Determining bat presence and activity in Petroglyph National Monument to inform visitor management

Petroglyph National Monument (PETR or Monument) is 7,212 acres and is located on the outskirts of the City of Albuquerque. Adjacent land is rapidly being developed leading to increased visitation with potential stress on natural resources. Among these resources are bats which geographically supports the highest species diversity in the United States. There is currently a data gap regarding bat presence/absence in PETR and how visitor activities, as well as the establishment of, maintenance, or closure of trails, could impact bat populations. Characterizing seasonal bat use will help support the Visitor Use Management Plan We surveyed 10 sites with remote acoustic detectors (Wildlife Acoustics SM4bat) for a total of 2,964 detector nights from October 2022 to October 2023 within five focal resource management areas. Analytic data collecting and acoustic analysis followed established USFWS guidelines and protocols. We acoustically detected 21 species: Pallid bat, Townsend’s big-eared bat, big brown bat, spotted bat, western red bat, hoary bat, silver-haired bat, California myotis, western small-footed bat, long-eared myotis, little brown bat, Arizona myotis, fringed myotis, cave myotis, Yuma myotis, pocketed free-tailed bat, canyon bat, and Mexican free-tailed bat. The Mexican free-tailed bat had by far the most detections across the monument, followed by the canyon bat and hoary bat. We calculated nightly activity levels for each species (mean number of calls per night) and species diversity index (0=low 1=high) at each sampling location. Overall bat annual temporal activity was highest in August. While acoustic surveys cannot determine number of individuals on the landscape or determine specific roosting locations, it demonstrated spatially what areas are being used by bats and how frequently in PETR. This data will prove to be a useful management tool for determining potential actions at each focal area of interest on the Monument. We provided managers with specific recommendations for the five management areas of interest. General recommendations include minimizing potential negative impacts, avoiding direct impacts to possible roosting areas (e.g. cave, lava tubes) or conducting visual survey prior to action and if possible, and avoiding times when bat uses is highest.