Should You Feed Birds in Winter?

American goldfinches are just a few of the colorful birds you’re likely to attract by putting out birdseed in winter. But are you helping or hindering their survival?. Mr.TinDC [CC BY-ND 2.0]/Flickr

Watching birds at your feeder during the barren winter months is a great way to stay connected with nature and help creatures that might otherwise struggle to find their next meal. In fact, about 40% of Americans put out backyard feeders loaded with birdseed or suet.

But just because it's a joy to watch the colorful parade of northern cardinals, red-bellied woodpeckers, American goldfinches and cedar waxwings flitting outside your window, is it really the best thing for them? Should you help your feathered friends whenever possible or does it go against nature, making them dependent on humans and weakening their natural ability to forage for food on their own?

First, the good news

According to the Nature Conservancy, much of the current research suggests that putting out goodies for wild birds generally gives them a leg up on survival during frigid weather when food isn't readily available. One Wisconsin study, for instance, found that black-capped chickadees with plenty of seeds from their human neighbors showed a significantly elevated overwinter survival rate (69%) compared to those left to fend for themselves (37% survival rate).

In fact, a majority of studies indicate that birds relying on feeders generally enjoy higher breeding success than those that don't. They lay eggs earlier, produce more of them and their chicks weigh more. This is especially true when winters are harsh or birds are trying to eke out a living in poor-quality habitats or facing other extreme challenges.

Killing with kindness?

A closer look at the research suggests that, for some birds at least, easy access to kindhearted human offerings may be too much of a good thing, diminishing their resilience and ability to survive.

One study in the United Kingdom, for example, found that blue tits (European kin to the black-capped chickadee) didn't fare well after a winter diet of human-supplied fat balls (made from suet and seeds). Birds had lower breeding success in the spring, chicks weighed less, and they experienced lower survival rates than chicks whose parents scavenged for their own food. Another U.K. study revealed similar findings.

Granted, these are only two studies among many more showing the opposite results (i.e., increased breeding hardiness among human-fed wild birds). Possible explanations for the outlier findings, according to the authors, may be that the particular diet studied was unbalanced and too high in fat or that winter feeding may help less healthy birds survive when they ordinarily wouldn't. Poorer health often equates to lower breeding ability.

Whatever the reasons, these findings suggest more research is needed on the possible detriments of bird feeding, including whether only certain bird species are negatively affected, what kind of feed is best, and the ideal amount of food.

Another reason to exercise caution before setting out birdseed comes from studies showing that multiple bird species crowding together unnaturally at feeders boosts their chances of contracting parasites and diseases.

An additional downside is the increased risk of window collisions as birds take flight from feeder perches. Muhlenberg College ornithologist Daniel Klem has found that deadly bird strikes are most common when feeders are 15 to 30 feet from windows. Even feeders as close as three feet away can result in occasional window collision deaths.

Another problem with feeders is the rising presence of unwelcome visitors: most notably Cooper's and sharp-shinned hawks on the prowl for easy backyard meals. Populations of these winged predators have grown rapidly in recent decades.

While there's no real evidence that wild bird populations are declining as a result of backyard predation, watching hawks swoop in for a bloody kill may not be the tranquil nature scene you signed up for when you first put out birdseed. Plus, the expanding popularity of backyard bird feeders is enticing more hawks to stay for the winter instead of migrating, possibly changing the balance of nature and leading to other unintended negative consequences.

Cooper's hawk at feeder
Cooper's hawks are an increasingly frequent sight at backyard bird feeders where the pickings are easy. USFWS Mountain-Prairie [CC BY 2.0]/Flickr

To feed or not to feed

Given the potential drawbacks of backyard bird feeding, it can be tough to decide whether or not it's the right thing to do.

Here are some considerations.

First, remember there are numerous documented benefits for many bird species, and there are also benefits for humans who feed them. These include insect control, flower pollination and weed control around the yard, as well as the chance to get up close and personal with nature (maybe even take some great photos). The joy that comes from connecting with wild creatures can even turn into a passion for environmental conservation and advocacy. Inspire enough people to action through backyard birding, and it may result in better protection for the planet.

Still undecided? The National Audubon Society suggests asking three questions:

Is a particular bird species at risk? As counterintuitive as it might seem, if you find that a particular bird is threatened, endangered or otherwise struggling, it's best to forgo offering food. You don't want to further threaten the species by inadvertently introducing disease or inflicting other unintentional harm.

Is the food appropriate and safely provided? If you're going to feed birds, it's important to offer them the healthiest food in the safest, most sanitary way possible. If you don't have the time and commitment to do it right, bird feeding probably isn't a good idea.

Will feeding change birds' behavior? Are your feeders enticing birds to migrate to an area where they're not well known or may be hunted? Might they become habituated to humans, increasing their risk of danger or encouraging them to aggressively approach people for handouts (think seagulls)? If so, it's probably best not to feed them.

Beneficial bird feeding basics

If you decide to go ahead with installing feeders, here are some tips to ensure you're creating the healthiest and safest experience for the birds.

1. Have more than one feeder and put them at varying levels to avoid crowding and lessen the likelihood of disease. Different bird species prefer eating at different heights, which should decrease the number of unhealthy interspecies interactions.

2. Fill each feeder with high-quality birdseed and invest in the right feeders for specific seed types. That's because each bird species has its favorite foods and favorite ways of eating. This helps keep species separate so they stay healthy and thrive. Here's a guide to which seeds and feeder types are best for attracting specific birds. Learn more about the healthiest and worst foods for birds here. If your time is limited but you still want to help birds around your home, consider planting native shrubs and trees in your yard that are known avian favorites, such as elderberry, sassafras, American mountain ash and coneflower.

3. Scrub feeders at least twice a year using dish detergent, then soak in a 10% non-chlorine bleach solution to remove harmful, disease-causing bacteria. Let them dry in the sun. Also regularly rake up uneaten seeds and other debris beneath feeders that can get soggy and spoil or sprout dangerous mold — none of which is good for birds.

4. Place bird feeders where birds will be safe from windows and traffic. Put feeders less than three feet from windows or even suction cup them to the glass to lessen the chance of bird strikes. It will give you a better view, too. Also place visual warnings like decals or netting on windows to deter birds from flying into them. Feeders that are too big to hang near windows should be placed 30 feet away or farther. Also make sure feeders aren't near streets or roads where birds may collide with vehicles.

5. Create cover by surrounding bird feeders with native trees and shrubs to avoid turning your feathered friends into sitting ducks for predators. This partially hides feeders and gives birds a place to dart when threatened. Make sure shrubs aren't so close that predators can hide in them within striking distance. Tarps and umbrellas also work as cover. Don't offer birds food on the ground, which makes them even easier prey. And, by all means, keep cats indoors.

Watch this video for more bird-feeding health and safety tips.