Birds of Indian Subcontinent

Patterns of Seasonal Abundance and Social Segregation in Inland and Coastal Plain Swamp Sparrows in a Delaware Tidal Marsh (Patrones de Abundancia Estacional y Segregación Social en Poblaciones del Interior y Costeras de Melospiza georgiana nigrescens en

Publication Type:Journal Article
Year of Publication:2010
Authors:Greenberg, R, Olsen, BJ, Etterson, MA
Journal:The Condor
Date Published:2010
ISBN Number:00105422
Keywords:Emberizidae, Melospiza, Melospiza georgiana, United States, Zonotrichia, Zonotrichia georgiana
Abstract:Abstract. The Coastal Plain Swamp Sparrow (Melospiza georgiana nigrescens) breeds in coastal marshes of the mid-Atlantic United States. During the nonbreeding season, these marshes are occupied by this subspecies and the two interior-breeding subspecies M. g. georgiana and M. g. ericrypta (collectively, interior Swamp Sparrows). From September to May, 2005–2006 and 2007–2008, we surveyed marshes in which nigrescens breeds; >90% of these birds had been color-banded by the end of the previous breeding season. This allowed us to determine the nonbreeding occupancy of the breeding site by individuals that bred locally, Coastal Plain Swamp Sparrows that did not breed there, and interior Swamp Sparrows. Locally breeding birds disappeared from the breeding site by mid-October, although nonlocal nigrescens occupied it from October to late November. Locally breeding birds reappeared in April without any pulse of migration of nigrescens. Interior-breeding sparrows were abundant in the autumn and appeared in smaller numbers later in the nonbreeding season. The seasonal pattern of nigrescens was similar in both years, and its departure and arrival dates appear to coincide with changes in the frequency of freezing temperatures. The temporal pattern of interior Swamp Sparrows in the two years was more varied. Finally, during the autumn peak of Swamp Sparrow migration, the subspecies tended strongly to segregate in subspecies-specific flocks, suggesting that Swamp Sparrows preferentially interact with morphologically similar birds, a behavior which may have implications for divergence in species recognition mechanisms and speciation.
Short Title:The Condor
Taxonomic name: 
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith