It appears that backyard birding has replaced bowling as America’s new pastime of choice. Most families have left bowling behind in exchange for more healthy pursuits such as biking, jogging, power walking, working out and yoga. It seems backyard birding has joined this shortlist now that COVID-19 has boxed us in. And bird-feeding is the rock upon which backyard bird appreciation is founded.

Some 57 million Americans feed the birds. Americans spend $4 billion on bird seed each year (about a billion pounds of seed). Given how little a seed weighs, that’s a lot of seeds! In addition, millions of pounds of suet are deployed for the birds each year. These cakes of fat (some with seeds or mealworms embedded inside) are a huge draw with many birds — especially the woodpeckers. Clearly, today bird feeding is a big business.

As with any big business, worrisome questions arise. Does it make sense to be investing billions on supplementing the nutrition of wild birds, when more than 45 million Americans report going to bed hungry at least once a week. Is this a proper alignment of our charitable priorities? I suspect that if we can afford to feed the birds, we probably can afford to help feed our fellow Americans, but that is a whole different discussion.

What becomes obvious with some consideration is that our feeding the birds is a massive, unintentional experiment being practiced on our nation’s birdlife — perhaps the largest and most pervasive field experiment ever performed in history other than our better-known ongoing experiment altering the chemistry of our earth’s atmosphere through civilization’s massive emissions of carbon dioxide and other greenhouse gases.

In what way is bird feeding an experiment? We are offering daily nutritional supplements to free-ranging wild animals that inhabit our neighborhoods. Some of this food provisions rats, chipmunks, and squirrels (especially the last), but let’s just focus on the birds here. For better or worse, the unconstrained provisioning of seed and suet impacts the lives of individual birds as well as the livelihoods of entire bird species populations. Studies have shown, for instance, that the population of our beloved northern cardinal has both increased and geographically expanded over the last few decades, apparently a result of decades of bird feeding.

The example of the cardinal supports the obvious assumption that feeding the birds is a beneficial activity for our feathered friends. There is no doubt that providing sunflower seeds for a Carolina chickadee on a chilly winter day must help that little songbird stave off the cold during the long night that follows. But what other influences might feeding have?

Bird feeding has the potential to impact the health, reproduction, behavior, demography, seasonal migration, and geographic distribution of particular species. And by impacting one species, we are probably impacting the way this species interacts with other species, creating cascading ecological effects throughout the bird realm. I can explain this using a single hypothetical example.

Witness the blue jay. This familiar feeder visitor ranges from Quebec to Florida. Like the American Robin, this is a species in which most (but not all) individuals of the species migrate southward in winter. In addition, the jay is a crow-relative, and, like the crow, is a nest predator — taking eggs and nestlings of other songbirds. Some populations of blue jays that normally migrated south in winter now remain in northerly habitats, subsisting on the provender of backyard feeders. Moreover, many local blue jay populations have increased with the winter bounty of food (winter being the season when most birds meet their maker). Good for the blue jay!

But enhanced populations of the blue jay might cause the decline of another species, the wood thrush, a forest-dwelling songbird famous for its flutelike song. The blue jay is an important predator of the nest and eggs of many birds, such as wood thrushes. So, without knowing it, our feeding of blue jays in winter may indeed lead to the population decline of the wood thrushes that nest in the DC area each summer — an unintended consequence of our feeding the birds.

Here are some other potential unintended impacts to consider: birds sharing virulent diseases at feeders (West Nile virus, conjunctivitis); cats and hawks preying preferentially on birds rendered vulnerable when at backyard feeders; birds regularly striking windows when being flushed from a feeder by a predator; birds’ diets being altered by lipid-rich offerings from feeders; and birds becoming overly dependent upon feeders for their daily feeding regimen. The reader may think these are minor issues for our birdlife. But recall, for instance, that free-ranging cats alone kill more than a billion birds every year in North America.

An alternative to putting out seed and suet is to plant one’s yard with native trees, shrubs, and vines that produce food for the birds. This is a long-term intervention that can produce long-term benefits to the birds, without fostering the artificial impacts mentioned above. For instance, native oaks not only produce crops of nutritious acorns in autumn, but also foster native caterpillars in spring, which are important prey for warblers and chickadees preparing to breed. 

We feed the birds for one simple reason — this activity brings us joy. The birds that come into our yards are little missionaries from Mother Nature, giving us a direct link to the natural world around us, especially in a time of pandemic. If engaging with our neighborhood birdlife increases our awareness and appreciation for the natural world, that is a good thing. But it’s time to face the fact that we really do not know the multifarious effects of bird feeding — a mammoth and unconstrained experiment on hundreds of millions of birds across hundreds of thousands of square miles. It’s time that research scientists got to work studying the impacts, both good and bad, of feeding the birds in our backyard. And, moreover, we ourselves need to spend a bit more time thinking and taking action to address food insecurity in America.

Bruce Beehler is a local naturalist and author of 12 books, including “Natural Encounters,” and “Birds of Maryland, Delaware, and the District of Columbia.”

Published on Feb 09, 2021