Frequent Flyers: Bats of Deem Hills

Go out for a stroll on any summer morning or evening, and you are likely to catch a glimpse of twilight’s most frequent flyers: bats. With superpowers far superior to those of their comic avatar, bats are some of the most diverse and abundant of Earth’s creatures. More than one out of five mammal species in the world are bats. Likewise, about 20% of the 138 mammal species in Arizona are bats, with twenty-eight kinds patrolling the night skies throughout the state, especially during the warmer months. Here on the urban fringe of Phoenix, about a dozen species are likely to flutter through while foraging.

While most of our leather-winged neighbors migrate south or hibernate during the cooler winter season, one species, the California Leaf-nosed Bat, is active year round in central Arizona. More drought and cold tolerant than other bat species, they are also well adapted to life in the desert suburbs. The California Leaf-nose is more common in neighborhoods close to natural open space like the Deem Hills, where they can find refuge in cliff crevices and old mine tunnels.

Unlike most other desert bats, the Leaf-nose is an expert at hunting ground dwelling insects and other prey, relying mostly on their excellent eyesight and stellar sense of hearing. Combined with their sixth sense of echolocation, which is augmented by their leaf-like nose flap and extra large ears, these bats can swoop down and snatch a caterpillar resting on a shrub or grab an unsuspecting beetle wandering across the desert, with laser-like precision. During the summer months, they forage mostly by night, but in the winter, it is not uncommon to see them hunting in warmer daytime hours when their prey is also most active.

Two close relatives of the California Leaf-nose, the Lesser Long-nose and Mexican Long-tongued bats, are important pollinators for agaves, saguaros and other cacti. They both have extra-long tongues, longer noses and smaller ears than their cousin, adaptations that make it easier for to them lap up nectar. Flowers of bat-pollinated plants are usually large, tubular, bright white and bloom at night, attracting bats and other night-flying visitors. While these two bat species are abundant in more southern regions of the Sonoran desert, they rarely make it this far north, where saguaros rely on many species of insects and birds for pollination. The Lesser Long-nose bat is currently listed as a federally endangered species.

Bats are fun to see in the wild, but if you don’t want to share your home with bats, be sure to seal all openings in your roof and attic with fine meshed screens. The best time to bat-proof your home is in the fall or winter when most bats migrate south or leave dwellings to hibernate in the wild.

All bats are protected by state laws; it is illegal to hunt, capture, harm or kill a bat. To help protect bats, stay away from mine tunnels and natural caves where they hang out. For lots more information on Arizona’s bats, check out these on-line bat sources:
Arizona Fish and Game Department www.azgfd.gov
Western Bat Working Group www.wbwg.org