With the recent snow has come an increase in bird activity at our feeders and the small patches of open ground we’ve cleared under them. When all the birds are trying to access the limited space available, it’s not surprising that there seems to be more situations in which one species displaces another and takes over the feeding opportunity. How often does the feisty Carolina wren drive off a house finch? What about a house sparrow? What happens when a blue jay makes an appearance? Or a downy woodpecker? Who wins the fight for the suet between a downy woodpecker and a hairy? How does the black-capped chickadee fair in competitive interactions at the feeders?

To answer some of these questions, researchers asked participants in the Cornell Lab of Ornithology’s Project FeederWatch to record the winners and losers of such competitive interactions, when possible. They came up with a unique dataset that allowed them to construct the first-ever dominance hierarchy for 136 species of North American birds that frequent backyard feeders.

This first of a series of research papers from the dataset was published in 2017 under the wonderfully descriptive title: “Fighting over food unites the birds of North America in a continental dominance hierarchy.” 

It won’t shock even the most casual of bird observers to learn that they found that the largest birds were at the top of the list of most dominant. Anyone who has wild turkeys coming to feed in the backyard knows there aren’t really any other birds that will tangle with something that big! And, yes, wild turkey was at the very top of the list from the 2017 paper.

Other larger birds that were among the most dominant included ravens and crows as well as Canada goose and mallard. There were some oddities in there, too, of birds that don’t occur as often at backyard feeding stations like great blue heron and herring gull.

Certain birds occur higher in the dominance ranking than expected based solely on their size. One of the best examples is within the woodpeckers. There are 13 woodpecker species in the top 50—that’s above blue jay and red-winged blackbird. There are 12 woodpeckers listed as more dominant than European starling (though not our familiar hairy and downy woodpeckers). The authors guessed that the proportionately long beaks and strong pecking abilities of woodpeckers made them formidable foes in competitive interactions even for larger birds. Within the woodpeckers, hairy woodpeckers do dominate over the smaller downy woodpecker.

Small birds dominate the bottom of the list, with species like black-capped chickadee—despite their feisty reputation—and American goldfinch at the bottom of the pecking order. Carolina wren is shown as below house sparrow, song sparrow, and white-throated sparrow in the dominance hierarchy but above tufted titmouse and house finch. We were surprised to see song sparrow listed above white-throated sparrow and house sparrow, considering it is smaller than the latter two species. It’s made us want to watch more closely to see if this holds up at our feeder!

The authors note that there are exceptions in individual cases and that there can be geographical variation and likely seasonal differences in how birds interact as well. Still, this first-of-its-kind dataset is very revealing, and scientists are probing it for even more fascinating results.

The question of who was most dominant at the feeders in our yard is often resolved by the arrival of a furry creature who displaces the birds in all directions—a gray squirrel. But then there is at least one bird we’ve seen that scatters even the seemingly fearless gray squirrel, and that is the Cooper’s hawk. That’s true dominance.

Jeffrey V. Wells, Ph.D., is a Fellow of the Cornell Lab of Ornithology and Vice President of Boreal Conservation for National Audubon. Dr. Wells is one of the nation's leading bird experts and conservation biologists. He is a coauthor of the seminal “Birds of Maine” book and author of the “Birder’s Conservation Handbook.” His grandfather, the late John Chase, was a columnist for the Boothbay Register for many years. Allison Childs Wells, formerly of the Cornell Lab of Ornithology, is a senior director at the Natural Resources Council of Maine, a nonprofit membership organization working statewide to protect the nature of Maine. Both are widely published natural history writers and are the authors of the popular books, “Maine’s Favorite Birds” (Down East Books) and “Birds of Aruba, Bonaire, and Curaçao: A Site and Field Guide,” (Cornell University Press).