The natural world is one vast bird nursery in the summertime, with ducks and geese, songbirds and flycatchers and woodpeckers all raising their youngsters, sometimes under the watchful eyes of us humans.
From time to time I pause to think about how very arduous birds’ lives are, how hard they work to carry out the imperative hard-wired into their brains to pass their genes on to a new generation.
Many millions of birds migrate from the tropics each spring, to breed and nest in wide (or at least wider) open spaces with abundant insects to feed nestlings. Each bird works to attract a high quality mate with strong survival skills, to pass these attributes on to their young. And they build strong nests to hold their eggs and protect young birds for the two weeks or so they’ll spend inside.
It’s a tough job and there are hazards at every turn. So many other wild creatures, themselves engaged in rearing their young, are on the lookout for the high protein meal bird eggs and nestlings represent. Raccoons are champions at snatching bird eggs with their grasping paws. The same is true of gray and red squirrels and the occasional possum. Once the young hatch they become fair game for any and all larger birds, from crows to blue jays to grackles and red-bellied woodpeckers. And young birds are constantly at the mercy of marauding cats.
But birds have a secret weapon in this fight to raise a family, one honed by evolutionary forces over the eons: Both the female and male are generally on the job, first by protecting eggs, then bringing back food to youngsters to help them mature quickly and leave the nest before predators home in on them. This is not the way it’s done in most of the mammal world, where females are solo parents.
Naturalist Mary Holland, in her book, “Naturally Curious,” describes a red-bellied woodpecker pair, with both birds working to excavate a nest cavity in a tree, both taking turns incubating the eggs, and then both feeding the young, in the nest and later out in the wild. (Not all birds share parenting duties so equitably, however, and most of the nest-building and egg-sitting still falls to females in other species.)
“In approximately 85 percent of bird species, both the male and female of a mating pair contribute to the feeding and guarding of their offspring,” Holland states.
This vigilance by both parents increases the odds that they will successfully fledge at least some of their brood. If something dire happens to one parent, the odds of producing fledglings quickly go down. Each of those little beaks in the nest, averaging four for a robin to eight for a chickadee, needs to be stuffed with high-protein insects from dawn to dusk. A single parent simply can’t keep chicks adequately fed, and each absence from the nest leaves it vulnerable to predators.
Not every bird species takes this dual parent approach. Species in which male birds don’t help raise their offspring include hummingbirds, ducks and killdeer. And in some species, notably shorebirds known as phalaropes, females leave parenting duties entirely to the males.
But double duty helps. The robin’s nest on my neighbor’s eave was tended by both parents this past spring, and both brought food back to the hungry beaks with metronome-like regularity. In an unguarded moment the neighborhood suddenly erupted in a cacophony of bird shrieks and a chase: A grackle was carrying off one of the nestlings. The robins didn’t make that mistake again and ushered three young birds into the backyard a week or so later.
The next time you notice a robin with a speckled chest, or a shaggy-looking cardinal with a dark beak, you might acknowledge all the hard work that went into these young birds’ upbringing. Their parents may make it look easy, but it’s the hardest thing birds do all year.
St. Paul resident Val Cunningham, who volunteers with the St. Paul Audubon Society and writes about nature for local, regional and national newspapers and magazines, can be reached at firstname.lastname@example.org.