Birding and Bird Conservation
Two tanager species migrate north from the Neotropics to breed in eastern North America. Pennsylvania’s two “tanagers” are actually part of the Cardinal family, Cardinalidae, that also includes some grosbeaks, buntings, other tanagers, and cardinals. The word tanager comes from a South American Indian word denoting a small, brightly colored bird. In tropical forests, mixed feeding flocks may include over a dozen kinds of species in plumages of red, yellow, green, blue and purple. Each of these two tanagers actually spends more time in the rainforests of South America in winter than they spend on their northern nesting grounds. So, they truly offer a glimpse of the tropics in Pennsylvania.
Scarlet Tanager (Piranga olivacea)
Male scarlet tanagers are noted for their bright fluorescent red color. Males arrive on the breeding range (eastern North America from southern Canada to the Carolinas) in late April and early May, just as trees are beginning to leaf out. Their bodies are red, and their wings and tails are jet black. Females, which show up a few days later, are a greenish yellow that blends with the leaves in which they rest and feed. In winter, male tanagers look green like females, so their plumage can have a confusing mix of red, green, and yellow while they molt in early fall and in spring. Adults are about seven inches in length.
Scarlet tanagers favor dry, upland oak woods, especially more mature woods. They also inhabit mixed and coniferous forests and shade plantings in suburbs and parks. Males claim two- to six-acre territories by singing almost constantly from prominent perches and driving away competing males. The song sounds like
ieeveet, five to nine slightly hoarse notes (“like a robin with a sore throat,” said Roger Tory Peterson). The call note “chip-berrr” is one of the most commonly heard sounds of the Pennsylvania summer woods. Males whose territories adjoin sometimes perch along shared boundaries and countersing. Males return to previous years’ territories, but it is thought that females lack this strong homing instinct, so that they rarely take the same mate in succeeding years.
Insects and fruits form the bulk of the diet. Females forage higher in the tree canopy than males. Both sexes work slowly and methodically, inspecting leaves, twigs and branches and picking at leaf clusters near the ends of twigs. Sometimes they make short flights to catch flying insects, particularly bees and wasps. They eat caterpillars, moths, adult and larval beetles, dragonflies, aphids, snails, spiders, worms and millipedes. During cold snaps they land on the ground and hunt for beetles, earthworms and other terrestrial prey. They also eat tender buds, wild fruits and berries, and cultivated fruits such as cherries.
Scarlet tanagers nest in late May and June. To rear a brood, a pair needs at least four wooded acres, with eight the optimum. During courtship the male flies to a perch below the female; he droops his wings and spreads his tail to show off his brilliant back. If the female strays outside his territory, he chases her back into it. Tanagers mate frequently, with the female crouching and calling to entice the male. She chooses the nest site and builds the nest herself, over three to seven days, while the male sings from perches at the mid-forest level. Tanagers nest lower than they forage; nests are eight to 75 feet up (usually 18 to 50 feet), often near the end of a horizontal branch in an oak, with a view of the ground and with clear flyways from nearby trees. The nest is flattish and rather flimsy, made of twigs and rootlets and lined with grasses and stems. Some nests are so loosely woven that the eggs can be seen from beneath. The female lays two to five eggs, usually four. The eggs are pale blue-green marked with brown.
The female incubates them for about two weeks, with the male bringing food to her. Both parents feed insects and fruit to the young, which leave the nest after 9 to 12 days. The parents keep feeding them for two more weeks. Only one brood is produced each summer.
Fledglings are brown, with slight streaking. In late summer the adults molt, and for a while the male is a patchwork of red, yellow and green. He ends up looking like the female, but retains his black wings and tail. Scarlet tanagers leave Pennsylvania in September and early October.
They migrate mainly through the Caribbean lowlands of Middle America and spend most of the year east of the Andes in remote forests of Colombia, Ecuador, Peru and Bolivia. There they sometimes join mixed-species flocks and feed in the canopy (along with other tanagers) and in fruiting trees.
One scarlet tanager that had been banded lived for ten years; most, however, probably don’t survive for half that long. They are preyed on by hawks, falcons and owls. Tanagers attack squirrels and blue jays, which nevertheless manage to rifle many nests. Crows also eat eggs and fledglings. Brown-headed cowbirds parasitize more than half of all tanager nests in some areas, particularly where the forest has been fragmented by logging or home development.
Scarlet tanagers nest statewide in Pennsylvania and are more common than many people think, though they are absent from treeless urban areas and intensively farmed lands. The highest populations occur in mature, extensive forests and are a fairly common species in the state’s game lands. Pennsylvania’s forests support ten percent of the world’s population of scarlet tanagers. As a result, Pennsylvania has high stewardship responsibility for this species. For this reason, it is a high priority conservation species in the Wildlife Action Plan. It is important that the commonwealth manages its forests in such a way as to retain healthy populations of this beautiful and appealing songbird for the enjoyment of future generations.
Summer Tanager (Piranga rubra)
This tanager breeds mainly in the Southeastern U.S., where it is called the “summer redbird.” The summer tanager is slightly larger than the scarlet tanager and it has a much larger bill. The male has rosy red plumage all over while the females are a mustard yellow. Female scarlet tanagers have greener plumage. The song of the summer tanager is a lot like the sweet sound of an American robin, not hoarse like a scarlet tanager. The call note of summer tanager is a distinctive, insistent “piti-uck”.
Its range extends sporadically into southern Pennsylvania. It was formerly found regularly in Greene County and other southwestern counties, but this colorful songbird has declined from the northern part of its breeding range in recent years. It is now only rarely encountered in southern Pennsylvania counties. The summer tanager’s future in Pennsylvania as a nesting species seems tenuous. Summer tanagers inhabit dry upland forests, with a preference for slightly open oak woods and edges. In summer they eat mainly insects: caterpillars, moths, beetles, cicadas, grasshoppers, flies and others; often they tear open wasp nests to feed on larvae, apparently without being stung. They also eat fruits and berries, especially in migration and on their wintering grounds. The summer tanager’s breeding and nesting habits are similar to those of the scarlet tanager. In migration, they sometime overshoot their nesting range and wander north before returning south to their breeding territories. Summer tanagers fly south each fall, most crossing over the Gulf of Mexico to spend the majority of the year on a large range that extends from central Mexico to Bolivia and Brazil.