Return to the Bat Cave

Aside from trapping small, crawly mammals, I'm also interesting in the kind that fly - bats.

And, I'd also like to move the cam trapping ball forward on them. I know perfect photos of flying bats can be captured - the amazing Michael Durham does it with his eyes closed. But, I'd like to see if it can be refined using $200 homebrew cam traps, instead of $2,000+ pro setups. I've seen the Codge show some success, so thought I'd give it a go too.

Thus, once the bats returned to the bat cave down in the Tehachapis, I set another cam.

Here's the few serendipity shots it caught. Nothing good, but showing some potential. I say "serendipity" because most are photographed somewhat incidentally - the photographed bat happens to be in the scene 2 seconds or so after a bat or rodent triggered the waking of the cam trap. The cam is way too slow for direct real-time photography, so density or frequency of bats is a must if you hope to have one in the scene when the shutter finally snaps.

In this case, the mouth of a bat cave, as they're coming and going.

These first 3 shots seem to be a Myotis (thanks Codger for your help). Might just be Myotis californicus, the California Myotis. But, it could be Myotis ciliolabrum, the Western Small-footed Myotis. Like the Codge, I lean towards ciliolabrum - a Species of Special Concern in CA.


Buffy body, dark wings and mask, and medium ears suggest Myotis ciliolabrum


Side shot that may be the same Myotis species


Butt shot that may be the same Myotis species

This next photo might be the same Myotis species as well, but the head looks rustier, and the ears smaller, suggesting maybe a 2nd/different Myotis species.


Perhaps a different Myotis? Body looks pale, head rusty and ears small and dark

Finally, this last photo definitely seems to show a different species from the others. Likely choices are Myotis evotis, the Long-eared Myotis, and Corynorhinus townsendii, Townsend's Big-eared Bat. Both are Species of Special Concern that range into the Tehachapis.


Bat that appears to be brown all over with big ears - Townsend's Big-eared?

The technique definitely needs more work.

But as I said, it shows some potential.

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References:

• Camera Trap Codger - Night Roost
• Camera Trap Codger - Poison Water Guzzlers - Predators
• Camera Trap Codger - Spooks in the Rock Pile
• Smithsonian National Museum of Natural History - Townsend's Big-eared Bat
• Smithsonian National Museum of Natural History - California Myotis
• Smithsonian National Museum of Natural History - Western Small-footed Myotis
• Smithsonian National Museum of Natural History - Long-eared Myotis
• Michael Durham Photography - Bats / (also on flickr)
• California Department of Fish & Game - Species of Special Concern
• The Nature of a Man (this blog) - The Bat Cave

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Cirque de No Soleil

Regular readers of my musings may remember that one of the personal projects I've undertaken, as an apprentice cam trapper, is to refine my skills and technique for getting micro mammals - the little warm fuzzies that most people just refer to as "eeeek - kill it!!!!"

Yes, rats and mice. But, more specifically, the wonderful panoply of gnawing natives we have here in California - the deer mice, jumping mice and pocketmice, the woodrats and kangaroo rats, and even the voles, moles and shrews.

And, extra more specifically, I want to be able to consistently photograph them well enough to determine their species, and hopefully the different individuals within a scene/set.

Several great rationalizations I use for this project:

- I like the little critters, and think they deserve some love and attention. It's a hard life sneaking around at night, spreading seeds all over, and then ending up the cornerstone food and livelihood for a local flying or fleet-of-foot predator.

- I think it could be an interesting complement to "classical" small mammal trapping survey methods that use buckets and drift nets, and/or sherman live traps. While you don't get weight or sex or population density, it has potential for pure presence/absence detection, and is much easier to manage - you don't have to worry about the animal's safety and health, nor set your traps at sunset, and check at sunrise, which can be really tough in remote areas.

- It works well with "short sets" - a term I use for sets of 1-3 days/nights. Such as during a weekend camping trip. Put out a few seeds where you see signs of activity, and you'll generally get shots of the local Rodentia in a day or 2. You don't need to leave the cam out for a month.

So, here's some short set shots of 5 species, from various places, using my Pentax 8 and 10 mega pixel homebrew cam traps. They include a variety of experimental tweaks, such as: scene setup, distance to scene, height of cam, zoom use, and adjustment of exposure value.

First, a couple I just caught near Mono Lake:


Desert Woodrat, Neotoma bryanti, near Mono Lake


Dark Kangaroo Mouse, Microdipodops megacephalus, near Mono Lake

The above cute k-mouse should not be confused with k-rats, of course...


Heermann's Kangaroo Rat, Dipodomys heermanni, on the Chimineas Ranch



Sometimes you can easily tell individuals apart. These 2 are obviously different woodrats - the first the midden owner (with ear notches), and the second a visitor, and perhaps relative:


Big-eared Woodrat, Neotoma macrotis (formerly fuscipes), near Mariposa



Good clear close ups of mice allow you to compare tail and body lengths - key characters for determining many species. Sometimes you even get a showoff that makes it quite easy:


Juvenile Pinyon Mouse, Peromyscus truei, in perfect pike - with
sunflower seed in mouth for extra degree of difficulty


Adult Pinyon Mouse, Peromyscus truei, with big ears and buff stripe on side



Getting multiple species at a single set can be helpful for determining relative size and proportions, and thus species. Or, you can include a ruler in the scene. :)


Big-eared Woodrat, Neotoma macrotis (formerly fuscipes), near Mariposa


Juvenile Pinyon Mouse, Peromyscus truei, w/o buff stripe, near Mariposa

I seem to be becoming a better mouse trap.

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References:

• randomtruth on flickr - my set of small mammal trapping "short set" photos
• The Nature of a Man (this blog) - The Artist Formerly Known as Lepida
• The Nature of a Man (this blog) - Mama Homemaker

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Herp Holiday 2011

When I returned home from our May herp holiday in the east Mojave, I thought about writing a post to showcase the gang's incredible finds.

But there were so many, I couldn't figure out where to start.

17 herp species - 16 reptiles and an amphib - in 3 days. 10 of the species first timers for me, and a few of those total lifelisters.

But, as I've now learned this year - go to the Mojave with a bunch of plant geeks, and you see more amazing flora than you'd ever think could exist in a desert.

Go to the Mojave with a bunch of herpers, and...

Well - you be the judge.

Here's what we saw...


Our main camp was in the Granite Mountains


The beautiful Kelso Dunes was also a hot spot (argh - sorry)


Desert lawnmower with creosote-stained lips


We admired 3 of these gentle souls from telephoto distance. As a threatened species,
it's a must to give them that respect


The Prey - Fringe-toed Lizard, Uma scoparia


The Predator - Leopard Lizard, Gambelia wislizenii


Chuckwalla, Sauromalus obesus, a handsome herbivore


Another grazer - Desert Iguana, Dipsosaurus dorsalis


Beauty Desert Horned Lizard, Phrynosoma platyrhinos


Tiny Desert Night Lizard, Xantusia vigilis


Yellow-backed Spiny Lizard, Sceloporus uniformis, just before he ravaged my finger


Mr. Attitude: Western Banded Gecko, Coleonyx variegatus


Gilbert's Skink, Plestiodon gilberti, in full mating cheekiness

The five slithers...


Glossy Snake, Arizona elegans


Lovely Long-nosed Snake, Rhinocheilus lecontei


Shovel-nosed Snakes, Chionactis occipitalis - 2 color morphs (white is uncommon)


Mojave Green Rattlesnake, Crotalus scutulatus


Sidewinder, Crotalus cerastes

And, the too cute phib we were quite surprised to find...


Red-spotted Toad, Bufo punctatus

Incredible, huh?

Thanks again Jake, John, Sean and Dave - that was a tour worth far more than the cost.

Can I book a seat on next year's trip yet?

Here's the full set of 162 photos, with many more of each species, and all the wildflowers.

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References:

• Camera Trapping Campus - Camera Trapping Campus
• Camera Trapping Campus - Phibs in the Desert

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The Artist Formerly Known as Lepida

Speaking of woodrats...

While on an amazing east Mojave herping trip with my friends at Camera Trapping Campus, we decided to try some single night sets to see if we could get good pics of the region's Rodentia.

Which, as any Cali cam trapper who does his research will know, includes woodrats. In this case the desert woodrat, called Neotoma lepida, and now, through the magic of molecular biology and classification condensing, called Neotoma bryanti on the west side of the Sierra Nevada.

And I like woodrats.


Landscape around our camp site in the east Mojave's New York Mountains


Typical cam trap set for woodrats (and k-rats)

Similar to the big-eared woodrat, Neotoma macrotis, and the dusky-footed woodrat, Neotoma fuscipes, desert woodrats live solo in fortress-like middens they build in almost any crack, crevice or hidey hole they can find.

And, while these species' ranges often overlap, with good cam traps you can actually tell them apart in photos. Compared to fuscipes/macrotis, Neotoma lepida/bryanti are smaller, more compact, lighter and grayer, and they have a fuzzier tail. And, they're even a bit cuter.

Here's 3 desert woodrats from 3 different places in California:


Desert woodrat, Neotoma lepida, in the east Mojave


Desert woodrat, Neotoma lepida, in Mono Lake Basin


Desert woodrat, Neotoma bryanti, in the Tehachapi Mountains

House/midden design is another key difference between the species. And, like fuscipes, desert woodrat dens show how resourceful and artistic they are. But, while fuscipes are fans of sticks and leaves, lepida/bryanti collect stones, cacti and yucca for their midden art.


House in rock jumble with fortress of chamise branches, small rocks, coyote turds
and cow pies, and even a couple of shotgun shells


House in Yucca whipplei, made from rocks, chamise and dried yucca stalks


House in cave with fortress made just of small rocks

Houses are often used by multiple generations, and aside from protection from predators,
they also regulate heat and humidity, and repel rain.

Here's 3 pics of a terrific crevice midden we found in the Granite Mountains in the east Mojave. It appears to be very old - as you can see by the many, many layers of built-up debris...


Large (left) end of rock crevice midden filled with cholla and sage brush


Smaller end of crevice - what was once a 12" high crack is now 3/4 filled in


Layers of built-up poop and plant matter, along with fresh juniper twigs

The artist both known and formerly known as lepida - gotta love 'em.

Editor's Note: this post was updated to include better/proper photos of desert woodrats. The previous version of the post had a few mistaken IDs that proved to be Peromyscus mice.

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References:

• Camera Trapping Campus - In the Land of Chollas
• The Nature of a Man - Mama Homemaker
• Wikipedia - Neotoma lepida

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