Date of Award

1-1-1995

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biology

Abstract

Preserving genetic diversity is important for maintaining the evolutionary potential and fitness of endangered species such as the Hawaiian goose (Branta sandvicensis), or nene. I used DNA fingerprinting to assess genetic diversity in captive nene from Hawaii and England and in wild nene from Hawaii. I used pedigrees and DNA fingerprinting to assess the effects of inbreeding on reproductive success in captive nene. I determined (1) differences in mean similarity coefficients between unrelated and related nene within and between captive colonies and the relationship between coancestry and similarity coefficients in captive nene from Hawaii, (2) differences in mean similarity coefficients among wild populations and between wild nene and captive nene from Hawaii, and (3) the relationship between inbreeding and reproductive success in captive nene.Similarity coefficients for unrelated and related captive nene from England were higher than those from Hawaii. Within each captive colony, related nene had higher similarity coefficients than unrelated nene. Coancestry and similarity coefficients in captive birds from Hawaii were positively related. Among wild populations, Hawaii Volcanoes National Park (HVNP) had the lowest similarity coefficients and Kauai had the highest. Captive birds from Hawaii had higher similarity coefficients than wild birds at HVNP and lower similarity coefficients than wild birds on Kauai and at Puuwaawaa. As inbreeding increased, hatchability and survivorship decreased in the Hawaiian colony and hatchability decreased in the English colony.More founders at the Hawaiian colony contributed to its lower similarity coefficients when compared to the English colony. Lower genetic variation may increase the difficulty in distinguishing relatedness among individuals using DNA fingerprinting and may increase the error in estimating the relationship between coancestry and similarity. Successful recruitment of wild nene may have decreased similarity at HVNP, whereas inbreeding and captive-release techniques may have increased similarity on Kauai and at Puuwaawaa. Varying levels of inbreeding or fixation by drift may explain genetic differences between wild and captive populations. Lower hatchability and survivorship are typical responses to inbreeding. Fertility may be influenced by the number of successive clutches laid, and clutch size may be influenced by husbandry. Other factors affecting reproductive success include climate and disease.

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