Spatio-Temporal Foraging Activity of Bats in the Agricultural Landscape

As the primary predator of night-flying insects, bats are generally regarded as playing a vital role in suppressing insect populations. Areas of tree cover are important habitat for bats in modified agricultural landscapes, and in Nebraska, forest- dependent tree-roosting bats in particular are affected negatively by habitat fragmentation.  

Goals

The purpose of this study is to investigate the use of monocultural fields by insectivorous bats in different land use configurations in Nebraska’s intensively managed agricultural landscape. Understanding the spatial patterns of each species over space and time will lead to a better understanding of bat foraging ecology, the ecosystem services they provide by eating harmful insects, and additional measures to conserve these species. To do this we are systematically placing acoustic detectors in a variety of crop fields and recording the echolocation calls different bats make when active at night.


Current Status

We will also be studying federally threatened Northern Long-Eared bats through capture and telemetry efforts, in order to understand the roosting ecology of this imperiled species at the western edge of its range.

Immediate findings from this study have revealed spatial trends among the eight different bat species recorded since the start of the project, with dramatic differences in activity patterns over time and open crop field airspace. Species affinities for the various habitat types have also become apparent in the amount of space each covers. The extents of these foraging distributions present a different way to view bat movements, offering a deeper insight into bat ecology, with considerable implications for the ecosystem services they may provide.

Acoustic bat detector deployed in Gage County, Nebrasaka. Photo: Christopher Fill
Acoustic bat detector deployed in Gage County, Nebrasaka. Photo: Christopher Fill
Acoustic bat detector deployed in Gage County, Nebrasaka. Photo: Christopher Fill
Acoustic bat detector deployed in Gage County, Nebrasaka. Photo: Christopher Fill
Principal Investigator(s)
-Dirac Twidwell
-Eric A. North

Graduate Student(s)
-Christopher Fill, M.S.


Project Duration
January 2018-May 2020

Funding
-National Science Foundation Program (NRT)
-National Park Service

Project Location
Lancaster and Gage counties, Nebraska
Cooperators