Here is the latest For the Birds column, which runs in several New England newspapers.
A lot of birdwatcherslook forward to the spring warbler migration. Not only do our woods fill with colorful, vocal birds, but the timing is such that it follows winter and several months of gloomy weather.
From late April through early June, the birding world is abuzz and excited with what warblers are being seen and where.
Their fall migration, conversely, creates almost no buzz. Even the warblers themselves are mostly quiet. Instead of heralding their arrival from the tree tops like they do in spring, they lay low silent.
For many species, the blazing colors they sport in May are replaced by drab browns and grays – again, drawing as little attention to the themselves as possible. Because they are quiet and drably colored, the fall warbler migration can be challenging, confusing, frustrating and even humbling for birdwatchers.
On top of that, the first-year birds, now only a few months old, are in their first migration and have not developed their adult plumage. In other words, most warblers look vastly different than they did in the spring and many species resemble each other. Nailing down positive IDs can be a chore.
I’ll stray from the warbler world for a dramatic example, but to some degree or another, the same scenario plays itself out with warbler species. The male scarlet tanager during spring migration is perhaps the crown jewel of all songbirds in New England. Its black wings and tail contrast magnificently with its brilliant, eye-popping red plumage. In the fall, however, those same males are olive green and dull yellow.
Fall warbler plumage can vary by individuals within a species, adding to the difficulty of identifying the birds you see. Over the last few weeks, I’ve seen several common yellowthroats of varying plumage. One male still popped with its familiar spring plumage. The females I saw, however, ranged from having bright yellow throats to being mostly brown with hints of yellow.
The warbler I see the most in the fall is the yellow-rumped warbler. Most are first-year or females, so the plumage is rather bland, but the yellow spot on the rump is always a giveaway – assuming you catch a glimpse from the just-right angle.
I also saw a flash of warblers I couldn’t identify with certainty. That happens a lot in the fall. In the spring, if you see a warbler only briefly, you can use your ears to help spot the tiny bird again among the leaves. In the fall, the birds don’t give away their whereabouts with songs, so the bird is often not found again.
Frustrating and humbling, like I said. But always worth the effort, regardless of whether a positive ID is made or not.