KIRTLAND’S WARBLERS: ABACO’S RARE TREASURES


Kirtland's Warbler, Abaco Bahamas (Bruce Hallett)

KIRTLAND’S WARBLER: ABACO’S RARE TREASURES

This is a challenging topic that I have been (shamefully) putting off. My task is a full-scale facing-up to an extremely rare, very small, and rather adorable adversary, the Kirtland’s Warbler (Setophaga kirtlandii). There are probably more dedicated KIWA experts out there than there are birds of this scarce species. Estimates of bird numbers vary wildly, but if I take a consensus of the mean of an approximate average of the median as ± 5000 individuals, I’d probably be in the ballpark named “Current Thinking“. 

Kirtland's Warbler, Abaco Bahamas (Bruce Hallett)

THAT SOUNDS QUITE RARE, RIGHT?

Around 50 years ago, the species was all but extinct – perhaps fewer than 500 birds in total, a barely sustainable population. In 1975, Brudenell-Bruce estimated 1000. I’ll mention some of the reasons later. In the 1970s, the Kirtland’s Warbler Recovery Plan was instituted with the twin objectives of protecting the vulnerable breeding habitat – basically large areas of jack pine; and of monitoring and management aimed at encouraging an increase in numbers. Around that time, they became IUCN listed as vulnerable, but more recently, population growth has resulted in a recategorisation to the more optimistic near-threatened category.

Kirtland's Warbler, Abaco Bahamas (Bruce Hallett)

AND THEY LIVE  WHERE, EXACTLY?

In spring and summer almost the entire KIWA population lives and breeds in very specific areas of Michigan and Ontario, where jack pines are found. There are signs that the range has expanded slightly in Michigan and more widely into Wisconsin and Ohio as the numbers have increased.

A Kirtland’s Warbler in the jack pines of Michigan (Vince Cavalieri)Kirtland's Warbler, Michigan (©Vince Cavalieri)

In the fall and winter the population migrates to the Bahamas & TCI, where they tend to choose remote scrub and coppice areas to live until the spring when they return north in April. This range map shows the extremely specialist habitat choices of these migratory birds.

A Kirtland’s Warbler in Ohio Kirtland's Warbler, Ohio (Tom Sheley)

SO THEY ARE REALLY FOUND ON ABACO?

Yes – but they are notoriously hard to find. To give you an idea, I checked the eBird stats for Abaco sightings over the last 10 years: 9 successful trips reported, with 18 birds seen in all**.  There were 3 groups comprising 6, 4, and 2 birds; and the rest were single birds. Abaco ornithologist and guide Woody Bracey is the go-to man for finding these little birds. Two years ago we were in his party that saw 4 in the space of a couple of hours. I was supposedly the photographer, but unaccountably found myself in completely the wrong place for the first 3. The 4th flew off a branch and straight at my head as I raised the camera… I felt the wind as it passed on its way deep into the coppice. I’m not proud of my effort; the fuzzy lemon item beyond the twigs and leaves is a KIWA (you’ll have to take my word for it…).

Kirtland's Warbler, Abaco Bahamas (Rolling Harbour / KS)

HAVE ANY BEEN SEEN ON ABACO THIS YEAR?

Last week, Woody took another party to the main hotspot in the Abaco National Park, a protected area at the southern end of the island. The park is huge, covering more than 20,000 acres of (mostly) pine forest. These birds are tiny, about 14 cms long and weighing 14 gms. Despite which they found a female and then a male KIWA in their favoured habitat beyond the pine forest. Those are the only 2 I’ve heard about this winter season.

Kirtland’s Warbler, Abaco Bahamas, 12 April 2018 Kirtland's Warbler, Abaco Bahamas (Woody Bracey)

WHAT DO I LOOK OUT FOR?

  • Gray head with a blueish tinge, gray-brown back
  • Yellow throat & underside, with some dark streaking
  • Females are paler and more streaked
  • Split eye rings – white crescents above and below eyes
  • Frequent tail pumping and bobbing (‘tail-wagging’ J. Bond)

WHAT DO THEY SOUND LIKE?

Some would say ‘chip-chip-chip-too-too-weet-weet’. Elsewhere I have found they produce ‘a loud tchip, song an emphatic flip lip lip-lip-lip-tip-tip CHIDIP‘ (Arnott). You be the judge!

 Ross Gallardy / Xeno-Canto

Kirtland's Warbler, Abaco Bahamas (Tony Hepburn)

WHAT ARE THE MAIN THREATS TO THE SPECIES?

  • Mankind is the primary threat. The breeding areas are particularly vulnerable from deforestation and clearance of the jack pines that are essential for successful nesting and breeding – and therefore the survival of the species.
  • Encroachment of development is another threat, as with so many species.
  • There is a further threat of nest parasitism by brown-headed cowbirds, to which KIWAs are especially vulnerable.
  • In the winter grounds where the habitat is mostly remote or in protected areas, there is rather less of a problem from these factors – for now at least.
  • Overall, habitat degradation at one end of the migration – in particular the breeding grounds – poses a serious risk; at both ends, extinction could loom again.

Kirtland's Warbler, Abaco Bahamas (Woody Bracey)

WHO WAS MR KIRTLAND?

Jared Potter Kirtland (1793-1877) portrait

Jared Potter Kirtland (1793-1877)

Jared P. Kirtland (1793 – 1877) was an Ohio scholar, doctor, judge, politician and amateur naturalist. He was a man of many and varied interests and talents, not-untypical of his time. In the field of natural history, Kirtland’s name lives on in his warbler; and also in a couple of snake species.

The Bahamas Postal Service is commendably active in producing wildlife stamps

**I realise eBird is not the be-all and end-all for sighting reports. It hasn’t been in existence for as long as 10 years, and not everyone uses it anyway. And awareness of the Bahamas as the winter home for KIWAs is a surprisingly recent development (as with piping plovers). As awareness increases, so do birder interest, habitat knowledge, and consequently reports of sightings.

Another example of the ‘twigs in the way’ problem for photographers

Credits: Bruce Hallett (1, 2, 3); Vince Cavalieri (4); Tom Sheley (5); Unattributable (me, in fact) 6; Woody Bracey (7, 9); Tony Hepburn (8); Lionel Levene (10); Birds of North America (range map); Ross Gallardy / Xeno-Canto (audio file); Birdorable (cartoon); BPS (KIWA stamp). Special thanks for all use permissions for images of this rare bird.

BLACKPOLL WARBLERS ON ABACO: UNCOMMON TRANSIENTS


Blackpoll Walbler dendroica_striata_mn-cephas-wiki

BLACKPOLL WARBLERS ON ABACO: UNCOMMON TRANSIENTS

The Blackpoll Warbler Setophaga striata is a “TR3” on Abaco. Which is to say, the species is classified as an uncommon transient in its migration, and as such it is rarely seen on Abaco. Apart from anything else the window of opportunity of seeing one in the Fall or in Spring is limited by the length of time they pause on Abaco to catch their breath. Also, they are small birds that do not draw attention to themselves. They hang around in the coppice foliage rather than parading out in the open; and their call is a tiny ‘tsip‘ sound (as with so many other small birds…). 

Blackpoll Warbler, Man-o-War Cay, Abaco (Charmaine Albury)

Fortunately, on Abaco’s warbler magnet Man-o-War Cay, alert birder Charmaine Albury was out and about with her camera to record a sighting. I should say that during the writing of THE BIRDS OF ABACO, I never managed to obtain a single image – however poor – of a Blackpoll Warbler actually taken on Abaco (a qualification for inclusion) from any of the many sources I used. So sadly, this pretty warbler does not feature in the book.

Blackpoll Warbler, Man-o-War Cay, Abaco (Charmaine Albury)

The summer breeding area for blackpolls covers northern North America from Alaska through most of Canada, the Great Lakes region and New England. In the fall, they fly South to the Greater Antilles and the northeastern coasts of South America. The summer and winter areas are very distinct, as the distribution map shows:

dendroica_striata_map-svg

Despite their diminutive size**, blackpoll warblers generally undertake their  long-distance migration – often over open water – non-stop or with a single stopover.  Their migration has been the subject of many scientific studies. One of the longest distance non-stop overwater flights ever recorded for a migratory songbird was made by a BLWA. Which all goes to explain why the species is so rarely seen along the migration route: unlike many migrating birds, they make few, if any, stops along the way.

Blackpoll Warbler, Man-o-War Cay, Abaco (Charmaine Albury)

Of the many stats I have read through, I chose one to demonstrate the stamina of these little birds. In one study, an number were fitted with tiny geolocators. These revealed an average migration journey of around 1600 miles, with the non-stop trip being completed in 3 days by at least one bird.

f1-medium

“Transoceanic migration by a 12 g songbird”

The maps above show blackpoll warbler migrations recorded for 5 birds in a study that indicates that, while a direct overwater route is preferred in the fall migration, the return journey in spring is more leisurely, and overland (it looks as though only 3 birds made it home).

The study quoted is by William V. DeLuca, Bradley K. Woodworth, Christopher C. Rimmer, Peter P. Marra, Philip D. Taylor, Kent P. McFarland, Stuart A. Mackenzie, D. Ryan Norris (

Blackpoll Warbler, Man-o-War Cay, Abaco (Charmaine Albury)

** I came across the statement that “The blackpoll warbler… attains the weight of a ball point pen”. I find this an unhelpful comparison. I know what is meant, but I find it hard to think of a ball of feathers in terms of a writing instrument. Maybe it’s just me? [Astute Reader: I’m afraid so…]

YOU MENTIONED THAT THEY GO ‘TSIP’. WHAT DOES THAT EVEN SOUND LIKE?

Credits: header image of a summer bird, Cephas; all other photos by Charmaine Albury, taken on Man-o-War Cay Abaco; birdsong Xeno-Canto / wikimedia commons

PRETTY PALMS: CHEERY WARBLERS ON SUNNY ABACO


220px-Palm_Warbler,_Indiatlatlantic

PRETTY PALMS: CHEERY WARBLERS ON SUNNY ABACO

Palm Warblers Setophaga palmarum are cheerful little birds. Keen feeders, foraging around on the ground, in the coppice, or where there are pines. They are one of only 3 warbler species that bobs its tail, not just when it’s happy but much of the time. Maybe it is happy much of the time. The other 2 species are the relatively familiar Prairie Warbler; and the vanishingly rare – on Abaco, at least – Kirtland’s Warbler, the avian Holy Grail for birdwatchers on the island. 

The male palm warbler in breeding plumage has a smart chestnut cap and what might be described as a ‘buttery’ BTM, to use a polite text-abbrev. The females are paler and have less yellow on them. The photos below were taken in March this year, mostly by Mrs RH (I can’t now recall who took what so I’ll give a general credit until she claims her ones). You’ll see the wide variety of types of place you might encounter one of these little birds. The last picture isn’t great as a photograph… but it’s a classic bit of acrobatic personal grooming.

CALL [audio http://www.xeno-canto.org/sounds/uploaded/HNJLXSFHYB/palm_warbler_callnotes_xc.mp3]

Palm Warbler, Abaco 7 Palm Warbler, Abaco 6 Palm Warbler, Abaco 5 Palm Warbler, Abaco 4 Palm Warbler, Abaco 3 Palm Warbler Abaco 2 Palm Warbler Abaco 1Thank you for admiring me…Palm Warbler, Abaco 9…now please excuse me if I scratch my ear for a moment…Palm Warbler, Abaco 8Header thumbnail image credit: Wiki

PROTHONOTARY WARBLERS ON ABACO, BAHAMAS: WHAT’S IN A NAME?


PROTHONOTARY WARBLERS ON ABACO, BAHAMAS

Janene Roessler has kindly sent news of a sighting yesterday of a prothonotary warbler on a feeder at Bahama Palm Shores, Abaco [Later addition] Now, with thanks to Ann Capling, here is that very warbler on the feeder –  a fine photo considering it was taken indoors through glass.Apparently there hasn’t been one recorded there since 2007. I know of one seen further south on the island near the Delphi Club in April 2010 (see photo and caption below). I’ve never seen one myself. It seems fitting to celebrate the news with a post about these little birds…

This very pretty species of warbler Protonotaria citrea is the only member of its genus. The male birds are very colourful, with the females and juveniles being a bit duller. In flight, the underside of their tails are white at the base, and dark at the tip Photo Credit Craig Nash (Peregrine’s Blog) This fantastic photo was taken on the main drive of the Delphi Club, Abaco

These warblers are native to the eastern US where they breed, wintering further south in the West Indies and Central & South America. Their nesting arrangements are unusual: “It is the only eastern warbler that nests in natural or artificial cavities, sometimes using old downy woodpecker holes. The male often builds several incomplete, unused nests in his territory; the female builds the real nest” where she lays 3 – 7 eggs. So either the male is cleverly creating decoy nests away from the real nest; or maybe he is showing typically male behaviour in starting several home DIY projects at once and not getting round to finishing any of them…

Female Prothonotary Warbler (wiki)

I can never cope with those phonetic descriptions of bird calls… So many small birds are described as going ‘tseep’ or ‘tweep’ or ‘seeep’, yet in practice sound different from each other. So here, courtesy of the admirable Xeno-Canto and recordist Don Jones, is how they sound in real life

Listed as of ‘Least Concern’ (except in Canada, where they are ‘endangered’), the sad fact is that like so many species PNs are declining in numbers due to habitat loss. They are also bullied by other birds, in particular the brown-headed cowbird; and the house wren with which they compete for nest sites.

And the cumbersome name? Although at one time known by the helpful name ‘Golden Swamp Warbler’, the bird was renamed after senior Roman Catholic church officials called PROTONOTARII whose robes were (are?) supposedly golden. For full but quite dull details click on the green word back there. Bizarrely, the wiki-link doesn’t seem to confirm the goldenness of the robes at all. I think I’ll vote for a return to the simpler description…

Male Prothonotary Warbler (wiki)

POST SCRIPT: By complete coincidence, the National Audubon Society posted this lovely PN picture on its Facebook page this very day, with the caption Start your Monday morning off right with this cute Prothonotary Warbler peeking out of a heart shaped tree hole! Have you seen any of these birds yet? Photo by Mark Musselman”