Here's another type identification error that regularly occurs, this one happened just this past weekend. A birder I know well was getting our group on a resting Bay-breasted Warbler perched on a branch about 20 feet above our heads. The ten or so birders were admiring it through their binoculars, but I was busy looking for a Mourning Warbler that was singing across the creek.
Eventually, I decided to look at the Bay-breasted. It was an angled view with its back to us, but something didn't look quite right about it to me. I gave a quick double-pish so that the bird might turn around. Sure enough, it cocked his head toward us, whereupon I immediately recognized it for a Chestnut-sided Warbler.
When this was discovered, I quickly asked the birders, “Who called this a Bay-breasted Warbler?” The birder I know said it was another birder who already walked on. This was a case where ID and/or report reliability was assumed. Even though the bird wasn't initially providing the best view ― and it's generally a good thing to trust ― one should still go through salient field marks to verify it's actually the species being observed.
Rather than chastise the group, we all had a good laugh about it. This isn't the first time this sort of thing has happened in my company and I'm sure many of you have observed it as well. Worse, though, is when it's done habitually in the form of competitive sport birding.
I know of a lister who relied upon an errant identification of a Connecticut Warbler at Cherokee Marsh, which was heard-only. It was submitted to eBird, but later on the birder who originally reported it discovered the song was actually a tricky Northern Waterthrush. This is a common misidentification I've observed this season as well, especially where we're at in warbler migration. But before the correction to eBird was made, the lister in question chased the reputed Connecticut and eBirded it as such.
1. Get into car.
2. Drive to reported spot.
3. Listen for CONW.
4. Hear CONW (brzzt!)
5. eBird CONW.
There are emphatic syncopated Northern Waterthrush songs in a single phrase that can fool novice and even intermediate birders ― it happens every spring. Connecticut Warblers arrive into southern Wisconsin mid to late May and by this time understory vegetation is pretty dense, so it can be challenging to visually confirm the ID. Generally, most of the Northern Waterthrushes have already passed through by the time the Connecticuts arrive, but there can be some overlap.
The moral of this story is to bird every bird and don't necessarily assume an ID that's being passed to you from another birder ― confirm it yourself, but do so objectively.
Chestnut-sided Warbler © 2021 Mike McDowell