The American Robin: One Of Us

By Curtiss Clark

In summer, they escape our notice the same way taxicabs escape our notice in New York City. There are so many of them, we don’t see them, until we look for them, and then there they are in plain view. But in early spring, when the robins return, we stop to be certain we see that familiar red breast, we take note of when and where we see them, and we mention it at the office. We never noticed when they left, but they are back, and that is all that matters.

Even those who can’t distinguish a flicker from a finch know what robins look like. They are one of us. Family. Native. As a matter of course, we have made it our state bird here in Connecticut, as have the people of Michigan and Wisconsin. We often tether our notions of who we are to a place, and in our mind’s eye, it is a place with robins. Their contented chirping is the soundtrack of our summer afternoons. We all know the color robin’s-egg blue. Who knows the color of the catbird’s egg? (Dark green.)

We have adapted to robins. But even more, robins have adapted to us. They love suburban lawns.

Long ago, American robins left their thrush relatives behind in the forest to live the easy life that America rolled out before them on wide expanses of obsessively cultivated and closely cropped grass. They got tired of hopping and fluttering through undergrowth obstructions in their endless search for earthworms and other invertebrate protein morsels, finding it much easier to navigate the smorgasbord of the typical American lawn.

Forty years ago, Frank Heppner, an ornithologist at the University of Rhode Island, studied the robin’s search for earthworms and found that the length of the grass was a critical factor for the birds when they selected where to forage. He noticed that robins had far greater success in finding worms in areas where the grass was short or sparse, where their search pattern was not altered by obstructions.

Subsequent studies showed that robins spend progressively less time foraging as the grass grows longer on a lawn. The birds also were found to exploit human efforts at lawn care, spending more time searching for worms right after a mowing when they were suddenly exposed and vulnerable. Robins were also attracted to lawn sprinklers, which draw earthworms to the surface the same way rain does. Consequently, dry periods that bring only hardship to the shy birds foraging the forest floor can mean extra rations for robins working the well-watered neighborhoods of suburbia.

Anyone who has watched a robin search for worms knows that the birds have developed a peculiar strategy for success. They seem to be intent on surprising their prey. Rather than working one particular area of the lawn methodically, where the wary worm might see his fate coming, a robin will sprint eight or ten feet to a spot, stop, cock its head and survey the area for several seconds, and then sprint another eight or ten feet to another area. By the time the earthworm becomes aware of the robin’s looming presence, it’s too late.

As much as we have helped the robins with our obsession with lawns, the advantages don’t come without a cost. The Neighborhood Nestwatch project of the Smithsonian Migratory Bird Center has found that robins and their nestlings living in suburbia have lead levels in their blood about twice those of birds living in forests and rural areas. Earthworms, as they plow and aerate the dirt in human habitats, collect contaminants on their slimy epidermis, including lead from paint and gasoline commonly found in suburban soil. Because the worms constitute such a large part of the robins’ diet, they are more susceptible to lead poisoning than other birds.

And now we are finding that the hazards of living in community with robins are mutual. Two summers ago, Theodore Andreadis, the chief medical etymologist at the Connecticut Agricultural Experiment Station in New Haven, reported that robins play a significant role in spreading West Nile Virus around the state. After testing the DNA of the blood found in three local species of mosquito, 40 percent of those samples proved to be blood from American robins. Blood from crows, which are commonly thought to be major carriers of the virus, showed up in only one percent of the samples.

So it turns out that the robins’ troubles are our troubles, and our troubles are their troubles. That’s the way it is with those we embrace in close community. They are one of us. Family. Native. And we’re glad to have them back in plain view.