Date of Award

Spring 1997

Document Type

Legacy Thesis

Degree Name

Bachelor of Science (BS)

Department

Biology

College

College of Science

First Advisor

Mary Crowe

Abstract/Description

Early literature on the ghost crab, Ocypode quadrata, established that it was a nocturnal scavenger. However, studies conducted in the late 1970's and early 1980's show that the ghost crab fulfills a variety of ecological roles during the day and night along the shores of the Eastern Atlantic coast. These later studies also showed that ghost crab activity, dispersion and density may be negatively influenced by human activity. My study had a two-fold purpose: 1) determine twilight activity patterns of ghost crabs on an island with little human activity and 2) determine the prevalence of three feeding strategies: predation, scavenging and substrate feeding, during twilight activity periods. Data on prey availability and twilight behavioral activity were collected biweekly from late August till early November 1996. My results show that ghost crabs active at twilight spend 50% of time engaged in burrow maintenance, spend 29% of time moving within a 3 meter diameter of hole and 0% of their time outside of this area. Twenty-one percent of the crab's time is spent foraging; of this 50% is spent substrate feeding, and 49% scavenging on debris. It is important to document ghost crab activity under natural conditions in order to understand how humans influence their ecology. The Eastern Atlantic beaches are quickly being developed and, although the ghost crabs habitat (the beach) is still present, humans may be changing when and how the ghost crab exists in its habitat. ..

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