A Father's Day Top Ten: Animal Father

This 1996 archive on the best animal kingdom superdads includes comments by retired professor Richard J. Clark:

9. Hardest Working Dad

He starts by establishing his territory and attracting a mate with his "three or five hooter" call. Then, since his own species has no architects or builders, both partners much go househunting for places like old squirrel nests, hawk nests or hollowed-out tree stumps. "I've even seen an owl take over a red-tailed hawk's nest," says ornithologist Richard J. Clark at York College of Pennsylvania. In late winter, the female lays her two or three eggs and the male's marathon begins. While she keeps those eggs from freezing, he brings home the bacon (or, in the owl's case, rats, mice, squirrels -- and even prey as large as pheasants). In most bird species, says Clark, the female is the smaller animal, but not birds of prey. So the male great horned owl must feed himself and another adult about 25 percent larger than he. With two or three hatchlings crying for food, his burden multiplies, especially since the mother is caring for owlets that can't maintain their own body temperature for the first days or weeks of life. After about a month, however, she starts to help hunt. It's a good thing, too; the fledglings will grow bigger than their parents and require as much as one-fourth their body weight in daily food intake.