Vireos return to Northland in late May
Along with all the other unfolding of spring at this time, May is a month filled with migrants. Early in these 31 days, we noted the return of hermit and Swainson thrushes, phoebes, tree swallows, yellow-bellied sapsuckers, flickers and a few warblers, yellow-rump, black and white and palm. With the warmer longer days of mid-month, the pace increased and the more birds were heading north. It seemed like each woods walk revealed new avian returnees, located by sight and sound.
As we entered the second half of this month, rose-breasted grosbeaks have come back to their nesting range and immediately proclaimed territorial ownership with loud sounds and calls. The small least flycatchers repeat their "chebek" calls in the trees, a short call from a little bird. If we were fortunate, we had a chance to see and hear the loud and colorful Baltimore oriole from the high branches. The brown and shy veery churns out its unusual song from the understory of the forest. All of these bird happenings blend with colors of the forest floor flora. Higher up in the trees, white blossoms of plum, cherry and juneberry add to the greening woods.
Now as we go through the last week of May, we are seeing a largely shaded woods that holds a new set of blooming wildflowers, those that are shade-tolerant: baneberry, sarsaparilla, wild lily-of-the-valley and starflower. And more of the spring songbird migration continues. In the latter days of this month, we'll note the birds that had returned earlier, but we'll add more to this list. It is now that we see the insect-eating crested flycatcher, kingbird and wood peewee. Hummingbirds appear in our yard to sample nectar blended with some insects.
A house wren sings at a birdhouse or other such nesting site in preparation for a home. Swallows of several kinds feed while on wing, often over bodies of water, while chimney swifts twitter above buildings to get their meals. A flock of squeaking cedar waxwings call from the top of a nearby tree. Gray catbirds sing their mixed songs from the forest understory. And the scarlet tanager, with its red body and black wings, sings its robin-like song in the woods.
Though many warblers have already returned to the Northland by mid-month, many more are here now. Twenty-six species are recorded in the region each spring. A good warbler walk in late May can reveal more than 20 kinds to the observant nature watcher.
Like many others in the Northland, I try to see and record all these avian phenomena, but I think the bird group that I most anticipate and enjoy finding and listening to are the vireos.
Vireos are small birds, only slightly larger than warblers and easy to overlook. Our region is host to five kinds that range from common — seen or heard nearly every day — to unusual that are detected only sporadically. Three are named after body parts: red-eyed (by far our most common), blue-headed and yellow-throated. The other two have different names: warbling (its song) and Philadelphia (where one was caught).
None are particularly colorful. Most have drab greenish-olive feathers on the back with lighter features beneath. Indeed, the name of vireo essentially means green. Maybe it is the yellow-throated vireo with its bright feathers beneath the beak that is the most colorful of this group. It may be that the label of "vireo" is what makes the bird seem more uncommon than it actually is. It is one of only a few birds that we regularly call by its Latin name.
Vireos are insect eaters and so return to their home range each spring at about the same time insects are hatching. They differ from the similar warblers by having a small hook on the end of the bill. Vireos build nests in the fork of branches on trees, often low enough for us to look inside. Nests are made of twigs and birch bark and usually remain on the tree after the leaves fall, maybe even all winter.
With the exception of warbling vireos, they sing short songs of just a couple of notes. Best known are the repetitious two notes of the red-eyed vireos, often described as saying, "See me, hear me." Blue-headed and yellow-throated vireos sing similar phrases, but more slurred.
I'm always glad to see and hear the yellow-throated vireos each spring. While the blue-headed and red-eyed vireos may nest more in the north, the yellow-throated is essentially a southern bird. Its range barely reaches the Northland. Once arriving in late May, they commence to singing and do so in the coming weeks of warm weather. Now that the yellow-throated and other vireos have returned, I look forward to weeks of color and songs during my regular woods walks and I suspect that they will be nesting here, too.
Retired teacher Larry Weber is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods,” “Webwood” and “In a Patch of Goldenrods.” Contact him c/o firstname.lastname@example.org.