Missing birds

Q: There aren’t any birds at my feeders. I’m used to having lots of them. What’s going on?

A: I wish I could tell you that there's an easy answer to your question but there isn't. Bird populations normally fluctuate seasonally and from one year to the next. One way to find out whether others are reporting a similar lack of species is by visiting eBird. A joint project of the Cornell Lab of Ornithology and National Audubon Society, eBird enables bird watchers from around the continent to record what they’re seeing and share their sightings with others. You can check reports for your county and go back four or five years to see whether you notice any kind of decline in the data.

Although I can’t tell you exactly what's going on in your neighborhood, there are several common causes for bird population fluctuations.

• Habitat changes affect bird populations. If there has been a change in your neighborhood, such as trees being cut down or new houses being built, that could be the reason you are seeing fewer birds.
• Natural food supplies—such as cones, berries, seeds, and insects—fluctuate from year to year, causing birds to shift ranges to take advantage of food surpluses or to compensate for food shortages.
• Weather patterns often cause birds to shift ranges, especially in winter.
• Birds of prey sometimes move into an area, causing the local birds to feed elsewhere until the predator moves on.

Let's both hope that your birds return soon.

Hawks at Feeders

Q. We have a hawk that comes to our yard on a regular basis, and yesterday he got a Mourning Dove. How can I get rid of him and keep the songbirds and doves?

A. Like the other birds, the hawk is coming to your yard because there is a source of food. If you want to discourage the hawk, you'll have to take your feeders down for a few days to disperse the hawk’s food source--smaller birds. In the wild, birds face constantly fluctuating food supplies, so songbirds, doves, and hawks alike will survive by finding food elsewhere. Try putting your feeders up again in a week or two. The songbirds and doves will come back but, with luck, the hawk will have found better hunting grounds somewhere else. You can learn more about feeder problems and solutions at our Project FeederWatch web site.

Where Have All the Robins Gone?

Q. What happened to all the robins? I’m not seeing them any more.

A. Each year in late summer and fall, robins leave the territories where they’ve raised their young. They spend fall and winter in flocks, traveling to places where they can find more food. In fall, we receive questions from people in some areas who are wondering where the robins have gone, and questions from people elsewhere who are incredulous because they’ve been inundated with large flocks of robins.

By flocking, the robins benefit by having more eyes to look out for predators and to find food. You probably won’t see individual robins again until spring when the demands of finding and defending a territory cause them to leave the flock and strike out on their own.

Although robins are one of the most familiar and widespread birds in North America, their patterns of movement are poorly understood. In fall, their migrations are often influenced by the availability of fruit, but in spring they move in response to the availability of soil invertebrates, such as earthworms. Their numbers in particular places may vary from year to year.

Robin sightings reported by participants of the Great Backyard Bird Count show that robins tend to avoid areas with deep snow cover. This makes sense, since they often search for food in the soil. You can read more about these results on the Great Backyard Bird Count web site.

You can help scientists document the seasonal movements of robins by participating in the Great Backyard Bird Count in February or by reporting your sightings to eBird. This online checklist program allows you to keep track of your own bird lists, see the changes in numbers throughout the year, and explore maps showing where else the birds are being seen.

For more information about robins, including a map showing their summer and winter ranges, visit our Online Bird Guide.

Window Collisions

Q: A bird keeps flying into my window. Why is it doing this? I’m afraid it will hurt itself--what should I do?

A: The behavior you mention often occurs in spring. This is the time of year when most birds are busy establishing their territories, finding a mate, laying eggs, and raising their young. They are very protective of their territory and will attack and try to drive away any bird they view as a possible competitor or a threat to their young. When they see their own reflection in your window, they assume they’re seeing a competitor and so they attack their own image. Both males and females may do this, especially species that often nest close to houses, such as American Robins, Northern Cardinals, Chipping Sparrows, and Song Sparrows.

This territorial reaction may be so strong that the bird may exhaust itself, but it usually doesn't result in fatal injury. Try covering the outside of the window with netting or fabric so the reflection is no longer visible. You can also try drawing soap streaks across the window to break up the reflection. You will probably be able to take down the netting and remove the soap several weeks later, when passions aren't running quite so high.

Other kinds of window collisions can be much more serious. Visit our Window Collisions page for ways to avoid this potentially lethal problem.