The first hummingbird feeder I got can hold a cup of sugar water and has enough spots for eight hummingbirds. It hangs outside my kitchen window. I imagined doing the dishes while watching squads of eight little hummingbirds as they swooped down to perch and suckle nectar, shoulder to feathery shoulder.
Instead, only one bird visited the feeder at a time. That bird would take a furtive sip, then look back up at the sky. As soon as he bent for another sip, a second hummingbird darted down like a dive-bomber and chased him away. Hoping to give peace a chance, I hung another feeder around the side of the house. This feeder has spots for four birds. But the dive-bombing hummer who had chased every rival from the kitchen feeder had no intention of sharing this one, either. He took up a high-ground position on the telephone wire, where he guarded both feeders at once and proclaimed his territory with a buzzy “tik-tik-tik-tik.”
Then I learned about hummingbird territoriality from Hummingbirds: Their Life and Behavior, by Esther Quesada Tyrrell. That’s when I gave up the naive hope of watching hummers play together nicely.
“On many occasions we have seen humming birds go straight for the eyes of enemy hummers with their bills in an attempt, perhaps, to pierce or gouge them out. … If the feuding pair is close enough, it is possible to hear the loud smack that results when they collide.” In one of the book’s photos, an Anna’s hummingbird hovers in midair above another bird resting on a branch. The bird in midair reaches down with his sharp toes and yanks the sitting rival off his perch.
Low-level skirmishes like this take place all year around the hanging feeders in residential neighborhoods. In the backcountry, a territorial war erupts once a year, when the first wild flowers bloom. The hummingbird battles around Grizzly Lake in northwestern California, for example, were chronicled by University of Oregon student Clifton Leroy Gass. Gass spent the summer in the mountain meadows there in 1973 collecting data for his Ph.D. dissertation: “Meadow 3 had less than 500 flowers and no hummingbird territories on July 11,” he wrote. “By July 15 it had 3,165 columbine flowers, 135 paintbrush inflorescences, and 15 territorial (rufous) hummingbirds.”
Gass represented the data in scale maps he drew of the birds’ territory. An “X” indicated a bird’s perch, and curved arrows radiated out from that perch to show a bird’s flight paths. Arrows indicated flights to flowers or sorties to intercept intruders.
Gass found that the birds continually adjusted the size of their territories in a struggle to balance nectar intake with energy output. A large territory is essential because the nectar available in a single flower is minuscule; it takes 60-80 flowers to yield a single drop. And if a rival bird sucks the nectar out of a flower first, it takes 24-48 hours for the flower to regenerate the next fraction of a drop. But the bird’s territory becomes too large if that bird burns more fuel feeding and patrolling than it can take in. The birds’ speedy metabolism consumes the small amount of nectar in their tiny bodies so quickly that hummingbirds generally zoom around on the brink of starvation.
Of course, the energy-resource equation is drastically different for the birds around my house; I provision them with two bottomless nectar fountains. If the birds declared a truce and went on a communal bender to suck my feeders dry, I’d replenish the feeders as fast as I could. How come they can’t appreciate the bounty?
It must be the primordial anxiety shared by all living things: There seems to be never enough. No matter how rich the environment, the population of living things inevitably expands to the “carrying capacity,” the maximum number of individuals that environment can safely accommodate. To be alive is to inhabit a narrow “fortunate zone” where you expect competition and worry that scarcity will eventually close in.
This has always been true, at least until we humans learned to manipulate the environment. In many countries, we now can reliably produce enough to live comfortably, but for some of us, the problem then becomes one of consuming too much or hoarding. Like the hummers, we can’t shake the worry that there won’t be enough stuff around next time, or that we should have more good things on hand, or that we might be able to get a better version of whatever it is we need, or that (perhaps most terrifying of all) somebody else might be trying to take away what’s ours. We are smart enough to produce the abundance. Are we smart enough to share and sustain it?
Meanwhile, I’m a slave to my feeders and to those voracious little dive-bombers.
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