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A continuously operating acoustic monitoring station for Bosque-flying bats in central New Mexico.
Orr, Teri*,1, Gannon, William1, Greenlee, Erin1, Racz, Gabor1, 1 University of New Mexico, Albuquerque, New Mexico, USA
ABSTRACT- Landscape and even continental-wide perturbations may affect survivorship and distribution of bats. Since all North American vespertilionid insectivorous bats echolocate, monitoring bat calls is an efficient way to detect their presence. It is also possible to identify most bat species by examining a clear call sequence. In this project we deployed one acoustic monitoring system to record calls of free flying bats in the Bosque of the Rio Grande in Albuquerque, New Mexico at the Rio Grande Nature Center. The monitoring system consisted of an Anabat acoustic detector, an interface module, and two DOS driven computers. A laptop computer collects, stores, and permits download of call data to the other PC for analysis. Call file headers were cleaned and saved and standard analysis was conducted on all calls using Analook software. One advantage of using a monitoring system of this type is that large amounts of data can be continually generated for long periods of time and stored. In this paper, we investigate temporal variation (e.g., within a night, season, year) and activity of bats surrounding the detector site. Analysis of call file data has revealed trends in total calls per night (abundance) and changes in number of species detected during monitoring. Using natural sonic categories, sound space was divided in order to partition different groups of calls based on minimum frequency (kHz). Three groups were created: high frequency (40-60 kHz), low frequency (20-32 kHz), and intermediate frequency bat calls. Several interesting temporal, activity, and biodiversity patterns will be discussed.
Key words: acoustic, Anabat, bats, New Mexico