Scarlet Tanager Life History

Habitat

Scarlet Tanagers breed in mature deciduous forests and mixed deciduous-coniferous forests in eastern North America. They nest in oak, pine-oak, oak-hickory, beech, hemlock-hardwood, and occasionally pure eastern hemlock forests. In Canada they sometimes extend into boreal forests in stands of aspen, balsam poplar, and birch. Breeding Scarlet Tanagers prefer large forest tracts with large trees. During spring and fall they use similar forest habitats as well as open spaces such as parks and gardens. When they arrive in the southern United States coast in early spring they feed in shrubby vegetation, grassy fields, and on the ground. Scarlet Tanagers winter in mature forests and forest edges in northern and western South America, mostly on hills and mountains. They range south as far as the Bolivian lowlands.Back to top

Food

Scarlet Tanagers eat mainly insects along with some fruit and tender buds. Their invertebrate diet includes ants, sawflies, moths, butterflies, beetles, flies, cicadas, leafhoppers, spittlebugs, treehoppers, plant lice, scale insects, termites, grasshoppers, locusts, dragonflies, dobsonflies, snails, earthworms, and spiders. While searching for these tidbits they walk along branches high in the canopy or (rarely) along the ground, or vertically on tree trunks to probe the bark. Scarlet Tanagers perch or hover with fast wingbeats to grab insects from leaves, bark, and flowers, and they catch flying insects like bees, wasps, and hornets from the air. They swallow small larvae whole, but they kill larger prey by pressing it into a branch. In the winter, they forage in mixed-species flocks with woodcreepers, flycatchers, barbets, and tropical tanagers.Back to top

Nesting

Nest Placement

The female chooses the nest site, usually selecting a shaded spot within a cluster of leaves at a juncture of small branches. Nests are often fairly high (50 feet or more from the ground) on a nearly horizontal branch well away from the trunk. The site usually has an unobstructed view of the ground and open flyways from nearby trees. Scarlet Tanagers tend to nest in mature deciduous trees such as maple, beech, and oak, but they also nest in eastern hemlock.

Nest Description

The female gathers nesting material from the forest floor and builds a flimsy nest in 3–4 days, spending relatively little time on it each day. She drops material onto the nest, hops in, and molds it into shape by pressing her body against the sides and bottom, then getting out and weaving in loose ends. The nest is a loosely woven saucer of twigs, grasses, plant stalks, bark strips, rootlets, and pine needles. It has a shallow and asymmetrical interior space, lined with grass, fine rootlets, fine plant fibers, vine tendrils, and pine needles.

Nesting Facts

Behavior

Scarlet Tanagers are strong fliers, making swift, direct flights and migrating long distances in fall and spring. Males arrive early on their breeding grounds to defend loose territories that include mating, nesting, and foraging areas. Territorial singing battles sometimes can escalate to confrontations, where one or both males spread and droop their wings and raise their tail in threat. If neither backs down, the standoff culminates in one male chasing another. Scarlet Tanagers are monogamous within each breeding season but switch mates from year to year. Parents feed their young for up to two weeks after the birds fledge, and then the family disperses before migrating. On wintering grounds Scarlet Tanagers join up with other species in foraging flocks.Back to top

Conservation

Scarlet Tanager populations held steady between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 2.6 million and rates them 12 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. Scarlet Tanagers are an interior forest species, so changes in land-use—fragmentation of forests from development and regrowth as cleared land reverts to forest—may be responsible for changes in population trends over time. In fragmented landscapes, nests are in greater danger of being parasitized by Brown-headed Cowbirds and attacked by predators that operate along habitat edges. To safeguard the Scarlet Tanager population, researchers recommend preserving and restoring mature forest habitat for breeding, migrating, and wintering birds.

Credits

Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.

Mowbray, Thomas B. (1999). Scarlet Tanager (Piranga olivacea), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.

Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.

Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.

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