Birdwise: the red-eyed vireo is a singing wonder
Like the oven bird and the scarlet tanager, it is more often heard than seen. A glimpse reveals an olive green bird with a contrasting slate gray cap, black eye stripes framing a white eyebrow, and bright red eyes. But its rather understated appearance is not the most famous feature of this vireo.
âThe red-eyed vireo is eminently famous as a singer,â noted ornithologist Arthur C. Bent. “No other of our birds sings with such perseverance all day long, and because his long series of utterances, given in short and emphatic sentences, for hours, recalls a long sermon, he won the title of ‘Preacher “. ‘”
One intrepid researcher counted the number of songs sung by a red-eyed male vireo in the territory – the bird sang over 20,000 times in just 14 hours!
But the seemingly endless song of the red-eyed vireo is notable for more than just stamina.
In addition to his vocal endurance, a red-eyed male vireo commands a large repertoire of sung phrases. Unlike other passerines, who sing the same song over and over, the “vocabulary” of this talented vireo – which averages 47 different phrases – allows a male to sing over 30 types of songs and combine them into up to to 80 different songs! Moreover, each male combines these phrases and types of songs in his own way.
Researchers recorded 12,500 different types of red-eyed vireo song, an astonishing attribute for a supposedly unpretentious songbird.
Unlike its song, the red-eyed vireo’s call is a whiny meow that looks a bit like that of a gray cat-cat. Both males and females call aggressively in response to potential predators or intruders entering their territory.
The Red-eyed Vireo is one of the most common migratory songbirds nesting in North America, with a breeding range spanning the boreal forests of southern Canada and the deciduous forests of northwestern Canada. central and eastern United States.
These small songbirds are powerful migrants, roaming long distances at night in groups of 30 or in mixed species groups with migrating warblers, tanagers and flycatchers.
The red-eyed vireo flies to northern South America for the winter, concentrating mostly in the Amazon basin. Wintering red-eyed vireos may remain with mixed-species groups on their wintering grounds.
Like the Cape Warbler, Wood Thrush, and many other neotropical migrants, the Red-eyed Vireo is primarily insectivorous during the breeding season, capturing a wide variety of insects including caterpillars, beetles, cicadas, wasps and grasshoppers.
It moves slowly through the canopy while foraging for food, scooping up prey from leaves or stems with its sturdy, slightly hooked bill. It also flies to catch bugs in the air, sometimes continuing to sing as it secures its meal.
Interestingly, pairs of nesting red-eyed vireos feed at different heights in the canopy, with males foraging higher in trees, closer to their song perches, and females foraging at lower levels, closer. of their nests.
As fall migration approaches, the red-eyed vireo adds a variety of berries and seeds to its diet, packing the fat it needs to fuel its long-distance journey. During the winter, he switches to a predominantly fruity diet.
Male red-eyed vireos return to breeding grounds before females. Each male stakes and defends a territory by song, patrolling a number of song perches around its territory and aggressively attacking and chasing intruding males throughout the breeding season.
Newly arrived females each choose a nesting site within a male’s territory. After mating, the female builds a cup-shaped hanging nest between the fork of two tree branches, often hidden under hanging vegetation that provides additional security.
While not quite as while that of a Baltimore oriole, the pocket-shaped nest of grasses, roots, bark bands, and cobwebs is easy to identify. Unfortunately, these beautiful nests are often found by the brown-headed cowbird, a brood parasite that lays its eggs in the nests of other birds.
After completing her brood, the red-eyed vireo female incubates her three to four eggs and broods the young after they hatch. The male will provide the female with food, starting during nest construction and continuing while she takes care of the young. Red-eyed vireos often nest several times per season, especially if the first nest fails.
Juvenile red-eyed vireos are easily identified by the color of their brown eyes. They do not reach the red eyes of an adult until their second year.
Although the red-eyed vireo remains abundant, it faces the same threats that rarer birds face, particularly habitat loss and fragmentation on its breeding and wintering grounds. It is frequently the victim of collisions with glass, towers and wind turbines.