Author: Anne White | Published: October 24, 2024 | Category: Species Spotlight
This article originally appeared in The Source Weekly on October 16, 2024.
When the sun sets on the dramatic cliffs of the Owyhee Canyonlands, more than a dozen bat species take flight
By day, southern Oregon’s Owyhee Canyonlands stuns visitors with its colorful rock formations, vibrant wildflowers and bountiful wildlife species. But at night, when darkness falls over the rock spires and canyon walls illuminated only by the glow of starlight, the shadows of bats silently flittering through the air is a truly delightful sight.Although fabled as ominous creatures belonging to a particular hallowed eve, bats are integral to ecosystems worldwide. Bats can eat as much as their body weight in insects each night, controlling invertebrate populations. They’re also responsible for pollinating plants and dispersing seeds and nutrients in their excrement; a valuable fertilizer for plant growth. So impressive are these small creatures that the storied naturalist William Henry Hudson declared bats “a very wonderful creature, one of Nature’s triumphs and masterpieces.”
Fifteen bat species are known to reside in Oregon’s Owyhee, including five species recognized by both federal and state agencies as species of concern, listed below.
Pallid bat. Pallid bat is one of the larger bats in the Owyhee that prefers to roost in rocky crevices and canyons. Unlike other bats that feed during flight, the pallid bat primarily forages on the ground, eating beetles, spiders, crickets and scorpions, and occasionally small lizards. The pallid bat regularly has two pups (i.e., baby bats) per year compared to most bats’ single pup litter.
Fringed myotis. Fringed myotis (“myotis” means mouse ear) wings are particularly resistant to punctures and the species occupies a mosaic habitat of juniper woodland and open grasslands or steppe, roosting in snags, on cliffs, or in cavernous spaces. Relative to other bat species, fringed myotis are less effective at conserving water and therefore, select habitat near streams.
Long-legged myotis. Long-legged myotis, aptly named for its longer tibia than other myotis species, roosts in tree snags or beneath exfoliating tree bark, cliffs and cracks. Capable of flying up to 10 miles per hour, long-legged myotis will pursue moths—which make up as much as 78% of their diet— for long distances.
Townsend’s big-eared bat. Townsend’s big-eared bat is most often found in cavernous spaces, like caves and abandoned mines, and has uniquely large ears that measure nearly half of its body length. This species is a moth specialist and forages prey in or on vegetation rather than “open-air hawking” like many other bat species.
Spotted bat. With even larger ears than the Townsend’s big-eared bat, the spotted bat is the rarest bat species in Oregon and are solitary, never found in maternity colonies like most other bat species. Named for the distinctive white spots on its shoulder and rump, spotted bats have specific habitat needs, only roosting on large, isolated cliffs and within close proximity to foraging areas and open water sources.
As essential as bats are to their ecosystems, they’re equally vulnerable to disturbances such as climate change, habitat loss and fragmentation. Degraded water quality and human activity can also disturb bat populations, which are considered an indicator of habitat quality. Some species are known to abandon roosts when exposed to light for more than just a few seconds, or when subjected to increased or prolonged noise. Disturbance to roosting sites— both day and night roosts—is a top concern for all bat species. Day roosts provide bats a cool, dark and quiet place to sleep deeply; night roosts allow bats to stop and feed on prey, rest between foraging flights or socialize. White-nosed syndrome, a fungus that accelerates the use of fat reserves during hibernation, is a rapidly spreading and fatal disease among bat species that can be unknowingly spread by humans on clothing when visiting caves or mines. Please take care not to disturb bats at their roosts and thoroughly clean your clothing and shoes after visiting a cave where bats might be roosting.
The Owyhee Canyonlands is a vast and rich landscape that provides large, intact expanses of habitat and prey for more than a dozen bat species. Oregon Natural Desert Association is leading a national campaign to protect the Owyhee Canyonlands against improvident development and misuse, climate change and other factors to benefit bats and other wildlife, and future generations of wildlife watchers in Oregon’s high desert. Learn more at ProtecttheOwyhee.org.
— Anne White is the Policy Manager at Oregon Natural Desert Association, a conservation organization that protects and restores Oregon’s high desert public lands, waters and wildlife. Read more of her work at onda.org/author/anneonda-org/.
