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SPECIES ACCOUNT AMERICAN ROBIN (Turdus migratorius) Vineyard Overview: Perhaps the most familiar bird to most Islanders, the American Robin is a common and widespread nesting species, an abundant (sometimes mind-bogglingly abundant) migrant, and an often-numerous wintering species on the Vineyard. Robins do nest in natural areas on the Island, and members of migratory populations that visit us in the colder months can be surprisingly wild and wary. But this species adapts readily to humanmodified habitats, and most of the robins that nest on the Vineyard probably do so in yards and settled areas, where they are often successful, sometimes prolific breeders. The “first robin of spring” is a time-honored emblem of the changing seasons, but in fact this species is present year-round on the Vineyard. Wintering robins associate strongly with fruit-bearing shrubs and vines, which may mean anything from a crabapple tree in a yard to a greenbriar thicket in deep woodland. Numbers of wintering robins vary dramatically from year to year depending on the severity of the winter; paradoxically, a severe cold snap can actually increase the numbers of robins on the Vineyard, as birds from farther north seek refuge in more southern locations. As with many birds, snow cover poses a serious threat to wintering robins, since it makes food harder to find, and robin numbers typically thin out dramatically after a significant snowfall. In late winter and early spring, the northbound movement of robins becomes apparent, with numbers increasing and small flocks appearing in A familiar site nearly anywhere on the Vineyard: an alert American Robin. Photo: Lee Carney/USFWS places that lacked robins the day before. In late March and early April, males of this species begin to sing, and the gregarious habits that characterize winter flocks begin to give way to strong territoriality. By the mid-April, the flow of transient robins has largely stopped, and breeding individuals have begun building nests – robust structures of woven grass and mud, usually set in a fork in a tree or shrub branch somewhere between six and 20 feet off the ground. Pairs that lose their first set of eggs or young will try again, and successful breeders often attempt a second brood later in the summer. Identification: This is a bird that needs little introduction: the medium size, gray back, and reddish-orange underparts are distinctive and almost universally known. A closer look reveals a broken white ring (or sometimes a set of white “spectacles”) around the eye, a yellow beak, and grayish-white streaking on the throat. The Nature Conservancy Massachusetts Islands Office 18 Helen Avenue, Vineyard Haven, MA 02568 Brian Lawlor, Program Manager | [email protected] | (508) 693-6287 Ext. 10 The song of a robin, given mainly early in the morning and in the evening, is also easy to recognize. It consists of a series of short, whistled phrases, each with two or three notes: “Cheer up! Cheer up! Cheerily!” Ecological functions: American robins flourish in the semi-open conditions of residential neighborhoods, foraging on lawns as well as in more sheltered sites, feeding on fruit-bearing trees and shrubs, and nesting in a shrubs or small trees. As a common predator in these settings, robins are an important force in the regulation of invertebrate populations. Like most songbirds, robins rely heavily on insects as prey, and appear to be fairly indiscriminate in their prey selection. So they undoubtedly consume insects we consider beneficial as well as harmful ones. But the overall effect is probably to put pressure on any species or group of species that becomes especially common; by foraging on the most abundant and readily available prey items, robins tend to help keep insect populations in balance. The overall ecological impact of robins is undoubtedly helpful. Like other fruit-eating birds, robins help disperse the seeds of fruit-bearing trees and shrubs. And like other songbirds, robins are sometimes taken as prey by hawks, and their eggs and nestlings are vulnerable to predation by grackles, blue jays, and crows. Strategies: 1. Provide nesting habitat. Robins are not fussy about the species or even the size of trees and shrubs they nest in, but they like a concealed site for their nest. Maintaining shrubs and medium-sized trees, preferably with a dense canopy of branches and an associated understory, probably produces the kind of vegetation structure that robins nest in most successfully. 2. Limit predation. While we have no explanation for it, in our experience robins seem to be caught less often by hawks or falcons than their numbers would suggest. But as common birds in residential areas, they are vulnerable to predation by feral or outdoor cats, as well as by skunks or raccoons. Keep your cat indoors and avoid the features – uncovered garbage and den sites – that can attract skunks and raccoons. 3. Provide food and water. Fruit-bearing shrubs are attractive to robins, especially in the winter when other food sources are scarce. American holly and winterberry are two useful native ornamentals that offer wintertime food for robins. Robins are also enthusiastic bathers, so open water often attracts them. 4. Reduce mortality from window collisions. Comfortable around human habitation, robins are at risk for being injured or killed by colliding with windows. Placing decals on windows, to avoid the appearance that the window is empty space, may help reduce this risk. Placing netting outside windows is an even more effective method, though it is more complicated to do and may not appeal aesthetically to a homeowner. Notes: The appetite robins show for earthworms is remarkable, and the fact that sod lawns offer good habitat for earthworms probably accounts for some of the robin’s enthusiasm for foraging in yards. This bird is one of the few native species that actually benefits from the presence of lawns. In our view, however, foraging in lawns is neither necessary nor natural for robins (moreover, we note that all of our multiple earthworm species are not native to the Vineyard). So while we think it is desirable to encourage robins, maintaining lawn area is not how we recommend doing this! Robins, like most birds, have acute hearing and are reportedly able to find and catch earthworms by zeroing in on the sound the worms make as they move through the soil.