Black-throated Green Warbler (Dendroica virens), Sweetwater Wetlands, Pima County

This male Black-throated Green Warbler was discovered by Will Russell on 29 November 2008 at the Sweetwater Wetlands and photographed by Judy Ulreich and Paul Watson the same day.  One was also seen at this location last year on 4 November 2007. 

Prior to 1990 there were about 30 records for Arizona, but it has been much scarcer since with only about a half dozen records.  This pattern of decreased occurrence since 1990 seems to fit several other northerly breeding eastern warblers that are much less common as vagrants to the state than previously. 
 
In all plumages the wash of yellow across the vent just behind the legs is diagnostic for Black-throated Green Warbler, although it is not always as obvious as it is on this individual. 

29 November 2008, photo by Judy Ulreich

29 November 2008, photo by Paul Watson

All photographs copyright© by the photographer.