The birches that live fast and die young on this island are full of insects, and right now, are also full of Yellow-rumped Warblers. Most are from the "auduboni" group, the birds formerly known as Audubon's Warblers, identifiable in breeding season by their bright yellow throats and crowns. This group breeds throughout the southern half of the province, including Vancouver Island.
During spring migration it is also possible to see members of the coronata group, formerly known as Myrtle Warblers, identifiable in breeding season by their white throats and eyebrows. These are birds mainly of the east of this continent, but do breed in British Columbia, almost exclusively north of 55 degrees North latitude. It is estimated that here in the Georgia Depression ecoprovince, the ratio of auduboni to coronata birds seen is about 3:1 (Campbell et al., 2001).
Campbell, R.W., N.K. Dawe, I. McTaggart-Cowan, J.M. Cooper, G.W. Kaiser, A.C. Stewart and M.C.E. McNall. 2001. The Birds of British Columbia. Vol. 4. UBC Press.