American robins (Turdus migratorius) are popular backyard birds, and a familiar site on lawns across the country, tugging at earthworms or hopping about on freshly turned-over soil.
A symbol of the arrival of spring, American robins nest early in the season, laying distinctive bright blue eggs in their well-crafted nests. Here we take a closer look at the breeding and nesting habits of these inquisitive garden visitors.
American robins’ preferred nest sites can vary with geographical location. Woodland, farmland, and urban environments can all provide a suitable breeding habitat for robins, which will use both evergreen and deciduous trees. Tree forks may be used as a base, as well as supporting branches at relatively low heights as well as higher up towards the tops of trees.
Nest boxes and birdhouses may also be used if available, and robins may also choose manmade structures on which to start building their nests, such as ledges, window sills, planters, gutters, and under eaves of a shed or barn roof.
|Key American Robin Nesting Facts|
|Nesting season||April to August|
|Nesting material||Twigs, grass, dried leaves, mud, lined with finer materials|
|Nest type||Rounded cup-shape|
|Nest location||Trees, buildings, in woodland and urban environments|
|Number of broods||Two broods|
|Clutch size||3 - 4 eggs|
|Egg color||Sky blue and unmarked|
|Egg size||29 x 20 mm|
|Egg weight||6.3 g|
|Incubation period||13 - 14 days, by the female|
|Fledgling period||13 days after hatching|
|Reuse nests||No, but will return to same breeding territories|
|Use nest boxes||Sometimes will use open-fronted platform style|
The nest of an American Robin
Natural nests crafted by robins are bulky and rounded structures of twigs, grass, and dried leaves, held together with mud, and cased in an outer wall of mud. The interior is a rounded cup, pressed into shape by the female robin’s wings in the later stages of construction, and then cushioned with fine plant fibers and dead grass. The interior cup is approximately big enough to fit a baseball inside.
Close up of an American robin nest with four eggs inside
American robins are one of the earliest birds to begin nesting each year, with the first clutch of eggs laid in April and the final brood’s hatchlings leaving the nest by August. Nest-building begins while temperatures are still relatively chilly, but by the time the eggs are laid and the hatchlings emerge, it has begun to warm up.
Laying begins shortly after the construction of the nest is complete, with between 2 and 4 eggs being most common. Incubation lasts for up to 13-14 days and is the sole job of the female robin. On hatching, baby robins are initially brooded by females, while males take an active role in feeding.
Two to three broods are raised in a typical year. A fourth brood is rare but not unheard of.
American robin chicks in the nest with parent nearby
The female robin chooses a nest site and constructs the nest alone, using grass, twigs, and an outer casing of mud. A male robin may visit the nest site before and during construction, bringing nesting material to assist his mate.
Female robins craft bulky cup-shaped nests, with the rounded interior smoothed and shaped using wet mud from worm casts. Final touches include lining the interior with fine grass.
Nest construction takes around 5 to 7 days, although subsequent nests built in the same year may take less time to complete, once the female has mastered the art.
American Robin gathering nesting materials to build the nest
Fledgling robins leave the nest after around 13 days, and chicks continue to be cared for by parents for three further weeks. By this point, the female may already have returned to brooding duties for her subsequent clutch, leaving the male to tend to the newly fledged chicks alone.
Two to three broods a year is most common for American robin pairs, although on rare occasions a fourth brood may be attempted and successfully raised. A new nest is built for each fresh clutch of eggs.
American Robin sat on the nest, protecting the eggs
Robins tend to construct a new nest for each brood, even in the same year. However, they may revisit a previous nesting site to make use of materials or use it as a foundation on which to build a new nest.
American robins lay bright blue eggs, which give their name to the color known as ‘robin egg blue.’ Eggs are smooth and plain, with no speckles or other markings. They are roughly the same size and weight as a quarter.
Four blue American robin eggs in the nest
Up to three broods, sometimes four, can be laid each year, with the first clutch commonly timed in the middle of April. When multiple broods have been laid within the same year, it is not unusual for the final clutch to be laid in late July or even into August.
Female American robins lay 2 to 4 eggs, usually around three to five days after the nest construction has finished. They tend to lay one new egg a day until their clutch is complete, leaving the nest to feed in the early morning, before returning to the nest to continue laying a short time later. Once the clutch is complete, the female only briefly leaves the nest during the remaining incubation period.
American robins may use birdhouses but only if they are of a particular design and the nest box is placed in an appropriate location. Robins prefer an open-fronted style of box, similar to a nesting shelf, with a clear view out rather than being sheltered by vegetation. Such boxes will be more successful in attracting robin occupants if they are placed on the side of a building or tucked under the eaves of a roof.
Size of the nest box is also a consideration for a brooding robin; the birdhouse needs to be large enough for a robin to add its own base of twigs and mud on which to lay its eggs.
An American Robin feeding newly hatched chicks worms
When raising young, female robins sleep at their nests, while males gather at communal roosting sites in the branches of trees, in barns, or even under bridges. Once young robins become independent, they join the males overnight at the roosts. Adult female robins go to the roosts only after they have finished nesting.
Robin roosts can be huge, with even tens of thousands of birds overnighting at the same spot.
Provided the other conditions are suitable, there is no reason why a robin will not nest in a backyard. A shady tree on a lawn provides a good spot for potential nest building, and a dense thicket or shrubbery may also offer suitable shelter and protection.
Open-fronted birdhouses designed to attract robins can be attached to houses or sheds to encourage nesting near to human habitation.
Female American Robin looking after nestlings, who are barely visible
Like many nesting birds, if an American robin feels that its nest and eggs are under threat, it may desert the site and start again elsewhere. If a potential predator, e.g. cat, bird or even human, disturbs the robin’s nest site, it likely will sense it is unsafe to continue with attempting to raise its chicks at that site, abandon any unhatched eggs that it has laid, and will not return to continue with incubation.
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