[Ontbirds]yellow warbler, rusty cap

[Skip Shand/GL/York/CA]

Hello folks.

This morning I had a very brief backyard visit from a male yellow warbler 
with a distinct rusty tinge to its crown. This cap was not sharply defined 
at the margins, but the coloration was very clear, and it was a feature I 
haven't been aware of before. Have I just been missing something common? 
My guidebooks do tell me about the Mangrove variant that occurs in Florida 
and occasionally in Texas, but I don't have an in-depth warbler book near 
at hand. I'd be interested to hear, off-list, if anyone would like to 
enlighten me about this sighting.

The bird was very active, and moved on quickly. The sighting was near 
Bathurst and Eglinton, in Toronto.

Cheers,

Skip Shand