Simple chickadees observe a complex social hierarchy

4/24/2015 | 0

Missing toes on the right foot make this Black-capped Chickadee easy to distinguish. Photo by Laura Erickson.

Missing toes on the right foot make this Black-capped Chickadee easy to distinguish. Photo by Laura Erickson.

I’ve been hand-feeding mealworms to Black-capped Chickadees in my yard for many years, so I’ve had extraordinary opportunities to observe their behavior.

They’re not banded or color-marked. I recognize only one individual with certainty, the one missing the front toes on its right foot. When it alights on my hand, the stump gives it a feel different from that of the others. It was also the first to start grabbing two mealworms per trip, and now it often tries to take three, sometimes succeeding. Almost always, it follows the same path when it flies off, alighting on the same branch in the same tree to eat.

That particular chickadee often stares at me from the roof of a window feeder until I fetch the mealworms. It then flits off to a nearby branch as I crank open the window. That’s also when social interactions among my chickadees become interesting.

If no other chickadees are near, my stumpy guy comes to my hand and leisurely sorts through the mealworms. But it apparently holds a low social position within the flock. When others are around, as soon as my hand appears with the mealworms, dominant chickadees start making gargle calls that sound sweet but mean “Scram!” And even though it was the stumpy-footed bird that caught my attention in the first place, it has to bide its time until the higher-ranking chickadees have fed.

It may seem outrageous to us humans that the plucky little bird whose actions were essential in providing a food source must wait while all the other chickadees forage without having done anything. We’re tempted to apply anthropomorphic words like bullies to them. Of course, my sympathy for the chickadee with the injured foot makes me think it’s “plucky” and deserving of the first meal, chickadee social systems and flock dynamics notwithstanding.

Nutritious mealworms

If you purchase live mealworms in bulk, packaged in wads of newsprint, transfer them as quickly as possible to a non-toxic, nutritious medium such as oatmeal or a professional mealworm medium, and add potato peels or cut potatoes to provide moisture. In nesting season, I keep the mealworms in oatmeal supplemented with a few tablespoons of a powdered baby bird hand-feeding mixture from a pet shop. It makes the worms richer in calcium and vitamins.

Other flock members seem recognizable by their behaviors. A chickadee whose assertive gargle seems to send off all others is among the lightest in weight. One of the heavier birds often alights on the windowsill, vocalizes, and taps the glass to catch my attention. It jumps onto my hand even as I’m opening the window. Other chickadees gargle at it, but it either disputes their assessment of their relative rankings or dismisses social norms altogether. Is it a maverick, or am I missing crucial information about the flock? It would be wonderful to know.

I can’t help but dream up soap-opera story lines about the birds, but even without anthropomorphizing their individual characters and motives, the reality of their lives in the frozen north, and their strategies for surviving in cohesive flocks with a minimum of aggression, are endlessly fascinating. — Laura Erickson

Laura Erickson’s column “Attracting Birds” appears in every issue of BirdWatching magazine. Subscribe. This article appeared in the June 2015 issue. Laura is co-author of Into the Nest: Intimate Views of the Courting, Parenting and Family Lives of Birds and National Geographic Pocket Guide to Birds of North America, and she is the author of Laura’s Birding Blog. In February 2014, she received the American Birding Association’s highest honor: the Roger Tory Peterson Award.

BirdWatching Contributing Editor Laura Erickson

BirdWatching Contributing Editor Laura Erickson

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RELUCTANCE
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DOING GOOD
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MOMENTS OF GRACE
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Meet Laura Erickson at the Cornell Lab of Ornithology, Ithaca, New York, on Monday, May 4, 2015.