RED-WINGED BLACKBIRDS ON ABACO


Red-winged Blackbird, Abaco (Tom Sheley)

RED-WINGED BLACKBIRDS ON ABACO

The sounds are unmistakeable – a discordant chorus of soft chuckling noises like tongue-clicks as the RWTs flock into a bush, interrupted by harsh, metallic calls like rusty metal gate-hinges being forced open. Or maybe a lone bird mournfully repeating its eerie call from the mangroves far out on the Marls as the bonefishing skiffs slip silently along the shoreline. No other species sound quite like Agelaius phoeniceus.

Red-winged Blackbird, Abaco (Tom Sheley)

The handsome males sport flashy epaulets, most clearly visible in flight or in display – for example to impress a prospective mate. Again, they are unlikely to be confused with another species.

Red-winged Blackbird, Abaco Bahamas (Alex Hughes)

The females, as is often the way, are less showy. I have just read that they are ‘nondescript’, which is unnecessarily harsh I reckon. Here are a couple of examples.

And the darker brown ones that are clearly not handsome black males? These are young males in their first season, before they move on to the full adult male plumage. Previously I had designated them females (as I had assumed) until very gently corrected by the legendary Bruce Hallett. Not only was Bruce an essential part in the production of the Birds of Abaco, he also keeps a benign eye on my posts and occasionally steps in to clarify IDs etc.  I took the first male juvenile at Casuarina, when I also made the sound recording (below). The second was at Delphi – and with some ‘light’ issues, I notice…

Red-winged Blackbird, Abaco (Keith Salvesen / Rolling Harbour)Red-winged Blackbird, Abaco (Keith Salvesen / Rolling Harbour)

Fledglings are kind of cute…Red-winged Blackbird, Abaco (Tom Sheley))

SO WHAT DO THEY SOUND LIKE?

You may need to turn up the volume a bit. You will also here a lot of dove noise and, in the background, the sound of waves lapping onto the shore.

Red-winged Blackbird, Abaco (Keith Salvesen / Rolling Harbour)

Photo Credits: Tom Sheley (1, 2, 4, 5, 8); Alex Hughes (3); Keith Salvesen (6, 7, 9 & audio)

 

MANATEES IN THE BAHAMAS? WE GOTTEM!


MANATEES IN THE BAHAMAS? WE GOTTEM!

Not so long ago, most people had no idea that the waters of the Bahamas in general – and Abaco in particular – contained a small population of these curious, gentle, trusting creatures. When I first wrote about them and their adventures, there was surprise – maybe disbelief. A few years later, all that has changed thanks to the BMMRO and an outreach program that raised awareness – and consequently the sighting and reporting – of manatees. They are now widely recognised as they nose their way round harbours, docks and landing stages – and quite rightly they still excite delight and a degree of wonderment. 

You can find out more – lots more – about Bahamas manatees on my page HERE. I have a post in progress about recent manatee developments with a rescue one but alas I have found I have already run out of week through some kind of bizarre time / space continuum dislocation (specifically, flagrant time-mismanagement). So I am posting a few adorable images to be going on with. 

And remember, if you happen to see one, please do report it to the BMMRO or let me know. Useful data includes date, location and a description if possible of any damage – notches and nicks – to the paddle (= tail). It’s a good method for ID. Photos a bonus.  Every sighting adds to the database of knowledge about these strangest of creatures of the Bahamian seas. And you’ll be pleased to know that they are undoubtedly managing to breed in the Bahamas: there are baby manatees to prove it…

All photos: BMMRO

REDDISH EGRET HUNTING ON THE MARLS, ABACO


REDDISH EGRET HUNTING ON THE MARLS, ABACO

The trouble with reddish egrets is simple: they come in two colourways. There’s the conventional one which is indeed reddish, as one might hope and expect. Then there’s the snow white type (or ‘morph’). That’s the one featured here (with the other dark variety below, for comparison).

Both types are common breeding residents on Abaco. There are theories about which kind outnumbers the other; on balance I’m not sure the difference is very significant. Maybe reddish are a rather more frequently encountered than white, but there doesn’t seem to be much in it.

Looking back at photographs I took last spring, I found a sequence of a hunting white egret. Now these are not exhibition-quality photos. They were taken quite far out on the Marls, and a fair distance from the skiff I was standing on the front (prow?) of.

I had a smallish camera, and a fishing rod tucked under my arm rather hoping not to hear the usually welcome call “Hey RH**, bones at 10 o’clock moving left – 4 of them – give it 30 feet…” So this sequence is designed to give an idea of how the bird hunts the shallows. Rather than standing stock still and suddenly stabbing down to catch a fish, sometimes the egrets will stride purposefully though the shallow water, taking their chances as they move.

A small success at the start of the hunt (look carefully at the tip of the beak) A pause (and a slightly bad hair moment)

I always enjoy watching the actions of these birds make as they go about their work. But now the hunt is over; the egret has worked his way along the shoreline and he’s thinking out his next move… 

…which is to fly off and try his luck elsewhere

Your compensation for some mediocre – but hopefully illustrative – shots is a header image from the camera of the highly experienced birdman and photographer Danny Sauvageau. 

Finally, the way to tell that you are looking at a reddish egret, whichever version, rather than one of the other available egret / heron candidates is to look at the bill – pinkish, with a black tip. No other egreto-heronish species has this. 

A ‘proper’ reddish reddish egret taken in one of the brackish ponds at Crossing Rocks – always a good place to pull in and check for herons and egrets. This one, photographed in March, is in his handsome breeding plumage. Compare the bill with the white morph above – just the same.

** This not in fact how I am customarily addressed. I have a real name. Probably.

Credits: header image, Danny Sauvageau with thanks as always; all mediocre white morphs RH – also the rather better effort comparative photo of a ‘proper’ reddish one; cartoon by the inimitable Birdorable.

BIRD WING FEATHERS: A SIMPLE GUIDE TO THE MYSTERIES


BIRD WING FEATHERS: A SIMPLE GUIDE TO THE MYSTERIES
Thanks to the excellent ‘Myr’s Bytes’, say goodbye to ‘what’s the difference between primary & secondary feathers’ misery… This could be the clearest illustration and explanation of a bird’s wing you or I will ever see.

Myr's Bytes

It has been a while since I participated in Draw a Bird Day. I was happy to see some bird drawings in my blog reader this morning and decided to get inspired. I’ve been mostly sketching lately and none of the results have looked quite showable. But I did have a partially coloured drawing of some bird wings. And now, it’s fully coloured!

When I look at open and folded wings in bird photos, I often wonder – how do they fold and which feathers go where? John Muir Laws came to the rescue! The Laws Guide to Drawing Birds explains all this with beautiful illustrations. My two wing drawings are based on his illustrations of a passerine wing (dark grey with two white wing bars… I don’t know the species… some kind of flycatcher???). I did a good job of illustrating the layout of the different feather groups, but…

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BAHAMAS REEF FISH (43): CUBERA SNAPPER


BAHAMAS REEF FISH (43): CUBERA SNAPPER

The cubera snapper (Lutjanus cyanopterus) is the largest snapper species. Adults may grow to 5′ long but they average around 3′ long and weigh 40 lbs or so (the record apparently stands at a massive 126 lbs). These are game fish, and they are a commercially important species. They are also IUCN listed as vulnerable, perhaps for that very reason. 

10 CUBERA SNAPPER SNAPPY  FACTS

  • The largest of a large number of snapper species in the western Atlantic
  • Feed on fish, shrimps & crabs, with large strong teeth (see pics) and jaws
  • Among their (few) predators are sharks, barracuda, and moray eels
  • Edible, but beware of the danger of CIGUATERA poisoning
  • In summer months, spawning is governed by lunar cycles
  • Cuberas form huge spawning masses (to 10k) in offshore shallows
  • Sadly the resulting eggs and larvae are rich pickings for predators…
  • Youngsters live in sea grass or mangroves for protection
  • Cuberas are game fish with commercial importance
  • IUCN listed as vulnerable – largely courtesy of mankind (see »)

RANGE FINDER

Cubera Snapper Range Map (wiki)

CONSERVATION MATTERS

Overfishing is one of the greatest threats to the species. Those young fish that are not predated naturally and grow to adulthood are targets for fishermen. There’s no prissy ‘catch & release’, as with bonefish. At spawning time, as the fish instinctively (and predictably) mass as the moon dictates, so do the human predators. The spawning sites are where the best protection can be given, to ensure the annual reproductive cycle is uninterrupted. If not, ‘vulnerable’ will soon give way to ‘endangered’…

I’d been going to pull apart a long recipe for the “wonderfully sweet white meat ” of this fish for the tastiest morsels of info, then (not being a cook) I quickly tired of the idea. Sorry to disappoint. 

Credits: Melinda Riger for the wonderful photos; range map from wiki; magpie research pickings, including (but not limited to ) Nat Geo

COOKIECUTTER SHARKS: BEASTLY LITTLE SUCKERS


Cookiecutter Shark mouth, jaws & teeth (BMMRO Bahamas)

COOKIECUTTER SHARKS

BEASTLY LITTLE SUCKERS

The Cookiecutter shark Isistius brasiliensis (aka the less scary, more genial sounding ‘cigar shark’), might be an ideal candidate for a Room 101 nemesis.** These little beasts – a species of dogfish shark – are found in several mainly island-based areas dotted around the globe, including in Abaco waters.

 

HOW COME THE NAME?
These sharky little b@st@rds (*technical term*) attack marine mammals and fishes, gouging out perfect round plugs of skin and flesh, leaving what are sometimes called ‘crater wounds’. Then they eat them. Imagine getting hold of a really sharp domestic cookie cutter with circular rows of razor-sharp teeth, and grinding it hard into your thigh. There! That! 
The size of an adult shark:16″ max
The term ‘cookiecutter’ is also a pejorative slang term, meaning mass-produced, lacking in originality, or boringly samey, as in cookiecutter cars or TV genres etc. The little critters under consideration here are anything but…
                        

HORRIFYING COOKIECUTTER FACTS

  • Live in the depths, rise vertically in the day & dive back down at dusk
  • Undersides have light-emitting ‘photophores’ which emphasise…
  • …the dark collar which acts as a lure, resembling a small innocent fish
  • Bioluminescence lures prey & confuses predators (more on this below)
  • The glow is so strong it may last for some time after removal from water

  • Their lips are ‘suctorial’ = they attach tightly to their target
  • The jaws then gouge out the victim’s flesh in a remarkably neat circle
  • Omni-vicious: any medium to large ocean creature is vulnerable to attack
  • There are even occasional reports of humans being targeted

Here are two Blainville’s beaked whales that I photographed from the BMMRO research vessel. The top whale has a number of circular healed attack marks and a recent one. You can see how deep the gouged hole is. The other has well-healed scars.

Blainville's Beaked Whale - cookiecutter shark damage (Keith Salvesen)Blainville's Beaked Whale - cookiecutter shark damage (Keith Salvesen)

  • Multi-toothed: top rows of small teeth, rows of larger teeth on the bottom
  • The lower teeth are the cutters, acting like a saw when locked on
  • See header image and below for full details

    

HOW EXACTLY DO THEY DO WHAT DO THEY DO?
I can explain it no better than the renowned authority Prof. W. K. P. Dear:  “the suctorial lips ensure a tight seal. It then bites, using its narrow upper teeth as anchors while its razor sharp lower teeth slices into the prey. Finally, the shark twists and rotates its body to complete a circular cut, quite possibly aided by the initial forward momentum and subsequent struggles of its prey. The action of the lower teeth may also be assisted by back-and-forth vibrations of the jaw, a mechanism akin to that of an electric carving knife”.

                 ARE THESE SHARKS ‘PARASITES’, WOULD YOU SAY?

The behaviour of these sharks is an example of a symbiotic relationship between two species that is parasitic. This means essentially that one gains and the other suffers (e.g. no-see-ums!). This is distinct from commensalistic symbiosis, where one species gains and the other is unaffected (e.g. cattle egrets with cattle); and mutualistic symbiosis, where both gain (e.g. cleaner fish & groupers). So, in a word, yes.

  • An ‘ambush predator’: they ‘hover’ in the water column waiting…
  • They are capable of rapid movement to catch up & latch onto prey
  • They will eat a passing small fish, crustacean or even squid as a snack
  • Sometimes they operate in schools; there is safety in numbers
  • The schools are thought to increase the ‘lure’ effect of the dark collar

A beached whale that’s been heavily targeted

FUN FACT TO COUNTERACT THE BAD STUFF

In the late c20, more than 30 U.S. Navy submarines were forced back to base to repair damage caused by cookiecutter shark bites, either to the neoprene footings of sonar domes or to rubber-sheathed cables. The problems were solved by using fibreglass. Oceanographic equipment and telecommunications cables are also recorded as being damaged by these sharks.

Cookiecutter Shark – the real deal

 

MONSTERS OF THE DEEP

These great cards from the weirdly spelled WIERD ‘N’ WILD CREATURES provide excellent factual info. Their CCS card is no exception. You’ll find more details here about the effect of the bioluminescence and so on, written as clearly as I might hope to. 

Cookiecutter Shark Facts (Monsters of the Deep)Cookiecutter Shark Facts (Monsters of the Deep)

** “The worst thing in the world varies from individual to individual. It may be burial alive or death by fire, or by drowning, or by impalement, or fifty other deaths. There are cases where it is some quite trivial thing, not even fatal.” (George Orwell, 1984)

Alright now…Blainville's Beaked Whale - cookiecutter shark damage (Keith Salvesen)

Credits: BMMRO – header image; beaked whale photos – Keith Salvesen / BMMRO; Te Ara NZ for the main jaw image; all small images with thanks to Wiki and respective photographers who took the time to upload them for all to enjoy & learn from; ‘wierdnwonderful creatures’ for the monster card; range map from Wiki

PS Apologies to anyone who bothered to wade through this, and stayed awake long enough to notice that formatting gremlins struck halfway through

GRAYSBY (GROUPER): BAHAMAS REEF FISH (42)


Graysby (grouper) - Melinda Riger / Grand Bahama Scuba

GRAYSBY (GROUPER): BAHAMAS REEF FISH (42)

The Graysby Cephalopholis cruentata is a small, spotty grouper, which grows to a maximum of around 16 inches. These rather unassuming and solitary fish have a preference for coral reefs, where they can blend in with their surroundings on ledges and in caves and crevices during the day. At night, they become active – that’s when they feed on feed on small fish, crabs and shrimps. 

Graysby (grouper) - Melinda Riger / Grand Bahama ScubaGraysby (grouper) - Melinda Riger / Grand Bahama Scuba

The graysby has variable colouring in a range from light brown to pale gray, with all-over spots that may be red, orange or brownish. Often, they have 3 to 5 contrasting spots on their backs, along the base of the dorsal fin, as below:

Graysby (grouper) - Melinda Riger / Grand Bahama ScubaGraysby (grouper) - Melinda Riger / Grand Bahama Scuba

The long erectile dorsal fin comprises both spines and ‘rays’ – spines at the front, rays at the back. Like this:

The spots of a graysby can change in colour (at least to a limited extent), becoming either paler or darker. I imagine this is a protective feature to enable the fish to blend in more easily with its reef surroundings. 

Graysby (grouper) - Melinda Riger / Grand Bahama Scuba

Signalling to turn right…

I wondered if they are edible. I believe so – but then I also read that the larger adults carry the risk of ciguatera and raised mercury levels. So I’ll give it a miss thanks.

Photo & other credits: all photographs by Melinda Riger / Grand Bahama Scuba; aqua.org; SAMFC (drawing)