Birders often use the word “fallout” to describe a sudden opportunity to see a large number of species at one time. A fallout occurs when weather conditions force birds to interrupt their migration. Usually, this involves a deep low-pressure system that makes flying more difficult for birds. Low pressure systems often bring wind and rain.
That was the case last weekend, but Grand Forks was on the northern edge of the weather system and missed out on the worst of the weather, which nature apparently reserved for runners in Fargo’s marathon.
What birds encountered in the northern Red River Valley was a brisk wind from the northeast. Many chose to wait it out.
The result was a cascade that brought species after species of birds to local backyards and wetland habitats.
Cascade is not an official term, but it describes the succession of birds that arrived here, hints at the variety of species and even the thrill that each new arrival brought – increased because the birds didn’t arrive all at the same time, as in a classic fallout, but in a three-day sequence.
The effect was enhanced because the season is late; many species delayed their northbound movement as a succession of storms moved across the continent. Thrushes were later than normal, as pointed out last week, and so were such stalwarts as Harris’s sparrows.
Harris’s sparrows showed up in large numbers. More than one birder joked that they were uncountable across a wide front. Harris’s sparrows are a kind of specialty here. Their northbound route is a relatively narrow band that happens to include the Red River Valley, and very large numbers of the sparrows pass through every spring. Like other sparrows, Harris’s sparrows are seed eaters, and they take advantage of the smorgasbord of seeds that the local landscape provides and that local birders enthusiastically augment. Harris’s is a “hooded” sparrow with an extensive area of black over the head and breast, rather like a monk’s cowl, the bird books often tell us. It often is the last of about two dozen sparrow species to arrive in our area and one that doesn’t linger. Harris’s sparrows nest farther north.
The number of goldfinches was remarkable, but that’s not necessarily because they’d just arrived, and certainly not because they are moving on en masse. The goldfinch is among the most common breeding birds here, and increasing numbers spend winters. They undergo what amounts to a “full body molt,” emerging from a plain plumage into brilliant yellow.
Indigo buntings and eastern towhees were also among the sparrow-like birds that showed up. The indigo bunting is widespread but not common in our area; eastern towhees occur about as far west as the ridge marking the edge of the valley. The towhee is a special case, at least for me. I promise to share when events in the bird world slow down.
The seed eaters were upstaged by the fruit and insect eaters. These were the birds that crowded offerings of oranges (halved, please) and grape jelly (presented so that birds can’t get their feet in the jelly).
As many as a dozen Baltimore orioles competed for space at feeders in our backyard. They arrived in an interesting succession, brilliant orange and black males first and drabber yearling males a bit later and finally, the plainer, greenish-gray females.
Orchard orioles joined the parade; these are a smaller version of the Baltimore oriole and a darker bird, overall, tending toward brick red on the breast and with less white in the wings. They also are less common; we are at the northwestern edge of their breeding range.
Rose-breasted grosbeaks – perfectly capable of cracking seeds – also visited the fruit stands. Some watchers reported ruby-throated hummingbirds, as well.
A variety of warblers showed up at the sap wells that yellow-bellied sapsuckers have created in trees in our front yard. The most frequent customers were yellow-rumped warblers, always the first of the warbler species in our area. A magnolia warbler showed up at the sapsucker tree, as well, a first of that species in our yard list. A palm warbler foraged in the newly tilled garden. There were also reports of Cape May warblers, another uncommon and spectacular species, as well as Wilson’s and yellow warblers. These are likely the vanguard of warbler migration, which usually peaks about Memorial Day.
A single thrush lingered through the weekend, as well, and catbirds appeared as the weather settled. Barn swallow and eastern phoebes were here, too.
But spring migration isn’t finished yet — not until the cuckoo sings, probably well into June.