By Rob Thorn
“There were a bunch of Yellow-rumps and one or two Yellows,” said the birder, confident of his IDs. But when I scoured the flock at the edges of Schrock Lake, I could only find the Yellow-rumps. Then I spied two very yellow warblers, but not Yellow Warblers. Their yellow was confined to their throat and breast, while their back was a vivid green. Also, they had very noticeable wing bars. Ah, I thought, Pine Warblers. Common mistake to make. This is the warbler that always seems to look like a different species. To be fair, though, it was a cold day in early April: not exactly a good time for a Neotropical warbler like a Yellow.
Pine Warblers are one of our few bona fide temperate warblers. Along with Yellow-rumps and Orange-crowned, the majority of these birds spend their entire year in North America. Pine Warblers spend their winters in the longleaf pine forests of the Southeast, gleaning bugs from the pine needle clusters and from nearby evergreen live oaks. Many of them live in these forests year-round, but a percentage migrate north to set up shop in the White Pine and Jack Pine forests of the Northeast and Midwest.
Because they don’t have far to go, Pine Warblers are often one our earliest migrant warblers, arriving in late March and early April. In fact, some of them are even tougher than that, wintering in the Virginia Pine groves of Kentucky and southern Ohio. Occasionally we get some of these birds that stray to Columbus even in the dead of winter. Green Lawn Cemetery, with its collection of conifers, is a choice place to find them. These northern pioneers are often discovered at suet feeders: a strategy that must help them in the lean months of mid-winter. Here’s one picking at a suet cake: https://www.youtube.com/watch?v=QKGlgASEHL0
In early April, Pine Warblers are not picky about where to look for food, showing up just about anywhere. But by the end of the month, they start to become tightly associated with Pine trees, usually White pines or Virginia Pines here in Ohio. Their slowing trill is one of the first warbler songs you might hear, drifting down from the high canopy of a pine grove (here’s a video sample: https://www.youtube.com/watch?v=gPB7IoP9Cp4 ). Almost every substantial pine grove in the hilly country of eastern Ohio seems to have one. At this time they’re much easier to hear than to see, since most of their foraging is in the needle clusters high in the canopy. This foraging focus may put them into conflict with Brown-headed Nuthatches and Yellow-throated Warblers further south, and may help to explain why some of them migrate north to nest—
interestingly, most Midwestern Yellow-throated Warblers focus on Sycamores instead of the pines their southern relatives favor.
Pine Warblers almost always nest in pine trees, and their nest is hidden out towards the dense tips of the trees. Reproduction is rather quick: 10-12 days of incubation, followed by a similar time period of feeding nestlings up to fledging. Young Pine Warblers are the bane of summer and fall birding, since they usually lack the nice yellow breast and green back found in adults. They’re gray, with a white-ish breast and strong wing-bars; here’s one visiting a bird bath: https://www.youtube.com/watch?v=RoZu-nXV1oE Your best clue is where you find them; they, too, have a strong preference for pines. They also have very slow, deliberate movements for a warbler, acting more like a vireo.
Where can we see them? If we’ve reached May, their migration is pretty much over, so you’re looking for birds on territory. They are found throughout Ohio, but are much more common in the hilly unglaciated areas of eastern Ohio. Locally, you can listen for them (and maybe see them) in pine groves in Clear Creek Metro Park, Hocking Hills State Park, or Blackhand Gorge and the Flint Hills. They seem to do okay in any pines, even planted ones, and are one of the few warblers that has been able to increase their population in the past 30 years. Given how disrupted and manipulated their pine forest habitat has become, that’s a testament to the resilience of these tough little birds.