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.

Brood parasitic birds lay eggs amongst the clutches of other species, which then assume all costs of parental care on their behalf. This thesis addresses several puzzles of avian brood parasitism, using field studies and theoretical modelling of the generalist parasite, the shiny cowbird (Molothrus bonariensis) and select hosts in Argentina. Key findings and conclusions were: • High parasitism intensity in a host population can result in a cost to hosts of removing parasite eggs from their clutches, and so help to maintain host’s acceptance of parasite eggs in evolutionary equilibrium. The cost is to host egg survival: hosts that remove parasite eggs from the clutch increase the risk that their eggs are destroyed by subsequent parasites that visit the nest. • The principal benefit of mobbing as a front-line defence of hosts may be to reduce egg loss due to parasite attack, rather than prevent parasitism itself. • Differences in the acoustic structure of begging calls between parasites and their host’s young can be to the parasite’s advantage. Parents provisioned unparasitized broods more during broadcast at the nest of shiny cowbird calls than calls of their own species’ chicks, in both a common host and a non-host. The long tremulous quality of a cowbird’s call functions analogously to a rapid call rate, thereby exploiting a common provisioning rule of avian parents. • A trade-off for maximum growth in parasite nestlings will variously favour or not favour the evolution of nestmate-killing behaviour, depending on a parasite’s abilities, relative to host young, to solicit and attain provisions from host parents. Generalist parasites can encounter both sides of the trade-off in different hosts. Meanwhile, indirect fitness costs are unlikely to constrain the evolution of nestmate-killing in shiny cowbirds, as they rarely, if ever, share the nest with siblings.