“MEET THE FLOCKERS…” ON ABACO

March 22, 2019 by Rolling Harbour

“MEET THE FLOCKERS…” ON ABACO

I’ve been checking out jetties at Sandy Point, of which there are several. They look a bit rickety but are in fact sound except for having to step rounds piles of (empty) conch shells and occasional evidence on the timbers of recent fish-cleaning. This is a time of Laughing Gulls, and I have been recording their raucous hilarity. I may add a couple of sound files when I’ve downloaded them.

Sharing a joke

Right now, ruddy turnstones and laughing gulls seems to have formed a team of jetty birds, with a few royal terns in the mix and (as here) a random sanderling. The turnstones like to lie down in the hot sun on the jetty, possibly because it’s a bit breezier than on the burning sand of the beach.

Exhausted from turning stones

Random sanderling

These jokers are wild…

The jetties also attract pelicans, which use them to sun themselves and also to fish from. I will post about these remarkable birds another time. The largest flock of them I have seen so far is 5, one with a gold ‘breeding crown’.

The gulls also spend time on the beach, and flock on the sandbars that emerge at low tide

All photos: Keith Salvesen

TAKING TERNS KISSING: AN ABACO ROMANCE

March 19, 2019 by Rolling Harbour

TAKING TERNS KISSING: AN ABACO ROMANCE

There’s a time and a place for anthropomorphising animal behaviour in terms of human responses. Usually it’s best done with caution or not at all… I’m going to press ahead, though, with a romantic encounter between two Royal terns today at Sandy Point, Abaco. Ultimately, this appeared to be an approach, a come-on, a poorly executed attempt at intimacy, and ultimately a rejection. Or else it’s just bird interchange that we should not read too much into…

Good afternoon, I should like to get to know you better… Royal Terns, Sandy Point, Abaco Bahamas (Keith Salvesen)

Would you do me the honour of commencing a relationship? Royal Terns, Sandy Point, Abaco Bahamas (Keith Salvesen)

Indeed I would, kind Sir!

*Boastfully* I happen to be the most handsome and regal tern this side of Marsh Harbour

I’m going to give you a peck that you’ll never forget…

Whaaaaaa? Wait… Too much, too soon. I hardly know you

You’ve moved as far away as possible on this post – you have no idea what you’re missing Royal Terns, Sandy Point, Abaco Bahamas (Keith Salvesen)

I’ll be the judge of that. I’m off, don’t try to follow me… Royal Terns, Sandy Point, Abaco Bahamas (Keith Salvesen)

Credits: all photos (artfully taken in fairly poor light), corny storyline, inappropriate anthropomorphism – Keith Salvesen

THE GOLD-RIMMED LUCAYAN FLORIDA BATTUS POLYDAMAS SWALLOWTAIL

March 15, 2019 by Rolling Harbour

THE GOLD-RIMMED LUCAYAN FLORIDA BATTUS POLYDAMAS SWALLOWTAIL

The Polydamus ‘Gold-rimmed’ Swallowtail Battus polydamas is a familiar sight in the Bahamas. It’s known by all the names above, though not all at once to be fair. This is the medium-sized black-brown butterfly with gold accessories and a tasteful selection of red ornamental jewellery. It’s one that hardly stays still for a moment. Its perpetual motion tendencies make it a right little… well, they are hard to photograph. I’ve never taken a totally still photo with no blurring from the creature’s rapid wingbeats.

The subspecies Lucaeus found on Abaco (where these photos were all taken)and elsewhere in the Bahamas is not confined to the archipelago, and is commonly found in Florida. There it seems to be called (slightly possessively?) the Florida swallowtail. The main species is found more widely. Here’s a helpful range map that shows the butterfly’s range – quite a wide band but latitudinally limited in global terms.

Mostly, you will see the topside of these butterflies as they do the rounds of sweet-scented flowers, often pausing briefly while still frantically fluttering. Note the rather gorgeous red patterns on the underside of the creatures shown above. Now compare with the open-wing images below.

This butterfly flies year round in the Bahamas (in contrast to its northern range). It breeds throughout most of the year (except on the fringes of its range), which is probably why it is relatively common.

CAN YOU SHOW US ONE THAT YOU HAVE TAKEN, PLEASE?

Certainly (with reservations). Nice coral hibiscus; it’s a shame that the stamen (if that is the correct term for the sticky-out bit) is in the way. Plus the wretched thing is still on the move. From this weekend, I get the chance to nail one on Abaco, but I’m not optimistic. I think they mistrust me.

WHAT DOES ‘POLYDAMAS’ MEAN?

I anticipated that question, kind Reader. I had thought it was Graeco-Roman for ‘many’ something or other. Wingbeats, maybe. Not being able to consult Linnaeus who originally came up with the word, I did some research. It turns out that Polydamas was a Trojan warrior and friend of Hector. He features a lot in Homer’s Iliad as a kind of ‘Best Supporting Warrior’, though they seem to have differed about battle tactics. Of which digression, enough.

Polydamas tries to stop Hector from attacking the Greeks

Credits: Nina Henry; Charmaine Albury; Rhonda Pearce, Keith Salvesen

BAHAMA ORIOLE: HABITAT FIND FOR A RARE GEM

March 12, 2019 by Rolling Harbour

BAHAMA ORIOLE: HABITAT FIND FOR A RARE GEM

c300 LEFT IN THE WORLD – AND ALL ON ANDROS

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

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

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

SO, ANY GOOD NEWS THEN?

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

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

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

THE MAIN CAUSES OF THE CRITICAL DECLINE ON ANDROS

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

WHEN & WHY DID THE ORIOLES VANISH FROM ABACO?

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

ABSTRACT

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

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

↑ Mr Northrop with his Bird

IS THIS THE REAL LIFE? OR IS THIS JUST FANS AT SEA?

March 7, 2019 by Rolling Harbour

IS THIS THE REAL LIFE? OR IS THIS JUST FANS AT SEA?

The waters of Abaco teem with myriads of fish that depend on the coral reefs for shelter and safety, for breeding, for growing up in, and for nourishment. Sea fans (or gorgonians, to use the technical name) are animals too. They may look like plants and stay rooted to the spot, but like anemones these ‘soft corals’ are creatures of the reef and essential indicators of its health.

At the moment it can still be said that the static (‘sessile’) members of the Abaco reef community are relatively unscathed by the impact of (and I don’t want to get into any arguments here) whatever causes mass bleaching and the death of reefs elsewhere in the world.

The purple sea fan Gorgonia ventalina (classified by Linnaeus in 1785) is one of the most common species of sea fan, and a spectacular one at that. The main branches are linked by a lattice of smaller branches. Below the ‘skin’ is a skeleton made of calcite compounded with a form of collagen.

Sea fans are filter-feeders, and have polyps with eight tiny tentacles that catch plankton as it drifts past. They develop so that their orientation is across the prevailing current. This maximises the water passing by and consequently the supply of food as the fans gently wave in the flow.

Gorgonians have a chemical defense mechanism that protects against potential troublemakers. The main effect is to make themselves unpleasant to nibble or uproot.

One species impervious to this deterrent is the fascinating FLAMINGO TONGUE SNAIL (more of which quite soon). Other ‘safe’ species include the fireworm and BUTTERFLYFISHES.

One benefit of sea fans to mankind is that their defensive chemicals have been discovered to provide the basis for drug research and development. It’s tempting to say that by way of gratitude, we pollute the waters they need for their very existence. So, consider it said…

All the photos featured are by courtesy of Capt. Keith and Melinda Rogers of the well-known local scuba dive and snorkel centre DIVE ABACO, located in central Marsh Harbour. As prime enablers of reef exploration in Abaco waters, it can truly be said that they too have plenty of fans.

Credits: Keith and Melinda Rogers; Dive Abaco @DiveAbaco, Marsh Harbour, The Bahamas ** The answer to the questions in the Title is… it’s both!

GREEN HERON FISHING: GILPIN POND, ABACO, BAHAMAS

March 4, 2019 by Rolling Harbour

GREEN HERON FISHING

GILPIN POND, ABACO, BAHAMAS

The brackish pond at Gilpin Point near Crossing Rocks is generally a reliable place to find waterbirds. For those birding on South Abaco (in many respects, one big hotspot) Gilpin is definitely worth a visit at almost any time. Bear in mind it is (a) a longish private road (we got a puncture down there once…**) and (b) it is private land. However, the owner Perry Maillis is always welcoming to tidy birders who bring only enthusiasm and take only pictures. Plus he very kindly changed our wheel!

We found this small Green Heron quite easily. We’d watched it fly onto a stump in the pond near the jetty, then fly closer to the shoreline. By tiptoeing onto the jetty, we could see the bird perched close to the water, inspecting it with a fierce and predatory eye. Both eyes, in fact.

The hunting technique is deceptively simple. Note the long sharp stabbing beak. Note the large feet and claws for gripping securely Here’s how it is done. As a fish is sighted, so the heron leans gradually forwards, beak dipping closer to the water, the body more streamlined to look at. The procedure is beginning in the image above.

The stance means ‘small fish – 5 feet off – moving left and closing – prepare to strike‘. As the prey unwittingly approaches, the bird slowly tilts further forward unless its beak almost touches the water, the quicker and closer to strike.

The actual strike is so rapid that it is barely possible to see with the naked eye, let alone to photograph it clearly (not on my type of camera anyway). But the end result is rarely in doubt, with a small fish struggling but securely held in that long, clamping beak. It will be down the heron’s gullet in a matter of seconds.

I left the heron as it settled slowly back into ‘scanning the water mode’ while I went to watch some lesser yellowlegs nearby. Some minutes later, the heron was still contentedly fishing from its vantage point.

ROUGH GILPIN CHECKLIST

Species we have found on and around the pond include black-necked stilts, little blue heron, great blue heron, tricolored heron, snowy egret, reddish egret, yellow-crowned night heron, the relatively rare and very shy sora, hordes of white-cheeked pintails, northern pintails, lesser yellowlegs, belted kingfisher, turkey vulture, smooth-billed ani, American kestrel, Bahama woodstar, Cuban emerald, Mucovy duck (Perry’ pet!) – and the green heron of course.

As a bonus, Gilpin has become an increasingly regular stop for raucous flocks of Abaco parrots. Rarer species found there include American flamingo (rare vagrant), brown pelican, double-crested cormorants, and limpkins. On the beach 5 minutes walk away, there are usually shorebirds including rare piping plovers, Wilson’s plovers, turnstones; gull and tern species; and passing tropicbirds & magnificent frigatebirds flying high over the water.

FOR MORE ABOUT GREEN HERONS: SHARP-EYED SHARP BILLED

** I realise that strictly I should be saying ‘flat’ here, but that might be confusing for Euro-readers, who would understand that to mean that we had rented (or purchased) an apartment in a larger dwelling house containing similar accommodation.

All photos, Keith Salvesen except the cute chick, Charlie Skinner; and the cute cartoon GH, Birdorable…

ECHINODERMS, DOLLAR DOVES & PETRIFIED BISCUITS

February 27, 2019 by Rolling Harbour

ECHINODERMS, DOLLAR DOVES & PETRIFIED BISCUITS

Echinoderms (Gr. ‘Hedgehog Skin’) comprise a large variety of sea creatures characterised (mostly) by radial symmetry. In a nutshell a creature with radial (as opposed to bilateral) symmetry can be divided into equal portions from the centre, like a cake. It has no left or right side and no definable front or back. It is multidirectional from the centre, where the mouth is located. It obviously has a distinct upper side and an underside, but that has no bearing on this form of symmetry.

Within the family of radially symmetrical animals, echinoderms (starfish, sand dollars and sea urchins) are unique in having five-point radial symmetry. These are the creatures you are most likely to come across in Abaco. There are two particular aspects of dollars and biscuits that merit a closer look (made more difficult by me stupidly taking photos of white things on a white background).

DOLLAR DOVES

I’m sure all Bahamians know or are aware of at least one version of the famous ‘Sand Dollar’ poem, in which the various characteristics of the test (the skeleton of the creature) are given religious significance. One verse of the poem may be puzzling: “Now break the centre open And here you will release The five white doves awaiting To spread good will and peace”.

The Sand Dollar Legend

A few years back, Senior Granddaughter was looking at some Abaco sand dollars I’d given her for her growing collection of shells. She picked one up, shook it and it rattled. She said a friend at school had told her that a rattling sand dollar has ‘doves’ inside it, and asked if we could break it open and see. I’ve learnt that it is useless to argue with her – she has the tenacity of a trial lawyer – so we did. This is what we found.

Sand Dollar with a spiky interior like a white cave with stalagmites and stalagtites

Five white doves (in fact, the separated parts of the creature’s feeding apparatus)

Two broken pieces showing where the doves are centrally located

A regrettably poor photo of a single dove

The image below, from Pinterest, shows the ‘mouth’ with its dove-parts intact, in an arrangement called ‘Aristotle’s Lantern‘, a five-sided globular structure that supports the mouth and jaws of an echinoderm.

PETRIFIED BISCUITS

In common parlance ‘petrified’ is an extreme version of ‘terrified’. Literally, it means ‘turned to stone’ (L. petrus, a rock). It is descriptive of a state of fossilisation, where an animal skeleton or dead wood or plant matter turns over aeons into stone. Senior GD (a most inquisitive girl) followed up on the doves research after discovering a box containing random stones and fossils. She found these two items:

Fossilised sea biscuits Petrified / Fossilised Sea Biscuit (Keith Salvesen)

A closer look at the pair of rocks Petrified / Fossilised Sea Biscuit (Keith Salvesen)

The undersides of the fossils above – looking like stones but with some tell-tale small holes Petrified / Fossilised Sea Biscuit (Keith Salvesen)

A close-up of the pale biscuit Petrified / Fossilised Sea Biscuit (Keith Salvesen)

Sea biscuits on the beach at Delphi – familiar white skeletons (‘tests’) but not yet fossils

A ‘modern’ non-Jurassic Abaco sea biscuit in close-up

FUN FACT

Florida has an unofficial but proposed State Fossil, the ‘Sea Biscuit (Eocene Age)’. I didn’t know it before, but it turns out that more than 40 US States have State Fossils. Whatever next? State Bacteria? State Viruses?

SO HOW OLD MIGHT A PETRIFIED BISCUIT BE?

The fossil biscuits I have looked at, from Florida to Madagascar (see small image above), are said to come from three specific historic epochs – from the oldest, Jurassic (145m – 201m years ago), to Eocene (34m – 56m) and Pleistocene (0.01m – 2.6m).

HOW DOES THAT HELP ANYBODY? BE MORE PRECISE

By all means. Here is an excellent Geochart that gives an idea of the time span. A Jurassic sea biscuit would be more than 145m years old. This chart also helpfully helps avoid confusion with the Eon Era Period Epoch ordering.

geotimescale

You will find more echinoderm entertainment using this link to my fellow-blogger ‘Dear Kitty’ https://dearkitty1.wordpress.com/2007/01/01/big-hedgehog-small-sand-dollars-diving-schools/

All photos ‘in-house’ except the Delphi biscuits, Clare Latimer; & the single biscuit Rhonda Pearce; Sand Dollar poem on Postcard, Dexter Press; the Geochart was in my ‘useful chart photos’ folder but I can’t now find the source. I did try.