Range and Habitat Usage of Northern Long-Eared Bats in Nebraska

Goals

The listing of the Northern Long–Eared Bat (NLEB) as threatened under the U.S. Endangered Species Act in spring of 2015 highlighted the need to better understand the ecology of this species within Nebraska. This project aims to evaluate distribution and habitat usage of the Northern long–eared bat throughout the state. This critical information will allow managers and biologists to focus future conservation efforts on areas that will have the greatest positive impact. If federal restrictions are increased in the future, this work will also potentially limit intensive and costly consultations with the US Fish & Wildlife Service to only areas where NLEB is likely to occur, i.e., our results will result in better maps of habitat and geographic range. To achieve our objectives, this project will use a two–step process over the course of two field seasons.

Current Status

The first step of the project, implemented between late–May and Mid–August of 2015, is to better define the actual geographic range of the Northern long–eared bat within Nebraska by conducting statewide surveying. Acoustic detectors that record the echolocations of bats were deployed for six nights in 101 preselected 10km x 10km grids. Because each species of bat emits a unique echolocation, the collected recordings can be analyzed for species presence/non–detection. The acoustic detectors allow for simultaneous large–scale surveying in a variety of habitat types while requiring fewer person–hours compared to the physical trapping of bats. The results from this acoustic survey will be used to model the distribution of NLEB in Nebraska and to better understand the factors that limit occupancy. 

In part two of the project, five locations within the Nebraska range were intensively sampled to better determine habitat usage. Forty–six paired detectors are currently being deployed at each of the five study sites. Site measurements taken at the recording locations will provide insight into the factors that contribute to occupancy as well as detection probability of the species. 

Measuring tree diameter to assess environmental variables. Photo: Zac Warren
Measuring tree diameter to assess environmental variables. Photo: Zac Warren
Principal Investigator(s)
-Craig R. Allen, NE CFWRU
Graduate Student(s)
-Zachary Warren, M.S.
Project Duration
May 2015- May 2017
Funding
-Nebraska Department of Roads
Project Location
Statewide Nebraska