Baseline Population Estimates and Microclimate Data for Newly Established Overwintering Brazilian Freetailed Bat Colonies in Central Texas
Date
2015-01
Authors
Weaver, Sara
Simpson, Thomas R.
Baccus, John T.
Weckerly, Floyd W.
Journal Title
Journal ISSN
Volume Title
Publisher
Southwestern Association of Naturalists
Abstract
Behavioral changes of migratory species have been globally documented in recent decades. However, there is a paucity of research on changes in migratory bat species. Brazilian free-tailed bats (Tadarida brasiliensis) roost in central Texas from March to November. These bats have historically migrated south in late fall, leaving summer roosts unoccupied during winter. Recently, overwintering populations have been discovered in central Texas. The objectives of our study were to determine presence or absence of overwintering free-tailed bats at six known summer roosts, obtain baseline population estimates, and evaluate microclimates of roosts during winters of 2010–2011 and 2011–2012. We used data loggers to monitor temperature and humidity hourly. We estimated population sizes with digital images using ImageJ software, previously established roosting densities, or both. Our results indicated that occupied roosts were colder, had less stable temperatures, and had a stronger correlation between internal and external temperatures vs. unoccupied roosts. Population sizes increased at all occupied roosts from 2010 to 2011.
Description
Keywords
Tadarida brasiliensis, overwinter populations, Texas, roosting densities, migratory bat species, Biology
Citation
Weaver, S. P., Simpson, T. R., Baccus, J. T., Weckerly, F. W. (2015). Baseline population estimates and microclimate data for newly established overwintering Brazilian free-tailed bat colonies in central Texas. The Southwestern Naturalist, 60(2-3), pp. 151-157.