Using Avian Communities to Evaluate Salt Marsh Restoration

The objectives of this study were to document avian species inhabiting West River Memorial Park in New Haven, Connecticut and develop goals for restoration of a salt marsh bird community. Restoration goals were based on the breeding season bird community at the restoration site, breeding season communities of less disturbed salt marshes, and a literature review. Community descriptions included relative abundances of species and foraging guilds, nesting density, and obligate species. We conducted fixed-radius point counts and call-back surveys to develop a species list and estimate relative abundances. Nesting densities in less disturbed marshes were summarized from the literature. We also searched stands of common reed (Phragmites australis) at the restoration site to identify nesting species that would be affected by restoration. The number of species using West River Memorial Park was high (n=99), and 11 species were endangered, threatened, or of special concern. This indicates the importance of the park for avian diversity within an urban area. No species of concern would be negatively impacted by the restoration, and many would benefit. The species we observed most often in common reed during the breeding season was the red-winged blackbird, and only red-winged blackbird nests were found in common reed stands. The proportion of species shared by West River Memorial Park and the less disturbed marsh during breeding was high, and the relative abundance of foraging guilds was similar. However, relative abundances of species were different. Breeding bird densities of all species in Spartina spp. zones summarized from the literature suggest an average 2.5 breeding pairs ha (1 pair acre). These results suggest that restoration of a salt marsh bird community in West River Memorial Park is feasible. We discuss changes in species abundance that will be necessary to achieve restoration. We also recommend design criteria to address salt marsh bird habitat restoration problems in this park and urban areas in general. The value of birds has played a significant role in the movement to conserve – and now restore – salt marsh habitat (Casagrande, pp. 13-40, this volume). Udziela and Bennett (this volume) have shown the value placed on salt marshes as habitat for endangered bird species. These values indicate the need to predict the effects of restoration on birds. Such an evaluation requires reviewing current knowledge of avian salt marsh habitat and assessing the condition of West River Memorial Park. Salt marshes provide habitat for obligate species, which breed and forage only in salt and brackish marshes, and facultative species, which breed or forage in other habitats as well. Obligate, salt marsh species in Connecticut include sharp-tailed sparrow, seaside sparrow, and clapper rail (Greenlaw 1983, Robbins 1983, Craig 1990, Eddleman and Conway 1994). Both sparrow species have been 1 Common names follow the American Ornithologists’ Union system.