Birds & Birding

Winter Bird Feeding: Good or Bad for Birds?

January 5, 2015

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A downy woodpecker at a winter bird feeder. Photo: © Chris Helzer/TNC.
A downy woodpecker at a winter bird feeder. Photo: © Chris Helzer/TNC.

Winter bird feeding is one of the most popular ways for people to interact with nature, and most do it to help birds get through these tough months. But what does this really mean for conservation? Does feeding help or hurt birds?

More than 40 percent of U.S. households feed their backyard birds, and in the United Kingdom, the rate is as high as 75 percent.

Despite the widespread popularity of bird feeding, scientists are still building a basic understanding of its impacts.

As we might guess, a number of studies show generally positive impacts of bird feeding. For example, the overwinter survival of birds is enhanced by bird feeding.

This is especially true during the coldest times, when some hungry birds might otherwise lose the battle with the elements1.

A study conducted during winter in Wisconsin showed that black-capped chickadees with access to bird seed had a much higher overwinter survival rate (69 percent) as compared to those without access to human-provided seed (37 percent survival).

Black-capped chickadee. Photo: © Chris Helzer/TNC
Black-capped chickadee. Photo: © Chris Helzer/TNC

Furthermore, some studies have shown that birds making it through the winter in better physical condition see those benefits carry over into the nesting season.

Bird feeding produces significantly earlier egg laying dates, larger clutches of eggs, higher chick weights and higher overall breeding success across a wide range of bird species2,6.

The greatest impact of feeding is seen when birds are most challenged, such as after particularly harsh winters, or when birds are young and inexperienced, or when they are living in low-quality habitats2. Feeding can promote the survival and reproduction of the not-quite-fittest.

But in contrast to these straightforward results – showing that bird feeding makes for better-off birds – a few studies indicate that, at least in some situations, there may be unintended consequences of bird feeding.

A European relative of the black-capped chickadee, the blue tit, was studied in the United Kingdom to examine the impact of bird feeding on nesting success.

One research group3,4 found that birds fed during winter subsequently laid a smaller number of eggs that had lower hatching success and ultimately fledged fewer young than birds that weren’t fed at all. The offspring that did fledge weighed less and had a lower survival rate than the young of unfed birds.

An additional U.K. study of the blue tit and another chickadee-like species, the great tit, had similar findings.

Both species, when they had access to bird food, laid fewer eggs, had lower hatching success, and ultimately had fewer chicks fledged.  

Great tit. Photo: Flickr user Final Gather under a Creative Commons license.
Great tit. Photo: Flickr user Final Gather under a Creative Commons license.

Note, however, that these are just two studies demonstrating a negative effect of bird feeding – among a majority that show positive effects.

Nonetheless, the striking findings of lower reproductive success in supplementally fed birds need some explanation. Unfortunately, it was beyond the scope of these U.K. studies to definitively explain how bird feeding resulted in lower reproductive success, but the authors offer several possible hypotheses.

One possibility the authors suggest is that the bird feeding provided an irresistible diet that was unbalanced – too high in fat to produce high-quality eggs. More protein, micronutrients, and antioxidants than are provided by bird seed may be needed to produce high-quality eggs.

Another possibility is that bird feeding allowed individuals with a lower reproductive capacity which ordinarily would not survive the winter the chance to nest.

A final possibility is that the feeders were placed in poor quality nesting habitat – leading the birds to choose these suboptimal sites as nesting areas in the spring.

More research needs to be done across a wider geographic area and on more species to understand not only the impacts of bird feeding on reproductive success, but also on other factors such as disease transmission, species range expansion, and population trajectories.

Citizen scientists can help by participating in initiatives like Project FeederWatch that ask people with bird feeders to share their observations. What you see in your own backyard can contribute to the efforts to answer these questions.

Joe Smith

Joe Smith, PhD, explores the lives of the birds around us by sharing insights from scientific research. As an ecologist for a New Jersey-based conservation services company, he helps to restore coastal ecosystems and the migratory birds that depend on them. Joe lives in the birding hotspot of Cape May, NJ and has done field research with birds throughout the U.S. and Latin America. He writes about nature in his backyard at More from Joe

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  1. I am a lover of birds. I am specialized in ecosystems biologist. I ask myself a question: for birds may be good to feed them in winter. But for the ecosystem ?. Balance is our goal, not some species. Thank You.

    1. I so agree with this. I wonder if we artificially maintain high numbers of “tough guy” birds (House Sparrows, Blue Jays, Grackles, Cowbirds, etc.) by feeding them all winter, and then, in high numbers and in robust health, they go on to negatively impact our migratory birds.

      1. I feed birds. During the summer, I get sparrows. In the winter – no sparrows. No blue jays eating in my yard during the winter. Golden finches, house finches, chickadees, and more. Juncos come in from the woods. They get food and water. Each area is so different. I will wait for more real data before changing my practices.

    2. It would be hard at this point to determine what a natural balance really is, wouldn’t it? Humans have already so totally screwed up the natural balance.

        1. I have had a bird feeder for many years. The last few years seemed to be more crowded with birds than before and then the gophers, ground squirrels and tree squirrels became over bearing hanging around the feeder all the time. So took down the feeder and cleaned up the area. Waited about a month and now about once a week widely broadcast a scoop of seed around the back yard. The birds are now distributed around the yard and continue hunting for natural food in the leaves and soil along with the broadcasted seeds. I have not noticed any problems with doing this at this time. And actually enjoy watching the birds even more than when they were all stacked up at the feeder. Also no more concentration of bird droppings.

    3. I am interested in how feeding birds may lead to faster local population growth that ‘nature’ then may try to balance. I learned about population growth and food supply from reading Daniel Quinn.

  2. Unfortunately, feeding birds is like welfare: It’s only necessary presently because of habitat (food) loss but creates an unnatural dependency on humans, as well as the listed potential side effects. With no habitat loss, winter feeding would be entirely unnecessary. How did birds survive the millennia before humans began feeding? Without the problem, there wouldn’t be the need for a solution. Create more habitat and we’ll help eliminate the problem.

    1. I think the most blatant answer is the introduction of one of the world’s worst invasive species: the housecat. Without humans and their cats encroaching their territory, songbirds and other animals would have a significantly better chance of survival all year around.

      1. I take exception to this comment. I feed anywhere from 10 to 20 ferals at my home in DC. I have never seen a dead bird. In fact the cats are freaked by the birds. BTW, as the cats join the colony I send them through a TNR program where they are spayed/neuterd and vaccinated for Rabies and FDV.

        1. Pam:

          Due respect — and I’m a big lover of cats — but the impact of both feral and domestic house cats on wild bird populations has been very well established and is beyond question at this point (I link you to an excellent NY Times article on this topic at the end of my reply…see below).

          In fact, there have been NUMEROUS peer-reviewed scientific studies by PhD biologists and ecologists that have established without any doubt that both feral and domestic housecat populations have had a SIGNIFICANT effect on the populations of wild birds, rodents, and other wildlife. They are stealthy hunters, sometimes/often at NIGHT, so just because you haven’t personally observed one of the cats in your colonies hunting doesn’t mean it isn’t happening.

          Here’s just ONE of the zillions of popular news articles that discuss this and make reference to the scientific studies:

          Fairfax, VA

        2. You do not see any dead birds because they eat what they kill or perhaps unlike most cats who have been known to leave presents ( fresh kills ) for their owners, your cats don’t particularly like you hmmmm.

        3. We don’t have any cats, but I can tell you that the Broad Winged hawk and the Barred Owls take a fair share of birds each and every week . . .

      2. I agree totally. Four cats moved in next door. We stopped feeding the birds altogether….darn it !!!!!

      3. Penelope, Please comment with the research that backs up this claim. I am often hearing how house cats kill so many birds, but what I’ve experienced is them killing the slow, the weak, the disfigured among the bird population more often than the strong. Where is the research on how birds die from other causes? I learned that deer die worse deaths by not having a balance of predators in their environment.

  3. I have read that a great deal of bird seed is chemically treated—that might be a factor, as well.

    1. Yes, I stay away from seed treated with vitamins, etc. I don’t trust it and think it is overkill. However, we have no idea what kind of pesticides are on the seed we buy. It worries me a lot. I do plant flowers that make seed for them, too, but I’m pretty sure I couldn’t afford organic black oil sunflower seed even IF it was available here, which it is not.

  4. The two studies you mention in your article were conducted in England. I rely on U.S. research done on birds of the U.S. and look to Cornell U. and other leaders in the field. It is important to know the cleanliness of the feeders, what food was provided in the feeders, what the habitat was like, etc. It is my understanding that most birds still get the majority of food on their own in the wild, even in winter, and that they rely on bird feeders, that humans provide, as a supplement.

  5. The question we should ask is where does the bird seed come from? Does it come from fields where birds are kept away so they don’t “steal” the seed? If it is so, then many birds suffer so that we can enjoy the sight of birds in our yards.
    It seems that bird feeding does not help birds if we look at the larger picture.
    It would be better to grow plants that benefit birds in our own backyards instead of bringing food from them from distant places. Let us have lo cavore birds!

  6. One more way to feed birds is letting your native flowers go to seed so birds can eat them. Leaving berries on your shrubs (chokecherries for instance) also provides food into the fall and winter.

  7. I’ve always thought that the feeding was fine while you were feeding but the problem comes when you stop – maybe due to vacation travel nor just losing interest. Then the dependent birds are left helpless.

  8. While this post focused on the benefits and detriments to the fed birds, I’ve also heard that there are impacts to the larger ecosystem as birds shift their diet from their “natural” food source and the seed we put out. Any thoughts?

    1. PS: Just want to add:

      To post this article, which is based on only two studies, each with small sample size, and each focused only on one species, is unnecessarily alarmist.

  9. the birds seem to come to our feeders less when their is plenty to eat naturally. Could it perhaps be low quality bird seed, bird seed tainted with chemicals/ pesticides, or unclean feeders spreading disease or bacteria? Most people that put feeders out have no clue that the quality of seed matters and feeders need to be kept clean.

  10. Wisconsin winter bird feeding is bound to differ from Louisiana winter bird feeding. One feed has to be better than another feed.

  11. I found that when I supplied bird seed I had an abundance of jays move into my yard to build nests. When I witnessed a jay carrying a song bird chick towards its nest I began to question whether I was helping the corvid population or the songbird population. And I really didn’t care for the sound of a half dozen jay fledglings fighting over the feeder.

    My yard was much more peaceful without the feeder the next year.

    1. I agree about the jays. My first year feeding I had chickadees nest nearby. I attracted Steller’s and Scrub Jays and then their fledglings dominated the backyard and the chickadees haven’t nested nearby since. I switched to a jay proof feeder so the little birds can get in. The jays still show up to bully them, but leave soon afterwards since they can’t get at the food.

  12. We all want to support birds throughout the seasons and it seems… counterintuitive to argue that winter feeding is not helpful. It seems also disingenuous to propose this as a question, so that people who care about wildlife might worry that they are doing something wrong if they put birdseed out in the winter months. I don’t know if the goal is to drive web traffic, or actually inform better human behavior.

  13. I’ve been feeding birds for many years. It gets very expensive, especially the Niger Thistle, which the Finches can’t seem to get enough of. I buy the Black Oil Sunflower Seed in 50# bags, it seems to be the overall favorite, however, there is a pretty big difference in quality, with the discount joints like Menards, Lowes, etc. selling the really cheap crap, seems you “get what you pay for”, with lots of damaged, and empty shells. It’s the same as with the 50# mixed bird seed which it loaded with corn filler rather than quality seeds. I’ve been feeding shelled peanuts, and peanut butter suet cakes, which the Woodpeckers love. I’ve noticed some of them getting rather obese, and wonder if it’s causing them harm?

  14. I haven’t read the whole article, but am unclear why, if we are doubling the winter survival rate a lower birth and survival rate of chicks the following spring is seen as a negative. I’ve lived in the country a long time, and most populations have a self regulating mechanism. The prairie dog population increases so the foxes increase. Too many foxes and distemper appears. Foxes die off, the hare population increases (where my valley is in this cycle) then the raptor populations increases . . .and so it goes.

  15. My husband and I have been feeding birds for years. We maintain our feeders, cleaning and disinfecting them and we pay to have our feeders filled when we are away on vacation. Our yard is also a certified NWF habitat so our gardens, trees and pond provide the natural food and habitat for the birds, the feeders are supplemental and we believe help to maintain our feathered friends in harsh winters. We purchase our seed locally grown without chemicals. We feed everything from Wrens to Crows and even have a female wild turkey that eats off our front step! It’s hard to believe this could be harmful to the birds. Our feeders allow us to enjoy and respect wildlife. Perhaps it’s a give back for taking so much of the natural habitat from the animals.

  16. Has anyone considered the cause of lower bird-birth-count in places where humans winter-feed them might be due to the chemicals/preservatives in the bird food?

    Organic bird food is like human organic food: a LOT more expensive!

  17. I saw a robin carrying a headless hatchling, of unknown species, to wherever… (it dropped it in front of me.) All they want to do is survive and feed their young. No species of birds are “evil,” no species of birds are “mean.” It’s all about what they need to do to survive and take care of their young. Just like humans.

    Feed the birds and mammals, and enjoy watching these animals live each day. It’s the least we can do to give back what humans have destroyed of their environment.

    “Lots of people talk to animals,” said Pooh…”Not very many listen, though,”

    LISTEN to them, RESPECT them.

  18. Great article. Seems another point needs to be addressed: long-term vs. short-term. It may have some negative short-term aspects, but the long-term benefit of keeping perhaps millions of ordinary folks engaged in birds, and there subsequent financial and political support for bird-related issues and organizations, will be lost. I believe the most critical bird ‘habitat’ in today’s world is money and politics. Telling people to stop watching birds at their winter feeders may in fact be a very short-sighted conclusion, one which could ultimately cause their extinction though lack of funding and political distaste for the issue. Perhaps some researcher will ask how much money feeder owners supply to conservation groups? and how much money would be lost — not to mention political enmity that may develope — should they be required to remove their feeders? The worst scenario is that some Senator
    will obstruct conservation funding because of the animus created by short-sighted environmental policies — which is happening right now with Sage Grouse!

  19. Living here in Southern California winter feeding is never necessary. However, some people do like to attract more birds so they feed them. I would be having the same problem as Patty Ciesla with Scrub Jays at my house. The jays are the biggest reason for nest failure that I have when doing NestWatch with Cornell Lad of Ornithology. It would attract them and we have a lot of them. I found a solution to that by feeding by hand! I use walnuts or mealworms. I have a pair of Cal. Towhees and a pair of Oak Titmice that we feed regularly. In the spring I can sometimes get a House Wren to take mealworms and one year I was also feeding her second brood of fledgelings. This winter I am trying to train a Hermit Thrush to take mealworms. I found a big upside to this feeding by hand. The birds more closely associate me with the food. They drop a lot of their fear of us and even when we are not actively feeding they will come by and check us out from just a few feet away, or closer! We get to see a lot of their behavior up close and personal. It’s a lot more fun than seeing them twenty feet away at a feeder. And NO Scrub Jays! Maybe not a good solution for the harsh winters of the East Coast, but in mild climates it’s a fun solution. Go Birds!

  20. I live in the Laurentians and consider that 9 of my 10 acres are for the critters of the wild. Still, I fill my birdfeeders daily with sunflower seeds, and even have a friend do the same whenever I take a vacation. I also hang suet blocks for the birds. Although the area is rife with chokecherry trees, by January the fruit is long gone, and it seems that only the squirrels are interested in the plentiful pine cones.The colder it gets (last night it was -34F0, the more I worry about the birds.

  21. Birds that nest in urban areas are already known to have lower numbers of eggs, and chicks that are less well developed, than birds in rural areas. This is because there are generally fewer insects, larvae, caterpillars etc. in urban areas – especially in neatly kept gardens.

    The survey’s birds with greater access to human feeding are probably in urban areas and the birds with no access to human feeding are probably in rural areas. So the disparity is almost certainly explained by the location and is not likely to be a detrimental affect of human feeding.

  22. A Yellow Rumped Warlber has been coming to my suet feeder in Denver in January. I wonder if it would survive without the suet?

  23. The way i see it is i am just replacing what the land developers are taking away from them everyday by cutting down the trees and taking away their homes.

  24. Considering that humanity has pushed out more habitat that supports birds, I feel that bird feeding helps to offset that in a minor way. “Survival of the fittest” implies unimpeded habitat, or time to adjust. We are killing birds at massive rates, with our glass buildings, deforestation and general disruption. The speed with which we destroy cannot be effectively offset by evolutionary changes, which take time. Feeding a few birds can’t hurt them. I realize it tends to favour the seed eaters, but better them than no help at all. Making bird friendly habitat gardens helps too. And cutting back on pesticides.

  25. While I admit I didn’t read the cited work about the 69% survival of chickadees vs 37% without the birds being fed I wanted to point out that this seems quite difficult to maintain a good quality control for, and so this should not be called a survival rate.

    Birds being fed are of course much easier to observe and much more likely to continue to return to the same area each day. The control group had a 40% return rate, but I wouldn’t call this a survival rate. Certainly if times got tough I would expect almost all species of birds to move entirely or expand their foraging range unless they had a consistent feeder to take advantage of.

  26. Feeders of birds should consider that an open and plentiful food source may cause birds to unnaturally delay their migratory progress southward and become confronted with harsh weather conditions which may jeopardize their short-term survival. Also, these feeders become concentrations points at which interactions and possible disease transmission can occur between species that do not typically come in contact.

  27. I’m interested in your statement that more than 40% of US households and 75% of British households feed birds. Would you please provide references for those figures? I’m interested in human impacts and would like to read more about that. Thank you.

  28. I believe there is value in feeding all who will come to eat, and doing so year round. A choice of foods should be offered, in a variety of feeders, always with plenty of good nearby cover. The result should generally be greater health, greater survival during times when natural food supplies are scarce, better reproduction. I prefer to feed year round, without ever missing a day or letting the feeders get empty. There will always be undesirable outcomes. While feeding is “unnatural”, so is everything else we’ve done to nature. Feeding is small compensation to wildlife for the damage we’ve done to their environment. “Feed the animals” is good advice.

  29. The disturbance of “survival of the fittest” appears to be one consequence of feeding birds during the Winter Months. I agree with comment that siding survival of less healthy birds shall produce statistics affected by inclusion of information skewed by their presence. I do not see this probable impact as absolutely a negative. However, I do agree that feeding stations locations need to be assessed as to optimizing positive impacts; versus, causing relatively unattractive breeding areas being enhanced

  30. I’m curious, has anyone noticed if feeding birds all winter has changed some migrating birds to non migrating birds?

  31. These are only two studies, with small sample size. More studies are needed before any conclusions can be drawn.

    One of the cited studies suggests that it is the quality of the provisioned food matters. When fat sources were supplemented with vitamin E, the negative effects on egg quality were mitigated. Even where this supplement was absent, however, overall population of the Blue Tit species (studied) increased through feeding.

    Here’s a quote from one of the cited sources:

    “Our study is the first to report deleterious effects of provisioning that were carried over from one season to the next. We emphasize, however, that our study focussed on egg phenotypes; it will be important to see how these effects translate into fitness consequences. The mechanism by which these negative effects were generated is of key importance; the provision of energy-rich fat supplements in winter had negative consequences for female egg investment several weeks after provisioning stopped. Yet at the population level, this was mitigated by the provision of fat together with vitamin E. This is the first direct evidence that the specific nutritional composition of provisioned foods may determine whether carry-over effects on breeding performance are positive or negative at the population level. Therefore, where provisioning is practiced as a conservation tool, careful consideration should be given to the nutritional composition of foods. Whether winter provisioning of garden bird species is considered to be beneficial or deleterious may depend on whether effects are interpreted at the level of individuals or populations. Provisioning may lead to a reduction in average levels of egg quality at the population level. However, if provisioning enables certain low-quality individuals to breed, when they might otherwise have died or survived only as non-breeders, this would clearly enhance their lifetime reproductive success and may in fact boost the overall population size. It is evident that further work at the level of individuals is needed to understand how winter feeding may be used to benefit wild bird populations in the future.”

  32. I live in a midwestern rural area with lots of hardwoods, undergrowth, and open fields so suspect my sunflower seed and suet is more supplemental than essential. I get a wide variety of birds native to the area with few passing through. Been winter feeding birds for 30+ years but the discussion above has about convinced me to stop. When the this bag of seed and suet cakes are gone (160# seed and two dozen suet cakes so far this season),think I’m done. No more participation in the GBBC either. They’ll be out in the woods or at the next closest feeder and I won’t see them to count. If I’m doing more harm than good, what’s the point?

  33. Birds in nature don’t eat beef fat, high in hormones. Millet is a low-quality seed. I avoid suet with beef fat and I don’t give them suet with millet in it. Yes, the suet I give them is more expensive, but I figure it’s better for them. Cheap bird food made with crappy ingredients may be the problem.

  34. I must admit that I feed birds primarily to watch them, so I compromise by putting a small amount of seed (1/2 cup or so) in the feeder every day. It’s not enough to make them dependent on my feeder, but enough to keep them coming back to check for seed.

  35. I have often wondered whether feeding birds detracts from their finding moth eggs, pupa etc of insects we want to keep in check. That would be their normal food but bird feeders are easier and birds are not stupid. Does it have any effect on insect populations? Also of course infections and disease can be spread more easily. The” bringing into the fold” of new bird enthusiasts sometimes outweighs these negatives as they are more likely then to regard protecting the ecosystem as important. It is a delicate balance. We do not want to harm the birds so more research is needed. thanks for engaging in the conversation.

  36. A fourth possibility for the negative effect on breeding seen in the tits is that reproduction may be affected by population. That is, when the spring population is low, the birds are biologically programmed to a higher reproductive rate to replace winter-kill, whereas when more birds survive there is less need for replacements, and reproductive rates drop.

  37. Seems like the balance is for feeding in the MN/WI border area. As always, organic is better. The blue tit studies in the much warmer UK, are not directly applied here. Each year more birds at the feeder from chickadees to pileateds. But keep the information coming.

  38. Every 2 or 3 weeks a Cooper’s or Sharp-shinned Hawk takes advantage of the chance to feed on birds gathered at my feeders. The former is becoming more common; the latter, less so. I wonder why they do not come more often.

    1. Because they don’t just eat at your house! I have a Coopers Hawk that comes by a couple times a month to chase the birds through the bushes. Sometimes he gets one, most times he bashes around in the bushes until he is tired and leaves. If I find dove feathers, he has eaten well. He picks the bird clean and then takes them home so not to mark his nest. The studies indicate they run home feeders like a trout line, moving from one to another to keep the birds unwary. That behaviour is a direct result of home bird feeders, but who doesn’t like raptors? They have to eat also and in the grand scheme of things, their health is an indicator of your health. You are lucky to have one to watch, their antics are priceless.

  39. It seems to me that relying on bird feeders to support winter birds tends to favor some bird species over others and invariably leads to large numbers of “undesirable” birds hogging the feeders (House Sparrows, House Finches, Starlings, grackles, etc.). I much prefer to focus on making my yard a source of food, not only by planting native fruit-bearing and seed-bearing plants, but also and perhaps more importantly, not keeping a “clean and tidy” yard. Leaf litter, fallen branches, and seed heads from summer flowers provide a natural source of food and provide nooks and crannies for overwintering moths, butterflies, and other insects. When I see flocks of birds feeding in my yard and avoiding my neighbors’ yards of manicured lawns and exotic plants, I know I’m on the right track. If more people focused on backyard feeding through providing habitat, I can’t help thinking that would benefit birds (and beneficial insects) more.

    1. I disagree. Compare the number of species that inhabit your area, the birders have counted them for you already. Provide the necessary food and feeders for them and no one gets left out. I have not seen an increase in the more aggressive birds versus the more timid ones, just separate them. They don’t eat the same thing and that is where you can control to some degree the variety of species. If some idiots hadn’t have decided to introduce every species mentioned by Shakespeare, you wouldn’t have near as many of those species but the damage is done and now we live with the starlings. Try moving the feeders apart and smaller stations make for less mass bird mobs swapping parasites and Lord knows what. Don’t forget the ground feeders as well, they have to eat too and don’t like getting too far from their cover. It just takes some common sense.

  40. here in upstate NY right now we have 15 inches of snow in this harsh winter. I feed all types of birds with as all natural (i.e. no blocks made with beef byproducts for instance and you can make your own DIY healthier anyway) with all types of feeders and keep a natural landscape with several bird house. I have water as well and see all kinds of birds. some are bullies in nature and you can see it up close. but overall I think it is a positive impact. cats k)(*ll FAR more birds every day and sometimes you see the gr98usome results but you can only put up so many fences to keep them out anyway and there are NO laws to force people to be responsible owners…so I think positive impact FAR outweight neg. since there are so many other variable (bats for instance here are about wiped out right now from white nose fungus and used to love those and insects now are out of control as well as all kinds of invasive species (here we have asian longhorned ashborer and jap beetle whose grubs are a HUGE nuisance (but STILL keep all 100% garden and lawns since other animals like those as well). milky spore and nematodes largey control them. there are SO many factors we are, as humankind, influencing, so in overall scheme of things, I will keep a variety of birdhouses and feeders and I think it is a net positive (without doing a stat signicant replicable scientific study) and US politicians hate science anyway! so it would be ignored anyway.

  41. Hold on here a second, once again, we are being mislead by what probably will turn out to be a data anomaly. Two studies against several hundred to the contrary is a reason to do more study, not make dire predictions. We capture and band our birds to do a SCIENTIFIC study of whether or not feeding affects numbers and without a doubt, it makes more birds, period. Diversity comes from providing the needs to as many of your birds as possible, expensive, maybe, worth it, no doubt. Because people have invaded their environment, the balance is tipped against them. Oh and by the way, a bit of layena or other chicken food supplement will add calcium to their diet and make stronger eggs, yes, it has been studied. Common sense, which seems to disappear every time this discussion happens, would dictate there is a way to overcome the few problems with feeding versus the benefits. For me it is obvious, I feed my birds!

  42. None of those studies takes into consideration the bird populations on the land devoted to growing bird seed. I bet that birds are regarded as pests and kept away from the crops. Bird seed acreage has been growing exponentially in recent years. I am sure this is not good for the birds.

  43. I work at a wildlife hospital near Vancouver, BC. This winter we are recommending people take their feeders down due to an outbreak in salmonellosis in Pine Siskins. Salmonella runs on a four year cycle, and this is the fourth year, meaning we expect to see 100-200 Pine Siskins admitted showing symptoms. With an almost 100% mortality rate, the risk is too great for these flocking birds to spread disease at feeders, even if the feeders are properly cleaned. We also see increases in House Finches with avian conjunctivitis in areas where feeders are available.

  44. We just put up a feeder for the first time this fall. We are retirees who live in rural Vermont surrounded by both conifers, deciduous and fruit (apple) trees. We purchase our feed at the local Feed store in West Lebanon, NH, just across the river from where we live. We hang the feeder off of the deck on a pole so that vermin won’t be able to visit, however, we have a red squirrel that runs around the deck floorWe’ve been pleased to see chickadees, nuthatches, titmouse, junco, blue jays on a regular basis. Occasionally we will see a cardinals, both male and female, although the female seems to be the better eater. Both redheaded and hairy woodpeckers also visit, but usually when the others are not hogging the feeder. The birds stayed away for a few days after we saw the squirrel. Could that be why? Also wild turkeys and wintering Canada geese are around. Live in Quechee, just down the road from VINS.

  45. I’ve been feeding birds on my one acre backyard for over 23 years, it is a sanctuary for wild life, tons of flowering plants have been planted over the years to feed and maintain their life style, it’s been a trial of errors figuring out what to plant and not as between the chipmunks, squirrels rabbits and an occasional deer they can really wipe out a landscape masterpiece in one evening. I feed seed mainly thrown on the ground at different places thruout the sagebrush and around trees, away from the main yard, feeding in the brush gives them sufficient cover from the predatory birds that hunt them which I have witnessed on occasion, 😞 But that’s nature. Anyway I can really babble on about all ” my” wildlife, I enjoy it and I don’t feel like inhibiting their natural environment.

  46. We have found that supplemental winter feeding in our area of southeastern Pima County, Arizona, has produced larger egg clutches and higher numbers of healthy, viable offspring among our local Gambel’s quail, cactus wren and house finch populations.

  47. As a long-time contributer to Cornell projects (on and off for more than 18 years; I once *meticulously* maintained a high of 15+ feeding stations on our 5-acre “certified wildlife habitat” property for ~8yrs for Project Feederwatch), and student who loved ornithology, systems thinking, and forest ecology studies in college (B.S. Env. Studies, UNH), who later worked for a very popular birding store for several years, and eventually became a trained speaker on wildlife conservation topics for UNH Cooperative Ext and NH Fish & Game, my opinion is it all depends on what you’re using for seed, whether you cycle on and off properly, and how sanitary you keep your feeders. Low quality, i.e. “cheap,” seed from big box stores, fed 24/7/365 in poorly maintained feeders, whether it’s NBD or not, is bigtime bad for birds, primarily in terms of disease, but also in terms of interfering with nature in general.

    Thanks for the article. I appreciate the attention paid to the other habitat-related issues.

    J. Eno
    Greenland, NH

  48. If our gardeners planted more native plants and shrubs, the birds would have a better chance of finding natural food sources in the winter. If our gardeners left their spent plants standing through the winter, our birds would have an opportunity to pick at the seeds. We are taking away the open areas where birds can feed. We manage our gardens so they look good without a thought about natural habitats. We need to support birds somehow as we continue to take away their habitat. Research points one way, then another in many studies. I’m going to carry on and wait for more definitive recommendations.

  49. I live in SE Michigan in a semi-rural area near a lake. There is a wild area behind our property that is mostly wooded . I have a feeder pole at the back of my yard and I keep it stocked most of the year and all of the Winter. I have a suet feeder , a thistle feeder and a regular seed feeder. My regular feeder holds about 3 pounds of seed and I sometimes fill it twice a day. I get a wide variety of birds but mostly Sparrows of course. I get Cardinals , Finches, Chickadees, Doves. BlueJays , and Woodpeckers too.

    And plenty of squirrels on the ground. My metal pole is too slippery for them to climb …I finnaly won that battle. I feel that the sheer amount of birds I get tells me that my location is important . I don’t like the expense but I enjoy seeing them and feel good about feeding.

  50. Another strong possibility is that bird seed is probably produced using pesticides.

  51. Hi, My husband and I live in Riverton, Wyoming.
    we began feeding birds in late fall of 2014 and continued through spring2015 . In fall 2015 we began again and are still feeding. Habitat is good, year round water and lots of vegetation. I am beginning to think it may not be a good idea to feed. We have tons of common sparrows and some races. But this year I have seen NO chickadees!! Is it climate change or is it my over feeding the sparrows?

  52. I heard that if you feed the birds all summer you must feed them in the winter. Is it best to just feed them in the winter and let them fend for themselves in the summer?

  53. Could there be a parallel with other creatures who tend to produce more offspring when they are over-hunted or have high losses do to adverse weather, lack of food, or loss of habitat? The coyote comes to mind. “Adapt to survive”.

  54. There is another important aspect to the impact of bird feeding: the birdseed may be grown using large scale monoculture agriculture, with all the attendant consequences. This kind of agriculture replaces birding habitat with a very limited environment which may support a few migratory birds, but probably not the birds that would thrive in a more diverse habitat.

    So I feed, but I worry 🙂

  55. Interesting speculation about herbicides and pesticides in feeder seed…but how about the big picture with regard to lawn and garden care? If we are luring birds into the yard with food and habitat for our viewing pleasure, I think it’s prudent to ditch the residential chem use so prevalent in hopes of achieving that “monoculture golf course” look many desire. Non-toxic lawns with 39 different plants growing in them are actually interesting to me and the beetles and grubs living in them provide a nice balance of real living protein for birds visiting the seed feeders. Nothing like backyard birds taking Cotinis nitida in flight, it’s a pleasure to watch.

    Not denying the possibility of feeder nutrients alone being responsible for some of the negative data noted in studies, but I’d like to see a broader consideration of factors potentially responsible for such effects. Lots of nasty stuff can jump into the food chain when human activity in an area is considered and analyzed, every spring those lawn care flyers are mailed to any house with more than three blades of grass growing. Nearby agricultural use of chems and effective concentrations required? Wow! It’s scary for human health, too.

    Could be that the feeder seed is the safest stuff around and it’s everything else we do that causes the problems in residential areas. Even after years of providing seed, I notice a huge shift in foraging behavior when live protein is available in the area thus skeptical of the “diet training” theories pertaining to birds. A midwinter stonefly hatch will result in backyard feeders being completely ignored by most every species as they head to the creeks to gorge themselves. Birds seem to exploit near every food source imaginable in an area and some we don’t even think of, thus it’s difficult to narrow down the problem.

  56. Sooooo, To feed, or not to feed must be the question…..what do you suggest???

  57. Hi Joe, very useful information, thanks. I think you may be right that the studies showing negative impacts of feeding birds may be influenced by a number of factors. We find that if birds are fed a varied and balanced diet then they generally thrive and create a long-lasting colony. It may be that some commercial mixes are too high in fillers/carbohydrates and not high enough in proteins and minerals. We find that for the winter, mealworm rich mixes, niger seeds and nuts aid in the local bird population’s survival.

    On another note, trying to promote people helping our native greenfinch populations here in the UK which are showing alarming declines, would be great if you could share


  58. I thought it would be good to join the feeder watch, since I have seen some very unique birds for my area of the country. However, I object to having to pay a fee for giving you free data.

  59. Thanks for the great, informative article. We’re trying to educate the public here in Australia about the best practices of wild bird feeding. It can be a contentious issue down here, mostly due to the lack of information and knowledge.