My PhD was entitled "An analysis of sperm whale social structure: patterns of association and genetic relatedness". My field research was based in the Galápagos Islands breeding ground (on the equator, 1000km west of Ecuador, South America). Dr Hal Whitehead began a photo-identification study of this sperm whale population in 1985. Up to and including my field season in 1997, we now have records spanning 12 years.
I used photo-identification and behavioural data to examine patterns of association, and hence, relationships between individual sperm whales. Genetic techniques using Mitochondrial d-loop and microsatellite markers, and DNA extracted from sloughed skin samples, enabled me to compare association patterns to patterns of genetic relatedness.
Thesis Table of Contents:
|Christal, J., and H. Whitehead. 2001. Social affiliations within sperm whale (Physeter macrocephalus) groups. Ethology 107: 323-340.|
|Christal, J., H. Whitehead and E. Lettevall. 1998. Sperm whale social units: variation and change. Can. J. Zool. 76: 1431-1440|
|Whitehead, H., J. Christal, and S. Dufault. 1997. Past and distant whaling and the rapid decline of sperm whales off the Galápagos Islands. Conservation Biology 11: 1387-1396|
|Christal J., and H. Whitehead. 1997. Aggregations of mature male sperm whales on the Galápagos Islands breeding ground. Marine Mammal Science 13:59-69|
|Last Updated December, 1998 by Jenny Christal|