Date: 4/18/17 4:31 am From: Ted Floyd <tedfloyd57...> Subject: [cobirds] Yellow-rumped Warblers and eBird
Yesterday morning, Monday, Apr. 17, I was out at Greenlee Preserve, Boulder County, and saw two well-marked Yellow-rumped Warblers with yellow throats. But they weren't Audubon's warblers. They were hybrids, known to eBird as "Yellow-rumped Warbler (Myrtle x Audubon's)." The more I look at Yellow-rumped Warblers in Colorado in spring, the more I'm struck by just how many are either (a) apparent hybrids or (b) impossible to assign to one category or another.
eBird gives us four categories for Yellow-rumped Warblers in Colorado: (1) Yellow-rumped Warbler, (2) Yellow-rumped Warbler (Myrtle), (3) Yellow-rumped Warbler (Audubon's), and (4) Yellow-rumped Warbler (Myrtle x Audubon's). It's great to enter categories (2) and (3) if you get a good look at a slam-dunk Myrtle or Audubon's. But there's no shame--indeed there's rigor and credibility--in entering categories (1) and (4) when conditions warrant, which, at least based on my own experience, seems to be the case quite a bit of the time.
Here are pix of the two hybrid warblers at Greenlee yesterday: