A bat detector gives off a static crackle as a bat zooms by and dodges a mist net by mere inches. Another swoops too low, flying into the net on its way to steal some sugar water from a nearby hummingbird feeder. Research biologists work quickly to untangle the delicate nocturnal mammal, weigh, and measure it before releasing it back into the cool, Sonoran Desert night air.
The biologists wait patiently for their next capture, listening to the bat detector as it picks up the high frequency noises emitted by the bats flying overhead and converts them to audible frequencies.
Lesser long-nosed bats (Leptonycteris yerbabuenae) pollinate agave and saguaro plants, and have emptied bird enthusiasts' hummingbird feeders consistently every summer night in Tucson and other areas in southern Arizona. Since 1988, the lesser long-nosed bat – a large bat named for its small, upturned nose – has been listed as an endangered species due to the decline in roosting colonies within Arizona and Sonora.
"The outreach program was started in response to the numerous reports of bats feeding from hummingbird feeders," says Scott Richardson, the lead biologist for the lesser long-nosed bat in the U.S. Fish and Wildlife Service's (Service) Arizona Ecological Services Office in Tucson. "This switch to feeders was due to a widespread failure in the agave bloom in 2006."
The agave failure forced many bats to resort to bird feeders and inspired many residents to be part of the monitoring program. Since 2007, a number of Tucson residents have helped biologists like Richardson collect important data on bat populations by allowing monitoring efforts to take place in their backyards. This community support has also led to the discovery of new roosting sites.
"The transmitters placed on the bats after their capture have allow us to locate unknown roosting sites," says Richardson.
According to Richardson, lesser long-nosed bats are taking to nearby caves and abandoned mines during the day to rest. Because the species is sensitive to human disturbance within these roosting sites, discovery of these unknown sites allows for precautionary action; signs and fencing help inform the public of the presence of these rare bats and reduce disturbance.
Many Tucson residents have expressed a passion for the recovery of this endangered bat. What started as a small citizen science program with 30 to 40 volunteers has grown to a monitoring program with well over 100 volunteers. The combined efforts of Tucson residents, Service and Arizona Game and Fish Department biologists, and many conservation partners has established a successful monitoring program of a crucial pollinating species that calls the Sonoran Desert its home.
David Wahl is a volunteer at the U.S. Fish and Wildlife Service's Arizona Ecological Services Office
