SE California to W Texas: 24 Bats in 24 Days
Our main vacation this year was planned around attending a week-long workshop on bat monitoring techniques, held in southeast Arizona, and organized by Bat Conservation and Management, Inc. This workshop emphasizes acoustics (my primary interest) and trapping techniques, and provides an opportunity to handle a number of the bat species found in Cave Creek Canyon, in the Chiricahua Mountains. This canyon has a list of 21 bat species, more than any other comparably sized area in the continental U.S. and Canada. This workshop fills every year with professionals learning methods for bat censusing; we were the only amateurs present, but at least had more ultrasonic recording experience than the other participants.
We left home (central coastal California) in mid-May and checked for a few target native plants while passing through southern California, finding one extreme rarity we have sought for years (Aristocapsa insignis), known only from two sites in the world. Our first mammal stop was the Californian Mine, along the Colorado River, where we recorded 4 species of bats, including the target Cave Myotis, which is local in California. Next was Organ Pipe NM, where on our first night we had an uncharacteristic rain storm, but still recorded Lesser Long-nosed Bat, a nectar-feeding bat enjoying the numerous flowering Saguaros.
I had applied for a permit to try to record Underwood’s Mastiff (Bonneted) Bat at Quitobaquito Spring in Organ Pipe, which in the U.S. is known only from Pima Co., AZ. However, this area was only recently reopened (during daylight hours only) after a decade of being closed due to serious drug-related traffic across the border here. Two rangers accompanied us, with border patrol personnel monitoring. To our surprise, there were almost no bats until 30 minutes after sunset, when pandemonium erupted with the arrival of a group of mastiff bats, which continuously triggered our detector for 20 minutes, filling the air with their audible echolocation calls! We obtained about 60 good full-spectrum recordings of this species, after which they disappeared almost as abruptly as they arrived, leaving us in silence again — a truly remarkable experience! About 20 minutes after the mastiff bats left, masses of Pocketed Free-tailed Bats arrived and hogged the detector for over an hour.
The next day and a half were devoted to tracking down three SE Arizona birds Eileen had not yet seen: Buff-collared Nightjar and Five-striped and Botteri’s Sparrows. We were successful with all three, and managed to camp within a nightjar territory south of California Gulch, where the birds called throughout the night, which was quite a thrill! The next evening we met county and state biologists at Agua Caliente Park, NE of Tucson, where we recorded 9 bat species, including a number of Western Yellow Bats, which roost in the palms in this park. The last night before the bat workshop, we set up at Ash Spring in the Chiricahua Mountains, recording 5 species, including Southwestern Myotis, a species of somewhat limited distribution, but common here in oaks and sycamores.
During the 7-day workshop, 14 bat species were captured using mist nets or harp traps. The highlight for us was Lappet-faced Bat, though Western Red Bat was quite stunning. I personally acoustically recorded 17 bat species, and others added three more species, so 20 of 21 species known from the canyon were detected. On the last night, at the hummingbird feeders, one instructor was able to do slow-motion infrared videography while I did ultrasonic recording, allowing us to obtain confidently identified still frames and associated recordings of Mexican Long-tongued Bat — no mean feat! A bonus was Mexican Fox Squirrel at the Southwest Research Station; Cave Creek Canyon is the place to see this species in the U.S., but it can be hard to find.
After visiting Eileen’s folks in El Paso, we headed for Big Bend NP, a favorite place of ours. Here we found three of four target mammals. We saw Big Free-tailed Bat flying at dusk from the boardwalk over the cattail pond on the Rio Grande Nature Trail, where later at night we recorded Ghost-faced Bat, which has one of the most distinctive echolocation calls of any U.S. bat. We also recorded Big Free-tailed Bat at the mouth of Santa Elena Canyon and in Pine Canyon. We were too early for Mexican Long-nosed Bat, as the agaves were barely starting to flower. But in the Chisos Basin Campground, we saw Davis Mountains Cottontail, which was Eileen’s 200th native mammal species in the continental U.S. and Canada, a cause for celebration!
On the way home we recorded for one night at Washington Ranch, adjacent to Rattlesnake Springs (in Carlsbad Caverns NP, NM). Mexican Free-tailed Bats from Carlsbad dominated, and several Collared Peccaries snuffled through. The rest rooms at Rattlesnake Springs can have Pallid Bats roosting, but we found none this time. However, when Eileen tried using one of the two rest rooms, she frightened a short-tailed Peromyscus into a ventilation grate, and so as not to disturb it further, she tried the other rest room. This one had a rattlesnake in its ventilation grate, so she decided that she really didn’t need a bathroom after all.
Our last search was for White-sided Jackrabbit in the southern Animas Valley of SW New Mexico. This species is thought to be down to about 60 individuals in the U.S., all in this one location, most of which is private land. The populations in immediately adjacent Mexico may be gone, in which case this isolated population could be in serious danger of disappearing. We spent two hours spotlighting from Mileposts 32 to 41, on County Rd 01, south of Animas, but the only lagomorphs we found were two Black-tailed Jackrabbits a few miles apart.
In total we drove 4400 miles on this road trip and enjoyed many nights of beautiful camping. We detected 24 species of bats and 19 other mammals. The latter list could have been longer but the prime hours for finding most mammals were compromised by the intent focus on bats. The complete list of species is given below in taxonomic order. — Brian Keelan
Lesser Long-nosed Bat
Mexican Long-tongued Bat
Western Yellow Bat
Western Red Bat
Townsend’s Big-eared Bat
Dark-nosed (Small-footed) Myotis
Big Brown Bat
Western Mastiff Bat
Underwood’s Mastiff Bat
Pocketed Free-tailed Bat
Big Free-tailed Bat
Mexican Free-tailed Bat
Davis Mountains Cottontail
Mexican Fox Squirrel
California Ground Squirrel
Round-tailed Ground Squirrel
Spotted Ground Squirrel
Harris’ Antelope Squirrel
Botta’s Pocket Gopher
Woodrat (Neotoma sp.)
Deer Mouse (Peromyscus sp.)