Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

No description available.

Thesis (Ph. D.)--Washington State University, August 2008. / Includes bibliographical references.

Brood parasites avoid costs associated with raising young by adding eggs to another individual’s clutch and providing no parental care. When conspecific brood parasitism occurs in species with high parental investment, we expect hosts to suffer costs for raising an enlarged brood. Here I describe conspecific brood parasitism (CBP) in the prothonotary warbler using maternal exclusion analyses of 333 family groups. I found that 23.4% of clutches contained at least one offspring that was not matched to the social mother and determined that parasitism seems to be an opportunistic tactic. Hosts had lower average annual reproductive success than non-hosts, but CBP did not affect adult survival or nestling body condition and likelihood of recruitment. Clutches with CBP received less provisioning from the male, but not female, parent. Future research is needed to understand the effects of density and competition on the breeding behaviors of this and other similar species.

Intraspecific nest parasitism was studied in a group of colonial Red-breasted Mergansers (Mergus serrator) nesting on the Tern Islands of Kouchibouguac National Park in New Brunswick in 1992. Nest parasitism is very common in this colony, and may influence the high rate of nest abandonment observed. Emphasis was placed on determining rates of successful parasitism (i.e. eggs added during the laying period of the hen at that nest), which are evolutionarily significant, and can easily go undetected. Three methods were used to determine if a nest contained egg(s) from another hen: abnormally large clutch size: more than one egg laid per day: and comparisons of DNA fingerprints of the hen versus putative chicks. When eggs were added to a nest during incubation, the nest was also labelled parasitized, but such eggs were not fully incubated (non-term) and thus were not successful. A new method of blood sampling ducklings in pipped eggs was tested and found to have negative effects on survival. As many as 14.8% (13/88) of the ducklings sampled subsequently died. Researchers wishing to use this method should proceed with caution. DNA fingerprinting determined that 50.0% of nests tested (6/12) were successfully parasitized. Two of six parasitized nests would have gone undetected using the other criteria to detect parasitism, thus proving the value of DNA fingerprinting. Of hatched young genetically analyzed, 30.9% (17/55) were parasitic. Nest parasitism appears to be an alternative breeding strategy in this population. Extra-pair copulation, previously unrecorded in this species, was discovered through DNA fingerprinting in two of four nests analyzed.

The rate of intraspecific nest parasitism was determined for a colony of Red-breasted Mergansers (Mergus serrator) nesting on the Tern Islands in Kouchibouguac National Park, New Brunswick. In order to recognize instances of nest parasitism, field criteria and microsatellite analysis testing for parentage between attending hens and the eggs in their nests were used. Traditionally, molecular analysis has involved collecting blood samples from females and offspring, however, for the purpose of this study, DNA was extracted successfully from feathers, egg membranes, and unhatched embryos which were collected during the summers of 1999 and 2000. A total of 8 primer pairs which amplified microsatellite loci in closely related avian species were tested (Sfimu-2, Sfimu-3, Sfimu-4, Sfimu-5, Sfimu-6, Sfimu-7, Bcamu-6, and Alamu-1). Four of these primers produced product of the expected size (Sfimu-3, Sfimu-4, Sfimu-7, and Bcamu-6). Amplification of these loci, however was inconsistent and subsequent sequence analysis revealed that the amplicons did not contain tandem repeats and therefore were not useful in genotyping. From field criteria we were able to establish rates of parasitism of 46% and 44% for each season. Rates of parasitism tended to be higher at the beginning of the season, compared to nests initiated later. Field criteria bring support to several hypotheses on causes of nest parasitism, indicating that more than one may influence rates of parasitism in a population.

No description available.

No description available.

Urbanization introduces a set of novel stressors for animals in these modified habitats. Developing young, in particular, can be at risk due to increased predation, exposure, and high food intake requirements. Song sparrows (Melospiza melodia) are a model wild songbird system that persist in both urban and rural habitats, and have young that develop very quickly. I investigated how urbanization changes the arthropod community, how that in turn affects nestling diet, and ultimately if there were any differences in nestling amino acid profiles or body condition between habitat types. Prior work found that urban habitats also have far higher rates of brood parasitism, which can additionally restrict food intake for urban nestlings. However, this prior work has also found that urban song sparrow adults avoid consequences for living in urban habitats, so I wanted to see if nestlings were also able to avoid the consequences of urban living. In chapter one, I found our urban arthropod communities had lower average arthropod abundance, biomass, and diversity when compared to rural arthropod communities. Song sparrow nestling diets differed somewhat in composition of arthropod prey items by habitat, but urban and rural nestlings had the same average biomass of stomach contents. In chapter two, I investigated whether different habitat types or brood parasitism altered body size and amino acid concentration of song sparrow nestlings. Only gamma-aminobutyric acid differed, being significantly lower in urban, parasitized nestlings. No groups differed in metrics of body condition. In chapter three, I performed a meta-analysis to investigate how brood-parasitic brown-headed cowbirds (Molothrus ater) affect host clutch size and nest success. Host clutch sizes were lower when parasitized, but surprisingly non-parasitized nests were more likely to fail. Despite lower arthropod food availability and high levels of brood parasitism, urban song sparrow nestlings are not compromised, supporting the conclusion that urbanization does not necessarily have negative consequences for individuals of this species. / Doctor of Philosophy / Urbanization introduces a set of new challenges for animals. Young animals, in particular, can be at risk due to increased predation, exposure, and lack of food. Song sparrows (Melospiza melodia) are a model wild songbird system that persist in both urban and rural habitats, and have young that develop very quickly and rely on parents providing a diet of arthropods, including spiders and insects. I investigated how urbanization changes the arthropod community, how that in turn affects nestling diet, and ultimately if there were any differences in nutrition or body condition. Urban habitats also have higher rates of cowbirds laying their eggs in the nests of other species, which can make it even harder for urban song sparrow nestlings to get enough food. However, this prior work has also found that urban song sparrow adults avoid consequences for living in urban habitats, so I wanted to see if nestlings were also able to avoid the consequences of urban living. In chapter one I found our urban arthropod communities had lower average number and mass of arthropods, when compared to rural arthropod communities. Song sparrow nestling diets differed somewhat in composition of arthropod prey items by habitat, but urban and rural nestlings had the same average biomass of stomach contents. In chapter two, I investigated whether different habitat types or having cowbird 'siblings' resulted in different nutrition and body size of song sparrow nestlings. Out of nearly 30 measures of nutrition only one differed, being significantly lower in urban nestlings with siblings. No groups differed in body size. For chapter three I analyzed the literature to investigate how brown-headed cowbirds (Molothrus ater) affect the number of eggs host birds lay and host nest success. Host clutch sizes were lower when cowbirds were present, but surprisingly, it was nests without cowbirds that were more likely to fail. Despite lower arthropod food availability and high levels of cowbird presence, urban song sparrow nestlings avoided negative consequences, supporting the conclusion that urbanization does not necessarily harm individuals of this species.