The American Robin (Turdus migratorius) is one of most recognizable songbirds in North America. It is associated with the arrival of spring, when its cherished song is often the first one heard, and can be seen darting across American lawns searching for earthworms. You can hear the robin singing a melodious song early in the morning and often late into the evening.
It is so well-known that during a bird study sponsored by the State Federation of Women’s Clubs, public schoolchildren voted for the American Robin to become the state bird, receiving twice as many votes as other birds. It was eventually named the Wisconsin State Bird on June 4, 1949. This demonstrates the familiarity and affection that has been developed for the American Robin. Still, there is much about this bird species people may not be aware of.
Characteristics of the Robin
Robins are a part of the thrush family, which are plump, small to medium-sized birds with soft plumage. Thrushes are found on every continent except Antarctica, and locally include the Wood Thrush, Eastern Bluebird, and Hermit Thrush, as well as others. The American Robin is the only member of its genus that occurs solely throughout the North American continent. It is a woodland bird, but is also found in open spaces, such as lawns, parks, and agricultural developments.
Robins are sexually dimorphic, which means the sexes have visual differences. In robins, these differences can be more subdued from other species. Males have a dark black head and bold orange breast. Females have similar patterns but lack the dark head and are generally more pale and smaller. Immature birds can resemble females, but with dark speckling on their breast, and light speckles on their back.
Migration Patterns
The American Robin’s range includes Canada, North America, and Mexico. They are short to medium distance migrants, with most northern species migrating in the fall to the southern US and Mexico. In the last two decades, it has been found that some robins are staying closer to their breeding territories, migrating less than 100 kilometers and overwintering near their nesting grounds. Their migration patterns are often food dependent, and some robins adopt a nomadic style, migrating only far enough to search for the closest food sources.
In the winter, robins form flocks, typically comprised of a dozen birds but sometimes reaching into the hundreds, and roost in trees throughout the season. They are active in small groups during the day, looking for berries and fruit, but will return to the ground in spring when worms are available. When it is time to nest, the birds become less social and leave the group to defend a territory.
What do Robins Eat?
Robins eat soft-bodied invertebrates, insects, and earthworms in the spring and summer. They benefited greatly from European settlement, when the earthworm was introduced to Wisconsin. The adaptable robin was able to live within the same habitat as humans, taking advantage of the earthworm as a plentiful food source. The turning of soil on land developed post-settlement ensured a large number of earthworms. The presence of lots of open land provided the robin with an abundance of this food, which is its main source of protein. In suburban developments, robins hunt earthworms on lawns by sight, not sound as is commonly thought. They use bursting forward movements with their head cocked, using one eye to look for movement on the grass, pouncing on their prey and seizing it, pulling it up with their beaks using their strong legs.
In fall and winter, or in the later part of the day when worms are unavailable, robins eat fruit and berries, which are a good source of vitamins. Food is often sourced from dogwoods, and also includes serviceberries and other berries. They especially benefit from insect-infested fruit, which provides more nutrients. Robins are seed spreaders, dropping the seeds from the plants whose berries they eat. This can include the berries from invasive plants such as buckthorn and other invasive, berry producing plants, helping them to spread.
The Melodious Song of the American Robin
Thrushes are known as one of the most melodious bird families, and when people think of beautiful bird songs, it’s often a song from the thrush family that comes to mind. Their complex, harmonious songs originate from having multiple vocal cords, called a syrinx. This allows them to create separate notes at the same time, that are then melodiously blended together. The Wood Thrush, a relative of the American Robin, has a hauntingly beautiful song that exemplifies this ethereal nature. But the American Robin is no exception among thrushes – their lovely song is filled with complex vocalizations including its signature cheerful warble, a recognizable tune on spring mornings.
Robins begin regularly singing in March, when they start to look for mates. Males sing more before they are coupled, mainly to attract females and to maintain territories. Nestlings begin to vocalize when they hatch, using a begging call as a way to get food. They learn songs by imitating their neighbors when they are young, but songs are also made up of individually invented components. Knowing the robin’s vocal patterns can tell a listener a lot about the environment. It uses an alarm note as a call for danger in response to predators, to warn other birds, and as a way to communicate with young when nesting.
The Robins’ Life Cycle
The robin is an early nester, beginning in April and continuing until July. The nest is a combined layer of twigs and other fibers, reinforced with a layer of mud, then covered with very fine material on the surface. During nesting season, inter-male aggression is common. Males defend their territory and will sometimes physically grapple with other males who overstep their boundaries, especially when space is limited.
Much of the time, robins are monogamous, but they will occasionally switch partners during a nesting season. Robins can build nests on porches and in rafters and may return to it every year during nesting season, so they are sometimes found close to human activity. They are protected under the Migratory Bird Treaty Act, so please do not move their nests, but rather consider it an opportunity to observe nature happening right on your doorstep.
The robin averages two, and sometimes three broods, consisting of about three to five eggs each. The time it takes from incubating eggs, to young robins hatching, fledging, and then surviving on their own is approximately 36-40 days. The eggs are a beautiful blue color, which is caused by the substance biliverdin. Biliverdin is found in healthy females, and more brilliant blue eggs reflect better health. This blue color is often described as soft, clear, and tranquil, and is the inspiration for many human-made varieties such as house paint. Crayola has had a robin’s egg blue crayon since 1993, and Tiffany & Co’s signature “Tiffany’s Blue” jewelry box is inspired from this color.
Conservation Status of the American Robin
The population of the American Robin is healthy, estimated at 380 million birds and growing. It is currently a species of low conservation concern, but this hasn’t always been the case. Earlier in history the species was vulnerable to overhunting. Later, when DDT was widely used as a pesticide, robins were affected, and their population declined. When DDT was banned in the early 70s, robins experienced a recovery and their numbers rebounded. Now, their main threats are due to lawn pesticides and predation from cats.
If you’d like to see more robins in your yard, they can be attracted using bird baths and by planting native plants with berries. To keep them healthy, avoid using pesticides on your lawn. With spring underway, the robin is already singing its joyful melody. You can see robins in your neighborhood, but a visit to the Center may also reveal a prime spot to view this common, but surprisingly complex bird species.
Written with contributions from: Michelle Allison, Aubrey Ellickson Fulsaas, Zoe Finney, and Don Quintenz
