Home & Garden Columns
Predation: where would Animal Planet be without it? There’s not nearly as much drama in browsing.
There’s no question that predators, large and small, are essential players in ecosystems. Kill off the mountain lions and wolves on the Kaibab Plateau and the mule deer multiply like rabbits, eating themselves into a population crash. Remove the coyotes from Californial chaparral, if you can, and smaller predators like foxes and feral cats do in the ground-nesting birds. With the loss of jaguars and harpy eagles, rainforest fragments surrounded by the waters of Venezuela’s Lago Guri are picked clean by herbivores—howler monkeys, rodents, iguanas—run amuck.
But sometimes you can’t help but be ambivalent about the process: you find yourself feeling for the victims.
This spring a pair of bushtits built their pendulous felted nest in the Lady Banks rose that covers our kitchen window. As the days got longer, I could watch them at work as I did the dishes. Then one day I noticed that the nest had been ripped apart. The bushtits either abandoned the nesting attempt or moved elsewhere.
There were no witnesses, but I tended to suspect the neighborhood scrub-jays. That was reinforced a bit later when I noticed an agitated pair of American goldfinches in the back yard scolding a jay.
The western scrub-jay acquired its hyphen ten years ago when ornithologists divided the former scrub jay taxon into western, Florida, and island (as in Santa Cruz) species. That still leaves a lot of variation in color, size, bill shape, and behavior among westerns, and the splits may not be over yet.
All three of the scrub-jays are nest-robbers. It’s one of those corvid traits, shared with blue, Steller’s, Mexican, and gray jays, not to mention crows and ravens. Western scrub-jays aren’t obligate carnivores; 73 per cent of their food in one California study was of vegetable origin, heavy on the acorns. But they can’t seem to resist a tasty egg or nestling.
They’ve even been known to capture and kill adult songbirds. Some years back Paul Ehrlich observed scrub-jays on the Stanford campus taking down starlings and cliff swallows, pinning the birds with their feet and hammering them with their beaks. A friend in Berkeley tells me he watched a scrub-jay in his yard that appeared to be stalking a Bewick’s wren with malicious intent. Just a couple of weeks ago, another friend saw a goldfinch fly into a window near her seed feeder and fall stunned to her deck, where it was snatched up by a jay.
All this has not made the western scrub-jay, brainy and behaviorally flexible thought it may be, one of my favorite birds.
I don’t make a practice of feeding or otherwise accommodating them. But I’ve been known to make exceptions.
Last week Ron and I noticed that a pair of jays were harassing Matt the Cat when he went outside, diving toward him and scrawking at him. Matt just seemed baffled by the hostility. At one point when he had come inside, a jay followed him to the living room window, perched on a utility wire outside, and continued the invective.
Then our neighbor told us a baby bird was at large in her yard.
That explained the parental behavior. Ron found the fledgling, which was indeed a scrub-jay, its feathers just beginning to come in. It was giving what sounded like begging calls, thin quavering beeps. The adult jays were still hovering around and had been seen feeding it. We couldn’t determine where the nest was.
So what do you do? In hindsight, we probably should have taken the kid indoors overnight, secured it from the cat, and tried to feed it. But since the parents were still involved, we decided to let them take care of it. Another neighbor came by with a cottage cheese container padded with paper towels. We put the scrub-jay in it and lashed the container to a relatively concealed spot in the branches of a Japanese maple. I went back to the evening dishes.
And in the morning we found the bird dead. Exposure? Starvation? Injuries? We’ll never know. The adults seem to have left the neighborhood.
I’m not sure whether you gain or lose karma points by trying to help a scrub-jay instead of letting nature take its course. But there are times when you just have to violate the prime directive.