Identifier

etd-06042014-223737

Degree

Master of Science (MS)

Department

Renewable Natural Resources

Document Type

Thesis

Abstract

The population of Bald Eagles (Haliaeetus leucocephalus) nesting in Louisiana reached precariously low numbers in the early 1970’s, and although the population has since increased markedly, resident eagles remain a species of conservation concern in Louisiana. Using statewide aerial nest survey data from 1975–2008, I documented the history and quantified the recovery of the nesting population in Louisiana. Known active nests increased exponentially from 7 to 387 during this period, exhibiting a mean annual rate of increase of 11.1 ± 0.3% per year with no indications of slowing. By 1990, the nesting population in Louisiana had exceeded all goals of the Southeastern States Bald Eagle Recovery Plan. I used nest location and status data from the most recent year (2007–2008) of the nest monitoring program to examine landscape level nest site selection and success. Success of a nest was not greatly influenced by the physical characteristics around a site, whereas the initial selection of a nest site was most influenced by distance to the historical nest centroid and the proportion of open water and agricultural land within 3 km. Bald Eagles nest during the winter in Louisiana, but they are rarely observed in the state during summer. Therefore, I used satellite GPS transmitters to provide evidence of their undocumented summer migrations and examined parameters such as timing of departure and arrivals, stopover use, routes used, and seasonal and annual variations in these parameters. Marked eagles flew relatively direct routes, exhibiting high route fidelity going between Louisiana and their summering areas, which were spread out across much of Canada and south to Illinois. Using locations from their winter and summering areas, I estimated home range and core area size. Home ranges varied from 19.7–1,997.7 km2, but nesting Bald Eagles had smaller home ranges, on average, than did non-nesting birds. The sex of an individual can play an important role when considering variations in movements, home ranges, and habitat use. Accordingly, I evaluated the published field technique for sex determination of Bald Eagles, and upon documenting misclassifications, I developed a new formula applicable to Louisiana and other southern regions.

Date

2014

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Afton, Alan D

Share

COinS