Outside of the breeding season they will forage in almost any habitat and will eat a variety of seeds, nuts and berries. They have a wide variety of foraging techniques they will catch insects on the wing like a fly-catcher in addition to creeping along a branch and picking through the foliage. They flit around in the treetops looking for insects (they are largely insectivores in the summer), but also come to my suet feeder. And so, yellow-rumped warblers, a species that likes to breed in boreal forests, have arrived and are making themselves comfortable in my woods. My backyard with its dense forest of hemlock and white pine is also more boreal forest than temperate deciduous. The tops of our local hills - Mt Agamenticus, Blue Job and Bauneg Beg - are all part boreal forest.
And by April, the vanguard fleet of yellow-rumped warblers, having survived a winter of retrograde reflux, will remind you that a new season approaches.The line between boreal forest (the great northern coniferous forest) and temperate deciduous forest winds its way through our area. By February, our first migrants – turkey vulture, red-shouldered hawk, and red-winged blackbird – will begin to return. Their abundance here in the Northeast may decline as winter progresses, particularly during severe winters.īut fear not. We usually hear them – their distinctive flat “chek” or high “tseep” notes – before seeing them. southeastern coast, where no other swallows dare swoop and swirl.Īway from the coast in the northern portions of the Northeast, yellow-rumps are a prize on Christmas Bird Counts in December and early January. Tree swallows, classic insectivores, have a similar ability to digest bayberry and wax myrtle, which allows them to winter along the U.S. Whatever the strategy, the yellow-rump’s gastrointestinal talents probably account for its ability to inhabit a winter range farther north than its relatives, particularly along the Atlantic coast, where wax myrtle and bayberry can be abundant and where birders, in a day, might find butterbutts in the hundreds – abundance unlike any other wintering warbler in North America.
They may also pass the waxy fruits through their digestive systems more than once – a maneuver researchers call “retrograde reflux of intestinal contents.” You get the idea. To do so, it appears that yellow-rumps possess elevated levels of bile salts, which aid digestion of saturated fats. With insects in short supply, the yellow-rump turns to fruit: juniper, red cedar, viburnums, honeysuckles, mountain ash, and even poison ivy.īut this warbler’s greatest dietary feat is that it also eats the fruits of bayberry and wax myrtle ( Myrica spp.)– the raw materials of folksy candles. More to the point, in winter, when most of their kin are enjoying insects in the tropics, yellow-rumps are finding food across the southern U.S. I’ve seen them feeding nearly everywhere, from downtown lawns in Montpelier, Vermont, to wrack lines along the Atlantic coast. While the Cape May warbler and its northern relatives sequester themselves in spruce boughs during migration, the yellow-rump is an exhibitionist, often landing on a naked twig. In summer, when most warblers glean insects and other prey from foliage, the yellow-rump adds flycatching – snapping prey from mid air – to its repertoire. Universality is a trademark of this warbler, which birders affectionately call “butterbutt.” Although it breeds in coniferous woods across the northern half of the continent, the yellow-rump can feed in a range of habitats. Although the sunny sides to the breast have faded, the yellow-rump, while occasionally hidden below the folded wing tips, is universal year-round. Novice or careless birders might overlook this warbler, whose winter plumage hints at a brown, streaky sparrow. But the yellow-rumped warbler, feisty and flighty, is a lesson in adaptation. These sparkling birds eat mostly insects, which have died or gone dormant.
#Yellow rumped warbler winter plumage crack#
Find its buttery warmth even when life outside seems to groan or crunch or crack in the cold.īy now the songbird rainbow in our forest has vanished – most warblers have migrated south. It is an aster in winter, sun through the clouds – a force of nature called the yellow-rumped warbler.