THICK-BILLED VIREOS: ABACO’S ONLY PERMANENT RESIDENT VIREO
Unlike the other 7 vireo species found on Abaco seasonally or as transients, the Thick-billed Vireo Vireo crassirostris is an ever-present permanent resident of the coppice and scrub; and their unmistakeable repeating song can be heard almost everywhere.
Although TBVs are very easy to hear and track to a general area of coppice, I find actually seeing the bird creating the noise quite hard – let alone getting a clear camera shot. They always seem to be lurking several feet further away, deeper in the foliage, than the sound suggests.
Paul Driver / Xeno Canto
The main signifiers for this species, which in combination distinguish the TBV from the other vireo species on Abaco, are:
- Two white wing bars
- Yellow patch – usually quite prominent – between eye and beak
- Thick bill – which immediately rules it out of being one of the 37 warbler species on Abaco…
There are marked colour variations in the species according to maturity, season and to an extent gender (though m & f are quite similar). Here’s one that is causing wing-bar confusion by only showing traces. It also has quite dark upper parts.
Credits: Tom Reed (1), Craig Nash (2), Gerlinde Taurer (3), Bruce Hallett (4, 8), Tom Sheley (5, 9), Becky Marvil (6), Alex Hughes (7), Tony Hepburn (10); Paul Driver / Xeno Canto
Vireos haven’t had as much attention as they deserve hereabouts. I have posted about the BLACK-WHISKERED VIREO, but the 7 other vireo species found on Abaco haven’t had much of a look in. It’s a wrong that I shall right at once by featuring the rather shy Philadelphia Vireo Vireo philadelphicus. Here is the full list of the vireos recorded for Abaco, from which you will see that only the Thick-billed Vireo is a common permanent resident. The Black-whiskered vireo is a common summer breeding resident; there are 2 uncommon winter residents; and the other 4 are transients that chose Abaco as a resting place on their migrations.
This little bird tends to be described with such unkind adjectives as ‘drab’, ‘dull’ and ‘plain’, but like many under-appreciated species it has its own charm. The header image and the one above give excellent close-up views. The signifiers include the dark eyes, white eyebrows, the dark line through the eyes, the yellow underparts, and in the negative sense the complete absence of eye rings, wing bars or tail markings. And the thick bill is one quick way to distinguish it from similar-looking warbler species, with their generally smaller, pointy beaks.
The Philadelphia Vireo has a wide range, from its summer breeding grounds as far north as Canada down to its winter quarters in Mexico and South America. They have even, very rarely, been seen in Europe. The connection with Philadelphia is somewhat tenuous and arises because the bird was first identified in 1842 from a specimen collected near Philadelphia. However their visits there are brief, since at best it is only a stopover on their migration route…
Here is the song comparison between (in order) the Philly, the familiar TBV whose song accompanies everyday life on Abaco, and the Black-whiskered vireo. My TBV recording is rather quieter than the other 2.
Andrew Spencer / Xeno Canto
RH at Delphi
Brian Cox / Xeno-Canto
If you want to know how to record birdsong easily using an iPhone or equivalent CLICK HERE
Credits: Woody Bracey (2, 3); Brian McClure, Dominic Sherony, William H. Majoros, Xeno Canto, Wiki, Cornell Lab
There are 8 vireo species recorded for Abaco. The most common is the ubiquitous Thick-billed Vireo Vireo crassirostris – the only permanent resident vireo – whose cheery chirp is part of the background of bird song heard daily all over the island. The only other species you are likely to encounter without going out of your way is the summer resident BLACK-WHISKERED VIREO Vireo altiloquus, which breeds on Abaco. The other 6 are the White-eyed, Yellow-throated, Blue-headed, Warbling, Philadelphia, and Red-eyed Vireo. Of these, the first 2 are quite rare winter residents; and the other 4 are considered to be transients.
The BWV’s song is similar to the Thick-billed Vireo, but (luckily) identifiably different. I’m not a great one for phonetic attempts at turning a bird call into a human sentence of the ‘Quick!-come-to-pick-up-a-brick’ and the ‘Skin-me-a-nice-bit-of-bonefish’ type. The Black-whiskered Vireo’s song has been described as sounding like ‘Whip, Tom Kelly’. But not to me. See what you make of it…
Brian Cox / Xeno-Canto
As with other vireo species, the BWV has a stout bill, a feature that helps to distinguish vireos from the many thin-billed warbler species on Abaco. The main signifiers are found on this bird’s head: the dark stripe right through the eye; the long white eyebrows; and the noticeable black lines – the ‘whiskers’ – on the sides of the neck. Other identification pointers are the pale underside with a yellow tinge to the flanks and undertail; and the red eyes (the red-eyed vireo, a very similar bird, lacks the whiskers).
Black-whiskered vireos feed mostly on insects in trees, bushes and undergrowth. They can sometimes be seen hovering while they forage. They also vary their diet with small quantities of berries. Here are two great shots of a mother BWV feeding a very large chick with a berry, followed by some vile insect.
Image Credits: Bruce Hallett, Tom Shelley, Charlie Skinner, Charmaine Albury, Erik Gauger