Black-whiskered Vireo is the mangrove-loving tropical replacement of the Red-eyed Vireo; the latter once called the most numerous breeding bird in the forests of the eastern United States. Black-whiskered Vireos are most common in Florida throughout the Florida Keys. On the mainland they are regularly found north to Tampa Bay on the Gulf Coast http://myfwc.com/bba/docs/bba_BWVI.pdf
Black-whiskered Vireo arrives in this part of Florida rather "late" in migration - mid to late April and on arrival begins its monotonous song until some time in July when the nesting season ends.
This year I have been searching every conceivable patch of mangrove forest I can find in Manatee and Sarasota Counties here hoping to add this vireo to county bird lists. As of yesterday's latest futile attempt I still have not seen or heard it here. What's up with that?
Yesterday's foray was to Lido Key off St. Armand's Key just west of Sarasota. There is an abundance of mangrove forest there but I could not see or hear a single vireo. The same story has been true along Anna Maria Island, Longboat Key, on Siesta Key, and in mangroves near Venice and Osprey. Each attempt to find this bird has produced a big fat goose egg.
I'm not sure whats going on. Perhaps there is a contraction in the species range - something that always happens at the periphery. However with global warming making its march across the landscape you'd think the Black-whiskered Vireo would be expanding northward rather than maybe contracting southward. Whatever it is, they seem to be totally absent from otherwise preferred mangrove forests. This might be something to keep an eye on in the near future on Florida's west coast.
P.S. The photo is from the US Forest Service so there are no copyright issues - good old public domain