It was early May, peak warbler migration time in Missouri, and I was keeping my binoculars close to my desk. Whenever I heard a bird call out of the ordinary, I left the computer and was out the back door of my house in Jefferson City, scanning the canopy of trees in my yard.
Yellow-rumped warblers were feasting on small insects at the top of an elm tree, but there was also some elusive movement lower in the tree. Too big for a warbler. Was it a veery? A hermit thrush? Then I saw its bright russet breast, white eye ring and yellow bill.
“Just a robin,” I said out loud to no one. With those three words, I dismissed one of North America’s most successful birds, simply because it was so common. I immediately trained my binoculars on other movement in the trees, hoping to see something more unusual. But I saw the robin flick its tail, as if indignant, and fly to another branch to perch. It was just a robin, one of several at the moment, not only perching in my trees but hopping across my yard, and one of an estimated 320 million individuals living at any given time in North America.
From Pristine Forests to Parking Lot Islands
Like poison ivy, American robins can be found throughout Missouri; they live and nest in yards, woodlands and farms, but also parks in big cities and even strip mall parking lots.
Robins are the birds most all Missourians know by sight, the ones we absentmindedly watch out the window when we are talking on the phone: they do their run-bounce across lawns, then stop, cock their heads, scan for predators, yank a worm out of the ground, then run-bounce some more.
After a rain, we see them in puddles in parking lots as we wheel groceries to cars: there they are, splashing and flapping in temporary, asphalt birdbaths.
At dusk, when we are cleaning up after dinner and getting kids into bathtubs, robins often get overlooked, but they are out there, chasing each other around in our yards with erratic flight or singing as the day draws to a close.
Most all Missourians have heard robins as well, even if they don’t know which birds are producing the sound. Unless you are living in a high-rise in downtown Kansas City or St. Louis, you have no doubt awoken to the spring dawn chorus of birds—to us, the intense, wonderful sound of winter going away; to birds, a competitive madhouse of males trying to outdo each other, attract a mate and pass on genetic material to future generations.
In suburban and urban areas, the sweet racket is coming mostly from robins, cardinals, titmice, chickadees, house finches and wrens. In many rural areas, the dawn chorus may be laced with the more complicated calls of numerous warbler species, but often with the upbeat song of robins included in the mix.
We don’t think twice about robins being a part of Missouri’s bird life, but in fact they were not always so common here as they are today. In spring and summer, robins eat lots of earthworms. Earthworms live in moist, soft soil they can move around in. Around the time of Missouri statehood, as settlers moved westward across the United States and established towns and agricultural areas, they converted millions of acres of prairies, forests and other natural communities to cropland and pastures.
Since then, we have continued to convert natural landscapes into lawns, golf courses, parks and cemeteries, often accompanied by irrigation systems. All of these land use changes created millions of acres of short grass, soft soil and easy access to lots of earthworms and other soft invertebrates that robins eat. Thus, robins have come to thrive in Missouri, and they breed and winter in nearly every other state as well.
“Robins are found in a huge variety of habitats,” said Dr. Greg Butcher, director of Bird Conservation for the National Audubon Society, “and one of them happens to be suburbia.” Human development, including suburbia and farms, has not only produced a lot of good earthworm-foraging territory, but also, Dr. Butcher notes, more sources of fruits.
In the colder months, when soil hardens or freezes, robins switch from eating invertebrates to fruits. In fall, huge flocks of robins, some numbering in the thousands, migrate to lower elevations or southward in search of sources of fruit like chokecherries and berries of hawthorn, dogwood and sumac. Many robins live in Missouri year-round; those here in winter will wander from fruit source to fruit source. It seems that every winter I have seen snowy ground mottled with the bright orange remains of bittersweet berries, left in the wake of a hungry sweep of robins.
People have helped increase fruit supplies for robins in several ways. Directly, in the form of trees and shrubs planted for ornamental landscaping and to attract wildlife. These include native species but also the highly invasive and non-native shrub or bush honeysuckle, spread in part by robins and other birds ingesting the fruits and taking the seeds to new locales via their droppings. Indirectly, the suppression of fire across much of Missouri’s landscape has helped native eastern red cedar invade prairies, woodlands and glades. The tree’s blue “berries” (actually female cones) are readily eaten by robins and other birds.
Robins, Conservation and You
Populations of some birds, like the highly adaptable robin, have increased in response to human changes to the landscape. Of course, other species have not fared well at all. Many species dependent on vast, treeless prairies, wetlands, or forests have declined or have been extirpated due to human-caused habitat loss or degradation. Robins are known as a generalist species, as they can survive in many habitats. Species like greater prairie-chickens or cerulean warblers, on the other hand, are specialist species, dependent on specific, high-quality habitats—and in the case of these two species, large tracts of prairie and intact forest, respectively.
But even robins aren’t immune to all changes to the landscape. Because so many robins feed on earthworms and other invertebrates from lawns, they are vulnerable to chemicals like lawn fertilizers and pesticides. And, climate change is likely having an effect on robins as well.
“Their wintering range has changed,” said Dr. Greg Butcher, “and it could be attributable to increasingly warmer average temperatures.” While the historic winter range of robins includes the lower half of the lower 48 states inland and parts of southern Canada along the coast, “We are seeing robins—and in increasing numbers—wintering in parts of Montana, Minnesota and even Alaska,” said Butcher, “where 25 years ago, there were no winter records of robins in these areas.” With northward movement in response to warming temperatures and increasing fruit supplies, a lot has changed for robins in just 25 years.
You can help robins and other birds by landscaping with native shrubs, vines and trees that provide fruits for the birds to eat in fall and winter. Get rid of shrub honeysuckle, whose seeds are spread by birds and which invades natural areas to the detriment of many other animals and plants. Avoid using lawn chemicals, which not only kill beneficial insects and degrade stormwater quality, but can also poison robins and other birds that feed on invertebrates in lawns.
We humans crave novelty. Birders demonstrate this to great effect with bird checklists and the never-ending longing to see something new. But where would we be without common birds like robins living close to us, providing a wild streak to our daily lives? Robins represent the everyday elements of nature—like sunrises punctuated with bird song, nests discovered in corners of porches, and beautiful fragments of eggshell on the ground—that we often take for granted, and that we would crave if they were gone.
American Robin Facts
- Scientific Name: Turdus migratorius. Turdus is the Latin name for thrush. The species name is reflective of the migratory nature of robins, which travel in spring and fall to available food sources.
- Size: At an average of 10 inches from beak to tail, the American robin is the largest member of the thrush family regularly seen in Missouri.
- Appearance: Adult male and female coloration is the same (dark brown head, back and wings, russet breast, yellow beak) but females are generally paler, especially the head.
- Survival and reproduction: While a robin may nest three times in one year, only 40 percent of nests successfully produce young, and only 25 percent of fledged young survive to November. And, only about half of the robins alive in any year will make it to the next. The oldest robin known lived to almost 14 years of age, but the average 6-month-old robin only has another 1.7 years to live.
- Food: Earthworms and other invertebrates, including butterflies, moths, ants, spiders and beetles, especially in spring and summer. In fall and winter, robins spend more time in trees and shrubs eating fruits.
- Breeding Season: In Missouri, March to mid- to late August. Males assertively defend territory, flying at or even striking rival males chest to chest. Pairs generally stay together for the entire season.
- Nest: Made of mud, grass and twigs. Robins often incorporate worm castings into nests.
- Eggs/Young: Usually four eggs per brood. Robins will produce two to three broods each year.
- Incubation and Fledging: Females incubate eggs for approximately 12 to 14 days after laying the last egg. Fledglings usually leave the nest 14 to 16 days after hatching.
For more information on robins other common birds and birding in Missouri, visit MDC at mdc.mo.gov/node/235, the Cornell Lab of Ornithology at www.birds.cornell.edu, or Patuxent Wildlife Research Center at www.pwrc.usgs.gov. A wealth of information on birds and climate change is also available at http://web4.audubon.org/bird/bacc/index.html, maintained by the National Audubon Society.