BLUEHEAD WRASSE: PRIVATE LIFE LAID BARE

January 23, 2023 by Rolling Harbour

BLUEHEAD WRASSE: PRIVATE LIFE LAID BARE

The bluehead wrasse (or blue-headed wrasse) Thalassoma bifasciatum is a denizen of the coral reefs in the tropical waters of the western Atlantic Ocean. This bright little 4-inch fish is… a wrasse with a blue head. No more and no less. Unless it’s a juvenile. Then it is mainly bright yellow. It’s similar to BLUE TANG (aka ‘the Disney Dory’), which starts life bright yellow and grows up to be blue.

The species may be found singly, in pairs or small groups, or in schools. They have an important role to play in the life of the reef. They are CLEANER FISH, vital to the health and wellbeing of the larger species they attend to, and thus of the reef itself. This is ‘cleaning symbiosis’, a relationship of mutual benefit. The big fish get cleaned; the little fish have a useful function and – importantly for them – therefore don’t get eaten.

Having said that, blueheads are of course fair game as a snack for species that aren’t in the market for their cleaning services. Rather unfairly, some species that are quite content to let cleaner gobies pick around their gills and mouths are not so considerate of the wrasse (some types of grouper and moray eel, for example).

TELL US EXACTLY SEVEN BLUEHEAD WRASSE FACTS

Juveniles can alter the intensity of their colour, stripes & bars
The bluehead wrasse is a ‘protogynous sequential hermaphrodite’
All are born female**. Some change sex to male during maturation (see below)
Food includes zooplankton, small molluscs and small crustaceans…
…and parasites / other juicy bits (fungal growths, anyone?) from bigger fish
Main threats to the species are coral reef degradation / destruction and pollution
The bright colours invite aquarium use, but the trade in this species is not critical.

** Some sources suggest some are born male and remain male.

A juvenile bluehead – mostly yellow, with a pale underside

THE REMARKABLE SEX LIFE OF THE BLUEHEAD WRASSE

This is an unavoidable topic, I’m afraid. The bluehead’s sex life is the most interesting thing about them, and this is no time to be prudish. It has been the subject of extensive scientific research. As with many human relationships, “it’s complicated” but in a conch shell it boils down to this:

To recap, BWs are born female and as they mature, some become male.
Males reach an ‘initial phase’ when they can breed in groups with females
Some males grow larger & reach full colouration. This is the ‘terminal phase’
These large males aggressively chase away smaller ones & seek females to pair with
Their state of readiness is signalled by colour changes BUT the females know…
…that the smaller males have a sperm count higher than dominant males.

As the excellent organisation OCEANA puts it: Bluehead Wrasses may reproduce in four different ways throughout their lifetime: 1) as a female in a group spawning event; 2) as a female in a pair spawning event within the territory of a large male; 3) as a small male in a group spawning event; and 4) as a dominant, terminal male in a pair spawning event within its own territory.

A cropped still from a video I took at Fowl Cay marine reserve. I’ve looked at dozens of images online and not found one that was all blue with a yellow end to its tail fin. Perhaps it is just an all-blue alpha male.

Credits & Sources: Melinda Riger; Adam Rees; James St John; Oregon State edu / Pinterest; Wiki images; self; Oceana; IUCN; magpie pickings

FLAMINGO TONGUE SNAILS: DECORATIVE CORAL-DWELLERS

January 9, 2023 by Rolling Harbour

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. Whether alive or as shells, they are gratifyingly easy to identify. These snails live in the tropical waters of the Caribbean and the wider western Atlantic.

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.

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 protectively 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”. There’s more to them than that!

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 (a) startling in appearance and (b) on closer inspection by a predator, 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.

MANKIND’S CONTRIBUTION

It comes as little surprise to learn that man is 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 their allegedly dull shells Don’t be a collector; be a protector…

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

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

ABACO PARROT FOR A CHEERFUL YULETIDE & OPTIMISM FOR 2023

December 22, 2022 by Rolling Harbour

Thanks to all followers, likers, commenters, regular visitors, one-offs, local wildlife organisations, and friends of Rolling Harbour in general. This year we passed 1 million hits over the ten years of this blog. Proving that people love Abaco, the Bahamas, birds, marine mammals, manatees, reef fish, sharks, turtles, shore-life, shells, insects, plant life, bonefishing, lighthouses, local history, maps, conservation and a whole lot more; and are prepared to tolerate bad puns, haphazard presentation, and a less than rigourous scientific approach to it all.

Weirdest search term ever: How to dispose of dead bodies?

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

December 19, 2022 by Rolling Harbour

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS

Painted Tunicates Clavina picta are one of several species of tunicate ‘sea-squirts’ found in Bahamas and Caribbean waters. These creatures with their translucent bodies are usually found clustered together, sometimes in very large groups. One reason for this is that they are ‘sessile’, unable to move from where they have taken root on the coral.

HOW DO THEY FEED?

Like most if not all sea squirts, tunicates are filter feeders. Their structure is simple, and enables them to draw water into their body cavity. In fact they have 2 openings, an ‘oral siphon’ to suck in water; and an exit called the ‘atrial siphon’. Tiny particles of food (e.g. plankton) are separated internally from the water by means of a tiny organ (‘branchial basket’) like a sieve. The water is then expelled.

Diagram of adult solitary tunicate

WHAT DOES ‘TUNICATE’ MEAN?

The creatures have a flexible protective covering referred to as a ‘tunic’. ‘Coveringcates’ didn’t really work as a name, so the tunic aspect became the name.

IF THEY CAN’T MOVE, HOW DO THEY… (erm…) REPRODUCE?

Tunicates are broadly speaking asexual. Once a colony has become attached to corals or sponges, they are able to ‘bud’, ie to produce clones to join the colony. These are like tiny tadpoles and their first task is to settle and attach themselves to something suitable – for life – using a sticky secretion. Apparently they do this head first, then in effect turn themselves upside down as they develop the internal bits and pieces they need for adult life. The colony grows because (*speculation alert*) the most obvious place for the ‘tadpoles’ to take root is presumably in the immediate area they were formed.

APART FROM BEING STATIONARY & ASEXUAL, ANY OTHER ATTRIBUTES?

Some types of tunicate contain particular chemicals that are related to those used to combat some forms of cancer and a number of viruses. So they have a potential use in medical treatments, in particular in helping to repair tissue damage.

Credits: all fabulous close-up shots by Melinda Riger / Grand Bahama Scuba; diagram from depts.washington.edu; magpie pickings with a particular mention of an article by Sara MacSorley

WRY ‘CUDA & SARDONIC SMILES, ABACO BAHAMAS

December 6, 2022 by Rolling Harbour

WRY ‘CUDA & SARDONIC SMILES, ABACO BAHAMAS

There’s no doubt about it, barracudas have a particularly unwelcoming look to them. They exude menace. There’s something about the torpedo shape, the primitive head, and the uncomfortably snaggle-toothed grin-with-underbite that suggests a creature not to be underestimated.

And that smiley mouth – rather scornful and derisive, is it not? A powerful creature in its element, where you are the intruder… and it sees it like that too. An adult barracuda may grow to nearly 6 foot long. Your are only temporarily of its world, and (it observes) you are keeping your distance.

The dental arrangements of a ‘cuda are a wonder in themselves. The teeth are razor sharp; an orthodontist’s nightmare because they are all different sizes and grow at different angles. Some are conventionally set in the jaws, but some actually grow from the roof of the mouth. There are ‘normal’ sized teeth interspersed with wicked-looking fangs that randomly grow facing forwards, backwards and sideways.

WHY THE UNTIDY MOUTH FURNITURE?

The name Barracuda is thought to derive from the Spanish word barraco meaning (in one of its senses) “overlapping teeth”. The jaws that contain the teeth are strong, and the underbite adds to the effectiveness of ‘cuda predation. Prey is highly unlikely to escape once caught. When the jaws snap shut, the sharp angled teeth – particularly the back-facing ones (cf fishhook barbs) prevent the victim from pulling away. Then the munching and shredding can begin inside what is essentially a perfectly equipped multi-bladed mincing machine.

Credits: Melinda Rogers / Dive Abaco except #3 & #8 Melinda Riger / Grand Bahama Scuba

Here’s looking at you…

MANATEE AWARENESS MONTH!

November 22, 2022 by Rolling Harbour

MANATEE AWARENESS MONTH: BAHAMAS? WE GOTTEM!

Manatees are apex ‘gorgeous marine mammals’. Gentle, inquisitive, brave, long-distance-but-rather-slow-swimming, grass-grazing miracle ur-elephant descendants. They never made it out of the sea in the Miocene epoch.

West Indian Manatee, Bahamas (BMMRO / Charlotte Dunn / Keith Salvesen)

Incongruous in a world of fast sharks, snappy ‘cudas, large whales and leaping dolphins, they contentedly mooch around the seagrass beds. No one in the world has ever objected to or dissed a manatee. They bring only delight to the sea-world, and offer only charm to mankind.

Manatee Awareness Graphic (Peppermint Narwhal)

In the past, I’ve written about the small number of manatees that inhabit the turquoise inner waters of the Bahamas. They were carefully recorded with individual identifying features – usually nicks in the paddle, or scarring. Usually they were named and, where possible, fitted with a tracker. Their friendships and amorous hook-ups were noted. Despite a 16-month birth cycle, manatee-lets were born. Then Dorian struck, and the situation for manatees (as with many other creatures) became unclear. The good news is that they are now increasingly sighted, with photos taken and soc med posts to admire.

IS THERE A DOWNSIDE FOR THESE APPARENTLY BLISSFUL AND PEACEFUL CREATURES?

Yes indeed. It’s mankind, I’m afraid. Among the threats to the survival of these unusual, endearing, and legally protected creatures are, in no particular order:

Pollution of inshore waters and canals
Degradation of the (formerly limitless) sea-grass beds where they feed
Reduction or tainting of the fresh water sources that they need to survive
Understandable over-enthusiasm by admirers – especially in harbours – in dousing them with water from hoses and feeding them lettuce…
…and similar behaviours that may lead to a trusting dependance on humans
Unthinking or speed-selfish boat behaviour in or near harbours resulting in collisions
Simply not caring at all and carving them up, leaving often deep prop-scars. Few manatees escape at least a few of these. Some do not survive.
Probably I don’t need to mention man-caused Global Warming, but I just have.

Let’s celebrate this special month for manatees. Let’s hope that they can survive and prosper in these increasingly difficult and dangerous times for almost all species. Look at any of these photos… can we agree that these wonderful animals deserve care and protection.

All photos: Charlotte Dunn / BMMRO and research contributors; final image ‘Save the Manatee’

A MURMURATION OF STARLINGS

November 14, 2022 by Rolling Harbour

*European Starling Sturnus vulgaris – High Line NYC* – RH

We are all familiar with some of the collective nouns for birds – flocks, flights, broods, maybe companies (parrots) and so on. There are plenty of lesser known terms for specific birds, of which quite a few seem rather remarkable: a wisdom of owls, a murder of crows, a lamentation of swans, an unkindness of ravens, an exaltation of larks. Most of these refer to perceived characteristics of a particular species (the swan pining for a lost mate – they pair for life). Some date from medieval times.

MURMURATIONS OF STARLINGS

In the UK in late autumn, starlings start to gather in huge flocks in trees and open fields. Twitchers begin to gather too, in their all-weather plumage, ready to watch the sensational avian displays of thousands and thousands of starlings as they take to the air almost simultaneously. They swirl in densely packed random formation, drawing complex patterns across the sky. The group will constantly change direction and height, sometimes splitting into subgroups and reforming. They may suddenly drop to the ground in a teeming raucous mass, before taking off again to continue the display.

It is sometimes possible to sense when the flight is about to begin, In a huge packed group on the ground, there is a hint of restlessness. There is movement. A few birds seem to jump slightly. Then in a flash they are away into the sky.

A brief encounter with a small murmuration last week

Murmuration, early evening, Maiden Castle, Dorset (an iron-age hill fort) – iPhone

Starlings Sturnus vulgaris are a European species. They are now common in North America, less so in the Bahamas. The non-European distribution happened this way: All the European Starlings in North America are descended from 100 birds set loose in New York’s Central Park in the early 1890s. The birds were intentionally released by a group who wanted America to have all the birds that Shakespeare ever mentioned.* In return, gray squirrels were introduced into Europe at about the same time, with the population increasing exponentially and displacing the indigenous red squirrel..

* All About Birds – Cornell Lab

Photos: Keith Salvesen, Bruce Hallett, Wiki Commons; Video Clip Keith Salvesen; Cartoon by the very excellent Birdorable

ABACO’S THREE CUCKOO SPECIES

November 1, 2022 by Rolling Harbour

Yellow billed cuckoo, Abaco Bahamas (Tom Sheley)

ABACO’S THREE CUCKOO SPECIES

There are 3 cuckoo species recorded for Abaco, all permanent residents. Two are relatively scarce; the third is the much-loved gregarious and raucous Ani. Recently I was contacted about a cuckoo seen on Man-O-War Cay. The photo revealed more of a glimpse than a sighting… but it clearly was not an all-black Ani. So here are the 3 species to admire in all their glory – and in the case of the first 2, to highlight the differences between them.

YELLOW-BILLED CUCKOO (and header image)

MANGROVE CUCKOO

SMOOTH-BILLED ANI

Photo Credits: Tom Sheley, Tony Hepburn, Alex Hughes, Gerlinde Taurer, Nina Henry

BLUE CHROMIS: A FLASH OF COLOUR ON THE REEF

October 25, 2022 by Rolling Harbour

BLUE CHROMIS: A FLASH OF COLOUR ON THE REEF

Larger reef fish tend to get more attention than the tiddlers, for obvious reasons. Yet a reef would not properly exist without the small fish that drift and wriggle round the corals. Blue chromis (Chromis cyaneus) are among the first reef fish species I ever met when snorkelling at Fowl Cays.*

Blue chromis belong to the same group as damselfishes. These unmistakeable, bright reef denizens are very visible despite their tiny size. These fish are shoalers, so out on the reef you can enjoy them flickering around you as you swim along or hang in the water to admire the corals.

Like many a pretty and easily captured small fish that can be monetised once removed from its natural home environment, the blue chromis is popular for aquariums. Humans like to keep them in their own home environments safely away from oceans and reefs, unselfishly feeding the little things concocted food to keep their little lives going till the cat gets them. [Sorry, I don’t know what came over me there]

Blue chromis are adaptable and sociable, and will happily swim with other small reef fishes (as above). My own favourite combo is chromis mixed in with sergeant majors. But a shoal of them (mostly) alone is pretty special too….

I cynically mentioned ‘concocted’ food earlier. Here is one online care instruction for looking after them: “They are omnivores, meaning that they eat both meaty and plant based foods. They are not difficult to feed and will eat a variety of regular aquarium fare, frozen, live, and sometimes even dry food. Feeding them a variety of foods will help them retain their color in captivity. They sometimes feed on the algae in the tank”. So I think it’s ok to suggest that leaving the fish out on the reef might suit them better.

If tempted to ‘rescue’ some from their reef habitat, rest assured that they have been known to spawn in captivity. Blue chromis can usually be obtained for about $10-15. And don’t hold back on the frozen food (though maybe warm it up a bit before feeding time). I rest my case.

*I say ‘snorkelling’ rather than anything more impressive because I am a pathetic swimmer and I know my limitations…

Credits: Melinda Rodgers / Dive Abaco; Melinda Riger / G B Scuba

CAPE MAY WARBLERS: SPECIAL SPECIES FOR GLOBAL BIRD WEEKEND 2022

October 8, 2022 by Rolling Harbour

CAPE MAY WARBLERS + WHAT’S IN A NAME?

The history of ornithological classification and nomenclature is littered with peculiarities. The attractive migratory Cape May Warbler Setophaga tigrina is a very good example of premature evaluation.

The range of the species is well defined. In the summer the birds live within a broad band that straddles northern USA and Canada. In the winter they head south with all their migratory warbler cousins across the yellow band to (mainly) the Bahamas.

As with all migratory species, some birds each year will wander or be blown off-course; or will take a rest stop en route and decide to stick around. And so it was that in May 1812, a month before the Battle of Waterloo, the first ever specimen of the species was collected on Cape May NJ by George Ord during an exploratory trip with naturalist ALEXANDER WILSON (he of plover & snipe fame). To be specific, they had gone to shoot the birds they wanted to collect. The bodies, from large down to tiny, were after all the only irrefutable evidence of a new ‘find’ at that time. Detailed drawings could be made and descriptions composed. The later display of the specimens enabled the expansion of ornithological knowledge and methodology, and brought consequent renown. The great Audubon took the research method *treading very carefully here* rather further than one might be comfortable with today, with somewhat indiscriminate use of lead shot.

As Wilson later wrote (note the words ‘beautiful little species, ‘shooting excursion’ and ‘ransacked’):

THIS new and beautiful little species was discovered in a maple swamp, in Cape May county, not far from the coast, by Mr. George Ord of this city, who accompanied me on a shooting excursion to that quarter in the month of May last…The same swamp that furnished us with this elegant little stranger, and indeed several miles around it, were ransacked by us both for another specimen of the same; but without success. Fortunately it proved to be a male, and being in excellent plumage, enabled me to preserve a faithful portrait of the original.

The odd (indeed ‘Ord’) thing was that the first-ever specimen was a complete one-off in that location at that time. Not a single sighting of the species (named Sylvia maritima by Wilson) was reported on Cape May or in that area for more than a century. Then at last in 1920, another example was found. Nowadays the CMW is not in the least unusual in the location that gave it its name.

On Abaco, CMWs are classified as WR1, which is to say common winter residents. Males have striking chestnut cheeks in the breeding season, with strong streaking on the underside. Note also the black eyestripe. Females and juveniles are paler and the marking is less prominent. These warblers are insectivorous; in winter they may also feed on nectar and fruit. Behaviour-wise, they have aggressive tendencies in defence of their territory and of their food sources.

In researching this post, I discovered a strange (but slightly dull) fact. The CMW is unique among warblers in having a tubular tongue to enable nectar feeding (as with hummingbirds). This random fact hardly has the makings of lively conversation (though you might want to try it out) but considering the multitude of warbler species in existence, the CMW has the benefit of a rather special adaptation.

Tongue 2 (bottom left) is the CMW; No.5 is a bananaquit’s feathery tongue

WHAT SHOULD I LISTEN OUT FOR?

Unhelpfully, even the authorities have a tough time describing the song and call of a CMW. As with so many song-birds, variations on the theme “the song is a simple repetition of high tsi notes; the call is a thin sip” are the best you can hope for. However, it’s worth noting that the species generally prefers to sing from high perches, which might help with ID. But then so do other warblers I’m afraid. Here’s something more practical – the tsi and the sip:

ALL BIRDS, EXCEPT THE LAST, PHOTOGRAPHED ON ABACO, BAHAMAS

Photo Credits: Charmaine Albury [from The Birds of Abaco] (1); Bruce Hallett (2, 6); Sandy Walker (3, 4, 7); Becky Marvil (5); Danny Sauvageau (8).
Audubon Cartoon: On the Wings of the World; Grolleau & Royer / Nobrow (highly recommended)
Drawing, Nat Geo
Range map, Allaboutbirds / Cornell
Audio clips Martin St-Michel / Xeno-Canto;
Research refs include, with thanks, American Ornithological Society / Bob Montgomerie (Queen’s University); Camino Travel Costa Rica; OS

CURLY-TAILED LIZARDS ON ABACO, BAHAMAS

September 27, 2022 by Rolling Harbour

CURLY-TAILED LIZARDS ON ABACO, BAHAMAS

The northern curly-tailed lizard Leiocephalus carinatus, to give it its full name, resembles a tiny dragon with a twist in the tail. These little critters bask in the sun, or scuttle away into holes and crevices as you approach them. I suspect that even a confirmed herpophobic would find some charm in them. They are, of course, completely harmless to humans.

Surprisingly, the Bahamas is home not just to one but five different curly-tail species, and nine sub-species. Broadly-speaking, the variants are found on different and specific islands and have discrete local markings. Mostly they are brownish, but they may also be grey or with a greenish tinge like this one I recently photographed.

Curly-tail males, being territorial, turn somewhat aggressive around breeding time, which is basically most the the year, from February to October. Behaviours indicative of their territorial claims include tail curling / uncurling (of course), head-bobbing, strutting about in an agitated way and inflating the sides of their necks in a threatening kind of way. The tiny-tails, 2″ long when born, are known as ‘hatchlings’.

An impressive poolside ‘double curly’

THREATS TO CURLY TAILS

According to the Bahamas National Trust BNT, the main dangers to the curly-tails of the Bahamas are:

Dogs, cats, rats and introduced predators such as raccoons
Collection for the pet trade – curly tails are unprotected by CITES listing (also cute)
Collection of the rarer endemics by reptile enthusiasts seeking ‘exotics’
Development and habitat destruction (though it is noted that curly tails seem to adjust quite well in developed areas)

A curly tails sloughs its skin as it grows, as with snakes and other reptiles

WHY THE CURLY TAIL?

As mentioned above, for use in territorial posturing
In courtship displays by males to attract females (luckily a method not available to humans)
As a response to predators, confusing an attacker with movement at both ends
As a last resort, to detach to aid escape (the tail re-grows)
For fun and just because they can grow one and you cannot

Credits: all photos, Keith Salvesen except #2 & #6, Charles Skinner; BNT

WORLD SHOREBIRDS DAY . COMPLETE CHECKLIST FOR ABACO, BAHAMAS

September 5, 2022 by Rolling Harbour

WORLD SHOREBIRDS DAY: ABACO’S COMPLETE CHECKLIST

Abaco’s birding records compiled for over 20 years include 33 shorebird species. For a few, the islands and cays are a permanent residence; for many others they are winter quarters; some species are visitors transient in their migrations; a few are rare vagrants. The complete checklist of Abaco’s shorebirds is below, along with 3 links to specific posts.

I have divided the species into 3 categories: sandpipers & kin; plovers; and a catch-all ‘large shorebird’ group that includes one or two sandpipers. Of the 26 birds featured and shown in the main checklist below, 23 are ones you might reasonably hope or expect to encounter on Abaco, though some only if you are lucky or your field-craft is excellent. The others are the long-billed dowitcher, American avocet and Wilson’s phalarope (of which only one has ever been seen on Abaco, with a photo to prove it). Many of these are showcased in my book The Birds of Abaco.

CLICK A LINK TO INVESTIGATE

LARGE SHOREBIRDS

SANDPIPERS

PLOVERS

THE COMPLETE CHECKLIST

The codes tell you, for any particular bird, when you may see it (P = permanent, WR = winter resident, TR = transient, V = vagrant); whether it breeds (B) on Abaco; and your chance of seeing it, graded from easy (1) to vanishingly unlikely (5).

Black-necked Stilt Himantopus mexicanus PR B 3
American Avocet Recurvirostra americana WR 4
American Oystercatcher Haematopus palliatus PR B 2
Black-bellied Plover Pluvialis squatarola WR 1
American Golden-Plover Pluvialis dominica TR 4
Wilson’s Plover Ochthodromus wilsonia PR B 2
Semipalmated Plover Charadrius semipalmatus WR 2
Piping Plover Charadrius melodus WR 3
Killdeer Charadrius vociferus WR 2
Spotted Sandpiper Actitis macularius WR 1
Solitary Sandpiper Tringa solitaria WR 2
Greater Yellowlegs Tringa melanoleuca WR 2
Willet Tringa semipalmata PR B 2
Lesser Yellowlegs Tringa flavipes WR 3
Ruddy Turnstone Arenaria interpres PR 2
Red Knot Calidris canutus WR 3
Sanderling Calidris alba WR 1
Dunlin Calidris alpina WR 2
Least Sandpiper Calidris minutilla WR 2
White-rumped Sandpiper Calidris fuscicollis TR 3
Semipalmated Sandpiper Calidris pusilla TR 2
Western Sandpiper Calidris Mauri TR 2
Short-billed Dowitcher Limnodromus griseus WR 1
Long-billed Dowitcher Limnodromus scolopaceus WR 4
Wilson’s Snipe Gallinago delicata WR 3
Wilson’s Phalarope Phalaropus tricolor V 4

For the sake of completeness, the other 7 species of shorebird recorded for Abaco – all transients or vagrants – are:

Upland Sandpiper Bartramia longicauda TR 4
Whimbrel Numenius phaeopus TR 4
Hudsonian Godwit Limosa haemastica V5
Marbled Godwit Limosa fedoa V5
Buff-breasted Sandpiper Tryngites subruficollis V5
Pectoral Sandpiper Calidris melanotos TR 3
Stilt Sandpiper Calidris himantopus TR 3

Photo Credits: Tom Sheley, Bruce Hallett, Keith Salvesen

A WHITER SHADE OF TAIL? LEUCISM IN BIRDS

August 26, 2022 by Rolling Harbour

Leucistic Turkey Vulture, Florida Keys 2 (Amy at PoweredbyBirds

Leucistic Turkey Vulture (Amy Evenstad, PoweredByBirds.com)

A WHITER SHADE OF TAIL? LEUCISM IN BIRDS

And not just the tail*. Other parts of a bird. Sometimes most of a bird. More rarely, an entire bird. Whichever, a bird affected by leucism stands out from the crowd – out of the ordinary and therefore startling to the eye. I’d be very surprised if the fine turkey vulture in the header image didn’t make you look twice – maybe even to check if some devious photoshop trickery had been at work. Yet it’s just a normal TUVU in the Florida Keys, living a normal vulturine life.

LEUCISTIC DISCOVERY ON ABACO

A leucistic Western Spindalis discovered on Abaco by birder Keith Kemp

For comparison – the real deal

LEUCISM? EXCUSE ME, AND THAT IS?

First, what it is not. It is not albinism, which results from diminished or lost melanin production that affects pigmentation. One characteristic of the condition is the tendency to pink eyes, which of course is seen in humans as well as animals and birds. Meet the perfect example…

WELL, WHAT IS IT THEN?

Put simply, melanin is only one of many ingredients of pigmentation. Leucism is caused through pigment loss involving many types of pigment, not just melanin. In birds this results in unnaturally light or white colouring of feathers that may be partial or entire. The eyes of a bird with leucism are unaffected. At one extreme, if all pigment cells fail, a white bird will result; at the other extreme, pigment defects cause patches and blotches of pale or white on the bird, often called a ‘pied’ effect. The condition can be inherited.

A mallard on Abaco. The species is known for its wide colour variations in both sexes. Sometimes the variations go beyond the usual range: this is a leucistic bird

A leucistic common gallinule (moorhen) on Abaco

Leucistic rock pigeon

BAHAMA (WHITE-CHEEKED) PINTAIL: A PIGMENT PUZZLE

I have found more examples of leucism in the ‘Bahama Duck’ than any other local species on Abaco. But there is also scope for confusion. First, here’s a pintail that is undoubtedly leucistic – note that the eyes and beak are unaffected by pigmentation deficiency:

But not all pale variants can be so confidently labelled. In the first picture, bottom right, there is an obviously an ‘odd’ pintail, silvery rather than ruddy brown like the rest of them (and yes, I do see the coot in the pack as well…). The second photo shows the same bird on dry land.

This is known as a ‘silver pintail’. These are said to be a leuchistic variant, and they are stocked by poultry dealers as ornamental ducks at a higher price than the much-loved standard brown version. However this bird clearly retains the essential markings of a normal pintail that you might expect to be absent (at least in patches) in the ‘true’ leucistic bird. I’ve seen it described as a ‘gray morph’. I wonder where the line is drawn between a noticeable colour variant or morph in a bird; and an obviously pigment-abnormal, leucistic bird where the incidence and extent of the condition seems to be random.

A fine example of a ‘pied’ American Robin, an occasional visiting species on Abaco

Leucistic American Robin (Amy @ PoweredbyBirds)

Leucistic American Robin (Amy Evenstad, PoweredByBirds.com)

PIPING PLOVERS CAN BE LEUCISTIC TOO

PIPL are one of my bird species preoccupations, but until I checked them out I hadn’t imagined what a leucistic one would look like, or whether they had ever been recorded. I now have the answer…

These photos of a leucistic female were featured by Audubon Alliance for Coastal Waterbirds, Audubon Connecticut. They were taken by Jim Panaccione, a Biological Science Technician at Parker River National Wildlife Refuge, Newburyport, Massachusetts. I hope he won’t mind their illustrative use here… Despite the theory that leucistic birds may find it hard to find a mate – and might even be attacked by its own species – this pair successfully nested.

OPTIONAL MUSICAL & CULTURAL DIGRESSION

A WHITER SHADE OF PALE

*Obviously, it had to be ‘tail’ in the title to justify one of my clunky ‘jokes’ and an accompanying musical diversion. That’s just the way it is, I’m afraid. Bach’s well-known descending chord sequence of was of course ~~shamelessly ripped off by~~ ingeniously adapted by Procol Harum for ‘A Whiter Shade of Pale’, their first single in 1967. Relive a Summer of Love right here and now.

Any fret-tweakers might like to see the sheet music of Bach’s Air for guitar – you could even play it on Air Guitar – which is relatively easy, being in C major.

Air on a G String - J S Bach - Guitar Tab JPG

‘BACH IN A MINUET’

The best known commercial use of the tune was in the famed series of adverts that equated a mild cigar called Hamlet with happiness, accompanied by an excerpt from a jazzy version of Bach’s ‘Air on the G String’. Here is one of the best – and possibly the only advert to my knowledge to feature not one, but two excellent Sir Walter Raleigh jokes.

Credits: thanks to Amy Evenstad (PoweredByBirds.com) for use permission for her wonderful TUVU & AMRO photos; other photos by Keith Kemp & Bruce Hallett (Spindalis); Pinterest (rabbit); Nina Henry (mallard); Tony Hepburn (moorhen); Wiki (pigeon); Jim Edmonson (leucistic pintail); Keith Salvesen (silver pintail); Jim Panaccione / Audubon (piping plovers); Procol Harum, esp. Robin Trower for building a great career round being ‘reminiscent of Jimi Hendrix’; J.S. Bach for a nagging tune; Hamlet cigars for ingenuity & making me laugh

THANKS A MILLION! ROLLING HARBOUR: TEN YEARS OF HITS

August 13, 2022 by Rolling Harbour

*Cuban Emerald (f) . Abaco . Bahamas* – *Keith Salvesen*

ONE MILLION HITS ON THE STATS COUNTER (+ BONUS FROGFISH)

HAPPY DAYS AND HAPPY YEARS

A decade has passed since I sat down and tried to find out how on earth WordPress worked. The plan was to start a simple blog about Abaco, based on our very limited experiences as UK members of the Delphi Club fishing lodge perched on the cliff above a wonderful white sand bay known as Rolling Harbour.

By then, I’d become fascinated with the wildlife of the island, and in particular the birds. Most were species that I had never seen before, nor in many cases heard of. I only had a tiny pocket camera back then, but I was quite proud of my rubbish photos of distant birds that only I could identify. I fell for the cheerful call of the Thick-billed Vireos, the flash of the Hummingbirds, and the charm of the Bananaquits. Then I encountered the unique underground-nesting Parrots, found only on Abaco.

A FESTIVAL OF ABACO PARROTS

Having to some extent conquered the complexities of blog set-up, I started unpromisingly with a few practice posts and no clear development plan. THE FIRST POST was… see what we are dealing with here in terms of sophistication?

Gradually the site expanded: I learned more, the ideas formed, the content improved, and I upgraded the camera. Background research became easier as online information on related topics gradually improved. Hits started to come in, then people I knew began to sign up. Then people I didn’t know joined in. Then word got around. Within a year, there was something worthwhile that people seemed to like, even beyond the Bahamas.

*Western Spindalis . Abaco . Bahamas – Keith Salvesen*

At that time, social media activity on Abaco (and beyond) was far less. Fewer communication methods mainly confined to Facebook & Twitter: basic / unreliable wifi: simpler iphones (model #3); generally far less interest in all the stuff we now wade through. The daily traffic for Abaco on Facebook tended to be local and brief. Meanwhile the blog happily coasted along, gradually expanding, heedless of hashtags and the like that I was too idle to learn to use.

*Atala Hairstreak Eumaeus atala . Abaco . Bahamas – Keith Salvesen*

HURRICANE SANDY

Then in October 2012, the awesome power of Hurricane Sandy began to curve towards the northern Bahamas. I started to post Hurricane information using NOAA and similar resources. Trackers (static and interactive), path and intensity predictions, NASA satellite hotspot maps, advisories and so on. I watched, amazed, as my hits changed from a handful daily to every few seconds. The counter clicked over continuously. On one day there were 2,200+ hits. Comms were mostly down and island information was hard to come by. I started to get emails and messages from beyond Abaco with concerns about families, locations (eg Little Harbour), properties, boats etc. In some cases I was able to make contact directly or indirectly with someone who could help. Overall, there were 15,000+ hits over 10 days or so. From such scary and sad circumstances, I simply note that the blog’s following grew rapidly.

*Cuban Pewee . Abaco . Bahamas – Keith Salvesen*

THE BIRDS OF ABACO

In 2013, Peter Mantle began to contemplate a new project, besides having recently masterminded the Delphi Club. He suggested producing a spectacular book showcasing the wonderful bird life of Abaco (and by extension other parts of the Bahamas). My wife Sally, a publisher, would carry out the professional work as production manager, designer, and editor. Research, picture-sourcing and writing were to be my pigeon. 16 months later THE DELPHI CLUB GUIDE TO THE BIRDS OF ABACO had been printed in Florence and shipped to Nassau.

This is a good time to recall the extraordinarily positive response from all those who became involved in the project. The professionals guiding an amateur throughout the process; the 30 photographers whose pictures light up the book; and many others on Abaco and beyond who assisted with advice and encouragement. And the people who bought the book. And the people who didn’t but saw a copy and enjoyed it anyway.

Over the years ROLLING HARBOUR ABACO increased massively in scope, for example with Marine Mammals (BMMRO), Reef Fish, Corals, and so on. Also bonefishing, history, maps, lighthouses, museums and a whole lot else besides. As I learned more, the more rewarding the research and writing became. Here are a few themed highlights from the last decade.

MARINE MAMMALS . ABACO . BAHAMAS

*Dolphin & Calf . Abaco . Bahamas – BMMRO*

REEF DENIZENS

CORAL REEFS

SHARKS, RAYS & ‘CUDAS

ABACO PIPING PLOVER WATCH 2015-20

From 2014 on, I became involved in the research of the migration of PIPING PLOVERS from their breeding grounds in North America to overwinter in the Bahamas. These enchanting 2oz little birds make the journey of over 1000 miles from late July… and then back again in Spring. Many are banded in the breeding grounds, enabling individual birds to be identified and data recorded. This Citizen Scientist project involved people reporting sightings, collecting winter data for the summer Specialists.

*Piping Plover . Delphi . Abaco . Bahamas (Peter Mantle)*

The project spanned almost 5 years, cut short by the devastation of Abaco by Hurricane Dorian in 2019. Here are a few enchanting PIPL; and an example page from the record.

APPRECIATION

Over the decade, there have been 100s of people who have contributed to this little enterprise in some way: looking at posts; liking them; signing up for updates; providing information, ideas and encouragement; generously giving use permission for fantastic photos; commenting thoughtfully; correcting kindly; allowing me to join and even contribute to conservation, research and general natural history organisations; making the book a success; supporting and enabling APPW to provide valuable data; scores of people being friendly even though we never met. Thanks to everyone who has kept Rolling Harbour rolling along for so long, and – between you all – for 1m hits.

ODDEST SEARCH TERM: How to dispose of dead bodies?

VISITOR RECORD: 2,291 in 24 hours

COUNTER VIEWS:1,078,670 times by 587,400 visitors

WTF? (WHAT’S THAT FISH?): A COMPENDIUM OF SUBSURFACE WEIRDNESS

July 21, 2022 by Rolling Harbour

The astoundingly 5* strange Frogfish (Adam Rees / Scuba Works)

WTF? (WHAT’S THAT FISH?)

A COMPENDIUM OF SUBSURFACE WEIRDNESS

15 OF THE STRANGEST SEA CREATURES IN BAHAMAS WATERS

WTF? stands for ‘What’s That Fish’? But it might also be your exclamation when you come across one of these creatures. The WTF? series highlights some of the unusual, curious, weird and downright extraordinary fishes that inhabit the waters of Abaco and the northern Bahamas. Some represent local forms of a species found elsewhere in the world; others are in their own evolutionary cul-de-sac. Just as I think I have seen it all, so another oddity crops up somewhere that demands inclusion.

This page is intended to be the most direct route to an underwater menagerie of the piscine strangeness, with example photographs to whet your appetite to learn more about these fascinating denizens of the ocean. This series has been put together over several years, and clicking on any creature header will start you on a long dive into that fish’s environment and secrets.

To see a collection of the excellent WEIRD CREATURES “MONSTERS OF THE DEEP” trading cards click HERE

1. REMORAS

2. LETTUCE SEA SLUG

Lettuce_Sea_Slug_LASZLO ILYES

3. BATFISH

4. FROGFISH

Frogfish (Adam Rees, Scuba Works)

5. FILEFISH

6. SAND DIVER

7. SOAPFISH

8. GUITARFISH

9. HARLEQUIN BASS

10. FLYING GURNARD

Dactylopterus_volitans Flying Gurnard (cralize wiki)

11 STARGAZER FISH

12 TRUMPETFISH

13 ROUGHHEAD BLENNY

14. ARROW CRABS

15. PORCUPINEFISH

Credits are all given in the individual articles. Thanks to all those that have provide the photos, without which this type of illustrated, unscientifically scientific poke around in the ocean would not be possible.

BLACK WITCH MOTHS: HARBINGERS OF DEATH OR LOTTERY BANKERS?

July 7, 2022 by Rolling Harbour

BLACK WITCH MOTHS: HARBINGERS OF DEATH OR LOTTERY BANKERS?

Black Witch moths Ascalapha odorata are seriously bad news. Or wonderfully good news, depending where you are and who you talk to. First, let’s look at some of the local names for the creature, from which you will get a pretty clear idea of its somewhat negative folklore status, as well as its area of distribution. I do this not to demonstrate how effortlessly I can ‘borrow’ from Wiki, but rather to show how a simple moth can give rise to widespread superstition and even fear.

12 SCARY NAMES FOR ONE MOTH

Mariposa de la muerte (butterfly of death) – Mexico / Costa Rica
Pirpinto de la Yeta (something like ‘jinxing butterfly’) – Argentina
Tara Bruja (witch moth) – Venezuela)
Miquipapalotl (black death moth) – Mexico
Taparaco (something like ‘messenger in black’) – Peru
X-mahan-nah (‘invades your house’) – Mayan
Duppy Bat (lost soul / ghost /malevolent spirit) – Jamaica, Caribbean
Money Moth, Money Bat – Jamaica, Caribbean (including Bahamas)
Other names include Papillion-devil, La Sorcière Noire, Mourning moth, Sorrow moth.

WHICH MOTH?

These very large moths (wingspan up to 7″) are nocturnal, with females larger than the males. The diagnostic markings are a spot on each forewing shaped like a number nine or a comma. This spot is often green with orange highlights (seen in the header image). The hind wings are decorated with distinctive ‘eyes’. The overall effect is an example of aposematism – coloration or markings that act as signals to warn or repel predators. The link above will take you to an excellent Wiki article on the topic, including the debate on the topic between Alfred Russel Wallace and Charles Darwin

The stripy larval caterpillar can grow up to 7 cm in length.

‘BAD LUCK & TROUBLE’

The moth is a migratory species, flying from (roughly speaking) South America as far north as Florida and Texas. The worst luck is believed to come from having one flutter into your house. Once inside, it will either bring bad luck to the house – or if there is already misfortune there, it will make it even worse. There are variations on this belief – e.g. that the more corners of a room the moth visits, the more doomed the household.

ANY GOOD NEWS ABOUT THIS CREATURE, OR ALL GLOOM & DOOM?

Fortunately yes, and it’s high time to dispel the gloom hereabouts. In some places (e.g. Hawaii), it is believed that when a loved one has died and an Ascalapha odorata is seen soon after, it is the person’s soul returning to say farewell.

More promisingly still, in the Bahamas and wider Caribbean a far more positive and practical attitude is shown. If a Money Moth (or Money Bat) lands on you, you will receive some money. Or so it is said. I have never heard of this happening, but at least it is an optimistic approach to the moth. And Texas, thinking big, takes this several steps further to the prediction that you will win the lottery (I have a feeling this is a very modern theory).

WHY ARE YOU SCARING US WITH THIS THING?

Because at one time I had never heard of these moths, let alone seen one. Then one balmy Bahamian evening, at dusk, someone pointed out a large dark smudge on the door-frame. I only had a phone, and I had to use the flash. Here is the moth, with its evil little eyes shining in the bright light. Luckily, it was outside and not inside the building, which I hope diluted the malevolence radiation level. I didn’t realise the significance of the moth and the implications at the time of course, until I’d looked it up in Sibley’s indispensable ‘Compendium of Evil Moths‘**). It’s a poor photo, but it was useful for ID and I feel that taking a quick shot helped to ward off the worst of any unpleasantness. Though I remember that I fished very badly (even by my low standards and expectations) the following day…

CULTURAL SIGNIFICANCE IN LITERATURE

Remember Silence of the Lambs? Well in the book, pupae of the Black Witch moth were placed in the mouths of victims by serial killer ‘Buffalo Bill’ as his calling card – though for the film, the moth species was changed to a Death’s-head Hawkmoth, as featured on the poster.

You can read about Hannibal Lecter’s link to moths, and learn how for the film the pupae were made from sweets (Gummi Bears ™) so as to be harmless if swallowed, HERE

SO – BE HONEST – ARE THEY HARMFUL IN ANY WAY AND / OR WILL ONE MAKE ME RICH?

Taking one’s life in one’s hands…?

Photo credits: Charles J Sharp (1, 5) OS; Wiki (2); Julia Gotz (‘juliatrees’) (3)*; Keith Salvesen (4) Sources: Julia Gotz (‘juliatrees’), Terry Sovil, , Texasbutterflyranch.com, Wiki, Sibley’s ‘Compendium of Evil Moths‘**

*Julie closed her blog, from which photo 3 comes, in 2010. I’m hoping she won’t mind my resurrection of her image to illustrate the species… Black Witch moth photos are quite rare online

**Out of print. Actually, never in print.

BELLA MOTHS: COLOURFUL, POISONOUS & PROMISCUOUS

June 12, 2022 by Rolling Harbour

Day-flying_Bella_Moth_(Utetheisa_ornatrix) on Rattlebox Blossom (Bob Peterson, Florida)

BELLA MOTHS: COLOURFUL, POISONOUS & PROMISCUOUS

The BELLA MOTH Utetheisa ornatrix is also known as the ‘ornate moth’ or ‘rattlebox moth’ (a tall spiky plant of the species Crotalaria). The italianate ‘bella’ signifies beauty and all the many synonyms for it. These moths come in colours ranging from pink to red or orange, and yellow to white. Some have vivid coloration, others are less bright. Their black dot markings are broadly similar. Moths are often thought of as creatures of the night, so daytime would not be an auspicious time for moth-hunting. In fact there are many moth species that are active during the day (‘diurnal’), and the Bella Moth is one of them.

Bella Moth, Neem Farm, Abaco (Keith Salvesen) 1

Bella Moth, Neem Farm, Abaco (Keith Salvesen) 2

DEFENSIVE WARNINGS

The bright coloration is (as in many species) nature’s way of saying ‘leave me alone’ and in particular, ‘I am very unpleasant to eat’. It is called APOSEMATISM. The unpleasantness derives from toxins of the plants they feed on. This starts at the larval stage. The larvae feed on plants that contain poisonous alkaloids – in particular the yellow rattlebox plant – rendering them extremely unpalatable. both as larvae and adults. Bella adults in need of an alkaloid boost may cannibalise moth eggs, pupae or larvae to counter a deficiency.

Ornate_moth_(Utetheisa_ornatrix) Charles J Sharp wiki

BELLA MOTH SEX LIVES: ‘IT’S COMPLICATED’

Sexual encounters are dictated by females, who compete with other females for males
Females seeking to mate always outnumber available males
A female bella will release powerful pheromones at dusk to lure males
Related females uniquely engage in collective pheromone release
This is termed “female pheromonal chorusing”, an irresistible draw for the males
Several males will give the female chemical ‘nuptial gifts’ of both poison and sperm
The female chooses the best of her various suitors and copulates with 4 or 5 of them
The whole process of multiple copulation may take up to 12 hours
In some way I don’t understand, she is then able to select her preferred sperm provider
The sperm of the other males is rejected and they go away disappointed
Humans: do not try any of this, whether at home, in the office, in public, or when driving

Utetheisa_ornatrix (Dumi, Jamaica)

Credits: Bob Peterson (1, 6); Keith Salvesen (2, 3); Charles J Sharp (4); open wings by Dumi (5)

PEACOCK FLOUNDERS: NOW YOU SEE THEM…

June 2, 2022 by Rolling Harbour

PEACOCK FLOUNDERS

MASTERS OF SUBAQUATIC CAMOUFLAGE

I featured the extraordinary, colour-transforming PEACOCK FLOUNDER Bothus lunatus a while back as part of a Bahamas Reef Fish series. These really are remarkable creatures, and I have decided to return to them mainly because of the wonderful illustrative photos I was able to incorporate. There are plenty of flounder facts too, but if you just enjoy the pictures and skip the blurb I’ll understand.

ROVING EYES

In the fish shown here, you’ll see that – surprisingly – both eyes are on the upper-side of the fish, above the rather grumpy mouth, whereas the head is horizontal to the ocean floor. Oddest of all, juveniles are constructed conventionally with bilateral eyes, and look like ‘normal’ fish rather than flatfish.

As the fish matures, in some magic way the mechanics of which I can only guess at**, the right eye grows round to the topside and the flounder transforms from a ‘vertical’ fish to a flatfish. For this reason, the PF is known as a ‘left-eye’ flounder. Maybe in other flounder species in the world – the southern hemisphere maybe? – the eye that moves round to the upper-side is the left eye.

The eyes of this fish have another special trick up their sleeves (so to speak). They operate completely independently. Thus the creature can look left and right, or forwards and backwards, simultaneously. It’s an excellent system for detecting predators coming from any angle. It’s a superpower we might all benefit from.

DO THEY HAVE ANY OTHER TRICKS WE SHOULD KNOW ABOUT?

Yes they do indeed. If you have been admiring the fish shown so far, you’ll have noticed that the colour of each one differs from the others. In addition to the predator-protection that the eyes provide, the peacock flounder can make itself (near) invisible. They can rapidly change colour to match their surroundings. There are 3 reasons for this: to avoid / confuse predators; to conceal themselves on the sea-floor to catch passing prey; and, as dive expert Fred Riger has pointed out, “the male peacock flounder can, and does greatly intensify his colours to declare territory and attract females. When doing this the males will also signal with the left pectoral fin, sticking it straight up and waving it around.”

The same fish, photographed over several minutes as it moves over the ocean floor

Matching the background happens as the fish swims, and in a few seconds. When they rest on the sea-floor, the camouflage may even become total. In #4 above you can just about make out the eyes. The whole effect is known as ‘cryptic coloration’ or CRYPSIS. In contrast, the image below shows just how adaptable the transformation can be. Note how the fish can even mimic the pinkish tinge of the sand perfectly. If threatened, the fish will bury itself in the sand, with just its eyes showing.

HOW DO THEY MANAGE TO CHANGE COLOUR IN SECONDS?

It’s complicated! A simple answer is: a mix of hormones, pigment-cells and vision, all coordinating rapidly. The colour change works in two ways: pigments are selectively released to the skin cells; and other pigments can be selectively suppressed. An analogy might be image manipulation using variations in brightness, saturation etc. Not convinced? Then watch this short video and prepare to be impressed. Astonished, even.

WHAT IF A FLOUNDER CAN’T SEE CLEARLY FOR SOME REASON?

As with many (all?) superpowers, there is usually some kryptonite-style flaw. A flounder with a damaged eye, or one temporarily covered (by sand, for example) will have difficulty in changing colour – possibly at all, or at any rate with the swiftness it needs to have.

THESE SIDEWAYS FISH – HOW DO THEY… YOU KNOW…?

Take a look at the fish above with its top fin raised. It’s a ‘ready’ signal in a harem. Male flounders have a defined and defended territory within which live up to 6 females – a so-called ‘harem.’ I can do no better than borrow the description of the rituals from an article derived from scientific papers by Konstantinou, 1994; Miller, et al., 1991 in the website animaldiversity.org/…ounts/Bothus_lunatus To which I can only add, ’15 seconds, eh?’

“Mating activities usually begin just before dusk. At this time, a male and a female approach each other with the ocular pectoral fin erect. The two fish arch their backs and touch snouts. After this interaction the female swims away, and the male sometimes follows, approaching the female again from the left side. At this point the male pectoral fin is erect and the female pectoral fin moves up and down, possibly signalling willingness to mate. The male then positions himself underneath the female and mating begins. This process consists of a mating rise, during which the female and male rise in the water column together. On average, these rises last about 15 seconds. At the highest point of this rise, usually around 2 m above the substrate, gametes from both fish are simultaneously released, producing a cloud of sperm and eggs. Once the couple returns from the rise, the male “checks” to make sure mating was successful, and the pair separates quickly, swimming away from each other in opposite directions. Not all mating rises are successful, and the process of “checking” is thus important. The exact purpose of the mating rise in these flounders unknown; possible reasons for rising include better dispersal of gametes and predator avoidance.”

Peacock Flounder – Kim Rody Art

**This may in fact have been through sheer laziness

Credits: Melinda Riger & Virginia Cooper / Grand Bahama Scuba; Melinda Rogers / Dive Abaco; Adam Rees / Scuba Works; Kim Rody; animaldiversity.org; magpie pickings and other credits in the text

GULL-BILLED TERNS ON ABACO, BAHAMAS

May 10, 2022 by Rolling Harbour

GULL-BILLED TERNS ON ABACO

The gull-billed tern Gelochelidon nilotica had a name upgrade from Sterna nilotica some years ago, and was awarded the honour of its own genus.

Gull-billed Tern, Abaco (Alex Hughes) 04

Let’s be clear at the outset: there’s no such thing as a tern-billed gull. Which fortunately lessens the scope for species confusion.

Gull-billed Tern, Abaco (Alex Hughes) 05

There are 12 species of tern recorded for Abaco. Only one, the royal tern, is a permanent resident. There is one winter resident, the Forster’s tern and there a 6 summer resident terns of varying degrees of commonness. The other 4 are transient or vagrant, and ~~probably~~ definitely not worth making a special trip to Abaco to find. The G-BT is designated SB3, a summer breeding resident that is generally uncommon, though may be more common in particular areas.

gull-billed-tern

TERN TABLE** Tern Species Abaco **I know! Too tempting…

The bird gets its name from it short, thick gull-like bill. It’s quite large in tern terms, with a wingspan that may reach 3 foot. They lose their smart black caps in winter.

Gull-billed Tern, Abaco (Alex Hughes) 06

There are 6 species of G-BT worldwide, and it is found in every continent. While many terns plunge-dive for fish, the G-BT mostly feeds on insects in flight, and will also go after birds eggs and chicks. Small mammals and amphibians are also on the menu. The header image shows a G-BT with a small crab. I always imagined that they must eat fish. Surely they do? But I have looked at dozens of images online to find one noshing on a fish, with no success.

Gull-billed Tern, Abaco (Alex Hughes) 02

All photos were taken by Alex Hughes, a contributor to THE BIRDS OF ABACO, when he spent some time on Abaco some years ago in connection with the conservation of the Abaco Parrot and the preservation of the habitat integrity of their nesting area in the Abaco National Park

Gull-billed Tern, Abaco (Alex Hughes) 12

BRAIN WAVES: UNDERSEA CORAL MAZES & LABYRINTHS

April 27, 2022 by Rolling Harbour

BRAIN WAVES: UNDERSEA CORAL MAZES & LABYRINTHS

The most apposite description of brain coral Diploria labyrinthiformisis is essentially a no-brainer. How could you not call the creatures on this page anything else**. These corals come in wide varieties of shape and colour, and 4 types are found in Caribbean waters. They date from the Jurassic period.

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.

The hardness of this type of coral makes it an 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.

HOW ON EARTH DO THEY LIVE?

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

THE TRACKS LOOKS LIKE MAZES OR DO I MEAN LABYRINTHS?

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. Or never get to the centre at all.

** On the corals shown here, you will get lost in blind alleys almost at once. Therefore in human terms these are mazes. The taxonomic labyrinthiformisis is Latin derived from Greek, and applied generally to this kind of structure, whether in actual fact a labyrinth or a maze.

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

Here is a beautiful inscribed labyrinth dating from c12 or c13 from the porch of St Martin’s Cathedral in Lucca, Italy. Very beautiful but not such a challenge.