SPERM WHALE BONES & RESEARCH: LIFE AFTER DEATH


SPERM WHALE BONES & RESEARCH: LIFE AFTER DEATH

I made this short video last year at BMMRO HQ, Sandy Point, Abaco. A sperm whale had stranded earlier in the year, and after the necropsy some of the bones were taken from the beach for research. In order to clean them, the bones were sunk and anchored to the seabed offshore in quite shallow water. Strandings are always sad, of course, but  it is good to know that even after death the creature makes an important contribution to scientific research. In a sense, it has life after death.

BMMRO / Rolling Harbour Abaco / Keith Salvesen

CORAL REEFS AND HURRICANE DAMAGE ON ABACO BAHAMAS


Reef Corals, Abaco Bahamas (Melinda Rogers / Dive Abaco)

CORAL REEFS AND HURRICANE DAMAGE ON ABACO BAHAMAS

The spectacular coral reef chains of the Bahamas include the 3rd largest barrier reef in the world. Abaco’s reef system stretches from Little Harbour to beyond the northern end of the mainland, as Sandy Estabrook’s map shows. Inside the reef: the Sea of Abaco. Beyond the reef and the next landfall east: Western Sahara, south of the Canary Islands.Abaco Map Sandy Estabrook
A rainbow effect of filtered sunlight on sea fansReef Corals, Abaco Bahamas (Melinda Rogers / Dive Abaco)
Since the devastation of Abaco by Hurricane Dorian last September, a number of surveys have been carried out. Some of these relate to the impact of the storm on the natural world – the damaged forest and coppice, the bird-life including the Abaco specialities, and the marine life including marine mammals, fish, and reef structures and environments.
Reef Corals, Abaco Bahamas (Melinda Rogers / Dive Abaco)
A recent assessment by the Perry Institute for Marine Sciences (PIMS) in Abaco and Grand Bahama waters has been carried out on the coral reefs to determine the extent to which the vulnerable structure, ecology and environment has been damaged. Some details have just been published in the Nassau Guardian in an article by Paige McCartney. The LINK is below.
Reef Corals, Abaco Bahamas (Melinda Rogers / Dive Abaco)
DAMAGE FINDINGS IN BRIEF
  • 25 – 30% of the 29 reef sites surveyed are devastated
  • factors include damage from debris, silt burial, and bleaching
  • uprooted casuarina trees were caught in the storm surge, causing damage
  • in particular, corals have been smashed and reef structure destroyed
  • there is biomass loss – basically reduced populations of fish & other organisms

Reef Corals, Abaco Bahamas (Melinda Rogers / Dive Abaco)

RAYS OF LIGHT
Although the reef systems of both islands have been significantly damaged, in other areas little damage was found. Moreover, in some areas the storm had washed away some types of seaweed that are harmful to the reefs. The hope is that restoration of the damaged areas can be achieved with careful management.
Reef Corals, Abaco Bahamas (Melinda Rogers / Dive Abaco)
WHAT CAN BE DONE NOW?
Action towards restoration and future protection includes:
  • removal of debris and other deleterious matter (eg silt)
  • cutting back the non-native, invasive casuarinas from the shoreline
  • restoration programs (recent successes with ‘coral farming’ could be vital)
  • extending marine protected areas
  • developing a rapid response protocol to meet extreme situations

Reef Corals, Abaco Bahamas (Melinda Rogers / Dive Abaco)

The reports ends with some welcome news: Government departments have recently proposed putting $5 million towards a coral restoration project on Abaco, including the establishment of a and-based aquaculture facility to support coral growth in nurseries. Let’s hope that becomes a reality.

The publication of the PIMS report and its findings gives some hope of recovery for the fragile reef environment of the northern Bahamas. Other factors may reverse the optimism of course, not least the accelerating warming of the seas and the exponentially expanding pollution problem such as this, recently reported

This has been an opportunity to revisit the clear waters around Abaco where Melinda Rogers of Dive Abaco took these astonishing photos of coral on the local reefs. If the coral is destroyed or dies, this is what our children and their children will be be missing.

Click the brain coral to link to the Nassau Guardian Article

All photos, Melinda Rogers / Dive Abaco; Map, Sandy Estabrook; Nassau Guardian / Paige McCartney; Perry Institute for Marine Sciences (PIMS)

Reef Corals, Abaco Bahamas (Melinda Rogers / Dive Abaco)

BRAIN WAVES: UNDERSEA CORAL MAZES & LABYRINTHS


BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

BRAIN WAVES: UNDERSEA CORAL MAZES & LABYRINTHS

The name ‘brain coral’ is essentially a no-brainer. How could you not call the creatures on this page anything else. These corals come in wide varieties of colour, shape and – well, braininess – and are divided into two main families worldwide. 

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

Each ‘brain’ is in fact a complex colony consisting of genetically similar polyps. These secrete CALCIUM CARBONATE which forms a hard carapace. This chemical compound is found in minerals, the shells of sea creatures, eggs, and even pearls. In human terms it has many industrial applications and widespread medicinal use, most familiarly in the treatment of gastric problems. 

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

The hardness of this type of coral makes it a important component of reefs throughout warm water zones world-wide. The dense protection also guarantees (or did until our generation began systematically to dismantle the earth) –  extraordinary longevity. The largest brain corals develop to a height of almost 2 meters, and are believed to be several hundred years old.

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

HOW ON EARTH DO THEY LIVE?

If you look closely at the cropped image below and other images on this page, you will see hundreds of little tentacles nestled in the trenches on the surface. These corals feed at night, deploying their tentacles to catch food. This consists of tiny creatures and their algal contents. During the day, the tentacles are retracted into the sinuous grooves. Some brain corals have developed tentacles with defensive stings. 

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

THE TRACKS LOOKS LIKE MAZES OR DO I MEAN LABYRINTHS?

Mazes, I think. The difference between mazes and labyrinths is that labyrinths have a single continuous path which leads to the centre. As long as you keep going forward, you will get there eventually. You can’t get lost. Mazes have multiple paths which branch off and will not necessarily lead to the centre. There are dead ends. Therefore, you can get lost. Check out which type of puzzle occurs on brain coral. Answer below…**

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

CREDIT: all amazing underwater brain-work thanks to Melinda Rogers / Dive Abaco; Lucca Labyrinth, Keith Salvesen / Rolling Harbour

** On the coral I got lost straight away in blind alleys. Therefore these are mazes. Here is a beautiful inscribed labyrinth dating from c12 or c13 from the porch of St Martin Cathedral in Lucca, Italy. Very beautiful but not such a challenge.

Labyrinth (Maze), Porch Lucca Cathedral (Keith Salvesen)

BRAIN CORAL Abaco Bahamas (Melinda Rogers / Dive Abaco)

‘DEEP DIVERS IN DIVERS DEEPS’: CUVIER’S BEAKED WHALES


Cuvier's Beaked Whale, Bahamas (BMMRO / Charlotte Dunn)

‘DEEP DIVERS IN DIVERS DEEPS’: CUVIER’S BEAKED WHALES

JOURNEY TO THE WORLD’S MIDNIGHT ZONE

Please join me in a dive down from the sparkling surface of the turquoise sea to the twilight zone at 200 meters. You’ll pass plenty of sea-life on the way: manatees grazing on seagrass just below the surface; reef fish, barracudas, reef sharks, mahi-mahi, maybe an orca at 100 meters. Other familiar creatures that are found even lower include a few reef fish, some shark species and green sea turtles. You are now running out of clear light.

Cuvier's Beaked Whale, Bahamas (BMMRO / Charlotte Dunn)

As you descend from 200 meters the waters become murky, then inky. The variety of inhabitants and their numbers are gradually decreasing. There are eels, some sharks, squid, stranger deep-water creatures. You may be surprised to see familiar bottlenose dolphins, recorded as diving nearly 300 meters. At 332 meters you will equal the deepest point any human being has ever scuba-dived (Ahmed Gabr 2014). There is little light, but you still have a long way to go to reach your goal.

Dolphin dive depth (Neal)

Descending still deeper, species and numbers continue to thin out. Around the world the limits of larger recognisable species is being reached – more shark species, tuna, chinook salmon, emperor penguins, swordfish, the few corals that can survive the depth. As the light fades to black, giant creatures and strange fish abound. Huge crabs. Sunfish. The (no-longer-extinct) Coelocanth. Massive octopuses. 

Cuvier's Beaked Whale, Bahamas (BMMRO / Charlotte Dunn)

Deeper down, nearing 1000 meters now, there are still some familiar species. Leatherback turtles; Baird’s beaked whales (nb not in the Atlantic); and at 920 meters, the deepest recorded sperm whale dive. It’s pitch dark: you have reached the level that sunlight never penetrates. You are in the Midnight Zone.

Sperm whale dive depth (Neal)

DEEP OCEAN DWELLERS

In black depths below 1000 meters, creatures have adpated to create their own light sources – so-called bioluminescence. This is the realm of the self-lit anglerfish, the blobfish and the goblin shark. It’s the Attenborough world of deep sea exploration. The geology is changing: there are hypervents, volcanic rocks, heavy metals. Below are the deep ocean-floor trenches. Yet there are still recognisable species down here, diving astonishingly deep to 1800 meters to feed – not least the narwhal which makes this trip several times a day to feed.

We need to quicken up the descent now – we have to get down nearly twice as far as this to reach our destination…

Cuvier's Beaked Whale leap (M.Rosso GIMA - IUCN)

We pass large squid and isopods, the deepest diving shark – the Greenland, the 10 meter-long 700 kilo colossal squid – yet amazingly there are marine mammals yet to be encountered: at 2400 meters we drift past a huge elephant seal. There are evil-looking creatures down here with names to match – devilfish, viperfish, black swallowers that can eat a larger fish whole, vampire squid and zombie worms. 

At 3000 feet, we finally end our quest. We have reached the depth to which the world’s deepest diving mammal has been recorded: the Cuvier’s beaked whale Ziphius cavirostris


Cuvier's Beaked Whale (NOAA Fisheries)

Cuvier’s beaked whales, or “goose-beaked whales,” are not rare. For a start, unlike many beaked whale species, they inhabit most oceans and seas in the world and have the most extensive range. Unsurprisingly therefore, they are one of the most often sighted beaked whale species and one of the best studied. 

Cuvier's Beaked Whale Bahamas (BMMRO / Charlotte Dunn)

FIN FACT

You may be wondering about the pressure exerted on a creature at a depth of 3000 meters. The answer is, an astounding 300 atm (atmospheres), enough to crush all but the hardiest and best adapted of species. The question how these whales manage to survive at such a depth is one for the future…

The Cuvier’s is one of the 3 beaked whale species found in Bahamas waters. Like the rarer Blainville’s and Gervais’s beaked whales, the Cuvier’s is the subject of ongoing research by the BAHAMAS MARINE MAMMAL RESEARCH ORGANISATION BMMRO

Cuvier's Beaked Whale leap (BW - Getty - Times)

The research into marine mammal populations in the Bahamas and far beyond is focussed on the massive increase in single and mass strandings, including recently in a remote area of Scotland (Hebrides) where more than 40 Cuvier’s were washed ashore.

One significant area of research examines the effect on marine mammals of man-made noise. There is plenty of it in the world’s oceans caused by noise pollution in and around shipping channels that traverse marine mammal migration, feeding and breeding grounds; naval surface and submarine exercises; seismic surveys, sonar waves and undersea resource investigations. The evidence of sound / acoustic damage as an additional hazard for marine mammals is starting to look very clear.

Cuvier's Beaked Whale Bahamas (BMMRO / Charlotte Dunn)

DEEP WATER INFOGRAPHIC

Do not miss this wonderful work by Neal Agarwal. This article is based around it and includes facts and images derived from his incredibly complex structure that has resulted in a remarkably simple resource for layman and ocean-lover alike (I realise these categories may overlap). To see the entire masterpiece, double click of the box below – “it will be worth it”.

CREDITS: Neal Agarwal; BMMRO / Charlotte Dunn; M.Rosso GIMA – IUCN; NOAA Fisheries; BW – Getty – Times; Pierangelo Pirak / BBC Earth (depth infographic), general sources – BMMRO, IUCN, NOAA, WDC

As ever, the Bahamas Philatelic Bureau has produced a wonderful stamp special issue

THE DITZY CHICKS & THE BEACH BYRDS: BANDS TO ADMIRE


Piping Plover Chick Holgate NJ (Michelle Stantial)

‘KEITH’

‘THE DITZY CHICKS’ & ‘THE BEACH BYRDS’: BANDS TO ADMIRE

Piping plovers are rare, tiny, unutterably cute, weigh about 2oz – and every Fall they fly south 1000 miles or more to warmer climes. Abaco is one such clime. The data collected during the 4 years of the ABACO PIPING PLOVER WATCH project shows annual counts of ±250 individual birds found either in flocks in specific hotspots, or more randomly in small groups, pairs or singles. Certain areas on the Cays are also popular. Of all these, around 10% are banded. All the birds are banded in their breeding grounds, usually as chicks (apart from a few ‘pink flags’ banded as adults on Long Beach, South Abaco). 

Piping Plover Chick Holgate NJ (Michelle Stantial)

‘CHEROKEE’

SQUID’S KIDS

To set the scene (the story is developed below). The 3 tiny chicks with the ring bling in the large photos hatched at a Wildlife Refuge in New Jersey about 10 days ago. Their parents are Squid and Sophie. The scientists who captured, weighed, measured and banded them also named them, for reasons which will become apparent, Keith, Cherokee and Abaco. This post aims to explain the background story, and in particular the great significance of banding as a tool of research into rare species.

At the outset – and because a few people express concern –  I’d better add that no deleterious effects arise from banding. The bands are not constricting, and the birds are unaware of them. Individual banded birds are often seen year after year at either end of their migration or at both; and sometimes during stopovers along the way:  they have all survived being banded, Also, if the scientists and conservationists were to take risks with the chicks in their care by using inappropriate methods, they would in fact be damaging or destroying the very creatures they have dedicated their skills to preserving.

Piping Plover Chick

WHAT’S SO SPECIAL ABOUT THIS SPECIES?

PIPL are not just rare, they are IUCN Red-listed as ‘near-threatened’. Last Autumn the IUCN estimate for adult birds was 8000. The summer breeding grounds are located in quite specific areas of North America and Canada.

These vulnerable little shorebirds nest in scrapes on the beaches and forage on the shoreline. They face many dangers including predation (eg gulls, cats, foxes), human activities and disturbance (eg the inalienable right to use beaches for off-road fun), and habitat degradation (eg. development, encroachment, and pollution). This last is the greatest problem of the three, and it is of course the responsibility – or fault – of humans. Fortunately, the establishment of extensive coastal / shoreline wildlife refuges has provided managed habitat and careful protection in some areas.

Piping Plover Chick Holgate NJ (Michelle Stantial)

‘ABACO’

WHERE DOES BANDING COME INTO ALL THIS?

For the purposes of the ongoing scientific investigation and conservation research, the wildlife organisations in each area carry out programs to examine, measure, weigh and band birds on their ‘home’ beach. This process builds a database year on year against which the health of the birds and also the habitat can be measured. 

       

Banding enables individuals to be identified and observed in the breeding grounds; and crucially, where the birds overwinter (see below). Birds are given flags or bands or both in unique combinations. These may be put on one or both legs; mostly they will be on the upper leg(s), but sometimes the lower legs are also used; unique alphanumerics or coloured dots provide further means of ID. Some locations have a tradition of naming the chicks during banding. Thus ‘Green Flag AH3’ became ‘Atari’ . Felicia Fancybottom is the most exotic name so far (she had a random posterior-feather sticking out when banded).

On Abaco, we sometimes give unnamed overwintering banded birds an ID to avoid confusion, for easy reference, or actually just for fun. For example Green Flag 70E became (obviously) ‘Joe’.

Piping Plover Banding Box (Steph Egger)

Bander’s Box: H22 is now on ‘Harry Potter’

Piping Plover Chick NJ (Kim / CWFNJ)

HOW THE SYSTEM WORKS IN PRACTICE

MANY HAPPY RETURNS FOR ‘SQUID’

January 2, 2018 the female bird called ‘SQUID’ was resighted on Abaco at Casuarina. Her bands were: upper left, blue on black; upper right, green on red (photo below). Checks of the band combination produced the following information:

  • originated from the Holgate unit of Edwin B. Forsythe NWR in NJ, banded there as a female
  • monitored and researched by Conserve Wildlife Foundation NJ
  • recorded at the same location the previous summer so had already completed Fall and Sping migrartion, returning to the same beach where she hatched and fledged.
  • named for the bander’s mom’s cat
Piping Plover, Casuarina Abaco Bahamas (Keith Kemp)

‘SQUID’

July 29 2018 SQUID was resighted for the second year at the same location on Casuarina flats, Abaco, the first banded bird of the season. She was also the last to leave, in mid-March – a stay of of around 8 months. During that time, APPW beach monitor Keith Kemp saw Squid on several occasions, all in the immediate area of Cherokee Sound (of which Casuarina is a part).

LATE MAY / EARLY JUNE 2019 Resighted for the third season at EBF, and nested with male (as it has turned out) called Sophia! Sexing tiny newly hatched chicks is not an exact science. Originally there were 4 eggs, but on June 2 only 3 chicks hatched – ‘nature’ had intervened with the 4th. They were named ABACO, CHEROKEE… and KEITH (a kindly nod both to me and to monitor Keith Kemp). The chicks were captured by Michelle Stantial of SUNY, in conjunction with CWFNJ, to be banded, weighed, and measured so they can be monitored and assessed for growth, beach activity, and protection purposes. In a couple of months these chicks will themselves feel the urge to fly south, and will continue the annual PIPL migration cycle.

Piping Plover Chick Banding, Holgate NJ (Michelle Stantial / Todd Pover)

Squid being banded by Michelle Stantial in July 2017

 WHAT HAS THE RESEARCH REVEALED SO FAR – AND IS IT USEFUL?

SQUID is an excellent example of conservation, research, and science (both pro and citizen) in action. From his story we can conclude the following:

  • Squid has been on the same summer beach in NJ for 3 years running
  • She has also overwintered for 2 years running in the same location on Abaco
  • So she has flown 4 migrations of c1000 miles with extraordinary location accuracy
  • This is a prime example of ‘beach loyalty’, a vital ingredient for species conservation
  • At 2 oz, she is a doughty and determined survivor of all the dangers arising from such long journeys
  • The habitats at both ends of the migration are good and safe, without notable degradation 
  • The nesting success with A, C and K adds 3 more birds to the population, if they all fledge and survive
  • There is every chance that Squid will be seen on Abaco this Fall
  • There is some chance that at least one of the chicks will turn up on Abaco too; or in the Bahamas anyway

Piping Plover Chick, LBI (Northside Jim)

This story is one example of many similar ones that occur every season. One plover, Bahama Mama from Michigan, has spent the last 5 winters on the same Abaco shoreline. Overall, there is optimism that the conservation measures in place will prevent the decline and encourage the increase of the species. There’s a lot of dedication that goes into all this. I think it can be fairly said that the story of Squid and Sophia’s little family is a both reward for that dedication, and a sign of hope for the future.

NOT THE DITZY CHICKS!

Credits: Michelle Stantial / SUNY; Todd Pover / CWFNJ; Holgate Unit EBF NWR; Stephanie Egger (now with NOAA); photos from Keith Kemp, Kim / CWFNJ, ‘Northside’ Jim Verhagen LBI

Piping Plover Chick, LBI (Northside Jim)

Goodbye, and well done for sticking it out to the end

FLAMINGO TONGUE SNAILS: DECORATIVE CORAL-DWELLERS


Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

FLAMINGO TONGUE SNAILS: DECORATIVE CORAL-DWELLERS

FLAMINGO TONGUE SNAILS Cyphoma gibbous are small marine gastropod molluscs related to cowries. The living animal is brightly coloured and strikingly patterned, but that colour only exists in the ‘live’ parts – the so-called ‘mantle’. The shell itself is usually pale, and characterised by a thick ridge round the middle. These snails live in the tropical waters of the Caribbean and the wider western Atlantic. Whether alive or dead, they are gratifyingly easy to identify.

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

THE IMPORTANCE OF CORAL

Flamingo tongue snails feed by browsing on soft corals. Often, they will leave tracks behind them on the coral stems as they forage (see image below). But corals are not only food – they provide the ideal sites for the creature’s breeding cycle.

Flamingo Tongue Snails (Dive Abaco, Bahamas)Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

Adult females attach eggs to coral which they have recently fed upon. About 10 days later, the larvae hatch. They eventually settle onto other gorgonian corals such as Sea Fans. Juveniles tend to live on the underside of coral branches, while adults are far more visible and mobile. Where the snail leaves a feeding scar, the corals can regrow the polyps, and therefore the snail’s feeding preference is generally not harmful to the coral.

The principal purpose of the patterned mantle of tissue over the shell is to act as the creature’s breathing apparatus. The tissue absorbs oxygen and releases carbon dioxide. As it has been (unkindly?) described, the mantle is “basically their lungs, stretched out over their rather boring-looking shell”

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

THREATS AND DEFENCE

The species, once common, is becoming rarer. The natural predators include hogfish, pufferfish and spiny lobsters, though the spotted mantle provides some defence by being rather unpalatable. Gorgonian corals contain natural toxins, and instead of secreting these after feeding, the snail stores them. This supplements the defence provided by its APOSEMATIC COLORATION, the vivid colour and /or pattern warning sign to predators found in many animal species.

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

MANKIND’S CONTRIBUTION

It comes as little surprise to learn that man is now considered to be the greatest menace to these little creatures, and the reason for their significant decline in numbers. The threat comes from snorkelers and divers who mistakenly / ignorantly think that the colour of the mantle is the actual shell of the animal, collect up a whole bunch from the reef, and in due course are left with… dead snails and “boring-looking shells” (see photos below). Don’t be a collector; be a protector…

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

The photos below are of nude flamingo tongue shells from the Delphi Club Collection. Until I read the ‘boring-looking shell’ comment, I believed everyone thought they were rather lovely… I did, anyway. You decide!

Flamingo Tongue Snail Shell, Keith Salvesen AbacoFlamingo Tongue Snail Shell, Keith Salvesen Abaco

Image Credits:  Melinda Rogers / Dive Abaco; Keith Salvesen / Rolling Harbour

Flamingo Tongue Snails (Melinda Rogers, Dive Abaco, Bahamas)

BAHAMA ORIOLE: HABITAT FIND FOR A RARE GEM


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

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.

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, 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.

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.  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

Bahama Oriole Andros (C Ward BNT)

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.

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”. 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_NorthropBahama Oriole Stamp birdtheme.orgCredits: 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, Andros (D Belasco / abcbirds.org)