Master of Arts student, Department of Biology, College of William and Mary (1993-1995)

Tidepool value as foraging patches for breeding and migrating birds in tidal salt marshes in the lower Chesapeake Bay

Tidepools serve as patches of avian foraging habitat within the tidal salt marsh landscape. Natural tidepools (N=303) in 4 tidal salt marshes along the lower Chesapeake Bay were characterized for a variety of physical and biological components including: area, water depth, profile type, vegetation, prey, and benthic macrofauna. Tidepools were surveyed for bird use to determine the abundance and diversity of avian species using tidepools and to investigate relationships between avian use and various intrinsic and landscape-level tidepool components.

Overall, 6,475 birds of 54 species were observed associated with tidepools over a 6 month period. Less than half of all tidepools (46.53%) had birds associated with them and distribution of birds was not normal with 4 pools having 48% of all bird observations. Birds utilized pools mainly as foraging patches although use of pools varied with a species’ resource needs.

Tidepool area and water depth were highly significant in determining bird distribution and abundance. Tidepools >0.02 ha were much more attractive to all species of birds. Pools with both shallow (10 cm) water were used more often than purely shallow or deep pools. Pools with water >20 cm deep and steep, vertical sides, similar to those pools often constructed by wetland managers, were used significantly less than expected.