Last week I stopped filling the bird feeders. We only have two — a suet feeder and a squirrel-proof seed feeder, both hanging off the same tree about ten feet from my living room windows. I’ve kept them full since last fall and am delighted by the the variety of birds that have made it a habit of feeding on them.

red-bellied woodpecker

During the winter, the main visitors were the red-bellied woodpecker (above), downy, and hairy woodpeckers, chickadees, blue jays, and white-breasted nuthatches. They were particular about what they liked in the seed feeder and threw a lot of the seeds and corn on the ground. As well, the woodpeckers were messy, dropping chunks of suet.

This spillage brought a regular flock of mourning doves, northern juncos, and a pair of cardinals — not to mention, grey squirrels — to forage on the ground underneath the feeders.

More than a dozen mourning doves hidden in the underbrush

How many mourning doves can you see here?

The birds all tended to feed at around the same time, so we’d cycle between no birds and all the birds, but even when traffic was high, it was orderly. Some birds would feed, others would wait and except for some mild bickering, things went smoothly.

As the weather warmed and days got longer, new birds began to arrive. We were happy when our first pair of rose-breasted grosbeaks appeared, and later another pair. Soon the goldfinches, various warblers, brown-headed cowbirds and others showed up. Then, to our absolute delight, a pair of Baltimore orioles!

male baltimore oriole on a metal bar supporting the bird feeder.

It was truly thrilling to see this blazing orange bird we’d only ever glimpsed in the woods. Sometimes the male would sit on the feeder support bar and sing. I don’t think the female ever landed on the feeder, but I’d usually spot her nearby. Later a second male oriole began showing up.

At the same time, beneath the feeder, joining the ground-feeding doves, sparrows, and cardinals, the chipmunks and red squirrels arrived. We see few red squirrels at the feeder in winter; they seem to stick to the trees. And chipmunks spend their winters underground, so we don’t see those. But now here they were, all at once.

It is not normal for red squirrels and chipmunks to gather in such numbers. Red squirrels, particularly, are fiercely territorial, so seldom cross paths while foraging. Chipmunks are less territorial, but they do stick to confined home ranges that only overlap slightly. Now I was seeing two or three red squirrels and up to five chipmunks, all scrapping over fallen food. They’d eat, chase each other, and sometimes come into physical contact.

The same was true for many of the birds we were seeing at the feeder. While not strictly territorial, male orioles will defend areas around their nests and their mates against intruders. Male rose-breasted grosbeaks and male cardinals chase off other males of their species. The female grosbeak, I observed, was quick to chase other birds off the suet feeder. And woodpeckers, who had been feeding in relative peace all winter, were now  regularly fighting over the feeder.

All of this was recipe for disaster.

First of all, fights were breaking out that never would have occurred in a natural setting because these animals never would have overlapped. This increases injury and stress to the animals, which can make them vulnerable to illness.

pair of male grosbeaks flapping at each other over the feeder

Second, because of the fighting, we were experiencing more window strikes. Fortunately, to my knowledge, only one bird died hitting the window — a male bay-breasted warbler. But there were an uncomfortable number of cases where birds glanced heavily off the glass and had to perch on a branch or rest on the ground before taking flight again.

As well, male birds who were attracted to the feeder — especially the cardinals, orioles, and grosbeaks — would see their reflections in the window and fly down to the sill to do battle with the intruder. Usually these were low-level attacks, lots of fluttering and pecking on the glass, but I worried about an angry bird flying in too quickly and striking the glass.

And finally, in scattered populations, birds with infectious diseases would not normally come into contact with many other birds, so diseases spread slowly. But the abnormal density of animals at and under the feeder increases the risk of disease spreading among them.

The four diseases that most frequently affect birds that use feeders are: salmonella, trichomoniasis, aspergillosis, and avian pox. All of these diseases are transmitted from one bird to another at feeding stations, especially when overcrowding occurs. — Massachusetts Audubon Society

As well, once the weather warms, the feeder itself can be a source of infection. For instance, trichomoniasis a parasite that infects finches, flourishes in moist bird seed.

Usually transmitted at backyard feeders, finch trichomoniasis has not yet been detected in the United States. It has, however, been found in Canada’s Atlantic Provinces, where it has killed purple finches and American goldfinches.  — National Wildlife Foundation (Feb 2019)

So on that note, I’m shutting down the bird restaurant until fall. I’ll miss the variety of birds outside my window, but it’s good to be reminded that bird feeders are for us, not the birds. Except in extreme circumstances birds don’t need our help finding food, and in fact, may be better off without us.