The Better to Hear You With

That passage from “Little Red Riding Hood” could apply as easily to Townsend’s Big-eared Bat, Corynorhinus townsendii, as it does to the Big Bad Wolf. This docile little creature is not nearly as menacing, however, and a true friend to farmers and other folks plagued by insects.

I was fortunate enough to discover this roosting individual inside an abandoned house in Brown Canyon on the Buenos Aires National Wildlife Refuge in southern Arizona. Thanks to Philip Kline who had informed me of another species of bat in the same house. That bit of knowledge prompted me to venture into what had to be Hanta Virus Central to try my own luck. I found the solitary Townsend’s Big-eared Bat as a result.

Townsend’s Big-eared Bat occurs chiefly west of the Rocky Mountains from southern British Columbia through Mexico, but isolated populations in the Ozark Plateau and Appalachian Mountains are not thriving. Like most bats, this species is incredibly sensitive to any disturbance during hibernation in caves, mine shafts, and similar locations.

Those big ears come in very handy when the bat is hunting. Most insect-eating bats use echolocation to pinpoint their prey in flight, homing in on the audible signals bouncing off their moving target. Big-eared bats have raised this hunting style to an art form, and few moths can escape these nimble fliers.

This species roosts singly during the day in the summer months, but individuals cluster together during winter. Mating happens in late autumn or early winter, and each female gives birth to a single offspring in May or June. Maternity colonies can include several dozen to a few hundred females.

Look for this species in desert scrub or dry pine forest habitats for the most part. Note that many references still list it by its older scientific name, Plecotus townsendii. Besides the extra long ears, often folded back as the one ear in the image above shows, this bat is recognized by the pair of glandular bulbs that rise above the nostrils.

Additional sources of information include this great page by Texas Parks & Wildlife, and this page from Pima County government that likely addresses the subspecies imaged above since Brown Canyon is in the Baboquivari Mountains (pronounced Bab-o-KEEV-er-ee).

Brown Canyon

Last Tuesday, August 3rd, I had the privilege of joining my friends Philip Kline, Margarethe Brummermann, and Fred Heath in Brown Canyon on the Buenos Aires National Wildlife Refuge in western Pima County, Arizona. I also made new friends in Ken Kertell, Jake Mohlmann, and a couple from Cincinnati: John and Samantha.

Recent rains left Brown Canyon anything but “brown.” Wildflowers, butterflies, and dragonflies all added dashes of color to this unique landscape. In fact, reds, pinks (like the Fendler’s Globemallow below), oranges, and yellows were among the dominant colors of the surprisingly lush blooms of flowers.

There was still water in the upper reaches of the canyon, and a succession of pools in the scoured bedrock were patrolled by dragonflies including the Filagree Skimmer, a Giant Darner, and this Meadowhawk (Sympetrum sp.).

Most of those on this trip were looking for birds and butterflies and they were richly rewarded. Fifty-two species of butterflies and skippers were observed, including this Fatal Metalmark, Calephelis nemesis.

The canyon itself is very scenic, and steeped in a rich human history. Buildings, rusting cattle tanks, and even an old windmill are strewn throughout the landscape, and an old road and rock walls run parallel to the streambed. Not all the human habitations are derelict, however, as there is a very nice environmental education center complete with lodging for visitors.

The U.S. Fish & Wildlife Service is quite serious about regulating tourist traffic in Brown Canyon, and it cost our party $40 to visit for the day. We had to obtain a code for the keypad that opens the gate, and it took two tries to get all three of our vehicles through before the gate closed automatically behind us!

I heartily recommend a visit to this wonderful area, but strongly suggest that you watch the weather reports and make your trip after a good monsoon rainfall if you want to see the best of the flora and fauna. Remember to take plenty of water, sunscreen, sunglasses, and a broad-brimmed hat for maximum comfort during your hike.