December | 2014 | THE BIRDS OF ABACO

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

Thick-billed Vireo, Abaco Bahamas.Tom Sheley

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…

Thick-billed Vireo, Abaco (Becky Marvil 2).jpg

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.

This is a very yellow TBVWhereas this one has rather anaemic coloration Thick-billed Vireo, Abaco Bahamas .Tom Sheley Finally, this pretty TBV is very delicately marked

VIREO PAGE

BLACK-WHISKERED VIREO

PHILADELPHIA VIREO

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

COMMON YELLOWTHROATS ON ABACO: CHEERFUL WINTER WARBLERS

Abaco is fortunate to be home to the endemic BAHAMA YELLOWTHROAT Geothlypis rostrata, a striking bird with a dashing black mask and bright yellow body in the male. You can see it with its fellow endemics HERE. But there is similar winter resident species, the COMMON YELLOWTHROAT Geothlypis trichas, that can be seen on Abaco between October and March. Now is a very good time to look out for them. However, the two species are easy to confuse.

Common Yellowthroat (male) Common Yellowthroat, Gilpin Pond, Abaco Bahamas (Tom Sheley)

Bahama Yellowthroat (male)

WHAT’S THE DIFFERENCE?

SIZE – the BW is slightly larger and sturdier than the CW
BEAK – larger in the BW, and some might say it tends to be decurved
COLOUR – the BW is more colourful, with more extensive yellow underparts and mask
FEMALES – both species lack the mask and are duller; the female BW has a greyer head
HABITAT – both are found in the same areas; the CW prefers denser vegetation near water
DEBATEABLE – it seems to me the pale stripe behind the mask is usually less prominent in the BW

Common Yellowthroat male with conspicuous pale head-stripe 800px-Common_Yellowthroat_by_Dan_Pancamo

Both yellowthroat species are an endearing mix of shy and inquisitive. These birds are responsive to ‘pishing’, and once lured from cover they may remain nearby on low branches or shrubs watching you with interest as you watch them. Their song – similar in both species – is fairly easily imitated (or at least approximated), which may also bring them into the open – a source of great satisfaction to the amateur birder when it works. Unless it’s just coincidence, of course… The songs of the two species recorded below sound almost indistinguishable (except that the first one is professional and the second notably amateur…).

COMMON YELLOWTHROAT

Todd Wilson / Xeno Canto

BAHAMA YELLOWTHROAT

RH own recording

Female Common Yellowthroats are unassuming and quite delicate little birds. The first of these two images shows an immature bird, with its front beginning to become yellow. The second is a mature female. Common Yellowthroat (f, imm) Bruce Hallett IMG_9435 Common Yellowthroat (f) Bruce Hallett IMG_4057