The word "finch" is a vague term that is applied loosely to a large group of small seed-eating birds occurring on every continent (except Australia and Antarctica). The National Audubon Society's "Encyclopedia of North American Birds" puts the number of species at 436 worldwide and "about 83" in North America.
Don't worry. We're not going to deal with all of them in this column. Instead, we'll consider only those that are called finches, and of those, only those that occur in our area. That number is three: American goldfinch, purple finch and house finch.
One day last week, all three species showed up at a pile of sunflower seeds I'd spilled onto the deck.
These finches are similar, especially in winter plumage, but they can be separated relatively easily.
The goldfinch can be told from the others by its smaller size, lighter color and prominent white wing bars. At a glance, they seem trim and petite. Their underparts are clear, without streaking, and this is a quick and dependable way to distinguish them from pine siskins, which are heavily streaked and appear quite dark.
The purple finch and the house finch are larger birds, and males of both species show some color. Purple finches often show a deep red color, especially on the lower back. House finches more often seem pale orange or even yellow. The amount of color and its intensity varies from bird to bird and is suggestive, but not conclusive, in identifying individual birds. Purple finches appear stockier than house finches, though this, too, is a subtle difference that is best seen when the birds appear together. More obviously, house finches have square tales; purple finch tails are v-shaped. This is a reliable way to distinguish the males of these species. A square-tailed bird is a house finch; one with a scooped tail is a purple finch.
Separating female finches is easier. Female house finches are drab, even by finch standards. Female purple finches are hardly colorful, but striping is more intense on the underparts than in house finches. The definitive difference here is the area above the eye, technically called the "supercilium." It's white in purple finches, and this separates them reliably from house finches.
The presence of female purple finches can be an indicator that the less distinguishable birds nearby are male purple finches.
This discussion wasn't necessary 40 years ago, when Suezette and I first moved to Grand Forks. We've been here longer than house finches, which first showed up in the late 1980s.
House finches are - or were - a southwestern species. Like other finches, they were sometimes kept as caged birds, and it happened that some were released in New York in the early 1940s. Within four decades, they'd overspread the continent.
Here's a telling comment from "Birds of Manitoba," published by the province's Naturalist Society:
"It is astonishing that a species indigenous to southwestern North America, where it still nests in cavities of saguaro and other cacti, has become one of the most widespread garden birds in North America, even managing to overwinter in the Prairie Provinces. ... Just before house finches appeared in Manitoba the ranges of the eastern and western populations were equidistant from the province. Between 1983 and 1990, however, the eastern population expanded by rapid, long-distance jump-dispersal across Wisconsin, Minnesota and North Dakota."
Almost certainly, all three of these species will show up on Christmas Bird Counts this weekend - along with several species with other names that also are members of the finch family. These include such species as snow buntings, dark-eyed juncos, siskins, cardinals and potentially crossbills and redpolls, though they haven't yet graced my feeder array.
At midsummer, only two of the so-named finches would be expected here. House finches are common nesting birds, especially in urban environments, where they seem to favor dense cover. For several years, house finches nested in the shrubs planted against the foundation of the Herald building downtown. Goldfinches, too, are common nesting birds, and in summer plumage, males are brilliant yellow that contrasts sharply with black wings and black caps. Only the white wing bars are consistent between the seasons.
Purple finches are mostly winter visitors in our area, although there are a few nesting records in wooded areas. These are more numerous in Minnesota, of course. The state's breeding bird atlas ranks the purple finch as a regular but uncommon breeding species.
Roger Tory Peterson described the male purple finch as appearing "dipped in raspberry juice." This is an overstatement, but the summer bird is brighter - and quite unmistakable.
Too bad I can't anticipate their presence at my feeders in summer.