PINE WARBLERS ON ABACO: PINUS ENVY


Pine Warbler, Abaco Bahamas (Bruce Hallett)

PINE WARBLERS ON ABACO: PINUS ENVY

The Pine Warbler Setophaga pinus is one of 5 year-round resident warblers on Abaco. The other 33 warbler species (including the recently recorded CANADA WARBLER) are migratory and at this time of year they will be in their summer breeding grounds. The co-resident warblers are the 2 endemics – Bahama warbler and Bahama Yellowthroat – plus the olive-capped warbler and the yellow warbler. You can see all 5 HERE. All are to be envied. First, they are all bright, attractive birds. Secondly, they live in the Bahamas all year round, without needing to undertake a long exhausting flight twice a year, unlike the rest of their warbler compadres. And indeed, unlike many of the human inhabitants of Abaco.

Pine Warbler, Abaco Bahamas (Alex Hughes)

As the name strongly hints, the pine warbler is primarily a bird of the pine forests, of which Abaco has an abundance. The tall, straight trees were a vital local source of timber (cf SAWMILL SINK). As a historical note, felled pines were also exported to the UK to be made into the strong pit-props needed for coal-mines. 

Pine Warbler (immature), Abaco Bahamas (Bruce Hallett)

Q. WHAT IS THE NORMAL RANGE OF THIS BIRD? A. THIS IS!

Pine Warbler, Abaco Bahamas (Tom Reed)

Pine warblers have a broad diet and forage methodically. Pine cones are a fertile source for food,  and those robust, stabby, slightly down-curved beaks are ideal for getting the seeds out of the cones. Equally, these warblers use their beaks to prise out insects from the rough pine trunks and branches.

Pine Warbler, Abaco Bahamas (Tom Sheley)

WHAT OF THEIR NIDIFICATION?

The pine forest is obviously the preferred nesting habitat for these birds. On Abaco there are vast acres of forest, but I’m sure the warblers also nest in the smaller groups of pines found (for example) in or near some of the settlements; or around the edges of former sugar cane fields and the like. One nesting habit is slightly unusual – pine warblers tend to build their nests near the end of branches rather than near the trunk. I have no idea why – the trunk end of a branch looks far more secure **.

Pine Warbler (immature), Abaco Bahamas (Bruce Hallett)

DO YOU HAVE ANY ‘FUN FACTS’?

  • One source states that “The song of this bird is a musical trill. Their calls are slurred chips. I think we’ve all been there at some time, possibly when lunching at Pete’s Pub.

SLURRED CHIP Don Jones / Xeno-Canto

  • The longest pine in the world is the Benzodiazepine (14 letters)

** Milton Harris helpfully points out: “One theory on Pine Warbler nest location is that they are safer from predators by building at the end of a small branch.  Some other birds do the same.”

Photo Credits: Bruce Hallett (1, 3, 6); Alex Hughes (2); Tom Reed (4); Tom Sheley (5); Dick Daniels (7); Wiki (range map); Nat Geo (species drawings)

Pine Warbler (Dick Daniels wiki)

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)

HERMIT CRABS: SHELL-DWELLERS WITH MOBILE HOMES


Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

HERMIT CRABS: SHELL-DWELLERS WITH MOBILE HOMES

As everyone knows, Hermit Crabs get their name from the fact that from an early age they borrow empty seashells to live in. As they grow they trade up to a bigger one, leaving their previous home for a smaller crab to move into. It’s a benign** chain of recycling that the original gastropod occupant would no doubt approve of, were it still alive… The crabs are able to adapt their flexible bodies to their chosen shell. Mostly they are to be found in weathered (‘heritage’) rather than newly-empty shells for their home. [**except for fighting over shells] 

Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

 HERMIT CRAB FACTS TO ENLIVEN YOUR CONVERSATION

  • The crabs are mainly terrestrial, and make their homes in empty gastropod shells
  • Their bodies are soft, making them vulnerable to predation and heat.
  • They are basically naked – the shells protect their bodies & conceal them from predators
  • In that way they differ from other crab species that have hard ‘calcified’ shells / carapaces
  • Ideally the shell should be the right size to retract into completely, with no bits on display

Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

  • As they grow larger, they have to move into larger and larger shells to hide in
  • As the video below shows wonderfully, they may form queues and upsize in turns
  • Occasionally they make a housing mistake and chose a different home, eg a small tin

Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

  • The crabs may congregate in large groups which scatter rapidly when they sense danger
  • The demand for suitable shells can be competitive and the cause of inter-crab battles
  • Sometimes two or more will gang up on a rival to prevent its move to a particular shell

HERMIT CRABS CAN EVEN CLIMB TREES – WITH THEIR SHELLS ON TOO

Hermit Crab, Abaco Bahamas (Tom Sheley)

HERMIT CRABS EXCHANGING HOMES with DAVID ATTENBOROUGH

This is a short (c 4 mins) extract from BBC Earth, with David Attenborough explaining about the lives and habits of these little crabs with his usual authoritative care and precision . If you have the time I highly recommend taking a look.

Credits: All photos taken on Abaco by Keith Salvesen except for the tree-climber crab photographed by Tom Sheley; video from BBC Earth

Hermit Crab, Abaco Bahamas (Keith Salvesen / Rolling Harbour)

TUNICATES: SESSILE ASEXUAL SEA-SQUIRTS


Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

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.

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

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

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

WHAT DOES ‘TUNICATE’ MEAN?

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

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

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.

 

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

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.

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

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

Painted Tunicates Bahamas (Melinda Riger / GB Scuba)

 

LEUCOPHAEUS ATRICILLA: LAUGHING STOCK ON ABACO


PSSSST! WANNA HEAR A JOKE?

LEUCOPHAEUS ATRICILLA: LAUGHING STOCK ON ABACO

KNOCK KNOCK!

 

WHO’S THERE?

 

TWITTER!

 

TWITTER WHO?

 

HAR HAR! MADE YOU SOUND LIKE AN OWL…!

Photos & vid, Keith Salvesen; Joke, most people on Earth (though not with illustrative pics)

HOW FLAMINGOS WORK…


HOW FLAMINGOS WORK…

 

CREDITS: great photos from Inagua, Melissa Maura; vaguely interesting slo-mo movie, Keith Salvesen

 

The Tyrant


HOW TYRANT FLYCATCHERS GOT THEIR NAME (feat. Myr’s artwork & RH photos…)

Myr's Bytes

Happy Draw a Bird Day! To celebrate, I present, my first tyrant flycatcher drawing!

The Cuban Pewee, or Crescent-eyed Pewee, Contopus caribaeus, resides in Cuba and The Bahamas, and is occasionally sighted on the southeast coast of Florida. Keith Salvesen recently posted some lovely photos on his blog Rolling Harbour Abaco and he was cool with me using them for a Cuban Pewee drawing adventure.

I’m pleased that the bird in my drawing looks sweet-as-can-be and has a beautiful eye, and I like the colours and patterns of the branches and background. However, I’m not jazzed about the streakiness of the feathers. Hoping for more gentle feathery textures and easier control of varying grey shades, I grabbed 2H and HB graphite pencils and a kneaded eraser. I chose a different photo because that open bill is just marvellous! Clearly, Keith and the Cuban Pewees are good friends.

The…

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