NEST PROTECTION: WILSON’S PLOVERS ON ABACO (2)


Wilson's Plover, Abaco 12

NEST PROTECTION: WILSON’S PLOVERS ON ABACO (2)

This is the second of three vaguely planned posts about these delightful shore birds. They aren’t rare but they are approachable and fun to watch. During the nesting and hatching season, there may even be some gorgeous chicks on a beach near you (a phrase I never thought I’d find myself using). PART ONE identified the typical male and female adults found on the Delphi beach almost any day. 

Nettie's Point, Abaco - Trucks & Skiffs

This post is about nest protection. Not the ingenious methods of  the birds themselves, that will come next time. This is a story of protection by humans. The photograph above shows Nettie’s Point, one of the launching points for bonefishing skiffs being taken out to the Marls, a vast area of sea, low sand banks and mangroves where the fish are found. You hope. The skiffs gain access to open sea via an artificial channel carved out of rock. The early morning trip along it is one of the most exciting part of a fisherman’s day, as he or she sets out with a clean score sheet, a rod and a box of flies. And a cooler box with some food and maybe a Kalik beer or three.

Nettie's Point, Abaco - the cut to the sea

This June, a pair of plovers decided to locate their nesting ‘scrape’ right in the middle of the cleared area where the trucks normally turn. This was by no means a wise home-planning decision, and they might well have found themselves being promptly relocated. Or (worst case scenario) ending up under a large Toyota. But not a bit of it. Instead, these small birds were looked after by the guides like this: Nettie's Point, Abaco - Plover's nest protection

A makeshift castle was built all round the nest to protect it from any inadvertent truck-related tragedies. Meanwhile the male plover stood guard outside the castle, amiably watching the human activities. Nettie's Point, Abaco - Male Wilson's Plover guards nest

I kept my distance but in fact he was quite unperturbed, perhaps sensing that we were not a threat. He still kept a beady eye on the proceedings, though.Nettie's Point, Abaco - male Wilson's Plover guards a nest

Meanwhile, what of the wooden enclosure itself? At first glance, there didn’t look much to report. However, if you look in the centre of the picture, you’ll see the female peeping out from the nest.Nettie's Point, Abaco - Nest protection 2

I very slowly moved nearer, prepared to stop if the male became agitated, or if the female shifted her position. Both seemed quite relaxed, so I took a couple of shots and walked away to leave the birds in peace. Then I went fishing.Nettie's Point, Abaco - Female Wilson's Plover on NestNettie's Point, Abaco - Mrs Wilson's Plover on the nest

As a postscript, Nettie’s Point is the location of a remarkable geographical phenomenon, possibly the result of the cutting of the channel. Along one part of the cut, for about 30 feet, the water level sinks alarming in the middle, while remaining normal at each side. Then it levels out again. This remarkable mid-stream aquatic depression is quite disconcerting to motor through on a skiff, though eventually one gets used to it. Nettie's Point, Abaco - channel water phenomenon(Note: not every fact in this post is 100% true. If you have some salt handy, take a pinch)

BABY BONEFISH, CASUARINA, ABACO HIDING IN PLAIN SIGHT…


Casuarina Bay (to south)

BABY BONEFISH, CASUARINA, ABACO: HIDING IN PLAIN SIGHT…

Bonefish are difficult to see in the water at the best of times. Shining silver out of water, but pale grey shadows underwater. Fishing under cloud cover and / or (especially ‘and’) when there’s a ripple on the water can be atritional. Sight-casting becomes impossible, and the best recourse is to locate the cloudy patches of water that show where the fish are feeding on the bottom. Chucking the fly into – or beyond – one of these and stripping back may be the only way to get a fish in such adverse conditions. What’s needed is clear sky, sunlight, good polaroids, patience, and keen eyes to scan the water for dark shadows moving across the sand… Or, in my case, simply waiting for the guide to hiss “Hey! Rolling Harbour. Three fish, 40 feet, 10 o’clock moving right, see them? Go now!”. By then, there’s a 50 / 50 chance I may have located them and got my act together enough to (try to) cast at them…

This picture of an adult fish, just caught on the Marls and released at once, shows how a bonefish can easily blend in with its underwater surroundings… but it can’t hide the dark shadow it casts.Adult Bonefish, The Marls, Abaco Bahamas

Two days later we went to Casuarina with friends who wanted a day’s wading on the extensive flats there. This photo shows a juvenile fish close to the beach there, on a glorious sunny day with a light breeze (the header picture [double-click] was taken the same day – low water over pale sand as far as the eye can see). I’d never have noticed this little fish, had I not seen the dark shadow it cast on the sand, magnified by the distorting effect of the ripples.

Without the distortion from surface ripples, the bonefish shape can be clearly seen. It’s hard to imagine that by the time this little fish has reached a weight of 2 lbs, he will be capable of stripping your line down to the backing in seconds… or could he?

No, not, in fact. This fish, with its deeply forked ‘bonefish’ tail, is in fact a YELLOWFIN MOJARRA also known as shad. As Zach Zuckerman of the CAPE ELEUTHERA INSTITUTE writes in kindly emphasising that the fish above is not a bonefish, “the yellowfin mojarra… is related to the mottled mojarra mentioned in Chris Haak’s text (see below). Yellowfin mojarra and bones share the same habitats, and mojarra also feed off of benthic invertebrates”. Which brings me to some interesting recent findings by the CAPE ELEUTHERA INSTITUTE in conjunction with thBONEFISH & TARPON TRUST. We saw a single small fish. It looked like a bonefish (though I guess the yellow fin markings suggested otherwise). It was in fact a similar-looking species. Where are all the young bones? The babies? How do they protect themselves from the many predators of juvenile fish?

EVER WONDER WHY YOU DON’T SEE SCHOOLS OF TINY BONEFISH ON THE FLATS?

Article ref: blog.ceibahamas.org

“Since May 2011, Christopher Haak, a PhD student (and avid fisherman) at the University of Massachusetts, Amherst, along with other scientists, has been trying to solve the mystery of where juvenile bonefish live, from settlement through the time they join adult populations on the flats.  Exhaustive efforts to locate juveniles along the densely-developed coastlines of Florida were met with little success, leading researchers to the comparatively pristine shorelines of The Bahamas to continue their search.

For the past one-and-a-half years, they have scoured the coastlines of South Eleuthera, conducting 1000+ seine hauls, encompassing a broad range of coastal habitats. This project is funded by Bonefish & Tarpon Trust and based out of CEI.   These efforts (with the help of South-Eleutherans; thanks Denny and Kelsey Rankin!) have succeeded in locating over 800 juvenile bonefish as small as one inch in length, and have revealed some intriguing trends.  For example, contrary to what might be expected, juvenile bonefish do not appear to frequent the mangrove creek systems or expansive tidal flats commonly used by adults, preferring instead to remain along shallow, sheltered shorelines near deeper basins or channels.”

Can you find the juvenile bonefish among the mojarra in the picture below?

“Perhaps the most remarkable finding to date is that nearly every bonefish collected was in the company of much greater numbers of like-sized mojarras (a common schooling baitfish known to Bahamians as shad).  These juvenile bonefish exhibited markings and coloration not apparent in adult bonefish, but very similar to the mojarras with which they were caught.  By blending in with considerably greater numbers of the model species, the mimics may be reducing their predation risk, and increasing their chances of survival.  In the case of bonefish, this hypothesis would also explain why juveniles are so rarely observed; they are well hidden within schools of mojarras!  From a conservation perspective, this suggests that bonefish populations may be dependent upon healthy mojarra populations, important information for resource managers.

This research is also producing valuable information about the diverse juvenile fish communities that inhabit Eleuthera’s shores.  Myriad seine hauls of the island’s beaches, bays, sounds, and creeks have catalogued juvenile fishes from a wide array of species, including other flats inhabitants like permit, reef fish such as parrotfish, jacks, and wrasses, and some very unusual demersal critters such as shortnose batfish.  The high densities and diversity of juvenile fishes revealed by this study serves to highlight the importance of these nearshore habitats to healthy adult fish populations of all kinds, underscoring the need to preserve and care for our coastlines.”

ADDENDUM With thanks to Aaron Adams of the BONEFISH & TARPON TROUT for use permission, here is a great size indicator for baby bonefish, taken by him some years back in connection with a juvenile bonefish project.juvbonefish

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