Abstract The aim of this study was to investigate the species composition of prey caught in the forest, savanna and emerging habitats in which African Crowned Eagles Stephanoaetus coronatus breed in KwaZulu-Natal province, South Africa. At the 17 nest sites, the remains of 195 prey individuals were collected. The five dominant prey species caught were Rock Hyrax Procavia capensis, Vervet Monkey Chlorocebus pygerythrus, Blue Duiker Philantomba monticola, Greater Canerat Thryonomys swinderianus and Bushbuck Tragelaphus scriptus. All of these species respond positively to urban expansion. Only eagles that nested inside protected areas were recorded preying on domestic animals. In terms of biomass, Bushbuck was one of the dominant taxa, and the remains of an estimated 28.8 kg Bushbuck ram was found under a nest. The surprisingly high proportion of Rock Hyraxes and low proportion of Vervet Monkeys caught in emerging habitat may indicate that African Crowned Eagles nesting in this habitat are adapting to a more specialised feeding strategy compared with those nesting in habitats that are more natural. Future studies should investigate how and why prey proliferates in emerging habitats and examine the association between land uses and the diet of African Crowned Eagles.

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Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

The African Crowned Eagle, Stephanoaetus coronatus, is a large raptor with a particularly long breeding cycle, even considering its size (Newton 1979). The incubation period is 49–51 days, the nestling period is 104–115 days and the length of the post-fledging period is contentious and varies considerably within its distribution in Africa (Steyn 1982). In some regions where the bird breeds biennially, this period is up to 350 days (Brown and Amadon 1989, Shultz 2002), whereas in other regions the post-fledging period is shorter as pairs bred annually, even for nine years in succession (Vernon 1984). The reason for this discrepancy has been ascribed to environmental quality and seasonal variability, and differences in the main prey base, densities and mortalities between populations (Newton 1979, Jarvis et al. 1980, Steyn 1982, Vernon 1984, Boshoff et al. 1994, Shultz 2002). Furthermore, it is unclear if the fledglings disperse from the nesting area of their own free will or are evicted by the parents (Brown 1966, Oatley 1970).

acase@tulane.edu / Anthropogenic noise is an evolutionarily recent phenomenon and many animals respond by changing the pitch and timing of their vocalizations to avoid masking. A benefit to modifying a vocal mating signal in the context of noise is increased transmission distance. This same modification may pose a fitness cost if that signal feature is also sexually selected. Bird song is a well-studied sexual signal used in territory defense and mate attraction. Physically difficult to produce components of song are thought to be honest signals of male quality. One such trait is a male's ability to maximize the rate of note production at a given frequency bandwidth; this tradeoff is known as vocal performance. Studies have shown modifications to song in the context of noise, specifically to trill rate and bandwidth. Costs of these modifications may include increased conflict with neighboring males, which could potentially lead to decreased body condition, loss of a territory, or less time spent attracting a female. Few studies have investigated this tradeoff between environmentally induced selection (i.e. natural selection) and social selection (i.e. sexual selection) on song in an urban landscape. Therefore, a gap remains in our knowledge of the consequences on fitness of urban song adaptation for signalers. Using the white-crowned sparrow (Zonotrichia leucophrys) in the San Francisco Bay Area of California, the objectives of my dissertation research include 1) testing if vocal performance is a salient signal for white-crowned sparrows, 2) testing if receivers are responding specifically to variation in trill rate or bandwidth, and 3) testing the effect of ambient noise level on receiver assessment of vocal performance. Overall, my dissertation research suggests that both anthropogenic and natural soundscapes shape the evolution of song and receiver behavior. Modifications to song structure that increase signal detection come at the cost of decreased signal salience for male competitors. Additionally, anthropogenic noise appears to change how males utilize vocal performance. Therefore, species living in noisy areas may face consequences of decreased fitness over time due to masked honest signals and increased male-male conflict. / 1 / Jennifer N. Phillips

I examined genetic variation for two populations of Black-crowned Night Herons using a 467 base pair region of the mitochondrial DNA. One population inhabits an environment highly impacted by industrial waste, heavy metals, and urbanization; while the other, a reference population, comes from a contaminant-free area. I observed a total of 10 haplotypes, three of which the two populations share. One individual from the contaminated site was ostensibly heteroplasmic. I found no evidence of significant genetic differentiation between the two populations. Coalescent simulation results provided evidence that both populations have undergone or are currently undergoing population expansion. The results of the biological marker I developed showed a high diversity for the ND-6 gene, making it a useful biomarker of population effects.

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