It’s always risky to predict what a bird will do. But I’ll go out on a limb here and say that it looks to me like the two Burrowing Owls in the park are settling in. They’re in their third week. They’re obviously finding things to eat. We don’t see them feeding. They do that when the light is too weak for our eyes, but plenty good for theirs. But if they weren’t finding food here, they wouldn’t stay, would they.
A couple of years ago I got lucky and recovered a pellet that one of the then-resident owls had regurgitated. (See “The Owls Came Back, the Movie.”) The pellet is a 3D record of what the owl ate. It contained nothing but bug parts. There was no sign of this bird eating a mouse, a vole, or some other little mammal. It could, but it hadn’t.
The idea that Burrowing Owls eat Ground Squirrels, floated in a recent local article, would come as a big surprise to the Ground Squirrels in the park. They regularly go about their squirrel business in close proximity to the resident owls, often in their faces, without showing any signs of concern. Very occasionally a squirrel will snap an owl’s last nerve, and the owl spreads its wings and looks big and ferocious. Most of the time that backs the squirrel off, but I’ve also seen a squirrel ignore the show and walk right past the owl’s nose. Never have I seen a Burrowing Owl lunge or peck or otherwise physically attack a squirrel. This isn’t only because the squirrels as a rule are bigger and heavier than the owls, and there’s more of them. There are some hawks that will attack and sometimes kill and eat prey bigger than themselves. The reason is that owls and squirrels have a symbiosis going. They need each other, and they have common enemies. Both species keep a lookout for big raptors flying overhead, and warn each other. Four-legged hunters are another mutual concern. On November 10 I filmed and published an instance: owl and squirrel within a foot or two of one another, both rising in alertness to the sound of a dog barking nearby. See “Owls Active,” Nov. 10 2021.) Out in the wilderness where owls nest in Ground Squirrel burrows, the owls have been seen to attack, harass, and sometimes kill rattlesnakes that pursue the squirrels. Our Western Burrowing Owls totally depend on the burrows that the squirrels dig. Where ranchers or developers exterminate the squirrels, the owls also disappear.