Health assessment of American Oystercatchers (Haematopus palliatus palliatus) in Georgia and South Carolina.

ABSTRACT

The American Oystercatcher (Haematopus palliatus palliatus) is the only species of oystercatcher native to the Atlantic coast of North America and is restricted in distribution to intertidal shellfish beds in coastal areas. Currently, the American Oystercatcher population in South Carolina and Georgia is threatened by widespread habitat loss, resulting in low reproductive success and small population size. Oystercatchers could be an important indicator of ecosystem health because they depend on quality coastal breeding habitat and prey on bivalves, which can accumulate toxins and pathogens from the local environment. Data were collected from American Oystercatchers (n=171) captured at five sites in South Carolina and Georgia between 2001 and 2006. Iridial depigmentation was frequently noted during physical examination and was more prevalent in female birds. Female birds were larger than males on average, but ranges for weight and morphometric measurements had considerable overlap. Mean values were calculated for hematology, plasma biochemistry, and hormone levels, and prevalence of exposure to select pathogens was determined. Mercury was the only trace metal detected in blood samples. These data provide baseline health information needed for longitudinal monitoring and conservation efforts for American Oystercatchers. In addition, this study illustrates the potential use of this species as an indicator for the health of the southeastern US coastal nearshore ecosystem.