This winter may have brought many irruptive bird species to our yards and feeders, but one reader noticed the lack of a more common visitor.

“Like you and your readers my sunflower seed and thistle feeders this year have attracted an abundance of pine grosbeaks, lesser amounts of evening grosbeaks and many common redpolls, often foraging together,” Robert Howe wrote. “However, for several weeks (months?) I have not seen goldfinches at my feeders in East Machias. Looking back at my records for the same period last year I noted frequent visits by goldfinches but certainly no grosbeaks of either type and virtually no redpolls.

“I am wondering, first of all, if you or your readers had similar observations and secondly whether anyone could suggest if there might be a possible reason for any correlation.”

As are many other finches, goldfinches are nomadic and travel widely in search of food during the winter. According to the “Birds of North America,” species account, flocks can contain as many as 200 goldfinches, and can also include black-capped chickadees, common redpolls, and American tree sparrows. These three species will feed together, but goldfinches are often on the lower end of the feed station hierarchy. Other birds, especially pine siskins and house finches, will often oust them from their spot at a feeder.

It stands to reason that the larger finches, such as the grosbeaks, would gain first pick as well. However, choice of feeder type may help in this regard – larger birds prefer platform-type feeders, while cylindrical feeders are perfect for smaller and more agile birds such as goldfinches.

While the unusually large presence of winter finches this year may be a factor in the goldfinch’s distribution, it could just be a result of a normal cycle for the goldfinches. It’s possible their nomadic wanderings have brought them to another food source.

Whenever they do show up at a backyard feeding station in the coming weeks, look for changes in their plumage. Their dull, drab olive-green feathers will begin to be replaced, in males, by the brilliant yellow plumage of the breeding season. It shows up gradually, the birds appearing as if they’ve acquired yellow scarves as the feathers come in on their necks, and splashes of yellow appear on their bodies.

This is a big event for goldfinches, as they are undergoing a complete molt of all their body feathers. This puts a considerable amount of stress on their systems; as a result, goldfinches breed much later than other songbirds, nesting as late as June or July here in the East – an event that also seems timed to coincide with the flowering of thistle plants, an important food source.

Considering all the dire reports of habitat destruction and pollution, it is easy to jump to conclusion when birds that are normally seen in a certain locale don’t appear. Despite all the changes, natural cycles still continue, populations wax and wane, and food sources dry up in one place but explode in another. Detailed record-keeping, over an extended period of time, is necessary to determine if there really is a change in population numbers or distribution.

bdnsports@bangordailynews.net