As the migrating birds move north again from their ancestral homes to our south, and prepare for nesting season up here, it’s time to consider the various possibilities of the many similar birds we’re going to run into, foraging busily among the new leaves.  Although the numbers of many of the migrants have decreased significantly just in my lifetime, we can still expect to see a wide variety, even if we don’t often get half a dozen species in a tree together any more.  Today, we’ll take a look at the Vireos, a group of birds that are rather like large, thick-billed warblers.  They generally glean the foliage and bark for caterpillars and small flying insects, and may sing steadily while they forage.  Vireos tend to be more sedate than the lively, often flycatching, warblers, and aren’t as brightly colored and patterned, as a rule.  The first, and still the most common in the eastern woodlands, is the Red-eyed Vireo, generally found fairly high up in trees, foraging along the branches.  This one is pretty easily told by its heavily-bordered dark cap and black eyeline, even when the red eye is not very noticeable (which is the normal state of affairs).  It’s otherwise a fairly plain bird with an olive back and white underside.  It sings its very Robin-like song constantly, even while eating – not fast, but steadily and without stopping.

The next two vireos are fairly similar, and are like dull, plain versions of the Red-eyed Vireo.  They’re both tree foragers, but are found in more open areas rather than in the deeper woods.  The Warbling Vireo is fairly common, but local; I tend to find them most in wooded areas near water.  This one is the Gadwall of vireos – it’s just a very plain, unmarked bird, which is actually a very useful ID tip.  Most of the time, you’ll hear this bird before you see it – it has a loud, very noticeable song; like a sweeter, less scratchy House Finch.

Its cousin, the Philadelphia Vireo, is very similar, but a darker, and yellower bird with a very different song – different from the Warbling Vireo, anyway.  It’s very much like the Red-eyed Vireo’s song, and can be hard to tell apart.  Luckily the bird is easy to tell apart by sight!

The next vireo, the Blue-headed (formerly Solitary) Vireo is found more in wood edges along fields, but is also a branch and foliage gleaner like the Red-eyed.  It’s a shorter, stubbier bird with a relatively big, blueish head, white spectacles and white wingbars.  When starting out, this bird is often mistaken for a warbler, but one look at the relatively heavy, thick bill should set you right.  It’s like distinguishing plovers from sandpipers – the beak is different enough (usually) to point you in the right direction.  The song can be easily overlooked – it’s like a slow, more musical, slurred Red-eyed Vireo, with longer pauses between the phrases.

The Yellow-throated Vireo is very reminiscent of the Blue-headed Vireo, and has similar habits other than being a bird of taller trees and deeper woods.  However, the very yellow head and throat, with yellowish spectacles, makes it easier to pin down, once you use the thick bill to tell you it’s not a warbler.  The song is fairly Robin-like, but like the Scarlet Tanager, sounds relatively rough, unlike the clear whistles of the Red-eyed Vireo.  It usually includes a phrase that sounds like a rising “three-eight”, which is a good thing to listen for.

Finally, we come to the White-eyed Vireo; a bird of brushy fields and scrubby wood edges.  This bird looks similar to the last few, but behaves very differently and has a very different song.  It’s often hard to get a look at, as it skulks through the tangled scrub, but if you do get to see it, you’ll notice the green and grey head, with very bold yellow spectacles, white throat, white eyes and yellow flanks.  Most of the time, you’re just going to hear the loud, staccato, “Chick!-a-per-wee-oh, Chick!” song.