Date of Award
Master of Environmental Studies (MES)
M. Rebecca Bolt
Dialectic variation occurs in many bird species. Different factors have been investigated regarding dialectic variation, including cultural and genetic transmission of songs or calls, and geographic separation. In this study, the predator alarm call of the Florida Scrub-Jay to ground predators was recorded in three geographically separate subpopulations across Florida—Canaveral National Seashore/Merritt Island National Wildlife Refuge, Lyonia Preserve and Leisure Lakes/Lake June in Winter Scrub State Park—to examine any dialectic occurrence between these three subpopulations. Additionally, many bird species are recognized as having highly evolved predator recognition systems, often with different calls for specific predators. The Florida Scrub Jay has exhibited such varied call responses to predators. Three different ground predator treatments, an artificial snake, a live snake, and a live cat, were used to elicit alarm calls. Responses to each predator were then compared within a subpopulation. This study revealed that significant differences existed between subpopulations responding to the cat and artificial snake treatment, but no significant differences existed between subpopulations for the live snake treatment. These results indicate dialectic divergence between subpopulations in response to some species of ground predators, but not to the snake, with which the birds have evolved and are most familiar. Florida Scrub-Jay responses to the three ground predators were significantly different within two subpopulations, at Leisure Lakes/Lake June in Winter Scrub State Park and Lyonia Preserve, but not within the Canaveral National Seashore/Merritt Island National Wildlife Refuge subpopulation. Results from this study could be valuable to scientists, wildlife managers, and communities striving to improve their conservation efforts.
(Bales) Douglass, Sarah A., "Analysis of Response Calls to Diverse Ground Predators from Three Geographically Separate Florida Scrub-Jay (Aphelocoma coerulescens) Subpopulations" (2006). Master of Environmental Science Theses. 3.