Studying Bats in Rocky Mountain National Park

Townsend's big-eared bat. NPS.

The research

Bats are a new research focus at Rocky Mountain National Park. Since 2018, the park has worked with zoologist Jeremy Siemers of the Colorado Natural Heritage Program at Colorado State University to fill gaps in what's known about the park's bats — especially their diversity, abundance and health.

Where: the work feeds the national North American Bat Monitoring Program (NABat), which pools bat data from across the country to track population trends. The park spans 16 of NABat's 10 × 10 km grid cells. Surveys run at front-country sites where bats live in park buildings, such as Holzwarth Historic Site and Moraine Park, and across other habitats and elevations.

Three methods

Acoustic monitoring. Microphones record the ultrasonic calls bats use to echolocate, identifying species across the landscape without disturbing them. Since 2018 they have confirmed four long-suspected species in the park: the fringed myotis, big brown bat, hoary bat and Townsend's big-eared bat.

An acoustic monitor identifies bats by their echolocation calls. NPS.

Mist nets and harp traps. Captured bats let the team confirm species against the acoustic identifications and record body condition, sex and age. They also swab the wings and noses to test for Pd, the fungus that causes white-nose syndrome, a disease deadly to many bats.

A harp trap at Holzwarth Historic Site. NPS.

Infrared video. Cameras count bats emerging from roosts at dusk to estimate how many use them. In 2021, counts at buildings and nearby bat boxes housing maternity colonies ranged from 30 to 100 bats. The numbers will inform park management.

The research continues; preliminary results are in the NABat database.

Sources

Based on "Bat Research in Rocky Mountain National Park," Rocky Mountain National Park, National Park Service; a work of the United States government in the public domain. The article's NABat grid map is left out.