To answer yesterday’s quiz by RTPI Affiliate Sean Graesser, the Pine Swamp Warbler (Sylvia pusilla) was a bird Audubon originally painted as a new species of warbler. However, you may have figured out that it was the female Black-throated Blue Warbler (Setophaga caerulescens). This was an interesting mistake that highlighted the dimorphism between the male and female. It is one of the most drastic sexually dimorphic species of North American warblers.
