The problem with spring is that there's just too much going on. Every day brings a new species and new excitement to the birding world, and more consternation to the bird nerd writing a weekly column.
Should it be the apparent recovery of trumpeter swans? Or the turkey vulture soaring over the interstate? The raven that's hanging around a shelterbelt not far away? Or the dancing of a sharp-tailed grouse? The flickers foraging on the greensward? Or the welcome burst of meadowlark song? The call of the killdeer? The fox sparrow that suddenly shows up? The piebald junco rummaging in spilled seeds below the feeder?
You might notice the list of possibilities runs from largest to smallest, and in this case, the little guy wins. This is a newspaper and a newspaper website, and occurrences that are unusual or unexpected are the marrow of the news business, and so the junco wins.
A report of a strangely colored junco showed up on the Grand Cities Bird Club's site in early April. The photo attached clearly showed a junco. Juncos are common birds - among the most abundant in North America - and during migration they can overwhelm a handy food source.
Quite a lot of variation occurs among juncos, and 15 subspecies are recognized. Two of these show up here-both forms of the same species. The slate-colored junco is most likely, but some Oregon juncos show up, as well. The accepted common name for the species to which these forms belong is dark-eyed junco.
This spring brought reports of juncos with more white than usual. Such birds have a condition called leucism. The middle consonant is a hard sound, and the word is sometimes spelled leukism. Many will recognize the root of the word, leuk, which means white; it occurs in leukemia, a cancer that attacks white-blood cells in humans.
Technically, leucism describes the absence of pigment in parts of the body; it is fairly widespread, occurring in humans and other mammals, as well as in reptiles and-as we see from the junco-in birds, as well. It affects skin, hair, scales, cuticles and feathers - but not eyes. Piebald juncos have dark eyes.
Leucism seems to occur more frequently in juncos than in other birds, though I've seen robins and red-winged blackbirds with piebald plumage, and I hear reports of mottled robins and blackbirds almost every season.
These species have dark plumage, and it may be that the white aberrant plumage is more obvious and more often seen rather than being more frequent in the population of any of these species.
I've described some of these birds as albino or partly albino, but this is not the case. Albinism is a more thoroughgoing - and rarer - condition that affects pigmentation of the eyes as well the plumage. A junco with a dark eye, no matter how white the feathers, is a dark-eyed junco.
The juncos are birds of high latitudes and high altitudes. They nest across both the Rocky Mountain and Appalachian ranges, but the greatest extent of their territory is across the boreal belt of Canada and Alaska.
Unlike other northern migrants, such as redpolls and snow buntings, the juncos are not Arctic birds. Nor are they holarctic birds, occurring in both Eurasia and North America. With us, they are seasonal visitors, usually showing up in late March and hanging around through April, then recurring in October and sometimes lingering into late December - long enough to be tallied on Christmas Bird Counts. In some years, some juncos spend the winter, but that is unusual.
The juncos are ground feeders, often forming a kind of clean-up crew picking up seed that other birds cast on the ground. Unlike some of their close relatives, the ground loving sparrows, juncos are not exclusively terrestrial. They nest in trees, and males do their courting from tree tops. After the most recent unexpected storm, I saw groups of juncos sunning themselves in the topmost branches of trees.
Most of our juncos are the slate-colored form, uniformly a rich gray color from the upper breast and across the back with quite a sharp delineation between the breast and the white underparts, including the belly and undertail area.
Oregon juncos show up here almost every winter, but in smaller numbers. They show a rich brown on the back, but otherwise are quite similar to slate-colored juncos.
For the most part, juncos aren't nesters here. Slate-colored birds have been observed in the Turtle Mountains in nesting season, and white-winged juncos have been reported from the southwestern part of the state. The white-winged form is restricted to South Dakota's Black Hills, a high-altitude outcrop that presents the sort of habitat that juncos favor elsewhere.