Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 49-55). Also available via the Internet.

Bald Eagles in Cedar and Rush Valleys of western Utah were studied from 1975 to 1977. Arriving in mid-November, the eagles departed in mid-March. A statewide Bald Eagle census revealed 200 to 300 birds. Wintering eagle populations have remained stable for the past 10 years. Immatures comprised 35% of the population in 1975-76 and 33% in 1976-77. While Black-tailed jackrabbits are the primary food source of wintering eagles in western Utah, other mammalian carrion serve as supplementary food items. Eagles utilized 4 communal night roosts. Three day communal roosts were located on south facing slopes. The social existence of Bald Eagles on the wintering grounds may have survival value for immatures.

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This investigation compared statistical parameters for the blood serum chemistries of free ranging Osprey nestlings from Florida Bay and an Osprey population from Lake Istokpoga, in Central Florida (Chapter 1). Florida Bay Ospreys showed higher mean rank values for alanine aminotransferase (H=6.79, P=.009), alkaline phosphatase (H=6.48, P=.011), and sodium (H=5.7, P=.017), and Central Florida had higher mean rank values potassium (H=13.19, P=.000) and carbon dioxide (H=6.23, P=.013). Serum chemistries values were also compared between free-ranging Bald Eagle and Osprey nestling in Florida Bay estuary in southern Florida (Chapter 2). There were significant differences between serum values of Bald Eagle and Osprey nestlings. Bald Eagle serum values were higher for total protein (H=17.833, P=.00002), Albumin (H=7.449, P=.006), Aspartate aminotransferase (H=113.153, P =.0001), and Calcium (H=7.148, P = 008). Osprey serum values were higher for alanine aminotransferase (H=11.824, P = 0.0005), alkaline phosphatase (H=105.5, P =.0001), creatine kinase (H=13.465, P = 0.0002), carbon dioxide (H=4.443, P = 0.035) and cholinesterase (H=99.3, P=.0001). Sixteen nestling Bald Eagles were fitted with satellite platform transmitter terminal (PTT) or VHF radio transmitter package for a duration of six years (Chapter 3)= to identify their movement and dispersal. One of the 15 eagles migrated to North Carolina, whereas the other 14 (93%) confined their movements to Florida. Tracking duration per individual ranged from 82 to 1,531 days. We estimated first-year survival as 52% and 67% for the period from 1.5 to 3 years. Diamondback Terrapins (Chapter 4) were evaluated by an integrated assessment of physical, chemical, and physiological parameters. Extreme site fidelity of the turtles to mangrove habitat was evident along with a strong female biased sex ratio. There was a significant difference in the total number of individuals collected at the two sites (P =. 01) despite the total size and shorelines of the two sites being very nearly the same. Total recapture rate was 70% for combined population (TLK = 80% and CKW = 48%). We provide blood serum values and microbial cultures as baselines from these turtles in the wild. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

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Using aerial census techniques, I collected data on the population, reproduction and nesting habits of Bald Eagles in Florida Bay, Florida, for three consecutive breeding seasons (Oct - Mar, 1987 - 1990). For analysis I consolidated my data with those collected by Robertson et al. between 1959 and 1986 for a total of 26 seasons. The breeding population of Bald Eagles in Florida Bay has been stable since censuses began in 1959. However, numbers of subadult eagles in Florida Bay have declined sharply since the early 1960’s. Breeding density was apparently limited by territoriality. Nesting success was positively correlated with early commencement of nesting, number of active breeding territories and the history of individual breeding territories. Success was negatively correlated with the amount of rainfall during the breeding season. Most (87%) nesting failures occurred during the incubation stage. Nearly all nests were built in mangrove [Laguricularia racemosa, Avicenia germinans and Rhizophora mangle) trees and of these more than half were dead. The success of a nesting attempt was independent of changes in nests or nest sites.

The breeding behavior and feeding habits of the bald eagle (Haliaeetus leucocephalus L.) were studied during 1962 and 1963 on San Juan Island, Washington. The primary aim of the study was to acquire information which would relate to the general decline in bald eagle numbers. Thirteen bald eagle nests were found on San Juan Island. On the basis of the spacing of these nests, the density of breeding eagles was considered to be low. The number of bald eagles varied throughout the year; the highest numbers were present in February and the lowest numbers in October. The change in eagle numbers was caused by the fluctuating numbers of juveniles. Two active nests were kept under observation, one in 1962 and another in 1963. The breeding eagles showed hostility toward intruders such as adult and juvenile bald eagles and man in the vicinity of their nesting site. The birds showed indifference toward intrusions of red-tailed hawks, crows and gulls. The chronology of breeding activities on San Juan Island was approximated with the aid of local information and with findings of former investigators. Egg-laying occurs between March 4 and 19; hatching between April 8 and 14. The young spend 12 to 1 3 weeks in the nest during which time parental attention gradually decreases. During the first 5 weeks of the youngs' life the nest is constantly guarded by one of the parents. Parental attention markedly decreases after the young start their wing exercises at the age of 8 to 9 weeks. In general, the female parent spent three times as much time at the nest as did the male. Food was brought to the nest at irregular intervals by both the female and male parents. The young were fed mainly by the female during the first seven weeks of their life; later the young fed themselves. No appreciable change in the amount of food supplied to the young during their nest life was observed. Young of the same nest were similar in size and indications of maltreatment from the others or from the parents were not observed. Most of the food brought to the nest consisted of rabbit carrion. This type of food item was available throughout the year due to the rabbits' high mortality resulting from collision with automobiles on the roads. Fish was fed to the young during the first six weeks of their life; thereafter, mainly rabbit was consumed. Rabbit carrion was the primary source of food for young eagles in their post-nestling period. The destruction of breeding habitat by real estate developments is the major cause of decline in numbers of bald eagles on San Juan Island. / Forestry, Faculty of / Graduate

This research is focused on explaining the concentrations of mercury found in juvenile bald eagles (Halieattus leucocephallus) as a function of the physical and anthropogenic landscape. Due to it's location in the food chain this species is susceptible to a wide range of contaminants (xenobiotics), particularly those that bioaccumulate and biomagnify as they move through the food chain. Previous research has indicated that areas in coastal environments are less susceptible to methylation than those in freshwater environments. Sampling efforts for this research were conducted in such a manner as to obtain an equivalent number of samples from the coastal plain (expected to be low mercury) and the inland regions (expected to be statistically significantly higher). In all cases, results indicated that both feather and blood mercury concentrations were higher in the inland population (Blood: Prob > t = 0.0003, Feather: Prob > t = 0.0002). Utilizing classification and regression tree models (CART), we were able to relate metrics such as the percent of deciduous forest, percent of mixed forest, percent of pasture, and percent of wetland to measured blood mercury concentrations. We also found that the best models were produced using the USGS HUC 12 watersheds (the smallest watershed produced by the USGS). Moreover, we found that metrics describing the amount and type of fragmentation within the watersheds exhibited a significant influence on measured blood mercury concentrations. Contrary to previous research, we found wetlands to be negatively associated with higher blood mercury, whereas the abundance of core forest and a larger patch density (PD) in the deciduous and mixed land cover classes was positively associated with higher blood mercury concentrations. We also found that a higher percentage of pasture was associated with higher blood mercury. / Ph. D.

No description available.

In the interest of maintaining lands to fully support the military mission, Department of Defense (DOD) installations must manage competing objectives under constraints related to mission operations, regulation and compliance requirements, and budget reductions. Silviculture offers promise for ecosystem management while providing financial means through the sale of forest products. This study used forest inventory and bald eagle nest site data to investigate the potential effects of silviculture on bald eagle nesting habitat at Naval Support Facility Indian Head. Mahalanobis distance was used to define and classify preferred nesting substrate. Silviculture was simulated using the Forest Vegetation Simulator (FVS) to assess forest nesting substrate, economic yields and the tradeoffs between these two objectives. An alternative substrate model based on cumulative distribution functions (CDFs) and Boolean logic allowed evaluation of the strengths and weaknesses of the Mahalanobis distance method. The Mahalanobis distance model provided greater relative fit to the sample of nest sites compared to the CDF model but had lower discriminating power between presence and absence data. Simulation results indicate that top performing silvicultural treatments resulted in greater substrate availability compared to no-action over equal time periods. Uneven-age management was shown as the best system for providing nesting substrate as well as favorable economic yields in hardwood stands. Results also stress the importance of thinning in providing future nesting substrate and maintaining preferred substrate late in the rotation. Economic and habitat tradeoffs varied by treatment, suggesting that optimum prescriptions could be identified to provide for both objectives and minimize tradeoffs. / Master of Science