Most bats echolocate at a frequency unheard by the human ear, however, some desert species emit echolocation calls within the range of human hearing. 

Spotted bats (Euderma maculatum) are an elusive and widely-distributed species throughout the semi-arid deserts of North America. Sometimes called the “Oreo cookie bat,” they sport large, pink ears and spotted fur. Spotted bats roost high among sheer cliffs, but their clicking calls can be heard while they hunt for owlet moths in the canyons of Central Oregon.

The first spotted bat was “officially” documented in Oregon in 1979 when researchers in the Alvord Desert accidentally captured one in a mist net left open overnight. Only four more spotted bat records were reported in the state over the next 24 years, and the idea that spotted bats were extremely rare, or possibly even extirpated, took hold. In 2005, however, listening surveys combined with mist-netting surveys of Central Oregon revealed that spotted bats may be more abundant in the region than previously recognized.

Biologists still have limited understanding of spotted bat distribution and seasonal patterns in Oregon. What we do know is that their calls are most commonly heard near the canyons and cliffs of eastern Oregon’s High Desert.

Pallid bats (Antrozous pallidus) are another of Oregon's high desert bat species. They have a wide range, spanning from Canada to Mexico. While pallid bats typically produce inaudible, high-frequency echolocation calls, this behavior changes while rearing pups. When in the vicinity of summertime maternity roosts, pallid bats will lower the frequencies of their calls to within the range of human hearing.

Serendipitously, both the spotted bat and pallid bat are found in similar arid cliffs and canyons habitats such that both species can be effectively surveyed simultaneously.

That's a wrap for 2022!

The 2022 season is winding down. The official survey season ends on October 31st, but if you want to help us gain a better understanding of spotted and pallid bat seasonality, we more than welcome surveys throughout the year.

If you were interested in this project and have a moment, please fill out this survey.

We are hoping to revamp the project in 2023 to make things easier, more efficient, and more fun. To be kept up-to-date on the project, please email our volunteer coordinator and ask to be put on our mailing list.

Get involved!

We are sending volunteers out across Oregon's deserts to search for both the spotted and pallid bat. Surveys take place just after dark in a variety of locations, from city parks to the remote desert. This is a family-friendly research project and an excellent opportunity to get to know Oregon's night sky!

If you would like to receive project updates, please contact Sara Rose to be added to our list of volunteers. 

To learn more about the project and to find other ways to get involved in citizen science, check out CitSci.

Contact Us

Please note that there is no previous biology or backcountry knowledge required to become a community scientist. There are options for all physical abilities and outdoor experience. Find us on Facebook and Instagram.

For any questions, please contact Sara Rose, volunteer coordinator. We appreciate your interest in the Audible Bat Citizen Science Project.