Significant range expansion for Silvery Woolly Monkey?

During a birding visit to Peru in August 2015, I observed several monkey species in Manu National Park. Among these were several sightings of Woolly Monkeys. Several parties were seen in the area above the Cock of the Rock lodge at ca. 1500m altitude and another party (of two adults and a baby) was observed from the canopy tower of Amazonia Lodge at ca. 600m altitude. Supposedly, only the Gray Woolly Monkey Lagothrix cana tschudii occurs here (see e.g. HMW Vol. 3; Patterson et al. 2006). However, I noticed strong differences in colouration between the monkeys observed at 1500m and 600m altitude, while revisiting my pictures last winter.

After carefully reading the species accounts of the different Woolly Monkey species in HMW Vol. 3 (Primates), I have come to the conclusion, that most likely there were two different species involved in my observations. While the monkeys at 1500m altitude were indeed the expected Gray Woolly Monkey L. c. tschudii, the monkeys observed near Amazonia lodge, at 600m altitude are phenotypically Silvery/Poeppig’s Woolly Monkey L. (c.) poeppigii. If confirmed, this would constitute a southwards expansion for the known range of this species of ca. 500km!

My identification of the two species is mostly based on the colouration of the fur, as I could not find any other useful features for the ID. Any comments are most welcome.

Attached you find the pictures (unaltered, only cropped) of the Woolly Monkeys observed at Amazonia Lodge (pictures 1-3, presumed L. (c.) poeppigii) and above Cock of the Rock lodge (pictures 4-6, L. c. tschudii). Furthermore there is a video sequence, showing a female with a baby on Youtube, which one of the one participants recorded (The monkeys are shown 2:04-2:38)

Kind regards

Mathieu Waldeck

4 Comments

  • tomeslice

    Very interesting observation!
    I was there in 2007 (Jesus!) and saw woolly monkeys around cock-of-the-rock area on the Manu road as well, and thought they looked different than the ones we saw near Cocha Otorongo, which seemed more yellow. But my guide told me they were the same species…
    I’d be interested to see what the professionals among us would say.

    Cheers,
    Tomer

  • geomalia

    Hi Mathieu,

    Great observation! I saw the Woolly Monkeys on Manu Road in 2011. Unfortunately, coat color doesn’t seem to be a reliable identifying feature of Woolly Monkeys. See “Coat Color is not an Indicator of Subspecies Identity in Colombian Woolly Monkeys” by Botero and Stevenson: https://books.google.com/books?id=bnMeBAAAQBAJ&lpg=PA33&dq=woolly%20monkey%20taxonomy&pg=PA17#v=onepage&q&f=false. (I can email you a full copy of the chapter, if you’d like). Note that the “subspecies” referenced in the paper are now considered “species.” The Woolly Monkey taxa aren’t the same as those in Peru, but they probably exhibit a similar range of variation in coat color.

    Best,
    Ben
    http://www.tremarctos.com

  • Theo Linders

    Just out of interest, how well supported are these Woolly monkey splits in general? Primate taxonomists (especially those on Madagascar) seem notorious splitters, even with hardly any evidence….

    • Vladimir Dinets

      Not at all. Even the “old” species are very closely related and should probably be considered subspecies (except for the yellow-tailed).

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