Bat Blitzes Find Ten Bat Species in Great Basin National Park

First published in The Midden*, Great Basin National Park's newsletter, Vol. 20, No. 1, Summer 2020. By Kelsey Ekholm, Joseph Danielson and Bryan Hamilton, bat biologists.*

BioBlitz participants get a close look at a bat held by Nevada Department of Wildlife biologist Jason Williams. NPS photo by Gretchen Baker.

Most people have no idea how many bats fly overhead every night. Bats are the only mammals capable of true flight, and they hunt insects by echolocation — high-frequency calls mostly beyond human hearing, which insects can detect, dodge and even jam.

By eating insects, bats provide billions of dollars in services: lower food costs, less need for harmful pesticides, less disease spread by insects such as mosquitoes. But they face unprecedented threats — habitat loss, climate change, wind energy development and disease. White-nose syndrome, a fungal disease, has spread across the United States over the past decade, killing millions of bats.

Two blitzes

To learn more, the park led two bat surveys in the summer of 2019:

The aim: learn more about the bat communities in and around the park and how they use the landscape — vital for management as threats grow.

Setting up a net for one of the blitzes. NPS photo by Joseph Danielson.

How bats were surveyed

Teams went to water sources, flyways and places near roosts and caught bats in mist nets or a harp trap. For each bat they recorded species, sex, age, reproductive condition, weight and other measurements; every bat was released by hand, and none was collected. At most sites, acoustic surveys recorded bat calls at the same time.

What they found

The BioBlitz drew more than 60 participants and surveyed six sites over two nights: 821 bats of 8 species caught, 7 species detected by sound, 9 species in all:

• pallid bat (Antrozous pallidus);
• Townsend's big-eared bat (Corynorhinus townsendii);
• big brown bat (Eptesicus fuscus);
• hoary bat (Lasiurus cinereus);
• silver-haired bat (Lasionycteris noctivagans);
• western small-footed bat (Myotis ciliolabrum);
• long-eared myotis (M. evotis);
• long-legged myotis (M. volans);
• Mexican free-tailed bat (Tadarida brasiliensis).

Volunteers learn how to process a bat during the 2019 BioBlitz. NPS photo by Joseph Danielson.

The Bat Blitz brought 39 participants from nine park units — Great Basin, Death Valley, Joshua Tree, Lava Beds, Lake Mead, the Mojave Network, Pinnacles, Timpanogos Cave and Zion — plus the Nevada Department of Wildlife, the U.S. Fish and Wildlife Service, the Great Basin Institute, Christopher Newport University, Oregon State University and volunteers. Over four nights at 17 sites they caught 701 bats of 9 species and detected 10 species by sound — 10 species in all, adding the canyon bat (Parastrellus hesperus) to the BioBlitz list.

Two of the many bats caught during the blitzes. NPS photo by Joseph Danielson.

Why it matters

Volunteers let the park survey places it normally cannot reach, and many places at once — giving new insight into bat activity across elevations and habitats. Pairing captures with recordings helps biologists understand how calls vary within each species, and makes sense of past recordings. The data, funded by the National Park Service and the Southern Nevada Public Land Management Act, are being used to reduce the impacts of wind energy, recreational caving and disease on bats.

On the next warm summer evening, look up and think about the unseen aerial ballet between bats and insects — and how it helps us.

Sources

• National Park Service, Great Basin National Park, "Bat Blitzes Show Many Species in Park," The Midden, Vol. 20, No. 1, Summer 2020. https://www.nps.gov/articles/000/bat-blitzes-show-many-species-in-park.htm
• Three scientific names are misspelled in the original ("Antrozous pallidusi", "Lasionycteris noctivigans", "Parastrellus Hesperus") and corrected here.
• Rewritten in hubnx's own words.