Modeling Long-Term Changes, 1958-2011, In The Reproduction And Territory Dynamics Of Bald Eagles Of Florida Bay, Southern Coastal Everglades

Summary: As top-level piscivores, Bald Eagles are a compelling subject for the study of territory dynamics and are highly representative of the distinctive suite of avian species that occupy Florida Bay. Despite successful recovery of Bald Eagles (Haliaeetus leuocephalus) throughout the species range, the population breeding within Florida Bay has not mirrored this trend. Beginning in the late 1980s, Florida Bay has suffered in its capacity to support species diversity and abundance as a result of extreme changes in hydrology related to altered flows of incoming freshwater. In fact, Bald Eagle territory use in Florida Bay has declined by as much as 43% as year to year variation and sensitivity to transitions between territory states have increased. Florida Bay’s populations of other large, conspicuous fish-eating birds, including Ospreys, Great White Herons, Roseate Spoonbills, and Reddish Egrets each exhibit a similar pattern of decline. The effects of environmental degradation throughout Florida Bay are magnified at higher trophic levels. The negative trend in territory occupancy is most pronounced in southeast Florida Bay whereas effects on territory occupancy in the northwest are minimal. The presence of spatial patterns in territory occupancy, despite regionally available breeding birds, suggests that individuals are evaluating differences in habitat quality for which certain territories are no longer considered viable. Building on our current understanding of the health of this population of Bald Eagles, we have successfully implemented modeling approaches that identify key territory breeding decisions. Loss of early breeding season activity (occupied and active territories) despite maintaining high breeding success indicates that changes in territory dynamics are the result of a failure to breed and not a reproductive failure. As such, future conservation actions should promote early breeding season activity (decisions by breeding pairs to initiate nesting) i
2017
Includes bibliography.
Degree granted: Dissertation (Ph.D.)--Florida Atlantic University, 2017.
Collection: FAU Electronic Theses and Dissertations Collection