Daily and Seasonal Movements of Brown Pelicans in the Bahia Grande Wetland Complex: Technical Report
Author(s):
A.G. Birt, L.M. Koczur, A.R. Tamayo, R.F. Huch, A. Rodriguez
Publication Date:
October 2021
Abstract:
This research project implemented a series of studies that investigated the daily and seasonal movements of brown pelicans in the Bahia Grande Wetland Complex (BGWC) of South Texas. The project was motivated by brown pelican mortality that occurs along a stretch of highway (State Highway 48 [SH 48]) that links Brownsville, Texas, to Port Isabel, Texas. Brown pelican mortality is a conservation concern but is also a risk to the traveling public. The research undertaken in this project tracked individual pelicans using global positioning system devices. Researchers also undertook a banding and resight study, and other field methods employed to monitor pelicans in the region. These field methods were used to develop mathematical and statistical models that provide a holistic view of the movement ecology of pelicans in the region, and help explain the frequency of SH 48 crossings, and SH 48 pelican mortality events.
The study illuminates key roost and loafing sites used by pelicans in the BGWC as well as major flight corridors that connect them. These sites include pelican habitat within the BGWC that largely explain why pelicans regularly attempt crossings across SH 48. The analysis of field data collected during this project also identified the important seasonal migration trends of pelicans in the region and the temporal variation in the size of the BGWC population. Statistical models of pelican mortality show that, in addition to the daily and seasonal movements of pelicans in the region, mortality is associated with cold fronts that result in strong northwestern winds that create unfavorable flight conditions for pelicans crossing SH 48.
Report Number:
0-6970-R1
Electronic Link(s):
Document/Product
http://tti.tamu.edu/documents/0-6970-R1.pdf
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