RFI – California Bats / Small Mammals

I am planning a trip to California most of the large mammal info is on Mammalwatching.

I am after contacts for small mammal trapping and bat emergence, roosts etc.


General route San Francisco to LA, to Death valley, Yosemite to approx Redding, and back to SF.


Any info appreciated




  • vdinets

    There’s a Yuma myotis roost in a bat house at Clear Lake State Park office, a colony of Mexican freetails under one of the highway bridges along the northern access road to Yosemite, and some Townsend’s big-eared bats in the boulder cave in Pinnacles NM. Check out the abandoned mines in and around Death Valley – they have fringed myotis and other bats sometimes. Red Rock Canyon near Salton Sea has lots of bats, including spotted bats. Canyon and Western yellow bats roost in palms in canyons near the southern entrance to Joshua Tree.
    For rodents, Carrizo Plain is an absolute must. Check the tide chart for Palo Alto Wetlands – you can sometimes see saltmarsh harvest mice and ornate shrews during very high tides. Muir Woods have fog shrews (rarely seen) and jumping mice. Mono Lake area has all sagebrush species, plus a few surprises such as mountain beavers.

    • Curtis Hart

      How do you go about seeing a Yellow Bat in a palm tree. Are they ever visible from the ground with binoculars?

      • vdinets

        You look for droppings underneath, and wait for them to emerge. Usually canyon bats emerge first, then the yellow bats. Sometimes you see them crawling out, but sometimes they just drop down and take flight.

  • markhows

    Many thanks for the info, any additional info on Mountain beaver appreciated.

    Also does anyone know what are the rules / laws on live trapping small mammals?


    • Curtis Hart

      You would have to check the hunting/trapping laws for each state individually. All states will have a website, either a department of Fish and Game or department of Natural Resources. The best you can hope for is not finding it prohibited. The only state I know off hand is Michigan, where it is illegal, except near occupied dwellings.

      • Charles Hood, Palmdale, CA

        My understanding is that ANY trapping in California would require a permit from Calif Dept of Fish and Game (CDFG), and that if one were in a Federal park such as Yosemite, there would be additional layers of control. That said, I think you could trap fairly freely, if you are discrete. That means don’t do it in main campground in Yosemite Valley or around the lodges, but you could set out a trap overnight lots of places even in the Valley and check it in the morning and no rangers would know. As a side note, I have seen Ring-tailed Cat twice in Yosemite Valley: once by the main dining hall at the main lodge and once spotlighting in El Portal, just outside the park entrance. Of course, I have also NOT seen them about 100 or 200 times. Since you’re going to pass by Monterey, be aware that there’s excellent cetacean options on pelagic birding trips there: see the website for Debbi Shearwater’s trips. Those trips have up to date reports on marine mammals and ID is always reliable. As a travel planning note, when crossing from Death Valley / Mono Lake / Eastern Sierra back to Yosemite back to SF, note that the first fall storm will close Tioga Pass — as early as mid Oct or as late as Dec, depending on weather. Earlier closures are more typical than later. Last, it may not be widely known but at least one mountain lion now lives in central Los Angeles proper; it’s in Griffith Park, the scrubby range on which the Hollywood sign sits and the art deco dome of the Griffith Observatory — on a clear day, one could see this mountain from the airport. A mountain lion also left tracks yesterday in the middle of a desert suberb (the city of Lancaster, in the Antelope Valley), many many miles from the closest foothill habitat. I guess humans are not the only mammals to wander widely.

  • markhows

    Many thanks for all the help, ticket booked (Dept mid Jan) and report in due course. Mark

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