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Birds Often Bully Each Other at Backyard Feeders

A blue jay landed atop our largest birdfeeder 20 feet past our kitchen window, settling 8 inches from a red-bellied woodpecker eating a sunflower seed.


The woodpecker paused, looked up and bristled to its full height. At risk of sounding anthropomorphic, I thought its body language was asking the blue jay, “What the #&@# are you doing in my space?”


For its part, the jay seemed quizzical, as if teasing and taunting to see how far it could test the woodpecker’s patience.


I paused my dishwashing to watch, wondering if the tension would erupt into a feathered version of “Fight Club.” Nope. Seconds later the blue jay flew off, as if suddenly remembering an appointment elsewhere. The woodpecker relaxed and refocused on the sunflower seed.


Although that encounter went as expected, I never assumed the blue jay would flinch first. I’ve seen feeding red-bellied woodpeckers fly off the instant a jay landed, almost as if to say: “Pfft. Go for it. The eagle doesn’t hunt the earthworm.”


Yep. Just another day at the birdfeeder.


It’s rare to watch feeding birds for long and not see some bullying, sparring and back-biting. Bigger-bodied birds usually persuade smaller birds to flee, but not always. Sometimes flocks of sparrows stand their ground against bigger individual birds, and other times one belligerant blue jay makes every bird flee the ’hood.


You want peace, harmony and free love? You won’t find it at birdfeeders, especially in winter when food supplies can be tight and confined. To better understand the dominance hierarchy of birds, researchers at the Cornell Lab of Ornithology recently worked with Project Feeder Watch to collect bird-behavioral data from the program’s roughly 20,000 participants.


The research was led by Eliot Miller, who shared his findings in a January 2017 paper titled “Fighting over food unites the birds of North America in a continental dominance hierarchy.” Miller analyzed 7,653 observations of bird conflicts filed by those citizen scientists, and then ranked the fighting spirit of 136 bird species.


Miller’s computer analysis gave each species a “fight score” that describes their ability to compete. Wild turkeys scored the highest, earning a bullying 66.93, while Eurasian tree sparrows scored the lowest, a meekly -24.47. https://www.allaboutbirds.org/news/when-136-bird-species-show-up-at-a-feeder-which-one-wins/


Other noteworthy birds received these fight scores: ravens, 38.19; red-bellied woodpecker, 4.1; European starling, 3.1; hairy woodpecker, 2.4; blue jay, 2.3; Northern cardinal, -0.6; downy woodpecker, -0.64; Eastern bluebird, -0.84; house finch, -3.2; dark-eyed junco, -3.4; gold finch, -4.9; and black-capped chickadee, -5.1.


Miller’s analysis found that a bird’s size and weight are important, but don’t always predict its fighting spirit. Warblers and orioles, for instance, were more dominant than expected based on their body mass; while buntings, grosbeaks and mourning doves were less dominant than expected. He also found that hummingbirds are pugnacious, and aggressively defend favored flowers against other hummingbirds.


Not surprisingly, most woodpeckers punch above their weight class, perhaps because their heads and heavy bills are built for hammering, and their claws can cling to just about anything in any position. As a group, woodpeckers are some of the most dominant birds found at feeders. Therefore, even obnoxious, foul-mouthed blue jays routinely back down from hairy and red-bellied woodpeckers when alighting on the same feeder.


Again, though, you can’t assume the bird with a higher fight score will dominate those with lesser scores. Ravens dominate every one-on-one matchup with crows, but ravens often work alone, while crows form gangs to get their way and control turf.


Miller said other dominance patterns are “triangular.” In an Cornell University article by Alison Haigh, Miller said the house finch typically dominates the purple finch, and the purple finch dominates the dark-eyed junco, but a junco typically dominates a house finch.


Miller also said red-headed woodpeckers, red-bellied woodpeckers, and European starlings often find themselves competing for nesting cavities in trees. The woodpeckers might have figured out a workable dominance system eons ago, but starlings—an invasive species—complicated things by crossing the Atlantic for centuries with European immigrants.


Dominance hierarchies might also help dictate a bird’s range. Miller said red-breasted nuthatches, which score -3.5, might be able to breed farther south in higher numbers, but we’ll never know for sure because they can’t compete with the white-breasted nuthatches (-2.51) already living there.


Some folks, of course, see birds bullying each other at feeders, and want to call 911, hire a bird therapist, or put select seeds in different feeders to segregate the species. So-called bully birds typically like milo, wheat, millet, cracked corn, sunflower seeds and seed mixes. Therefore, some birdwatchers fill feeders with safflower seed to attract cardinals, and nyjer seed for finches. Those seeds also attract chickadees, nuthatches and grosbeaks.


Still others install wire-cage feeders, which not only baffle squirrels, but let small birds feed in peace while keeping out bigger, more aggressive birds.


Personally, I don’t worry much about bullying birds. Nature is a bird-peck-bird world, and our feathered friends seem to thrive on insults, threats and physical harassment.


Until they start writing mean tweets, and conspiring with Russian birds to corrupt their elections, how bad can they really have it?

Red-bellied woodpeckers, as well as most woodpecker species, aren’t easily intimidated by other birds of similar or larger size when eating at backyard birdfeeders. -- Patrick Durkin photo

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