Island Biogeography

Biogeography is defined as the study of the distribution of organisms, both past and present. It is a science that attempts to describe and understand patterns in the distribution of species and higher taxonomic groups. As such, the field draws heavily on ecological and evolutionary theory, yet also relies on geology and geography. Islands have often been the subject of important biogeographic work and have contributed substantially to existing biogeographic theory. The course covers the important elements of biogeographic theory within the context of islands. Specifically, we examine the biology of the flora and fauna of San Salvador Island and attempt to determine which factors have given rise to the existing animal and plant communities that characterize the island.

Students in Island Biogeography spend 3 weeks in residence at the Gerace Research Centre on San Salvador Island. Class activies include hikes through the rugged scrub-forest communities in the island's interior, snorkeling trips to many patch and several offshore reefs, plant community analysis, rocky intertidal community sampling, snorkeling in seagrass and mangrove habitats, a swim to an offshore island inhabited by iguanas, night snorkeling, and a descent into a water cave. SCUBA diving is possible for certified divers. In addition, students are exposed to the history and culture of the island. Daytime trips to terrestrial and marine habitats are supplemented by evening lectures, discussions, and student presentations.

During the last week of the trip, students conduct group research projects. Past projects have included:

  • comparisons of plant communities on exposed and sheltered shores
  • estimation of the size of the iguana population on Man Head Cay
  • mark-recapture studies of anole lizards and hermit crabs
  • effect of patch reef size on fish diversity
  • tide pool community composition
  • rate of fish colonization on artificial patch reefs
  • measurements of movement patterns of rocky intertidal snails

The opportunities to explore the biology and ecology of marine and terrestrial island habitats are unsurpassed on San Salvador Island. However, this course involves virtually non-stop physical activity during daylight hours and several hours of classroom work in the evenings, 6 days a week. Strong swimming abilities are REQUIRED!

The living facilities are primitive and opportunities for entertainment (other than the great outdoors!) are minimal. Students live in a former US Navy barracks and eat in a communal dining hall. Little food is produced on the island, so what we eat is what comes in by boat. Fresh water on the island is limited, and insects are numerous. Be prepared to rough it and enjoy the sea and island life!

Starting in 2001, this class will be offered in alternating (odd-numbered) years. For more information on the course or how to apply for enrollment, contact Doug Hamilton or Mark Kuhlmann.

Want to find out more about Island Biogeography or San Salvador Island? You can view pictures from past classes, or check out the Related Links at the side.