Anti-predatory behavior of northern bobwhite in the rolling plains of Texas

Date

2012-05

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Abstract

Northern bobwhites (Colinus virginianus; hereafter bobwhites) are a species of great economic importance but have declining populations range-wide. As a result, bobwhites are a highly researched species. Flight behavior and cover use patterns of northern bobwhites have been examined in several studies, all of which have contributed to a large set of habitat management recommendations for the species. However, the existing data lack quantitative measures of how bobwhites respond to natural threat, not solely direct human disturbance. I examined aspects of bobwhite behavior in response to four threat categories: researcher, hunter, raptor, and mammalian. I found that bobwhite flight distance is best predicted by threat type, covey size, and wind speed. I found that bobwhites flushed by the hunter threat (P = 0.034) and the raptor threat (P < 0.0001) selected for significantly higher visual obstruction at landing sites compared to availability. Raptor-flushed bobwhites also selected for significantly higher shrub density (P < 0.0001) and lower angle of obstruction (P <0.0001) at landing points than what were randomly available. In the process of data collection I also observed bobwhite roost locations (n=24) to have lower visual height obstruction (P = 0.03), lower shrub density (P = 0.02), and higher angles of obstruction (P = 0.005) than bobwhite diurnal locations. My results verify that bobwhite escape strategies and cover use vary among threat types. These results support current management recommendations of creating a patchwork of vegetation covers for bobwhite, but also indicate the importance of understanding of bobwhite behavior to improve management and conservation strategies.

To examine how bobwhites respond to a raptor threat, we used a trained northern goshawk (Accipiter gentilis), a bird often used for falconry. The practice of falconry is over 2000 years old. It is a form of hunting wild quarry in its natural state and habitat by means of a trained raptor. Researchers, specifically when studying wild raptors, have used techniques from falconry and at times used trained raptors for research purposes. Studies with trained raptors have investigated raptor flight characteristics and morphology, behaviors, predator ecology, and their effect on prey ecology and behavior. Despite the potential applications of falconry within the field of wildlife research, trained raptors are an under-used resource; this is 1 of only 2 studies to use a trained raptor to investigate prey species behavior in a non-captive setting. I review the methods and results for studies involving trained raptors within the field of wildlife research. I then discuss the logistical constraints and limitations of working with a raptor in a research setting. Finally, I offer suggestions for future research using trained raptors.


This thesis won 1st Place in the Texas Tech University Outstanding Thesis and Dissertation Award, Biological Life Sciences, 2013.


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Keywords

Birds of North America, Birds of Prey, Falconry, Northern Bobwhite

Citation