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Adaptations to tidal marshes in breeding populations of the swamp sparrow

Condor

By:
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Abstract

The Coastal Plain Swamp Sparrow (Melospiza georgiana nigrescens) was originally described from a small number of specimens from the tidal marshes of the Nanticoke River in southeastern Maryland. Based on our quantitative analysis of a larger series of specimens, we found that Swamp Sparrows collected during the breeding season from the Chesapeak and Delaware bays (and tributaries) and near the mouth of the Hudson River are generally less rusty, have more black in the crown and nape, and have larger bills than other Swamp Sparrows. Contrary to earlier accounts, we found M. g. nigrescens to be migratory, arriving after the spring migration and departing before the fall migration of the inland subspecies through the tidal marshes. The location of the wintering groups of M. g. nigrescens is unknown. We argue that the morphological and life history differences characterizing M. g. nigrescens reflect adaptation to tidal marshes. We base this hypothesis on the nature of the morphological differences, which are convergent with other tidal marsh breeding sparrows and other terrestrial vertebrates.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Adaptations to tidal marshes in breeding populations of the swamp sparrow
Series title:
Condor
Volume
92
Issue:
2
Year Published:
1990
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
393-404
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Condor
First page:
393
Last page:
404