Importance and Function of Foraging and Roost Habitat for Wintering American Oystercatchers

With changing climate and increased human populations, oyster reefs have been negatively affected by excessive wave action; contamination; overharvesting; decreased freshwater inputs; and shifts in oxygen, salinity, and turbidity regimes. In Florida's Big Bend, intertidal reefs dominated by the eastern oyster (Crassostrea virginica) have experienced a net decline in area of 66 % since the 1980s, a loss likely to have substantial impacts on reef-dependent wildlife. Our study examined the use of intertidal oyster reefs by wintering American oystercatchers (Haematopus palliatus) in this area. The minimum foraging time required to meet daily caloric needs was conservatively estimated at 37 min per adult oystercatcher, indicating that at present, foraging habitat is not a limiting factor within our study area. We found high-tide roosts to be away from all vegetation and limited in number. They were located in offshore oyster reef habitat, which has experienced an 88 % decline in area over the past 30 years. We suggest that offshore, high-tide roost habitat is a limiting factor and worthy of further attention.