BAHAMA ORIOLE: HABITAT FIND FOR A RARE GEM


Bahama Oriole, Andros (Dan Stonko / abcbirds.org)

BAHAMA ORIOLE: HABITAT FIND FOR A RARE GEM

c300 LEFT IN THE WORLD – AND ALL ON ANDROS

The future of the gorgeous endemic Bahama Oriole (Icterus northropi) hangs in the balance. IUCN Red Listed as ‘Critically Endangered’, the Oriole once lived on both Abaco and Andros. As recently as the 1990s, the species became extirpated on Abaco, leaving a small and fragile population in  fairly specific areas of Andros. These are places where the habitat is conducive to the orioles’ well-being, and in particular where they can safely breed and (with luck) replenish their depleted population.

Bahama Oriole, Andros (Michael Baltz / Bahama Oriole Project)

We hear a lot about habitat loss as a grave worldwide problem for an increasing number of species. Narrow that down to one species, one island, a few defined areas, and a tiny, barely sustainable population, then add mankind and his needs to the mix. Not much habitat degradation, clearances, predation or disease is needed to reduce 300 specimens to zero.

Bahama Oriole, Andros (Mary Kay Beach Dec 2018)

Which is where conservation and science come into play. The Bahamas archipelago benefits from an astonishing number of (broadly-speaking) environmental organisations that are involved in species and habitat protection, both terrestrial and marine. They range from international to Bahamas-wide and Governmental, to NFP organisations on the main islands, and on through local communities via citizen scientists to dedicated individuals. All are fighting a specific battle with a single aim; all face an increasing array of metaphorical weapons being deployed against them.

Bahama Oriole, Andros (Bahama Oriole Project FB header)

SO, ANY GOOD NEWS THEN?

Returning to the orioles – in many ways a perfect indicator bird species – recent research has led to an encouraging discovery.  The American Bird Conservancy (@ABCbirds) has just published the results of a new study in The Journal of Caribbean Ornithology. This involved several organisations –  Bahamas National Trust, the Bahama Oriole Project (@BahamaOrioleProject), UMBC Biology, and Birds Caribbean. It concerns new evidence about the nesting habits and habitats of the orioles that will have “…major implications for future conservation”.

The study is the outcome of the work of a dozen conservation specialists. In a coconut-shell, the orioles were thought to nest only in the coconut palms found near the coast. However the recent intensive research program reveals that ‘multiple pairs’ breed in the pines and the thatch palms of the forests, away from the coast. The implications of these new findings are significant, not least for a possible uplift in numbers and the way in which conservation measures can be adapted to the new discovery. For those wanting something more authoritative, the short Abstract of the study is given at the end. And if you’d like to read the whole article, click on the link below.

472-Article Text-1543-1-10-20180828

Bahama Oriole Andros (C Ward BNT)

THE MAIN CAUSES OF THE CRITICAL DECLINE ON ANDROS

  • Lethal Yellowing Disease of the coconut palms, prime nesting habitat for the oriole. In some areas the palms have been all but wiped out.
  • The arrival in the 1990s and spread of the Shiny Cowbird Molothrus bonariensis, a brood parasite that lays its eggs in the nests of other bird species
  • Habitat loss / development
  • Forestry work / forest fires
  • Feral cats and rodents
  • Disease has also been mentioned (but I haven’t actually pursued the specifics…)

Bahama Oriole, Andros (Thomas Nierle / Bahama Oriole Project)

WHEN & WHY DID THE ORIOLES VANISH FROM ABACO?

This is a classic ‘riddle wrapped in a mystery inside an enigma’. Various sources I have looked at use a formula such as “…became extirpated from Abaco in the 1990s”, or “disappeared for unknown reasons in the 1990s”. I’ve found no clear clue as to the cause – nor even when the last sighting of an oriole on Abaco was made. I haven’t found a single photo of one taken on Abaco at any time in history. To be fair the option of snapping everything with wings multiple times using a digital camera with a huge chip didn’t exist then. 

ABSTRACT

The Bahama Oriole (Icterus northropi) is a Critically Endangered species endemic to The Bahamas and currently found only on the Andros island complex. With the elevation of the Bahama Oriole to full species status in 2011, research suggested that there were fewer than 300 individuals remaining in the global population. The Bahama Oriole was also termed a “synanthropic species” based on data suggesting that the species nested almost exclusively within anthropogenic residential and agricultural habitats in introduced coconut palms (Cocos nucifera). These conclusions were based on population surveys primarily confined to settled areas near the coasts. However, we documented multiple pairs of orioles with breeding territories deep in pine forests, and we present the first records of Bahama Orioles nesting in pine forests—in both a Caribbean pine (Pinus caribaea) and native understory Key thatch palms (Leucothrinax morrisii). Given the predominance of the pine forests on Andros, this newly documented breeding habitat has important implications for developing population estimates and future conservation plans for the Bahama Oriole.

640px-Picture_of_John_Isaiah_NorthropBahama Oriole Stamp birdtheme.orgCredits: Dan Stonko / American Bird Conservancy, Michael Baltz / Bahama Oriole Project; Mary Kay Beach; Bahama Oriole Project FB header; C Ward / BNT; Thomas Nierle / Bahama Oriole Project; Bahamas Postal Service; BNT; D Belasco / American Bird Conservancy

          ↑ Mr Northrop with his BirdBahama Oriole, Andros (D Belasco / abcbirds.org)

BAHAMA ORIOLE: ABACO’S LOST ENDEMIC SPECIES


Bahama Oriole ABC : D. Belasco

BAHAMA ORIOLE: ABACO’S LOST ENDEMIC SPECIES

FEWER THAN 300 LEFT IN THE WORLD – AND ALL ON ANDROS

Having just posted about the endangered NASSAU GROUPER and its protection by the introduction of a 3-month closed season, it’s time to focus on a rare, beautiful and vulnerable bird, the Bahama Oriole (Icterus northropi). It is IUCN Red Listed as ‘Critically Endangered’. ENDEMIC to the Bahamas, this bird lived only on Abaco and Andros. Not any more. Now you’ll only find them on Andros, the species having been lost to Abaco in very recent memory. The 1990s, in fact. And on Andros, this lovely bird is now struggling against the threat of extinction and is found only in limited areas in very small numbers. The most optimistic population estimate I have found puts the total as fewer than 300 individuals… the consensus puts the likely total in the region of 250. Bahamas Oriole, Andros (Binkie Van Es)1 Bahamas Oriole, Andros (Binkie Van Es)2

THE SPECIES

In 2010, the Greater Antillean Oriole Icterus dominicensis was separated by the AMERICAN ORNOTHOLOGISTS’ UNION into 4 species, one being the Bahama Oriole. As the BNT wryly put it, “New species are always a source of excitement… but in this case the intrigue is overshadowed by a sense of alarm and urgency”. For by then this new species ‘in its own right’ was limited to certain parts of Andros, in small and diminishing numbers. It had already vanished from some areas – especially in North Andros – were it had formerly been abundant. The best estimates suggested 250 individual birds. Bahama Oriole - Harold Brewer (via PM) - Version 3

WHEN & WHY DID THEY VANISH FROM ABACO?

This is a classic ‘riddle wrapped in a mystery inside an enigma’. Various sources I have looked at use a formula such as “…became extirpated from Abaco in the 1990s”, or “disappeared for unknown reasons in the 1990s”. I’ve found no clear clue as to the cause – nor even when the last sighting of an oriole on Abaco was made. I haven’t found a photo of one taken on Abaco, although to be fair the option of snapping everything with wings several times using a digital camera with a large chip didn’t exist then. In the next para a number of crucial factors in the more recent decline of the Andros population are given; but as far as I can determine, some at least did not apply in the 1990s, or certainly not to the same extent. Maybe it was a combination of a degree of habitat loss and the gradual decline of a small population that could not breed prolifically enough to sustain the future population **. Bahama_Oriole (Mxmerce Wiki)

THE MAIN CAUSES OF THE CRITICAL DECLINE ON ANDROS

Lethal Yellowing Disease of the coconut palm, prime nesting habitat for the oriole. In some areas on Andros (e.g. Staniard Creek), the palm has been all but wiped out. 

The arrival and spread of the Shiny Cowbird Molothrus bonariensis, a brood parasite that lays its eggs in the nests of other bird species such as the yellow warbler, the black-whiskered vireo… and the oriole. The cowbird reached Andros in the mid-1990s. The first Abaco report that I have found is from 1999 (so presumably, as the oriole was already gone from the island by then, they were not a factor).  The cowbird is a summer resident on Abaco, though still relatively uncommon; and its range continues to expand northwards. Some might argue that the cowbird should be discouraged from spreading on Abaco right now for the sake of the indigenous warbler and vireo populations – before it is too late.

Habitat loss / island development (although Birdlife International notes “…the planting of coconut palms in residential areas has allowed the species to spread into human settlements”). Other factors put forward include forestry work, forest fires, diseases, rodents and feral cats – problems that affect many other birds such as the Abaco parrot. Bahamas Oriole (BNT / Carlton Ward) The photo below is a pleasure to include in this post. It was taken earlier this year on Andros by Christopher Johnson of Nassau. And here’s the thing. He is 13, and an avid birder. I’m sure he likes his X-Box time, but he certainly knows plenty about birds too. He’s quick off the mark with offering IDs – correct ones – for birds online, and when he saw this bird he knew the significance of it and managed to get some good shots too. This is my favourite, the oriole ‘vocalising’. See below for its song. Here is Christopher’s brief but enthusiastic field report: Awesome trip to Andros this past weekend! Was amazed to see the Bahama Oriole and its nest — feeling great”. Bahama Oriole, Andros (Christopher Johnson) 2

Bahama Oriole taken during a BMMRO research trip on AndrosBahama Oriole, Andros (BMMRO)

 Paul Driver / Xeno Canto

A GLIMMER OF HOPE?

In the same way that urgent conservation measures were put in place to halt and then reverse the critical decline of the Abaco parrot population, similar projects are in place for the Bahama Oriole on Andros. One proposal is to establish a ‘captive breeding’ program leading to reintroduction and reinforcement of the wild population. According to the American Bird Conservancy, this could even include reintroduction on Abaco… So perhaps in a decade or two, this fine bird will once again become firmly established as one of the birds of Abaco. Bahamas Oriole, Andros (Binkie Van Es)3 As I said in my Nassau Grouper post, a country’s attitude can to a degree be gauged by the pride with which it features its wildlife and natural resources in its stamps (I used North Korea for adverse comparison). In 2009 The Bahamas Postal Service even issued a ‘Rare Birds’ set featuring the Bahama Oriole.. I rest my case. Bahama Oriole Stamp birdtheme.org

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WHO WAS THE EPONYMOUS MR NORTHROP?

640px-Picture_of_John_Isaiah_Northrop

The comprehensive answer is provided by the University of Glasgow Library Research Annexe in relation to a fine  illustration from A Naturalist in the Bahamas (1910), reprinted in The Auk journal (below) at a time when Icterus northropi was still a mere subspecies: The yellow and black Bahama Oriole (Icterus Northropi) is a bird species unique to the Bahamas. The bird was named for American ornithologist and zoologist, John Isiah Northrop (1861–91); the illustration comes from an account of the trip Northrop and his botanist wife, Alice, took to the Bahamas in 1889 which was published in his memory: A Naturalist in the Bahamas: John I. Northrop, October 12 1861-June 25, 1891; a memorial volume (New York: Columbia University Press, 1910). It was edited and introduced by Henry Fairfield Osborn, professor of zoology at Columbia University where Northrop worked as a tutor and was killed in a laboratory explosion shortly (9 days) before the birth of his son John Howard Northrop (who became a Nobel prize-winning chemist). Icterus Northropi illustrated in A Naturalist in the Bahamas (plate 1)

RELATED MATERIAL

“Rediscovering the Bahama Oriole” Erik Gauger, author of the excellent Notes from the Road and photographic contributor to the Birds of Abaco has a good tale of the pursuit of the apparent sighting of a Bahama Oriole on Abaco 2o years after its (supposed?) extirpation. You can read it HERE The Auk Read more about this journal and the birding history of the Bahamas HERE There is a Care2Action ‘Save the Bahama Oriole Before It Is Too Late’ petition HERE. It seems to have stalled somewhat, so it would be good to generate some more signatories. ** Mathematically inclined? Find out about the application of the stochastic process to the oriole’s situation. In a nutshell, this concerns the combined effect of several random adverse factors on sustainability, given that the oriole’s already very small population, very limited range and particular habitat requirements militate against breeding expansion, and therefore increase the likelihood of extinction. We can only hope this is not an inevitability…

Image, audio and research credits: American Bird Conservancy, Binkie van Es, BNT / Carlton Ward, Birdlife International, Christopher Johnson, Cornell Neotropical, Harold Brewer, MxMerce, birdtheme.org, Wiki, Xeno Canto / Paul Driver; Uni of Glasgow / Roger Herriott

FIVE STARS: BAHAMAS ENDEMIC BIRDS (FOUR FROM ABACO)


20130106_Bahamas-Great Abaco_4846_Bahama Yellowthroat_Gerlinde Taurer copy

Bahama Yellowthroat (Gerlinde Taurer)

FIVE STARS: BAHAMAS ENDEMIC BIRDS (FOUR FROM ABACO)

The Caribbean Endemic Bird Festival is underway. You can find out more on the CARIBBEAN BIRDS FESTIVALS Facebook page. Abaco is fortunate to be home to 4 of the 5 endemic Bahamas species. The fifth, the beautiful BAHAMA ORIOLE Icterus northropi, was found on both Abaco and Andros until the 1990s, when it sadly became extirpated from Abaco. Now found only on Andros, there are thought to be fewer than 300 Orioles left – a barely sustainable number. The species is unsurprisingly IUCN listed as critically endangered. Here’s a picture of one as a reminder of what Abaco is now missing…

Bahama_Oriole (Wiki)

Bahama Oriole

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Abaco’s four endemic species are the tiny Bahama Woodstar hummingbird, the Bahama Yellowthroat, the Bahama Warbler (since 2011), and the Bahama Swallow. All are of course permanent breeding residents on Abaco and its outer Cays. None is exclusive to Abaco; all are relatively plentiful. The Woodstar is perhaps the hardest to find, not least because it competes territorially with the Cuban Emerald hummingbird. Even Woodstars can be found easily in some areas – Man-o-War Cay is a good place for them, for example. Here are some striking images of these four endemic bird species taken from the archives for “The Birds of Abaco” published last month. 

BAHAMA WOODSTAR Calliphlox evelynae 

Bahama Woodstar male 3.1.Abaco Bahamas.2.12.Tom Sheley copy

Bahama Woodstar (m) (Tom Sheley)

Bahama Woodstar (f) TL IMG_3213 2

Bahama Woodstar (f) Tara Lavallee

BAHAMA YELLOWTHROAT Geothlypis rostrata

Bahama Yellowthroat vocalizing.Abaco Bahamas.Tom Sheley

Bahama Yellowthroat (Tom Sheley)

Bahama Yellowthroat (M) BH IMG_0675 copy

Bahama Yellowthroat (Bruce Hallett)

BAHAMA WARBLER Setophaga flavescens

Bahama Warbler BH IMG_8398 copy - Version 2

Bahama Warbler (Bruce Hallett)

Bahama Warbler WB P1001012 copy

Bahama Warbler (Woody Bracey)

BAHAMA SWALLOW Tachycineta cyaneoviridis

Bahama Swallow CN

Bahama Swallow (Craig Nash)

bahama-swallow EG  copy

Bahama Swallow (Erik Gauger)

“The Delphi Club Guide to the Birds of Abaco”  was published as limited edition of 500 and has only been for sale for 8 weeks or so exclusively through the Delphi Club. Yesterday, we passed a happy milestone in that short time as the 250th copy was sold. Complimentary copies have also been donated to every school and relevant education department on Abaco to tie in with the excellent policy of teaching children from an early age the value of the natural world around them, the importance of its ecology, and the need for its conservation. The cover bird for the book was easy to choose – it just had to be a male Woodstar in all his glory with his splendid purple ‘gorget’. 

Bahama Woodstar (m) BH IMG_0917 copy

Bahama Woodstar (m) Bruce Hallett

JACKET GRAB JPG

Image credits as shown; otherwise, ‘cover bird’ by Tom Sheley, Bahama Oriole from Wiki and CEBF flyer from the Bahamas National Trust

EARLY BIRDS ON ABACO: CHARLES CORY’S EXPEDITIONS 1891


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EARLY BIRDS ON ABACO: CHARLES CORY’S EXPEDITIONS 1891

Before the explorations of the american ornithologist Charles Cory towards the end of the c19, there had been few if any serious attempts to record the birds of the Bahama Islands, especially the sparsely populated ones such as Abaco. The english naturalist Mark Catesby had published his  wonderful The Natural History of Carolina, Florida and the Bahama Islands as early as 1754, which of course included some birds, but it was far from avian-specific. During the 1880s, Cory forsook the golf course (his other passion – he even competed in the 1904 Olympics but, as it is intriguingly put, “…did not finish…”) to concentrate on birds. He commenced his research for his List of the Birds of the West Indies, published in 1886. The scope was wide, including Antilles, Jamaica, Cuba, Hispaniola and the Bahamas. The book simply listed birds by family, giving the bird names in Latin, and the locations where they were found. It’s scarcely an enticing read, and the ‘print on demand’ copy I obtained for about $15 is frankly horrid.00199p1

In 1891, Cory and his colleague Mr C.L. Winch paid more specific attention to the Bahamas, visiting several islands, taking specimens and recording their findings. Cory subsequently published these in the ornithological journal of record, The Auk, established in 1884 as a quarterly peer-reviewed scientific journal and the official publication of the American Ornithologists’ Union (AOU).  I’m not clear whether Cory actually accompanied Winch throughout the voyages, or whether they covered the islands separately. In any event, the first visit to Abaco took place in March 1891, when Mr Winch took specimens and recorded the species he encountered.00161p1

Cory : Winch 1891 March jpg

To save you the bother of taxing your brain with Latin  taxonomies (in some cases out-of-date), the species recorded are shown below. Every one of these species might be seen during a March visit nowadays.

COLUMN 1 Semipalmated Plover; Common Ground Dove; Turkey Vulture; Smooth-billed Ani; Belted Kingfisher; Hairy Woodpecker; Bahama Woodstar; Cuban Emerald; La Sagra’s Flycatcher; Loggerhead Kingbird; Greater Antillean Bullfinch; Black-faced Grassquit; Western Spindalis; Thick-billed Vireo; Black-whiskered Vireo

COLUMN 2 Bananaquit; Black & White Warbler; Kirtland’s Warbler; Yellow Warbler; Prairie Warbler; Yellow-rumped Warbler; Yellow-throated Warbler; Common Yellowthroat; Bahama Yellowthroat; Northern Waterthrush; Ovenbird; Blue-gray Gnatcatcher; Gray Catbird; Northern Mockingbird;  Red-legged Thrush

00103p1

In June they were back on Abaco; or at least, Mr Winch had returned. This time, the list of species was somewhat different, as one might expect in the summer season. It contains one particular curiosity: the Bahama Oriole. This fine bird was sadly extirpated from Abaco in the 1990s, and may now only be found on Andros. There are reckoned to be only about 300 left, so the species is on the brink of extinction.Bahama Oriole.jpg (Wiki)

Charles Cory 1857 – 1921Charles Barney Cory 1857-1921 (Wiki)Cory List copy jpg

COLUMN 1 Red-tailed Hawk; Mourning Dove; Common Nighthawk; Cuban Emerald; Bahama Woodstar; West Indian Woodpecker; Hairy Woodpecker; La Sagra’s Flycatcher; Cuban Pewee; Loggerhead Kingbird; Gray Kingbird; Bahama Oriole; Red-winged Blackbird

COLUMN 2  Greater Antillean Bullfinch; Western Spindalis; Thick-billed Vireo; Bahama Swallow; Bahama Yellowthroat; Pine Warbler; Olive-capped Warbler; Yellow-throated Warbler; Bananaquit; Blue-gray Gnatcatcher; Northern Mockingbird; Red-legged Thrush

Cory published his findings in The Auk
The Auk 1891

A regrettable ‘print-on-demand’ purchaseCory

Illustrations by John James Audubon 1785 – 1851 (who never visited Abaco)00422p1

For anyone with eyelids still open, you can read more about Bahamas birds and The Auk journal HERE