Jonathan Weber of Olcott posted this message on the GeneseeBirds Internet mailing list: “This is the first fall out of the eight I’ve been feeding birds in my wild garden at Olcott that I have seen so few species of winter songbirds. The scarcity is baffling, considering the diverse habitat with ample adjacent cover: fir, spruce and maple trees, a variety of bushes and two brush piles. I maintain an assortment of feeders there: thistle, suet and hanging or platform feeders with mixed seed.”

He added: “Neighbors, friends and relatives in the area along this Lake Ontario corridor with feeders out now are reporting the same shortage. I’m wondering if other members have noted similar observations this season around backyard feeders. Is it possible that I’m in a skip zone this season for migratory songbirds?”

Weber’s message is similar to at least a dozen others I have been receiving from across this region. Some of them ask questions: Is there a disease killing birds like white nose syndrome is killing bats and colony collapse disorder is killing bees? Are wind turbines killing these birds? Is this related to climate change? It seems clear to me that the answer to all of those questions is either no or very little. But the fundamental question remains: Where are the birds?

There are a number of possibilities. The first is Weber’s own answer. Birds have a wide range of choices for their migration stops and their over-wintering locales. They may have simply skipped his locality or chosen other feeders. I invite those of you who feed birds regularly to inform me about your experience this fall. Are the numbers of birds that are appearing at your feeders more than, less than or about the same as in previous years?

The more interesting question is why aren’t the birds there? Assuming that this phenomenon is general, consider some background and then some possible scenarios.

Bird feeders are not a natural part of the environment and birds are creatures driven by their genetic history. Their lives are also very short. They progress from egg to near adult in a month or two. During that growth period, parent birds are teaching their young how to feed themselves in their natural surroundings. This does not include your feeders. Songbirds teach their young to glean insects and to feed on berries and weed seeds.

Studies of bird stomachs carried out over a century ago show insects playing a major role in songbird diets through the summer and early autumn, but then things change. Insects become harder to find and bird diets turn to plant food as it becomes ripe at just the right time. For some species like titmouse, bobolink and bluebird, the proportion of plant food in their diets doubles.

Now think about how this year differed from previous years. This past spring and summer were the greenest I have ever experienced. And thank goodness. The previous year was especially tough on regional orchards. As a result of this summer’s unusually supportive weather with much sun and rain, local natural food is abundant locally. And, given the choice, shy birds will continue to take native offerings to those at your feeders.

Canada’s northern forests are also laden with food. Ron Pittaway’s annual “Winter Finch Forecast” summarizes those conditions: “Ontario’s cone crops (except white pine) and deciduous seed/berry crops are generally above average to excellent.” And he suggests that fewer numbers of northern species like crossbills, redpolls and siskins will retreat to southern Canada and the United States. In particular, fewer of those delightful red-breasted nuthatches will visit us this winter.

But, Pittaway tells us, we might have a few evening grosbeaks, a species now rebounding due to spruce budworm outbreaks in the north.

Despite these signs, once snow makes natural feeding tougher, at least some of those welcome visitors should return to your feeders. You’ll know soon enough.