Dining has its dangers. And I don’t mean indigestion or choking on a bone. I’m talking hazards for the local seed-eating birds—the doves, quail, sparrows, juncos, and finches that check out the seeds that I scatter on the ground each morning.
Winter’s icy chill has descended on this part of Arizona, and recent snow has frozen into a crunchy crust. Little soil is exposed, and even the shrubs continue to bear heavy blobs of snow. These are lean times for seed-eating birds; there is no dietary margin for error. Find enough to eat or die.
The birds flock into my yard, a veritable winter cornucopia of mixed bird seed, suet, peanut butter, and nectar (though it’s challenging to keep the hummingbird food thawed). For most, it’s scramble competition for food, and the birds are have to be efficient to get their share. For a few, notably the brash Western Scrub-Jays and scimitar-billed Crissal Thrashers, a little bullying goes a long way.
But even as the seed-eaters concentrate on finding and consuming as many little bits of energy as they can, they cannot relax their guard. Their furious activity makes their mixed flock highly visible for a long way, and there are predators that haunt these acres.
Fortunately, a group of many birds means many eyes. Suddenly there is a sharp alarm call, and the birds scatter in every direction, many disappearing into protective thickets of oak or manzanita, while others take off in beelines for distant shelter. A winged missile strafes the thickets, misses, and settles into a pinyon. It’s an adult Cooper’s Hawk. It gazes intently into the shrubs for signs of an over-exposed feathered morsel. If it sees movement, it likely will dive into the thicket, even forcing its way through on foot. This is a fierce bird, not easily deterred from its mission.
Yet most attacks end in failure. It’s not easy to be a predator, no matter how fierce or physically fit you may be. Your food does not sit passively for you to collect it. If seedeaters have a hard time finding food when their diet is plant seeds, then imagine the challenges of capturing food that absolutely does not want to become a meal. Every attack is energetically costly. To kick in the jets for that extra burst of speed is to burn half-a-sparrow’s worth of fuel. To dive into a thicket of plants armed with sharp branches risks injury, and an injured solitary predator operates with a handicap that can hasten starvation. It may be more satisfying to dine on warm breast of titmouse or thigh of thrush than on cold, hard seed of sunflower, but it’s a riskier strategy.
In addition, the accipiter has no friends (not that I think it worries about it). One chilly morning, an immature Cooper ’s Hawk, not yet decked out in the fine attire of an adult, landed in the yard in a sunny spot, a place to bask in the warmth of early solar rays. Comfort was its concern, not food, and all the neighborhood critters seemed to know it. A Rock Squirrel not 20 feet away took its own solar warm-up, and a Cliff Chipmunk scooted under the hawk without eliciting a quiver of interest. A jay, omnivore himself and no innocent to predation, did take interest and mobbed the hawk, screaming bloody murder and strafing the hawk in a blur of blue. To the hawk, this was mere nuisance, a minor annoyance. A dozen Bushtits foraged in scrub oak, lisping sweetly and without fear of the predator a few yards away. A basking hawk is no threat, but when hunger gnaws at its bony breast, the raptor becomes a killing machine that commands the utmost respect. (Boy, it’s impossible to describe this without becoming anthropomorphic, but I trust you’ll forgive the slip into projecting emotions onto these birds; look one in the eye when it’s hungry, and you’ll do the same).
Though successful attacks can be few and far between, they obviously do occur, and to witness them is to share in the rare but vital drama of natural selection in action. We omnivorous humans eat all over the food web, but sometimes we are at the highest trophic level, and the hunter instinct still stirs us at times. To the hawk, it’s always up there at the top of the food pyramid, energetically that lonely pinnacle, giving it figurative as well as literal right to look down on its prey.
Unable to be inside unless I am near a window, I have seen my share of successful attacks. I’ve watched Cooper’s Hawks take doves, quail, a flicker, and a young robin, the latter not long out of the nest and experientially naïve. The robin was in a tall pine outside my study window, maybe 25 feet away. The hawk appeared out of nowhere, and the robin panicked, flying blindly into the side of the house, knocking it to the deck for a moment. It collected its wits a bit and hopped up on the window sill a few feet from me. It huddled there even as the hawk landed on the metal fence at the edge of the high deck. The hawk stared. There was its intended meal, and right behind the prey was a huge, hairy human staring right back. A minute passed, then another. Stalemate?
But no, the hawk would not be deterred from young Turdus. Suddenly it crouched slightly, then shot to the window sill, grabbing the robin with one foot, giving me the evil eye for an instant (or so I believed), and dashing off to a favorite pine snag, where its talons squeezed the last life out of the fledgling. Then the plucky bird began (what else?) plucking its prey.
The Cooper’s Hawk seems to have adapted well to living in proximity to humans. Every neighborhood with decent cover and good populations of small birds will have one. These raptors are common in Tucson, where the reliable food supply allows them to have larger clutches, more energy for more eggs. Yet urban or suburban living has its own dangers, and in some cases, those larger populations may actually be what biologists call “sinks”—areas where higher mortality actually can exceed production of young. Those country birds with their smaller clutches might actually be providing the immigrants that keep the city populations high. Without rural flight to the cities, the populations there might decline and disappear. This is something to keep in mind as we convert more and more open space to the built environment. The wildlife that we enjoy might be dependent on those pockets of wildness nearby, just as many of us are dependent spiritually on them.
Cooper’s Hawk? I don’t really care that Cooper may have been a good ornithologist, good enough to have an ornithological society named after him. “Cooper” doesn’t do this bird justice. Maybe Accipiter terminator or Accipiter assassini. I’m just glad that I don’t have to keep looking over my shoulder as I eat! With lions, hyenas, and leopards on the prowl, my distant ancestors would have had to have been as cautious as are the towhees and goldfinches in my yard today. It’s easy to empathize.