claim with dignity if need be. If confirmed later, the observer receives full credit.

    * Credible rarity reports necessitate exclusion details. Meaning, one explains not only the ID logic but also why similar species may be excluded. Per definition, it’s easier to misidentify a common species than to encounter a rare one.

    * For rarities especially, eyewitness reports cannot constitute conclusive evidence for numerous reasons. Obtaining DNA or quality photo evidence is often difficult. Frequently tracks / footprints are unavailable or questionable.

    Ascertaining IDs requires persistence but mammal tourism entails limited time at a given site versus extended stays or field studies. Expectations must match.

    All this is recognized widely so, frustration notwithstanding, no need to feel bad about lacking unequivocal ID proof.

    Note: motion-triggered trail cameras and automated, continous sound recording devices are revolutionizing this field. Similarly, environmental DNA – i.e. DNA obtained from soil, water, scat etc.

    * Behavior is key to identifying many animals, as Vladimir notes. Different species walk, fly, swim, dive, climb, forage, dig, socialize and escape differently. Unfortunately, mammal behavior information is difficult to obtain vs., say, birds. Many mammal sightings are fleeting or involve trapping.

    Mammalwatchers ought to seek continuous observations as possible, take detailed notes and report them. Heat scopes help. Same for heeding tracks, signs, sounds, etc. closely. Mammal surveys often pursue signs rather than sightings.

    Example: pay careful attention to the sounds mammals make while moving through vegetation, dead leaves, over stones / gravel etc. Also to the sounds they make while climbing trees or digging . This can enable instant animal type recognition (e.g. leopard vs. macaque) and sometimes, where possibilities are limited, a very likely species ID.

    * Mammalwatching is all about sharing, the more the better. Still, as others state, one must weigh potential consequences to mammals when reporting them, rarities and otherwise.

    Most herp (amphibian & reptile) reports exclude precise location to forestall unscrupulous / criminal collecting. Similarly, the global birding / ornithology portal eBird masks precise locations of designated “sensitive species” where such may be subject to disturbance, persecution or collection.

    Thank you all for the great discussion, best regards,

    – Eran Tomer

  • Jurek

    Vladimir, you have incredible field experience. Given that people around you could not identify bats in flight, maybe write a series of notes / posts / articles explaining in detail identification of mammals in the field? Surely it would be of general interest, and help mammal watching grow.

    I generally agree with you that microbats do differ in flight, I noticed it myself. However, I don’t consider it a safe way to identification for now. And especially for a rare species in a part of the world where I have little experience.

    And – more general stuff. Since Jon asked explicitly ‘How do the birding community police reporting accuracy without getting into a huge fight?’ I will describe how bird reporting functions. This should be taken as a general information, and not the position of a particular Java trip and particular people.
    – Ornithology for many decades operated on principle of accepting sight records. They managed to avoid two extremes: relying only on a tiny part of records with photos or specimens, and being flooded by tall tales. Only in the last two decades, digital cameras changed this. However, today, a rare bird is usually first reported on sight.
    – Birdwatching community generally accepted standards of observations. Important is reporting length of observation, distance, quality of a sighting and visibility. These are crucial to evaluate your observation. Many birdwatching records are rejected because of brief sightings in poor conditions where an observer cannot be expected to certainly see and verify field marks.
    – A reliable report tells ID marks of species, except few very unmistakable species and mundane observations. Translating into mammal watching: there is no need to ID an elephant or every common macaque. But in Europe, most reports of wildcats by naturalists (!) and accompanied by photos (!) are domestic cats. And a good percentage of lynxes, too (!).
    – Reliable identification is based on several characters, not just one. Also characters not directly relevant to the ID are reported. This is important to get a feeling how much one really saw.Besides, knowledge is likely to change in future, and what appears irrelevant now can become important in few years time.
    – Quantify your expression. This is important on mammals, where soft characters like size, shape, texture of fur etc pay large role. For example: one reports a large bat with narrow wings. It is better to describe ‘large’ and ‘narrow’ in inches or by comparison to other bats or maybe birds. Every bat is large compared to some other, except the Bumblebee Bat.
    – Don’t take it personal. Other people cannot know what you saw. The only way one can transfer your knowledge is by telling it. People are not prejudiced against anyone because they are sceptical. They know that everybody makes mistakes, so want to avoid it.
    – It is perfectly OK to admit uncertain record or you are uncertain of something, or that you are ignorant on identification. Simply write it openly. It is a sign of strength to admit being weak in something. What is not OK is omitting or claiming something too hasty and fooling others into believing untruth. People in this thread given examples how a probable record reported as certain lead to others wasting time and money on wild goose chase, or monetary and reputation loss of a tour leader whose clients were disappointed.
    – There is only one standard of truth. Don’t claim possible as certain. Don’t claim more in private conversation and less in public. Others usually cannot tell how serious you were at the time, and don’t know your level of experience. You are either trusted or are not.
    – In birdwatching, there is something which mammalwatching lacks. There are rarities commitees, which are groups of 3-7 experienced people who verify published and unpublished reports of rare birds from a given country or state. In practice, every birdwatcher has a grudge that some of his records were rejected, but at the end people believe them. Beginners think rarities commitees are a sort of sport judges. In reality, rarities commitees are science gatekeepers. And most importantly, their archives are a collection of records which would otherwise be lost or unverifable after a time. I don’t expect rarities committees to appear in mammalwatching, though.

    • Vladimir Dinets

      There are now a few (very, very few) field guides that provide good information for identifying small mammals without catching them, but there’s still a huge amount of work to be done if we want such IDs to become more reliable or, in many cases, possible at all. I’ll be talking about small mammals at the mammalwatchers’ meeting in Spain this year, and will later post the powerpoint online.

  • Carlos Bocos

    Now that the report is back, I have some questions, some as tour leader myself and then some as a person that enjoys mammalwatching.

    Do actually make the list Leader Only stuff like your leopard, when you clearly states that only the leader saw it well enough to ID?

    Do you actually count ID uncertain things like your Long-tailed Giant Rat?

    How do you count stuff like Rousettus sp?

    Im curious because I don’t run mammal watching trips but as a mammal watcher, I like to have great views of the stuff I see. Because there are many super cool bats and rats, particularly when seen very well.

    And this is supposed to be a mammal watching holiday for the clients, for them to enjoy the mammals and learn about them.

    I wonder also, do the participants realize that they are watching a Bamboo Bat? Not actually one but two species? Did they realize about the differences?

    Pretty much the same for your two pipistrelles, your two miniopterus, your two Myotis, your two Macroglossus, your set of Cynopterus and so on? I would like to hear the participants comments about them because im genuinely interested into know if they realize about all those subtle differences.

    • Vladimir Dinets

      In Royle Safaris lists, all species are numbered, including those of which only tracks and/or sign were seen. There doesn’t seem to be a unified standard among tour companies.

      I personally list everything in my own trip reports, but number only species that I consider countable in my life list. That number is kind of meaningless for others because apparently no two mammalwatchers have exactly identical counting rules: people differ in their approach to bat detector records, heard-only species, reintroduced populations, fenced reserves, species IDed only by the guide, and countless other issues. It is not particularly important to me, either, because I’m not into competitive mammalwatching, but it’s a fun intellectual exercise in some cases, like figuring out which, if any, populations of Ovis aries or Canis familiaris are countable.

      I pointed out bamboo bats, trawling myotis, etc. to the clients, but in some cases I didn’t know the species or even the genera until I went through sonograms of microbats and photos of macrobats at home. What the clients choose to count of their lists is up to them.

  • Carlos Bocos

    Seems it matters, specially for participants. If you claim and leopard and appears highlighted at the beggining of the report but actually nobody saw It, what are we talking about?

    So you are right, people have different ways of counting, but with mammals we pretty much have the same way: we count what we see well enough to identify

    • Vladimir Dinets

      Well, I did everything I could to let everyone see it, to the point of nearly capsizing the boat. I would, of course, jump on the bank, catch the leopard and bring it back for everyone to see well, but I tried it the day before with a reticulated python and people weren’t as happy about it as I expected, besides, I didn’t have a capture permit. I am really sorry about this. I also don’t understand what is there to talk about, but if you think it’s a serious problem, I suggest you try organizing mammalwatching tours to tropical rainforests where every participant is guaranteed to see every species perfectly well.

  • Carlos Bocos

    Not about that, at all.
    Now i remember the title of this, which sight records are reportable?
    The sight records where you actually see the animal well enough! Thats all! You are making a list of 20 species of bats out of the blue, when all you saw where loads of micro bats flying around! I can take some of that food at a place where you live and that you know like the palm of your hand but here? You were even confusing Cynopterus with Rousettus. Cant even imagine what would you do with tons of microbats in flight, honestly.

    • Vladimir Dinets

      Yes, the purpose of this post was to discuss a general question, not a specific list. Note the said list has only 3 species of microbats IDed in flight without supporting photos or sonograms, and these 3 are highly distinctive.
      Of course, after the tour I tied up all participants and tortured them with a hot iron until they promised to list all bats on their life lists. Some of them didn’t do as promised, so I am now on my way to the home of one of them with an assault rifle and a bag of cement. He is sleeping with the fishes in the Hudson tonight! That’s how we do mammalwatching business around here.

  • Morgan Churchill

    As a birder I have read a fair few trip reports. In those reports posted by the company, species seen only by the guide are included, but they often have an annotation like “Guide Only” or “GO”. The same with heard only birds. There is usually some effort made to parse species seen by at least one participant vs only heard, since for counting purposes a lot of folks don’t count heard only species.

    Obviously “heard only” doesn’t make sense for most mammals (except perhaps being Tree Hyraxes). I would imagine that “Sonogram only” could be equivalent to use, however I have never seen a person annotate that in a trip list, although it might be mentioned in the trip report itself.

    Native vs Introduced I also often see notation in lists as well, although reintroduced species seem to be treated the same as wild species.

    • Vladimir Dinets

      Morgan: I think adding “comments” column is much better than adding indexes/codes. There would be just too many of those: “IDed to genus in flight and to species on sonogram”, “seen only by the guide and participant #16”, “only spout seen but identified to genus”, “only tracks and scat seen but smell unmistakable”, “roadkill but still twitching”, etc., etc., ad infinitum.

  • Jon Hall

    This has been a lively discussion and a useful one too I hope … and it is still going. It seems there is much we agree on. In particular that sight records are of course acceptable, though additional details and qualifications are called for sometimes, especially for rare species. And that trip reports should make clear which sightings are certain and which are at best probables and at worst wild guesses.

    A lot of this thread seems really to be about “What evidence do we reply on when we report sightings”, rather than “What sight records are reportable”. And that is a good question to ask about trip reports for the reasons Charles Foley and other pointed out (I agree with others that what people do or don’t count on their own life list doesn’t matter very much at all and is a personal thing).

    The amount of evidence needed to claim a sighting publicly is an important question. That said, in my experience – based on many trips with many people – is that most mammalwatchers do record their sightings in a similar way. I can think of only one or two occasions when I have been on a trip and there has been any lasting difference of opinion on what the ID was for a particular sighting and whether it was certain. There have been many friendly differences of opinion in real time, but once pictures have been looked at, sightings discussed and beers drunk, agreement is nearly always reached. Not sure if that is because mammalwatchers are such a good-natured bunch without big egos, or whether this is the same on most birding trips….

    So the Java report stood out because there was a good deal of difference among participants, which is what triggered this threat in the first place. Tom Clode recorded 17 species with a further 5 bats he wasn’t sure he could get to species level; Alex Meyer had 20 species with another 9 species that he wasn’t sure about to species level. And Vladimir recorded 50 species, with a footnote that some of the bats are not 100% certain plus annotations against other species which he counts as uncertain.

    Of course not everyone was together all the time on the trip which accounts for some of the differences, but this is still something of an unusual report in how wide the difference between what different participants recorded and the trip total.

    While I don’t think there can be (or ought to be) strict rules on how people report trips or record species – beyond what we have talked about – it is probably useful to think about some guidelines for the future so that reports are easier for readers to assess for themselves. For example would it be more helpful in a group report to list the species that everyone agrees on in the main trip list, and then continue on with a second set of possibilities./guesses etc? I think for me at least it would be useful … this could be good to talk about more at the mammalwatching meeting in Spain.

    On the particular conversation about IDing bats based on observations of flight patterns, relative sizes of similar species (when not seen side by side and roosting), habitat or echolocation then I remain skeptical.

    I can think of only a very few species that I would see as distinctive enough for me to ID in flight. For the rest I would definitely be guessing. I’ve spent time in the field with many of the world’s most experienced bat experts and I don’t recall any of them attempting to ID species in flight other than occasionally when they also have a detector and are in an area in which they were intimately familiar with species and their local calls (which as Charles said can differ from place to place for the same species).

    I can imagine that it might be possible to become familiar with different flight patterns of different genera after much practice as Vladimir did in Japan. And, when there are only a handful of species, that technique might be fairly reliable though probably not definitive. But I think applying it in an unfamiliar forest, with a large bat diversity, is “courageous”. But courage is good and I would love for this to work! But until there is a lot more evidence I hope that trip reports that attempt to ID bats in this ways will label such sightings very clearly as experimental (and preferably separately to the rest of the trip list).

    But I am not claiming to be a bat expert and hopefully the real experts might want to comment more on this at some point

    • Vladimir Dinets

      Jon: note the list has only 3 species of microbats IDed in flight without supporting photos or sonograms, and these 3 are highly distinctive (Kerivoula picta with its unique coloration, K. pellucida with translucent wings, and Java’s only Murina).

      • Jon Hall

        Thanks. Kerivoula picta is distinctive I agree. But I have caught K. pellucida and though the wings might be more transparent than most bats I imagine I would really struggle to see that feature in flight at night with any certainty. And are Murinas in flight necessarily all that different from Kerivoula or Pipistrelle? These at least are the questions I would ask myself but you were there and I wasn’t. I think Nils’s comments on the reliability of sonograms (below) are useful.

        • Vladimir Dinets

          Turns out, Kerivoula pellucida is obvious when seen against the sky at dusk. I had never seen it before, but I can’t think of any other bat that would be tiny and with transparent wings.
          Small Murina very reliably differ in flight from other bats of similar size (and the Murina found on Java is tiny). Larger ones also have slow flight with very slow wingbeats, but generally the larger bats get, the slower the wingbeats, so it is possible that large Murina can be confused with something else in the tropics (certainly not in Japan or adjacent mainland where M. ussuriensis reliably stands out). The problem with them is that they have very soft echolocation calls (they don’t need to “see” far because they fly so slowly and mostly through cluttered areas), so you need them to fly very close to the detector to confirm the ID. They have very loud contact calls but these are kind of seasonal (and in a weird way – I can tell more if anybody’s interested). With stationary detectors you get maybe one recording with echolocation calls for every hundred recordings with contact calls. And there’s very little published info on their vocalizations, particularly on contact calls. So even if you do obtain sound recordings, you can’t use them. Also, there’s probably a lot of undescribed Murina species between Sichuan and Sumatra, as some of them hunt in the canopy. On the other hand, since they fly so slowly, it’s really easy to see body color in flight, and some of them are bright-colored so you can use that for IDing (in Taiwan, for example).

  • Morgan Churchill

    I was just reporting what I see in bird reports. Of course many will also include brief comments in the list, and I don’t think anyone of them go into which participants saw what, other than distinguishing the guide versus everyone else. The latter I think is pretty trivial.

    Of course keep in mind that bird trip lists, depending on the location, can easily rack up 500 species overall. In which case some simple codes or direct statements can be key to preveninting your trip list from turning into the novel.

  • Jon Hall

    More on the bats … I asked Nils Bouillard about the reliability of bat call analysis (though he is too modest to admit it I see him as an expert on this)….
    I think a lot of people seriously underestimate the variability of bat calls. A lot of people consider using bat acoustics to ID species similar to using bird songs, except you just look up values in a table. I hear the words ‘bat call frequency ‘ far too often. There isn’t one single frequency that can help you, definitely not without context such as call duration and shape. Too many people still rely on peak frequency for ID, a remnant of the mostly bygone era of heterodyne detectors. It’s a terrible parameter to look at, mainly because it’s based on amplitude and amplitude varies with duration. The more time is spent at a certain frequency, the higher the amplitude.

    The vast majority of publications I’ve seen describing bat calls had one of the following issues: the calls were recorded upon release (that includes tents) or the data was presented as a simplistic table of values for various parameters with no indication of how those relate to each other. Sample size is often an issue too. If you want a representative sample for a species (doesn’t apply to high duty cycle species), you’re looking at 1000-1500 calls. I haven’t seen that yet.

    Then there’s the issues with poor quality recordings. The Echometer touch is very popular and is a decent recorder. The main issue is that most people don’t think about recorder placement. While it’s a non-issue for birds, it is essential for good bat recordings. Having it too close to your body leads to mushy calls, leading to unreliable identifications. It’s best to use an extension cable and a pole, which very few people use. While many bat species can be identified based on sound (all in Europe and the USA), not every sequence can be identified. Bad quality recordings seriously hinder the probability of identifying a bat correctly.

    Vladimir’s “Otomops”
    I never formally said it wasn’t Otomops. I said I didn’t see anything distinctive about the sequence. It matches a large number of Molossidae species in the general area. I’ve lost count of how many recordings of Molossidae ended up in the bin in Asia and Africa because of the plethora of overlapping species. Molossidae have an incredibly wide répertoire of calls, most of which aren’t described in the literature because most reference calls published to this day are still hand-releases. This is highly unlikely to lead to recordings of calls similar to free-flying bats. The combination of poor quality references and huge variability makes this family incredibly difficult to identify. Just looking at Tadarida brasiliensis, it overlaps with a dozen or so species, from several different families. And that’s mostly because of how well its repertoire has been described. Mops (including the bats previously in the genus Chaerephon) are incredibly variable too. Most Molossidae calls in SE Asia will be Chaerephon plicatus, simply because of how common it is and therefore how likely it is that every bat will produce odd calls every so often.

    So my conclusion on these recordings was that there was nothing on there to exclude Chaerephon plicatus for example.

    Additionally, the recordings are of very poor quality, probably because of how close the microphone was to the operator but also because, in my opinion, there wasn’t much of a line of sight.

    • Vladimir Dinets

      I think the main problem with recordings taken by me at Ujung Kulong was not the line of sight or echoes from my body (the bats were mostly overhead), but echoes from the boat. In some sonograms that echo is clearly visible.
      Note that all bat species IDed by sonograms on that trip are very common ones (except for one Myotis which is not particularly common, but it was also seen trawling and that narrowed it down a lot). The Otomops was IDed by ears; I think I’ve repeated at least ten times by now that sonograms are not good evidence for molossids.
      Unfortunately, peak frequency is often the only data published for a species. Particularly bad for species with CF component which is much more informative.

  • Carlos Bocos

    Jajaja exactly, Morgan! If i call out loads of species that actually no one see and no one can id and they finally make it to the trip list,participants will think that they were in a totally different trip lol.

  • Tom Clode

    Thanks for this Jon.

    A minor point to add to this is that I did not join all of the excursions on the tour due to illness – I wouldn’t want anyone to think that the delta between my number of 17 and the number in the TR is solely down to some controversy over ‘sight records’. I’m also keenly aware that Vladimir has done a lot of work to identify to species-level some of the bats I couldn’t ID in-situ (of course, this was been mentioned already). Given my commitment to context throughout this thread, I’d hate to give a misleading impression.

  • Morgan Churchill

    Although I don’t mind seeing/counting trapped rodents/shrews, I otherwise pretty much agree with this. There are certainly many hard to ID bird species, but they are more likely to “stick around” allowing longer observation, and often there vocals are diagnostic. Plus they are active during the day generally.

    In contrast, there might be several identical or nearly identical species of mouse in a given area, that only come out at night, and in which you might only see for a minute or less before they disappear. Trapping is great, but its not feasible or even legal to to trap in a lot of locations.

  • Jens

    Here is a related thought because I have often wondered why people include bat IDs from bat detectors on their species list in the first place. What does it actually mean if you document a bat with a bat detector? You may not see it and you may not hear it and it only gets picked up by a machine – the detector. Is that really what we want?
    Let’s do a thought experiment. What if we had a more comprehensive mammal detector, which – when you enter a forest – would automatically detect all mammals in it. Would you really put these on a list and “claim” them? And let’s go one step further. What if the detector could detect all mammals world-wide. You would just have to step out of your house, switch it on and then you are done – all mammals are detected. But is this really what we want?
    With eDNA things are beginning to move in this direction and it is obvious why science is going this way because absence/presence data of species inform important conservation decisions. But I would have thought that we are interested in something different – after all, the website is called mammal-watching and not mammal-detection.

    • Morgan Churchill

      I assume when people talk about bat detectors/sonograms its because they used them to confirm the identity of a bat they saw, not necessarily that folks are counting bats that they never saw but only knew were present with the detector.

      The former is reasonable I think for counting purposes. It’s not really all that different from using bird song to identify some poorly soon or morphologically indistinct flycatcher.

  • Manul

    For those who would be interested in the mentioned meeting, you can find more information here:
    We still have a couple of places left.

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