Black-throated green warblers linger in Maine

A reluctant trip to Baxter State Park over Columbus Day weekend yielded some surprising bird sightings.

I say reluctant because the dreary, constant rain made me loathe to leave my warm house and its creature comforts. But all trips to Baxter end up being worth it despite (and sometimes because of) inclement weather. We had reserved the bunkhouse at South Branch Pond campground, so at least we had a warm, dry place to stay. If we had been tenting or staying in a lean-to, the trip definitely would have been off!

So it was with good spirits we woke up Sunday morning to find only a light mist outside. We decided to hike the Ledges Trail, which is basically a short nature hike with just enough elevation to give good views (on a clear day). We then returned to the bunkhouse, had lunch, and decided to drive down to the Trout Brook Mountain trailhead. Compared to some of the hikes in Baxter, this one is short – approximately three miles round trip – and easy, with very few slightly steep or slippery sections, plus only a moderate elevation (around 1,700 feet, if I remember correctly). Perfect for a less-than-ideal day.

As soon as we started out, it began to rain in earnest. But we had committed ourselves, so we continued on. I’m not sure how far we had climbed when I began hearing call notes. Several birds were moving through the pine and spruce trees clustered among bare ledges. I focused my binoculars on a few and identified black-throated green warblers and at least a few yellow-rumped warblers. White-throated sparrows were also moving through the underbrush.

I wasn’t very surprised to see the yellow-rumped warblers; these are a hardy species and often the last warblers to migrate south come winter. They may even winter here, in milder areas along the coast, if they can find abundant amounts of their winter forage: bayberries. Unlike other warblers, yellow-rumps can digest the hard waxy coating of this berry and take advantage of this rich food source. They are also physiologically adapted to switching from a summer diet of insects to a winter diet of primarily fruit.

White-throated sparrows were not to be unexpected either; sparrows, in general, migrate later in autumn than do warblers; some may not migrate at all, switching to a diet of seeds during the cold season.

I was very surprised, however, to see the black-throated green warblers. It always seemed to me that the major migratory push for most warblers occurred around the middle of September, so mid-October was pushing it, I thought. Referring to the Peterson Field Guide to warblers, I found this was not necessarily the case, as it states that “significant numbers still move through [the Northeast] during the first week of October when nearly all other warblers have departed. Stragglers are widely recorded in the north through much of November.”

The warblers I was watching seemed to be having some success in their foraging attempts; I imagined they were finding insects made moribund by the cold and rain, hidden in the bark crevasses and evergreen needle clusters of the sodden trees. I hoped so; their lives depended on it.

NEWS bird columnist Chris Corio can be reached at bdnsports@bangordailynews.net