Birder’s Notebook: American Robin - An impressively adaptable bird
Almost everyone can recognize the distinctive red-breasted American robin. It’s a beautiful bird in the thrush family that is often underappreciated simply because it is so common.
The American robin is one of the most widespread songbirds in North America. It is found throughout the United States —except Hawai’i— and Canada. In Alaska, its breeding range covers all but the northernmost parts of the North Slope and the islands of the Bering Strait. Even there, robins are sometimes seen passing through in the spring and fall.
In addition to their wide geographical range, robins thrive and breed in remarkably diverse habitats from the parks and lawns of our largest cities to alpine tundra wilderness of the far north. They breed throughout the Seward Peninsula but are less common in the western regions.
Robins are one of the first songbirds to return to our region each spring, sometimes arriving as early as the last week of April, but more often during the first week of May.
It is always a great joy to awaken one spring morning and hear the melodious song of the first robin after a long, quiet winter.
Male robins arrive a few days before the females to establish their breeding territories, often returning to the same territory year after year. Their cheery, musical song —an iconic sound of spring — stakes their claim in the area and attracts potential mates.
Mate selection is based in part on the color of the breast. There are subtle variations in color and studies have found that robins select mates with breasts closest in color to their own. Males strut, flutter their wings and puff up their striped throats to court the female of their choice.
Robins are generally monogamous for the season. Males defend their mates from advances by other males by charging rivals in a running, crouched position. There is seldom physical contact, but robins will sometimes fight their own reflections in windows and mirrors.
The female robin selects a nest site and builds the nest while the male gathers and brings her the materials. She forms a cup of grass and twigs, pushing it into shape with a wing. She reinforces it with mud and lines the cup with fine grass. Nest construction takes about a week to complete.
In most parts of the robins’ range, the birds nest in trees and shrubs. Beyond the treeline on the Seward Peninsula they nest on driftwood, cliffs, rock piles and tors, as well as many human structures and equipment. In fact, human settlements have helped the species expand into the far north by providing protected nesting sites in the absence of trees.
Egg laying in our region happens between mid-May and early June. The female lays an average of four ‘robin’s-egg blue’ eggs, one day apart. She incubates for 12-13 days after the last egg is laid.
As is the case for many birds, the female carries the eggshells away from the nest after hatch. Empty shells could draw the attention of predators to the nest site.
Both parents feed and defend the nestlings. They regurgitate insects and berries into the gaping mouths of their young who compete with each other by attempting to raise their open, orange mouths higher and closer to the mouths of their parents than their nestmates.
In southern parts of their range, robins commonly rear two to three clutches of young in a breeding season. My research and observations make me doubt that multiple clutches are common in our northern region. However, failed nesting attempts can be followed by successful second clutches.
During the breeding season, our robins feed mostly on insects and larvae they find on the ground, on last year’s berries in the spring and on fresh berries in the fall.
Robins forage in a variety of ways to obtain different foods. Most commonly they make quick running bursts over the ground then pause in an upright stance while cocking their heads to look for prey on the ground.
Fall migration from the Seward Peninsula begins in late August. Most robins depart in September, but a few remain into October.
Much is still unknown about robin migration, including where our birds winter. While robins return consistently to the same areas to breed, banding studies show they are not faithful to specific wintering areas. Robins banded in Alaska have been found wintering in Texas and Iowa, some having made 3,000-mile migrations.
Robins can live up to 13 years, but more often have much shorter lives due largely to predation. Their high reproductive productivity allows the population to withstand the pressure of predation without population declines.
Robins are also sensitive to chemical poisoning because toxins concentrate in earthworms they feed heavily upon in their winter ranges. Following the use of DDT to control the Dutch elm disease in the 1950’s, robin numbers plummeted. After DDT was banned in 1972, the species quickly rebounded.
The future looks brighter for robins than it does for many bird species. Their ability to thrive in human altered landscapes and their omnivorous, versatile feeding habits make robins well suited to our rapidly changing world. While many more specialized bird species are declining in numbers, American robin populations are stable or increasing.
For this reason, robins should be appreciated more, not less, for being common!
A sad follow-up.
The red-necked grebe family I photographed for last week’s feature is no more. Before the story went to print, one of the parents was apparently struck and killed by a vehicle as it attempted to fly across the road from one pond to another to fish.
Grebes are heavy birds, built for diving. They require a long takeoff run and are slow to gain altitude — too slow apparently to clear vehicles barreling down the road.
When I discovered the flattened grebe in the road, two of the three grebettes were already gone. Within a day the remaining chick had disappeared, too. Without a parent to protect the youngsters while the surviving parent fished, the chicks were probably killed by hungry gulls.