Saturday, February 26, 2011
Warbler Guy, do female warblers sing? If so, which female warblers have songs? Or do only male warblers sing?
Nice question, Bernice (in Mondovi, CA).
At least nine species of temperate zone wood-warblers (representing six genera: Vermivora, Dendroica, Setophaga, Seiurus, Geothlypis, and Wilsonia) have been confirmed as singers based on field studies (Evans Ogden, Neudorf, Pitcher, and Strutchbury, 2003).
Given merely a minority of females sing among the world’s 4,000+ songbird species, what’s the payoff for this vocal behavior? One theory is that female singers may be adopting male-like behavior, especially among older females (Nolan, 1978). Another theory suggests female song results from female-female conflicts occurring in dense populations (Hobson and Sealy, 1990) or may be a function in intra-pair contact (Gilbert and Carroll, 1999).
Among the singing wood-warblers in the U.S., Dunn & Garrett state in Warblers (1997) that Yellow Warbler (ABOVE photo, a female, courtesy of the US Fish & Wildlife Service) song has been documented in at least one population in Manitoba, Canada (Dunn & Garrett, 1997).
Likewise, these two authors suggest in the same field guide that American Redstart females sing sporadically to rarely (if at all).