A Comparative Study of Urban and Natural Nesting Gray Hawks in the Lower Rio Grande Valley of South Texas

Author

Evan Farese, The University of Texas Rio Grande Valley

Date of Award

5-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Karl Berg

Second Advisor

Christopher Gabler

Third Advisor

Richard Kline

Abstract

Urbanization can negatively impact birds of prey, which occupy higher trophic levels. The Gray Hawk (Buteo plagiatus) is a neotropical raptor inhabiting the Lower Rio Grande Valley (LRGV) of Texas, where it is threatened. The species’ ecology has been little studied and it is unclear how urbanization may affect population viability. I studied Gray Hawk reproductive success, diet, and thermal ecology at nests in urban and natural habitats in the LRGV. Camera trap data showed adults at urban nests delivered mostly avian prey, while mammalian prey was most frequently brought to natural nests. Data from temperature loggers showed natural nests were slightly warmer, however, the reverse was true at night. Temperatures >40o C significantly altered parental care behaviors to reduce thermal stress despite possible energetic and developmental costs. Urban and natural nests had similar success rates. Results provide baseline data to inform Gray Hawk conservation and research efforts in the future.

Comments

Copyright 2025 Evan Farese. https://proquest.com/docview/3240632610

Recommended Citation

Farese, E. (2025). A Comparative Study of Urban and Natural Nesting Gray Hawks in the Lower Rio Grande Valley of South Texas [Master's thesis, The University of Texas Rio Grande Valley]. ScholarWorks @ UTRGV. https://scholarworks.utrgv.edu/etd/1676