October | 2018 | THE BIRDS OF ABACO

BLACK-THROATED BLUE WARBLERS ON ABACO

It’s warbler time of year on Abaco, and a good time to take a look at the Black-throated blue warbler Setophaga caerulescens. This small warbler has very particular breeding and overwintering ranges. In the summer they are found in the forests and woods of eastern North America. As the Fall approaches, they start to migrate south to the Caribbean and Central America. Abaco is one of their winter homes, as well as a likely transit stop on their way further south. Right now sightings are being reported on the mainland and the Cays.

WHAT DO I LOOK OUT FOR?

Males and females are quite different in appearance (‘sexually dimorphic’), and could even be mistaken for distinct species. Males are a deep slate-blue above (hence caerulescens) with a striking black face and throat, and white underparts. They are unmistakeable, and unlikely to be confused with any other warbler. Females are basically grayish-olive above and pale yellow underneath. For ID, look for a white stripe above the eye, a pale arc below it. In addition, both sexes have a diagnostic white patch on the the wing.

The bird cartoon site Birdorable as usual has a spot-on comparison of the sexes

These pretty warblers can be seen in gardens, coppice, and woodland. Although mainly insect-eaters, sometimes catching them in flight, they also eat fruit and seeds especially in winter. BTBWs are territorial, and will defend their chosen space against all-comers, including their own species.

WHAT DO I LISTEN OUT FOR?

One source asserts: “The bird’s song can be described as a buzzed zee-zee-zeeee with an upward inflection. Its call is a flat ctuk”. See what you think…

SONG Etienne Leroy / Xeno-Canto

CALL Paul Marvin / Xeno-Canto

ARE BTBWs THREATENED?

BTBWs are fairly common birds within their range, with a large population. The usual stuff is happening with them in terms of habitat destruction & co at both ends of their migration. For some already threatened species (e.g. Kirtland’s Warblers), habitat degradation at either end of the migration (let alone both) presages a downward spiral in population. With BTBWs, I have read both that the population is decreasing; and in another source, slightly increasing. For now, let’s regard the welfare of the species as being stable. However, the current causes of species decline will doubtless continue, and many regard increasingly evident climate change as being a determining factor for the well-being of migratory species. The birds are not yet out of the woods, so to speak… and maybe never will be.

CREDITS Photos: Gerlinde Taurer (1, 2); Becky Marvil (3); Bruce Hallett (4); Blaine Rothauser / CWFNJ (5); @daxroman / Birds Caribbean (7); Paul Reeves / Birds Caribbean (8). Range Map, Wiki; Cartoons, Birdorable; Video, Cornell Lab for Ornithology

PALM WARBLERS: ‘HEADS-UP FOR BUTTERBUTTS’

I realise that the title of this post has its unattractive aspects. This is a family blog, and we try to keep references to ‘butts’ and so forth to a minimum. But like it or not, the Palm Warbler is one of two species** that have acquired the nickname ‘butterbutt’. They weren’t even consulted; birders just went ahead with it without checking how they’d feel about it.

On the other hand, it’s easy to see how this minor linguistic outrage came about. It’s there for all to see, right under the bird’s… erm… stern. That flash of vivid yellow, together with the pale speckled front, a rusty brown cap and striking eye-stripe, is diagnostic for this Abaco winter resident species.

The ‘heads-up’ is because right now they are among you. In the gardens, on the grass, on the tracks, in the coppice, in the casuarinas. And they have an endearing habit of bobbing their… tails, let’s say, as they forage. Palm Warblers are inclined to be fairly inquisitive and tame, so if you are careful, they may stay around to let you watch them.

The PW above must, I think, have been photographed at the very end of the winter season, just before it headed north from Abaco. The strong colours suggest this guy is getting into the breeding mood. Compare him with the picture below, taken by the same photographer during the same period, of a slightly less garish stage of breeding plumage. But it’s on its way…

As often as not, a palm warbler will be fairly easy to spot. Not always, though. You may have to work a bit to locate one half-hidden in foliage. Its posterior may not even be visible.

Luckily, PWs are common enough in winter to give you a chance to shoot them in the open, as it were. Perched on a branch works just fine to capture the essential characteristics.

Keep an eye out for these pretty little warblers. They are enjoyable to watch, and relatively easy to get a photo of at close quarters. Just make sure you get the butterbutt into the picture.

** The other butterbutt bird is the descriptively-named YELLOW-RUMPED WARBLER, though its buttery bits are on the topside so there’s no risk of confusion (I photographed this one as a distance shot at the top of a tree with a small camera – but it captures the essentials!)

Credits: Bruce Hallett (1)*; Gerlinde Taurer (2, 7); Nina Henry (3, 4, 5); Peter Mantle (6); Keith Salvesen (8, 9)

* Possibly Tom Sheley – all I have got on the filename is ‘Fruit Farm’ so I can’t be sure of the photographer’s ID – apologies

THE BIRDS OF ABACO

The Definitive Guide to the Birds of Abaco, Bahamas

Monthly Archives: October 2018

BLACK-THROATED BLUE WARBLERS ON ABACO

BLACK-THROATED BLUE WARBLERS ON ABACO

PALM WARBLERS

PALM WARBLERS: ‘HEADS-UP FOR BUTTERBUTTS’