The Red-eyed Vireo (Vireo olivaceus) is a small passerine bird species found in North and South America. Adults have an average length of 6 inches (15 cm) and weigh between 0.4 to 0.5 ounces (11-14 g). They have a distinct red iris which contrasts against their grey crown and olive-green upperparts. Their underparts are off-white with a pale yellow wash on the sides, and they have two whitish wing bars. They have a hooked bill, which is perfect for catching insects on the wing.
During breeding season, Red-eyed Vireos can be found throughout eastern North America, from southern Canada to northern Florida, and as far west as the Great Plains. They prefer deciduous and mixed forests and can often be heard singing their persistent, cheerful, and melodious song from high in the tree canopy. Red-eyed Vireos migrate south to winter in Central and South America, with some individuals traveling as far as Argentina.
The Red-eyed Vireo is a highly active bird, constantly foraging for insects, which make up the majority of its diet. It is known to consume a variety of insects, including beetles, caterpillars, and spiders. They also eat some fruits and berries, especially during the winter months when insects are scarce. During migration, Red-eyed Vireos are known to stopover in forested areas and parks to rest and refuel before continuing their journey.
Red-eyed Vireos are monogamous and form breeding pairs each year. Females lay a clutch of 3 to 5 eggs, which are incubated for approximately two weeks. Both parents share the responsibility of incubating the eggs and feeding the chicks. The young birds fledge after approximately two weeks and are independent within a month. Red-eyed Vireos are common and widespread, with an estimated global population of 100 million individuals, and are not currently considered a threatened species.
Overall, the Red-eyed Vireo is a beautiful and fascinating bird species, known for its striking red eye, melodious song, and migratory habits. They are an important part of the forest ecosystem, playing a key role in insect control and pollination. With their distinctive field marks and behavior, they are a favorite among birdwatchers and nature enthusiasts.