ABACO’S 38 WARBLERS: AN ILLUSTRATED ID GUIDE (Pt 1)


Olive-capped Warbler, Abaco Bahamas (©Tom Sheley)

Olive-capped Warbler (resident species), Abaco Bahamas (©Tom Sheley)

ABACO’S 38 WARBLERS: AN ILLUSTRATED ID GUIDE (Pt 1)

IT’S STARTED The great winter migration of warblers and their imminent arrival in The Bahamas is underway. Any day now – if not already – the ‘winter’ / ‘Fall’ (late summer & early spring as well) warblers will be arriving on Abaco. There are 38 warbler species recorded for the main island and the cays. For years, it was just 37. Exactly a year ago, a CANADA WARBLER was seen and photographed by well-known birder Chris Johnson. It was a first for Abaco – and the first-ever report for the Bahamas as well. You’ll find the story HERE.

First-ever Canada Warbler for Abaco & the entire Bahamas: Aug 2018 (Chris Johnson)

Canada Warbler, Abaco Bahamas (1st record) (Chris Johnson)

Canada Warbler, Abaco Bahamas (1st record) (Chris Johnson)

This post is the first of 3 warbler posts for the Fall. A while back I compiled a basic (in retrospect) guide to Abaco’s warbler species. I’ll give a link and pdf in due course once I have rechecked (improved? rewritten?) it. [Note: of no value on eBay, @m@z@n or anywhere else]. Many of the warblers are far from easy to distinguish from each other. For example, many males have yellow or yellow-and-black plumage. The females are invariably less colourful – often brownish or olive – than the males (as are juveniles), and that can lead to confusion – and not only by me, I think.

Hooded Warbler, Abaco Bahamas (Chris Johnson)

Hooded Warbler, Abaco Bahamas (Chris Johnson)

The guide divides the original 37 species into categories, with a code for each bird to show. You’ll see below the codes relating to each of the 5 resident species:

  • Resident status – permanent / breeding, migratory or transient
  • Frequency – likelihood of seeing each species in its season, rated from 1 (very likely) to 5 (extreme rarities, maybe recorded once or twice since c1950
Bahama Warbler (endemic), Abaco Bahamas (Alex Hughes)

Bahama Warbler (endemic), Abaco Bahamas (Alex Hughes)

Numerically, the division of the 38 breaks down into 3 categories:

  • 5 permanent residents (PR) that breed on Abaco (B), of which two are ENDEMIC
  • 21 winter residents (WR) ranging from ‘everyday’ species to rarities like the rare, vulnerable Kirtland’s Warbler (now under threat from proposed development)
  • 12 transients, most of which you will be very lucky to encounter
Palm Warbler, Abaco Bahamas (Nina Henry)

Palm Warbler, Abaco Bahamas (Nina Henry)

The photos used in this series were almost all taken on Abaco / the Cays. There’ll be examples of the male of each warbler species, with some females for contrast. Where I have no Abaco / Baha images – especially with the transients – I have used other mainstream birding resources and Wiki. All due credits will be given at the foot of each post.

Bahama Yellowthroat, Abaco Bahamas (Gerlinde Taurer)

Bahama Yellowthroat, Abaco Bahamas (Gerlinde Taurer)

The warblers shown above are a mix of warbler species on Abaco: resident / endemic, winter migrants, and transient / vagrant. Time to take a look at the first category, the Bahamas-loving resident species that live and breed on Abaco

5 PERMANENT RESIDENTS

BAHAMA YELLOWTHROAT Geothlypis rostrata PR B 1  ENDEMIC

Bahama Yellowthroat (endemic), Abaco Bahamas (Gerlinde Taurer)

Bahama Yellowthroat (endemic), Abaco Bahamas (Gerlinde Taurer)

BAHAMA WARBLER Setophaga flavescens PR B 1 ENDEMIC

Bahama Warbler (endemic), Abaco Bahamas (Bruce Hallett)

Bahama Warbler (endemic), Abaco Bahamas (Bruce Hallett)

YELLOW WARBLER Setophaga petechia PR B 1 

Yellow Warbler, sunrise, Abaco Bahamas (Tom Sheley)

Yellow Warbler, sunrise, Abaco Bahamas (Tom Sheley)

OLIVE-CAPPED WARBLER Setophaga pityophila PR B 1 

Olive-capped Warbler, Abaco Bahamas (Bruce Hallett)

Olive-capped Warbler, Abaco Bahamas (Bruce Hallett)

PINE WARBLER Setophaga pinus PR B 1 

Pine Warbler, Abaco Bahamas (Tom Sheley)

Pine Warbler, Abaco Bahamas (Tom Sheley)

In Part 2: Winter migrants from common to rare

PHOTO CREDITS Tom Sheley (1, 9, 11); Chris Johnson (2, 3); Alex Hughes (4); Nina Henry (5); Gerlinde Taurer (6, 7); Bruce Hallett (8, 10); Photos mainly from the archive collected for“THE DELPHI CLUB GUIDE TO THE BIRDS OF ABACO” by Keith Salvesen

URCHIN RESEARCHIN’: SEA HEDGEHOGS OF THE REEF


Long-spined sea urchin Diadema antillarum (Melinda Rodgers / Dive Abaco)

URCHIN RESEARCHIN’: SEA HEDGEHOGS OF THE REEF

The long-spined sea urchin Diadema antillarum featured in this post is one of those creatures that handily offers its USP in its name, so you know what you are dealing with. Something prickly, for a start. These are creatures of the reef, and many places in the Caribbean and in the western Atlantic generally sustain healthy populations.

Long-spined sea urchin Diadema antillarum (Melinda Rodgers / Dive Abaco)

These animals are essentially herbivores, and their value to vulnerable coral reefs cannot be overstated. Where there is a healthy population of these urchins, the reef will be kept clean from smothering algae by their methodical grazing. They also eat sea grass.

Long-spined sea urchin Diadema antillarum (Melinda Rodgers / Dive Abaco)

HOW DO THE SPINES OF DIFFERENT KINDS OF URCHIN COMPARE?

Small sea urchins species have spines a few cms long at most. The long-spine variety exceed 10 cms, and the largest may have spines up to 30 cms (= 1 foot) long. The length, as shown here, means that when the creatures are safely lodged in crevices near their algae supply, their spines remain very visible.
Long-spined sea urchin Diadema antillarum (Melinda Riger / G B Scuba)
Anatomy of a long-spined sea urchin. You may possess a few of these organs yourself…

Long-spined sea urchin Diadema antillarum anatomy diagram (wiki)

Long-spined sea urchin Diadema antillarum (Melinda Rodgers / Dive Abaco)

CAN YOU GIVE US A TEST, PLEASE?

As with SAND DOLLARS and similar creatures, the skeleton of a sea urchin is known as a ‘test’. Urchin tests are remarkably beautiful, especially seen in sunlight. Here are 2 examples I photographed a while ago. You’ll immediately notice the delicate colours and the amazing complexity of the pattern and symmetry. The top one is (or is most like) a long-spined urchin test.
Long-spined sea urchin Test / Skeleton Diadema antillarum (Keith Salvesen / Rolling Harbour) Long-spined sea urchin Test / Skeleton Diadema antillarum (Keith Salvesen / Rolling Harbour)

A BIT ABOUT SYMMETRY

Sea urchins are born with bilateral symmetry – in effect, you could fold one in half. As they grow to adulthood, they retain symmetry but develop so-called ‘fivefold symmetry’, rather as if an orange contained 5 equal-sized segments. The graphic above gives a good idea of how the interior is arranged inside the segments.

Long-spined sea urchin Diadema antillarum (Melinda Rodgers / Dive Abaco)

A FEW FACTS TO HAND DOWN TO YOUR CHILDREN

  • Urchin fossil records date the species back to the Ordivician period, c 40m years ago
  • In the ’90s the population was decimated and still has not recovered fully
  • Urchins feel stress: a bad sign that the spines here are white rather than black
  • Urchins are not only warm water creatures: some kinds live in polar regions
  • Urchins are of particular use in scientific research, including genome studies
  • Some urchins end up in aquariums / aquaria, where I doubt the algae is so tasty
  • Kindest not to prod or tread on them
  • Their nearest relative (surprisingly) is said to be the Sea Cucumber 

Sea Cucumber (Melinda Riger / G B Scuba)

ARE THEY EDIBLE?

Apparently they are eaten in some parts of the world; their gonads and roe are considered a delicacy. As far as I know, they are not generally on the menu in the Bahamas. Correction invited. Personally, I could leave them or leave them.

CREDITS: Melinda Rodgers / Dive Abaco (1, 2, 3, 6, 9) taken Abaco; Melinda Riger / G B Scuba (4, 10, 11) taken Grand Bahama; Keith Salvesen / Rolling Harbour (7, 8) taken Abaco; Wiki graphic (5) taken from internet. RESEARCH Fred Riger for detailed  information; otherwise the usual magpie pickings…

Long-spined sea urchin Diadema antillarum (Melinda Riger / G B Scuba)

HERRING GULL STUDIES: EYE CONTACT


Herring Gull Studies (Ireland) - Keith Salvesen / Rolling Harbour

HERRING GULL STUDIES: EYE CONTACT

Getting close to a herring gull is not a particularly heroic act, and yet… they look quite intimidating. The glint in the eye is somewhat evil. And they can be fairly aggressive when the mood takes them. I once had my scalp raked by a herring gull when I got too near a breeding area on a small island in Scotland. It got me from behind. There was blood. Plenty of it. It was my own stupid fault, and a lesson learned.

 Herring Gull Studies (Ireland) - Keith Salvesen / Rolling Harbour

Behold a fine herring gull stepping ashore with its beady eye fixed on me. Behold it starting to advance towards me in a purposeful way… Then it noticed the camera and decided to pose instead of attack.

Herring Gull Studies (Ireland) - Keith Salvesen / Rolling Harbour

One complication for amateur birders is that these (and other) gulls take 4 years to reach maturity and the full adult plumage shown here . We’ve all seen those huge browny-gray-speckled babies crying pitifully to be fed, when they are nearly the same size as the food-providing parent. Over those few first years the plumage goes through several stages, and other colour changes – eyes and feet, for example – take place. Eventually they get to look as handsome as this one.

Herring Gull Studies (Ireland) - Keith Salvesen / Rolling Harbour

I photographed the bird featured here only last week, on the south coast of Ireland, which is a bit of a cheat. Strictly, you are looking at a European herring gull, although the differences from the American ‘Smithsonian’ herring gull is relatively small. I’ll say ‘negligible’ for present purposes.

Herring Gull Studies (Ireland) - Keith Salvesen / Rolling Harbour

WHAT’S THE PURPOSE OF THE RED BLOB ON THE UNDER-BEAK?

Good question, and one that historically was the subject of hot debate in ornithological circles. The short answer is that scientific investigation and experimentation led to the conclusion that the red blob is a kind of feeding cue for chicks, a target area for them to aim for food or to peck to say they are hungry. Some other gull species also have this clever beak feature.

Herring Gull Studies (Ireland) - Keith Salvesen / Rolling Harbour

“HAPPY FEET”

As we all know, there are gull species with yellow legs (not least the apty-named yellow-legged gull in Europe). Herring gulls have decidedly pink legs and feet, and interestingly constructed ones at that. This isn’t the moment for a lot of technical blurb about it – just take a look at these 2 images. Extraordinary, huh?

Herring Gull FEET Studies (Ireland) - Keith Salvesen / Rolling HarbourHerring Gull FEET Studies (Ireland) - Keith Salvesen / Rolling Harbour

RELATED POSTS

LAUGHING GULL 

BONAPARTE’S GULL

RING-BILLED GULL

All photos: Keith Salvesen / Rolling Harbour

Herring Gull Studies (Ireland) - Keith Salvesen / Rolling Harbour

 

BLUE CHROMIS: A FLASH OF COLOUR ON THE REEF


BLUE CHROMIS: A FLASH OF COLOUR ON THE REEF

I’ve gone pictorial for today because I have only got my phone with me while we are away. Composition is slow, close to decomposition – and the comms connection is close to disconnection

Blue chromis (Chromis cyaneus) belong to the same group of fishes 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, and for humans to keep in their own home environments, unselfishly feeding them concocted food.

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”. 

If you are 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).

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

INTERNATIONAL SHARK WEEK? IT’S SO OVER… EXCEPT HERE


Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

INTERNATIONAL SHARK WEEK? IT’S SO OVER… EXCEPT HERE

There’s never a day without a ‘Day’, nor a week without a ‘Week’. Almost all creatures under the sun are celebrated in some regular calendar-based time-frame. With the exception of No-see-ums: I’ve checked – there is no national or international Ceratopogonidae Day in any online calendar. 

Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

By a mere 2 days, I have missed Shark Week, a happening tied in with the Discovery Channel, and heralded by an amusing trailer that features no actual sharks… So, belatedly, here are some cool shark photos to enjoy, in case you didn’t get enough of them last week, or (like me) had other fish to fry.

Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba“I’m so glad we agreed to watch each other’s backs…”

Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

 Meet Nurse Betty, as she is known to diversSharks in Bahamas - Melinda Riger / Grand Bahama Scuba

MANGROVES: THE SHARK NURSERY

As all children are taught and some adults know, the mangroves that grow in the shallow waters around the islands of the Bahamas are of enormous ecological significance. This isn’t the place to expand on that now, but it is worth mentioning that the mangrove swamps are the nurseries of young sharks (‘pups’) until, as juveniles, they are old enough to leave the safely of their home for deeper waters. Check out the short video below.

Sharks in Bimini Bahamas - biminis-marine-protected-areaSharks in Bimini Bahamas - biminis-marine-protected-area

Spot the REMORA hitching a ride on this shark’s backSharks in Bahamas - Melinda Riger / Grand Bahama Scuba

Nurse shark – note the twin barbels (cf recent Goatfish article)Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

Sharks in Bahamas - Melinda Riger / Grand Bahama Scuba

HAMMERHEADS FROM BIMINI Sharks in Bimini Bahamas - Grant Johnson / 60 Pound Bullet   Sharks in Bimini Bahamas - Grant Johnson / 60 Pound Bullet

These wonderful photos were all taken in Bahamian waters. Melinda Riger of Grand Bahama Scuba is, as ever, the star snap-getter of sharks (and indeed all other marine creatures). Special thanks are also due to Grant Johnson / 60poundbullet and Neal Watson / Bimini Scuba Center for occasional use permission of photos – especially of hammerheads – that are, well, eye-popping. Video from ‘ZeroEye’

Sharks in Bimini Bahamas - Grant Johnson / 60 Pound Bullet

GULAR SACS: SCRATCHING THE SURFACE OF AN IN-DEPTH VIEW…


Brown Pelican, Gular Pouch / Sac (Phil Lanoue)

Large mouth, tiny snack…

GULAR SACS: SCRATCHING THE SURFACE OF AN IN-DEPTH VIEW…

A half-way intelligent microbe would make a better job of getting the internet into our home than the current ISP that nominally serves, at some expense, Maison Harbour. So I am restricted to posting 2 fantastic photos of gular pouches as a tempter for things to come when the dimwits in charge of the ‘provision’ of ‘service’ of ‘internix’ locate the act that they need to get together.

Spoiler Alert: ‘Gular Sacs’ has nothing to do with modern jazz. You need to go somewhere else for that…

Photo credits (if they load in the next fortnight or so): Phil Lanoue; Franz Delcroix – with thanks for use permission

Frigate bird male, gular pouch /sac (Frantz Delcroix)

BAHAMAS REEF FISH (53): YELLOW GOATFISH


Goatfish, Bahamas (Melinda Riger / G B Scuba)

BAHAMAS REEF FISH (53): YELLOW GOATFISH

GOATFISHES belong to the mullet family, a large group of species with a flexible membership. In other words, there is disagreement as to whether certain fish are mullet or not. For present purposes, it’s not our problem – no one doubts that the goatfish is a mullet.

Goatfish, Bahamas (Melinda Riger / G B Scuba)

SO WHY ARE THESE CALLED GOATFISH? WAS SOMEONE KIDDING?

These fish get their name for the pair of so-called ‘barbels’ below their mouths (see image below), thought to be reminiscent of a goatee beard. The name has Latin origin, ‘barbula‘, meaning a small beard. Linnaeus may have had a hand in this choice of description.

Goatfish, Bahamas (Melinda Riger / G B Scuba)

WHAT IS THE FUNCTION OF THE BARBELS?

The barbels are sensory organs which, depending on the creature, may be located on either side of the mouth, on the chin, or even extending from the nostrils. In broad terms, the barbels are where the taste buds are located. They help a fish to find food even when the water is stirred up or murky or at night, and are used to probe into sand or into holes in the reef for prey.  

Goatfish, Bahamas (Melinda Riger / G B Scuba)

WHY ARE THEY OFTEN SEEN WITH YELLOWTAIL SNAPPERS, GRUNTS & PORKFISH?

Goatfish have limited means of self-protection. They are not poisonous or venomous, they have no spines or razor-sharp teeth, nor ink to squirt. They do have an ability to change colour rapidly to blend into their surroundings – e.g. over pale sand – to make them less conspicuous to predators. Overall, however, they are docile and probably delicious to many other species. Their bright hues may have some function as aposematic colouring to warn, scare or repel potential predators, but this is possibly of limited use among the familiar reef denizens. So instead the goatfish goes in for so-called protective mimicry, as shown in the image above.

Goatfish, Bahamas (Melinda Riger / G B Scuba)

PROTECTIVE MIMICRY?

Goatfish and yellowtail snappers (in particular) are similar in size, appearance, coloration and behaviours, though the feeding patterns differ. The reason they are often found in mixed groups on the reef is for the individual protection they gain in a larger mixed school. This really amounts to taking advantage of safety in numbers (especially for the fishes in the middle). Here’s a very recent photo that shows exactly this scenario – a large mixed shoal of two almost indistinguishable fish species.

Goatfish & Yellowtail Snappers shoaling (Melinda Riger, GB Scuba)

IS THIS A ‘SPOT THE DIFFERENCE’ TEST?

If you’d like to make it so! (click on the image to enlarge it). Look out for the fish with the barbels (Goatfish); and the fish with the larger, more deeply forked tails (Snappers). A predator won’t take a great deal of notice of the finer points of difference of course, but overall this large mixed shoal gives a degree of protection to individual fish in the unit as a whole

Goatfish, Bahamas (Melinda Riger / G B Scuba)

ARE GOATFISH EDIBLE?

Goatfish are eaten in many ares of the world, though I can’t recall seeing it on a Bahamian menu. The Romans ate the local mullet / goatfish species, but then they ate many things that we do not now consider as permissible food – dormice in honey for example. Rather revoltingly, the goatfish were served live so that guests could watch them die and see the amazing change of colours in the process. Barbaric? But don’t we cook live… well, never mind that.

Goatfish, Bahamas (Melinda Riger / G B Scuba)

Photos: all great photos from Melinda Riger / Grand Bahama Scuba; magpie research pickings inc. the abstract of a scientific paper with about 23 authors; tip ‘o the hat to Wiki, no seriously

Goatfish, Bahamas (Melinda Riger / G B Scuba)