BAHAMA ORIOLE: HABITAT FIND FOR A RARE GEM

March 12, 2019 by Rolling Harbour

BAHAMA ORIOLE: HABITAT FIND FOR A RARE GEM

RARE, PRECIOUS – AND FOUND ONLY ON ANDROS, BAHAMAS

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.

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, then add mankind and his needs to the mix. The wrong mix of habitat degradation, clearances, predation or disease could cause the Andros population to disappear as well.

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.

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. A new study in The Journal of Caribbean Ornithology published by researchers from the University of Maryland, Baltimore County and Bahamas National Trust collaborating on the Bahama Oriole Project (@BahamaOrioleProject) reveals new evidence about the nesting habits and habitats of the orioles that will have “…major implications for future conservation” (this work was funded in part by the American Bird Conservancy and Birds Caribbean).

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. Indeed, these may prove to be the primary nesting locations. 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

THE MAIN CAUSES OF THE CRITICAL DECLINE ON ANDROS

Lethal Yellowing Disease of the coastal coconut palms, until very recently (see above) believed to be the prime nesting habitat for the oriole. In some areas the palms have been all but wiped out. The recent findings in the forests have clearly reduced the impact of this specific problem
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 within the population is also cited as a contributory cause

*The date of this arrival seems to correspond to when the orioles were extirpated from Abaco. However, see next para.

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”. However, Abaco birding expert Elwood ‘Woody’ Bracey comments (see below) that Bahama Orioles were last formally recorded on Abaco in 1973 by researcher Duncan Everette and his partner who were banding warblers in Southern Abaco in what is now the Abaco National Park. At that time, the Shiny Cowbird was only rarely found on Abaco, if at all.

I’ve found no clear clue as to the cause – nor even when the last evidences 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. As to past history, Kevin Omland of @BahamaOrioleProject says that there are at least 9 specimens in museums around the world collected from Abaco in the 1800s and early 1900s.

eBird map showing Bahama Oriole sightings distribution in c21

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_Northrop Bahama Oriole Stamp birdtheme.org Credits: Dan Stonko / American Bird Conservancy, Michael Baltz / Bahama Oriole Project / Kevin Omland; 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; Handbook of World Birds (drawing)

↑ Mr Northrop with his Bird

BAHAMA ORIOLE: ABACO’S LOST ENDEMIC SPECIES

December 5, 2014 by Rolling Harbour

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

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.

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 taken during a BMMRO research trip on Andros

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

♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦

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).

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

NASSAU GROUPER: VULNERABLE, ENDANGERED… & NOW PROTECTED

December 3, 2014 by Rolling Harbour

NASSAU GROUPER: VULNERABLE, ENDANGERED… & NOW PROTECTED

The Nassau grouper Epinephelus striatus is one of a number of Caribbean grouper species found generally in the Northern Bahamas and specifically in Abaco waters. Others include the Black, Tiger, and Yellowfin groupers, the Red Hind,and the Graysby. The Nassau grouper is special, however, not least because (unlike the others) it is on the IUCN Red List as an Endangered Species and is also a US National Marine Fisheries Service Species of Concern. It is considered the most important of the groupers for commercial fishing in the Caribbean, and the IUCN listing data suggests that a population decline of 60% occurred over the last three generations (27-30 years), a startling rate. The current population size is estimated at >10,000 mature individuals.

Nassau Grouper ©Melinda Riger @ G B Scuba copy 2

The Nassau Grouper is a creature of the coral reefs in the Caribbean and adjacent seas, though it can also be found in deep water. It feeds in the daytime on small fish and small crustaceans such as shrimps, crabs and lobsters. It lurks in caves and recesses in the reef, sucking in the prey that passes unsuspecting by. The coloration of an individual fish may vary considerably with conditions, and it can adapt its colour to its surroundings as camouflage.

Tiger grouper meets Nassau grouper

Spawning takes place in December and January as the seawater cools, always at full moon, and always in the same place. In the moonlight, huge numbers of the grouper gather together to mate in a mass spawning aggregation. This may continue for several days. However, the species is slow breeder, which is why overfishing is particularly damaging to the population as the depleted stock cannot readily be replaced.

CONSERVATION ISSUES

There are other besides factors commercial overfishing that make the Nassau grouper so vulnerable, including fishing during the breeding season; taking undersized fish; pollution and reef decline; habitat loss; and invasive species. The spawning areas are especially vulnerable to exploitation. In the Bahamas, as elsewhere, the government has now instituted a closed fishing season for the Nassau grouper. Here is the BREEF flyer, just circulated – and in fact the reason for this post, which reminded me that I had planned to write about this fish!

THREATS

The Bahamas National Trust sums up the multiple threats in this uncompromising way:

Nassau grouper is eaten by barracudas, lizard fish, dolphins, sharks and other large predators of the reef community. But the predators that have the biggest impact on the grouper population are humans. People are fishing groupers before they can grow to maturity and reproduce. Sex change may also cause a problem. In undisturbed areas there are usually equal numbers of male and females. In heavily fished areas there are often three or more times more females than males. This means many eggs will not be fertilized during spawning. Other threats include, habitat destruction, coral breakage from divers, siltation from construction, runoff from logging and agriculture, dredging, sewage, oil spills and other contaminants that harm coral reefs where Nassau Groupers live.

There’s an extent to which a country can be judged on its attitude to wildlife from the stamps it chooses to issue. It’s something to do with appreciation and promotion of the country’s natural resources. For example, North Korea rates nil in this respect, with stamps involving scary weaponry, flags, marching and eerily glowing leaders – not a single sparrow to be seen. By fortunate contrast the Bahamas and its Postal Service score very highly in celebrating the diversity of the wildlife of the islands. The Nassau Grouper was first featured on Bahamas stamps as long ago as 1971, some 25 years before the IUCN Red Listing, and probably before the sharp decline in population numbers had even begun.

In 2012 the Bahamas Postal Service released ‘a new definitive 16 stamp series’ depicting the marine life of The Bahamas. The Nassau has been promoted from 5c in 1971 to 70c in 2012. That’s inflation for you.

Finally in 2013 BREEF’s 20 years of marine conservation was commemorated with a distinguished and colourful set of 8 stamps, noting in their release: ‘Two of the new stamps feature the Nassau Grouper, a now endangered species that has experienced severe population decline throughout the region… BREEF is well known as an advocate for an annual closed season for the iconic Nassau Grouper during its winter breeding period. The push for the closed season was based on scientific evidence of population collapses throughout the region due to overfishing. BREEF is calling on the government to implement a fixed closed season for the Nassau Grouper in order to protect the species and the fishing industry. The closed season traditionally runs during the spawning season from December 1st until February 28th, to allow the fish to reproduce. BREEF is calling urgently for the announcement of this year’s Nassau Grouper closed season….’ And so it came to pass… Not only is the Nassau grouper now worth 2 x 65c; it is strictly protected for 3 months during its breeding season. Maybe philately even had a hand in getting somewhere…

Credits: Melinda Riger, Rick Smit, Open Source, BNT, BREEF, Wikimedia, Bahamas Postal Service

PHILATELY WILL GET YOU… NICE BAHAMAS WILDLIFE STAMPS

November 19, 2013 by Rolling Harbour

WILDLIFE STAMPS OF THE BAHAMAS

with guest expert PHIL LATTERLY

The Bahamas ‘does’ extremely nice stamps, in particular ones featuring the rich and varied wildlife of the islands. The islands spread from the subtropical climates of the north, on a level with Florida, to the near-tropical islands of the south. This ensures plenty of scope for designing pretty sticky bits of paper to stick onto other bits of paper. One of the small pleasures in life, near-lost to the tyranny of the email…

The sets of wildlife stamps are issued by the Bahamas Post Office. I’ll add to this collection piecemeal (including some from my own modest collection). The very latest commemorative issue heads the display.

1. SEA CREATURES

BREEF 20th Anniversary Issue – November 2013

REEF FISHES

2. BIRDS

February 2012: WWF Flamingo Issue

Best seen on Inagua, the island where they breed. Less often found elsewhere, and sadly now only as occasional ‘vagrants’ on Abaco. Flamingo post with wonderful pictures of adults, babies and nests HERE

PARROT POST

Found mainly on Abaco (the resident underground nesting variety) and Inagua (conventional nesters), where they breed. Small groups are now found elsewhere, e.g. Nassau, where there is a local monitoring programme, but I’m not sure that there is evidence of breeding there. Any info welcome… One (of several) lavishly illustrated parrot posts HERE

Impressive commemorative issues for the BAHAMAS NATIONAL TRUST

OTHER BIRD SPECIES

The KIRTLAND’S WARBLER is one of the rarest birds of the Bahamas, a winter resident that breeds only in a small area of Michigan. The entire population is numbers only a few thousand birds. The number of sightings annually on Abaco is very small – fewer than a dozen, and in some years none at all. Increasing knowledge about their favourite haunts is now improving the recording rate. I know of two seen this year, on the same day… a birder’s lifetime achievement.

This swallow is endemic to the Bahamas

Found on Abaco only as an occasional visitor.

WATERFOWL Credit as shown

3. ANIMALS

4 BUTTERFLIES & INSECTS

Credits: A compendious credit to sundry online sources including Bahamas PO, Bahamas Weekly, eBay and other sales / promotional sources, ads and the like, and unknown sources. I rarely find myself having to use this broad sweep approach: if your pic is here and you are upset, apologies, contact me to express your displeasure &co and I’ll take it down of course. But these are only non-rare small bits of paper; and this is a humble non-profit making info site of limited appeal in a Big Wide World. OK with that?