14 Jun 2010.
Baldpate Mountain, Mercer Co, NJ.
This female, along with her even brighter male partner, were ferrying caterpillars relentlessly to a nest that I never could find. I'm hoping the inhabitant of the nest was not a cowbird, which is much larger than its foster parents and has a relatively huge appetite.
The Blue-winged Warbler (Vermivora cyanoptera) is a fairly common New World warbler, 11.5 cm (4.5 in) long and weighing 8.5 g (0.30 oz). It breeds in eastern North America in southern Ontario and the eastern USA. Its range is extending northwards, where it is replacing the very closely related Golden-winged Warbler, Vermivora chrysoptera.