Male Prairie Warblers; notice the right bird has a distinctly orange throat, a plumage variation occasionally seen with males in the Florida Keys. It is unknown if the orange is caused by diet or genetics. (photo by Alex Sharp).
After nearly 2 weeks of lackluster migration, birds were on the move again and westerly winds brought them out to Key Biscayne in good numbers! Friday, April 8 started out as another slow day, although the overnight rain and morning temperature was refreshing after a stretch of humid 90-degree summertime days, courtesy of strong southerly winds. Flocks of birds started trickling in as the morning wore on, and we could hear groups of Prairie Warblers and Western Palm Warblers in the canopy while Worm-eating Warblers and Black & White Warblers appeared here and there in the woods. The waves of incoming migrants peaked between 1030 and 1200, and we briefly heard a Hooded Warbler calling. The day ended with 31 new birds banded of 7 species, including our first migrating Gray Catbirds.
This gorgeous male Kentucky Warbler was a treat on April 9; we only see these occasionally in South Florida. (photo by Alex Sharp).
Saturday April 9 we were greeted with a flurry of activity at sunrise as birds by the dozens woke up and darted through the vegetation. There were more individuals present than the previous day, and they seemed to have collected on Key Biscayne yesterday afternoon and evening as a strong northwest wind continued to blow. We banded 30 birds on the opening net run just after sunrise, most of them Prairie Warblers. We didn’t hear new flocks of incoming birds, but the birds already here kept us busy. Diversity was excellent with several first-of-season species noted, including Black-whiskered Vireo, one of the few species that arrives to breed in Florida from points further south. We ended the day with 57 new birds of 14 species, a far cry from the 3 to 5 bird days we had last week! Our wintering Wood Thrush was calling at sunrise both days, and the majority of Gray Catbirds are still in wintering condition, although additional migrant catbirds are joining them.
Several Blue-headed Vireos are wintering in the banding area, and we hear them singing every day. They should be leaving in the next couple of weeks for their breeding grounds in the Northeast. (photo by Alex Sharp).
Sunday, May 10 was not quite as busy and a few individuals banded on previous days were recaptured, showing us that migrants are using Cape Florida as a rest stop while they wait for the wind direction to change so they can continue their flight north. Still, there was some turnover as Worm-eating Warblers made up a greater proportion of the birds banded today.
From now until the middle of May spring migration will pick up in volume, although there will be periods of slow days here and there when the wind direction is unfavorable. Keep your eyes on the fruiting strangler figs!
The first Cape May Warbler of the season! (photo by Michelle Davis)
