Birds of Indian Subcontinent

Relationship between Habitat Area and the Distribution of Tidal Marsh Birds

Publication Type:Journal Article
Year of Publication:2002
Authors:Benoit, LK, Askins, RA
Journal:The Wilson Bulletin
Date Published:2002
ISBN Number:00435643
Keywords:Ammodramus, Ammodramus caudacutus, Ammodramus maritima, Ammodramus maritimus, Ammospiza, Ammospiza caudacuta, Ammospiza caudacutus, Ammospiza maritima, Ammospiza maritimus, Catoptrophorus, Catoptrophorus semipalmatus, Cistothorus, Cistothorus palustris, Emberizidae, Limicola, Melospiza, Melospiza georgiana, Nannus, Nannus troglodytes, Rallidae, Rallus, Rallus limicola, Scolopacidae, Telmatodytes, Telmatodytes palustris, Tringa, Tringa semipalmata, Troglodytes, Troglodytes troglodytes, Troglodytidae, Zonotrichia, Zonotrichia georgiana
Abstract:To assess the relationship between marsh area and relative abundance of tidal marsh bird species, we surveyed birds on 86 circular plots in 40 salt and brackish tidal marshes in Connecticut. We measured marsh area in two ways: the amount of contiguous marsh vegetation not interrupted by broad barriers (>500 m of open water or >50 m of upland habitat) and by narrow barriers (>30 m of open water or >10 m upland). We determined the relationship between marsh area and the relative abundance of particular species (mean number of individuals per survey plot) with linear or logistic regression. When the broad barrier definition was used, we found that all three species of short grass meadow specialists, Willets (Catoptrophorus semipalmatus), Seaside Sparrows (Ammodramus maritimus), and Saltmarsh Sharp-tailed Sparrows (A. caudacutus), were less abundant or absent in survey plots in smaller marshes. The Seaside Sparrow and Willet also showed a significant tendency to be less frequent in smaller marshes when the narrow barrier definition was used. In contrast, species that used a wider range of wetland types, as in the Virginia Rail (Rallus limicola), Marsh Wren (Cistothorus palustris), and Swamp Sparrow (Melospiza georgiana), were equally frequent on plots in marshes of different areas. Our results are consistent with the hypothesis that fragmentation of marsh systems with artificial habitat causes a decline in the density of short grass meadow specialists in the remaining patches of appropriate habitat.
Short Title:The Wilson Bulletin
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith