In some recent columns, I’ve focused on some of the summer songbirds — scarlet tanager, rose-breasted grosbeak – with flashy, bright plumages. Not all our summer nesting birds boast such vivid coloration. In fact, one family of songbirds — the vireos — is known for its dull plumage.
I’ve had some interesting encounters with vireos in the past few weeks. From early May through mid-June, a male red-eyed vireo sang daily from the woodland near my home. He would commence signing early in the morning and continue through late afternoon. I never saw him, which is not too surprising. Red-eyed vireos lead almost their entire lives in the forest canopy. If you do manage to observe one, you’ll see an olive green bird with white underpart. The red-eyed vireo, known scientifically as Vireo olivaceus, shows a narrow white eyebrow bordered above with black. It also has a grayish crown and the namesake red eye.
At a glance, the vireos would appear related to the wood warblers. Research into vireo DNA, however, has led many experts to contend that vireos are more closely related to crows and shrikes. Like the flycatcher, warbler and hummingbird families, the vireo family is exclusive to the New World. There are about 50 species of vireos. The majority reside in the tropics, but about a dozen species spend their nesting season within the United States.
In Southwest Virginia and Northeast Tennessee, vireos resident during the summer months include red-eyed, white-eyed, blue-headed, yellow-throated and warbling. Most people are likely unaware of vireos. Although not uncommon, these birds are much more frequently heard than seen. They spend much of their time in the forest canopy or in dense brush. When singing, they can remain at a perch, unmoving, for long periods of time.
On recent woodland walks I have heard the loud scolding calls of red-eyed vireos. This call, given apparently when the vireo is alarmed or irritated, is quite unlike the usual vocalizations produced by this bird. First and foremost, the call is louder than one would think could be produced by a bird that is only about six inches long.
During the summer season, the red-eyed vireo is also one of the most persistent of singing songbirds. Another of its common names is “Preacher Bird,” so called because of its tendency to unceasingly deliver it song. To give you an idea of just how persistently this bird sings, the red-eyed vireo holds the record for singing its song the most times in a single day. Some individuals have been recorded singing the series of emphatic syllables more than 20,000 times in a day. The song is not particularly musical, consisting of whistled phrases, each slightly different and punctuated with brief pauses.
The red-eyed vireo is still considered one of eastern North America’s most common summer breeding birds. At one time, this bird was probably the most common breeding bird in Eastern woodlands. It is still one of the most widespread, ranging from the Eastern United States into the Northwestern United States and across Canada. In fall, they withdraw to spend the winter in South America.
The term “vireo,” originating in Latin, can be translated into English as “green bird.” It’s an apt description, as many of these small birds are primarily dull green in coloration.
There is an endangered vireo, the black-capped vireo, a bird with a limited breeding range in Texas. Black-capped vireos numbers have dwindled to perilous levels due to the loss of low growing woody cover these birds need for breeding purposes. The cause of the loss of habitat varies, but includes the clearance of land for livestock as well as overgrazing by livestock and deer. In the past, fires regularly opened up such habitats. Due to modern fire control practices, such fires are no longer a natural occurrence. Since this species is already endangered, brown-headed cowbirds have also contributed to the problem since the cowbirds slip their own eggs into the nests of black-capped vireos.
Two others, Bell’s vireo and gray vireo, are identified as species of concern on the Audubon Watchlist. This listing spotlights species that may bear intense scrutiny to make certain they don’t become endangered.
Other vireos that can be found in the United States, for at least part of the year, include Philadelphia vireo, plumbeous vireo and Cassin’s vireo. A specialty of Florida is the black-whiskered vireo.
Many species of vireo are also found in the islands of the Caribbean, including Jamaican vireo, Cuban vireo and Puerto Rican vireo. Some of the more colorful common names for vireos include the yellow-green vireo, golden vireo and yellow-winged vireo.
In Central and South America, the vireo family expands to include many birds with common names such as “Shrike-Vireo,” “Greenlet” and “Peppershrike.” Some of the varied species include the lemon-chested greenlet, green shrike-vireo and the black-bellied peppershrike.
Known by the scientific name, Vireo gilvus, the warbling vireo is another member of this family of songbirds that can be found in the region. It is named for its distinctive, warbling song. Some experts have likened its song to that of the painted bunting. That must be about all the two birds have in common. In contrast with the gaudy painted bunting, the warbling vireo can quite honestly stake a claim as one of our most drab songbirds. Overall, this is a grayish little bird with a white eyeline that is paler than the rest of its plumage. Its legs are blue-gray in color and this species has a bill that is stout like other vireos and unlike the beaks of most warblers. It’s their plainness that is the most distinctive aspect of their appearance.
Many vireos construct deep cup- or basket-shaped nests, often in the higher branches of tall trees. Male and female share incubation duties and work together to feed their young.
Most vireos feed on insects during their summer stay north of the border. However, during migration they often feed on berries and continue to do so on their wintering grounds. Experts have noted that the white-throated vireo is particularly fond of gumbo-limbo seeds. This tropical tree can be found from southern Florida and Mexico, as well as throughout the Caribbean and in South America in Brazil and Venezuela.
At times, it’s important to use our ears, as well as our eyes, when trying to find birds. That’s particularly true of the vireos. The widespread family can be found in rural areas, as well as suburban settings. Tall stands of trees are one of the essential requirements. So, when you next hear some whistled phrases coming from the treetops, be sure to look up. You may get lucky.
To hear a singing red-eyed vireo, visit the link below to view a video of the bird on YouTube: