Dusky-Backed Shearwater Abaco | ROLLING HARBOUR ABACO

‘A SADNESS OF SHEARWATERS’ ON ABACO

If you are walking your favourite beach on Abaco right now, it’s quite possible you may see – or may already have seen – a very poorly seabird. Or one that is dead, I’m afraid. These are Audubon’s Shearwaters, also known as Dusky Petrels. They are the only permanent resident shearwater species on Abaco. Three others (Cory’s, Great and Sooty) are rare transients; and the last – the Manx – is a very rare off-course vagrant.

Each sad bird is part of a tragic and recurrent phenomenon, a so-called die-off event. As in previous years, a few of the birds that succumb may be Great Shearwaters mixed in with the Audubon’s. I first became aware of this problem in June 2015 and wrote two detailed posts about the situation. This bleak time lasted for about a week, and many reports came in from the mainland and the cays from Green Turtle Cay right down to Crossing Rocks, all duly mapped to get the overall picture.

There was thankfully no such problem in 2016, but in 2017 – also in June – there was another die-back event involving a large number of Audubon’s shearwaters (Puffinus lherminieri) appearing in the tideline and on beaches. Many were already dead. Some are still alive, but in a very poor state. The prospects for recovery for birds that were captured and cared for were not good.

Two years on, and the melancholy cycle is repeating itself. A few days ago, Melissa Maura, an expert in the care and recovery of creatures of all kinds, posted an alert and some sound advice:

A heads-up to all Island folk that it appears to be a summer when exhausted Shearwaters (pelagic seabirds) are washing up on our beaches in Eleuthera and Abaco. I have had two calls in 24 hours. Should you find one, understand that it will be in a severe state of exhaustion and stress and that excessive handling will kill it. Please put in a safe pen on a sandy surface, with shallow pan of fresh water and try locate either fresh fish (important) or squid from a bait shop. This may have to be administered by gently opening the beak and inserting one inch long piece of fish every couple of hours until stable. Ideally they need tube feeding, but very few folk can do this. Please contact me on private message if you find any…

An exhausted Audubon’s Shearwater, now being cared for by Melissa Maura

WHY DOES THIS SHEARWATER DIE-OFF HAPPEN?

This is a periodic phenomenon that looks to be settling into a 2-year cycle in the Northern Bahamas (Eleuthera is also affected). The cause is probably a combination of factors, very likely stemming from prevailing mid-summer climate conditions and/or the effect of climate change. This can lead to a shortage of food far out in the ocean where the birds spend their days. This in turn leads to weakness and exhaustion as the birds try to find food. The birds may then land (or fall) in the sea, to be washed ashore in a very bad state, or dead. In 2017, well-known bird expert Woody Bracey noted a correlation between poor fishing conditions out at sea, and an unusual absence of the frigatebirds that are a sure sign of a healthy fish population.

Shearwater washed up on the beach at Winding Bay a couple of days ago

ARE PLASTICS A CONTRIBUTORY FACTOR?

As we must all accept by now, most if not all these birds will unavoidably have ingested some of our discarded plastic. However, that in itself would not explain the simultaneous deaths of many birds of one type in a specific area, at exactly the same time of year, and for a few days only.

Audubon's Shearwater (Neotropical Birds / Cornell / Brian Sullivan)

WHAT ELSE CAN BE DONE?

The dead birds will be quickly removed by the turkey vultures. If you do find one, you might want to bury it. The prognosis for sick birds is not that good. They may have been carried a long way from open sea and they will be exhausted and starved. Those that are strong enough may recover naturally; but most will sadly die, being too weak and emaciated to survive. There is no available facility able to deal with a large number of very poorly or dying birds.

The most practical advice I can give is:

(1) move the bird gently into the shade if in the sun

(2) provide clean water in a shallow dish

(3) offer finely chopped fish BUT no bread (it’s very bad for birds)

(4) if this seems to be working, then carry on until the bird is strong enough to fly (this may be quite a commitment)

(5) do not reproach yourself if a bird you try to help dies. Many will be in such bad shape by the time they are washed up that they are unlikely to survive whatever steps you take

(6) remember that this a part – a sad part – of the life-cycle of these birds, and (as with other species), a degree attrition is an inevitable aspect of natural life

I’d be interested to hear any other accounts of this year’s dieback, especially of any recovery stories. By all means do this as a comment, or email me, DM, or FB.

Credits: thanks to those on Abaco who have been reporting this event over the last few days; Dominic Sherony (1); Melissa Maura (2, 5); Keith Kemp (3); Kinlarak / wiki (4); Rhonda Pearce (6); Brian Sullivan / Neotropical Birds / Cornell (7); )Richard Crossley / Crossley Guides for the composite picture

AUDUBON’S SHEARWATER (DUSKY PETREL): SAD NEWS FROM ABACO

Just 2 short years ago, Abaco experienced a shearwater die-off event, when during a period of a week or so numerous dead and dying Great Shearwaters were washed up on many of Abaco’s beaches. You can read about it HERE and a follow-up HERE. This map shows the affected area in 2015.

Now comes news of another such sad event, with a large number of Audubon’s shearwaters (Puffinus lherminieri) appearing in the tideline and on beaches at Bahama Palm Shores, Casuarina, Winding Bay and doubtless elsewhere. Many are already dead. Some are still alive, but in a very poor state.

SHEARWATER DIE-OFF

These upsetting beach finds seem to be a periodic phenomenon, and very likely result from climate conditions or shortage of food out in the ocean – or a combination. Although most will unavoidably have ingested plastics, that would not explain the simultaneous deaths. Poor fishing conditions – they eat fish and squid – will weaken and exhaust the birds as they try to find food. Woody Bracey thinks this the most likely cause, having noticed recent poor deep-sea fishing conditions and an unusual absence of the frigatebirds that are a sure sign of fish.

WHAT CAN BE DONE?

The dead birds will be quickly removed by the turkey vultures. If you do find one, you might want to bury it. The prognosis for sick birds, sadly, is not good. They may have been carried a long way from open sea and they will be exhausted and starved. Those that are strong enough may recover naturally; but most will sadly die, being too weak and emaciated to survive. There is no available facility able to deal with a large number of very poorly or dying birds.

The most practical advice I can give is:

(1) move the bird gently into the shade if in the sun

(2) provide water in a shallow dish

(3) offer finely chopped fish BUT no bread – it’s very bad for birds…

(4) if it seems to be working, then carry on until the bird is strong enough to fly (this may be quite a commitment).

(5) do not reproach yourself if a bird you try to help dies. Many will be in such bad shape by the time they are washed up that they are unlikely to survive whatever steps you take.

WHAT DO I LOOK OUT FOR?

This poor shearwater was one of a number of dead birds found by Keith Kemp at Casuarina yesterday. I realise such images can be upsetting, so I am confining photos of the birds to just two so you will recognise one if you see it.

AUDUBON’S SHEARWATERS IN AN EGGSHELL

Belong to the petrel family
Named ‘Puffinus lherminieri’ after French naturalist Felix Louis L’Herminier
Also known as the Dusky-backed Shearwater – or by Audubon as the Dusky Petrel
Forages by diving out of flight or from the surface; or by surface-feeding
Colony breeders, nesting in rock crevices, in burrows, or under thick vegetation
Mated pairs spend much time together at nest site. They like rubbing bills together
Their ‘twittering calls and mewing’ are usually only heard at night

Audubon’s ‘Dusky Petrel’

I’d be interested to hear any other accounts of the current event, especially of any recovery stories. By all means do this as a comment, or email me / PM on FB

Finally, for those who wonder how pioneer naturalists went about their work observing a species, collecting specimens and recording their findings, here is Audubon’s own account for the ‘Dusky Petrel’, Plate 299 in his magisterial work.

Dusky Petrel (Plate 299)

On the 26th of June, 1826, while becalmed on the Gulf of Mexico, off the western shores of Florida, I observed that the birds of this species, of which some had been seen daily since we left the mouth of the Mississippi, had become very numerous. The mate of the vessel killed four at one shot, and, at my request, brought them on board. From one of them I drew the figure which has been engraved (see above). The notes made at the time are now before me, and afford me the means of presenting you with a short account of the habits of this bird.

They skim very low over the sea in search of the floating bunches of marine plants, usually called the gulf weed, so abundant here as sometimes to occupy a space of half an acre or more. In proceeding, they flap their wings six or seven times in succession, and then sail for three or four seconds with great ease, having their tail much spread, and their long wings extended at right angles with the body. On approaching a mass of weeds, they raise their wings obliquely, drop their legs and feet, run as it were on the water, and at length alight on the sea, where they swim with as much ease as Ducks, and dive freely, at times passing several feet under the surface in pursuit of the fishes, which, on perceiving their enemy, swim off, but are frequently seized with great agility. Four or five, sometimes fifteen or twenty of these birds, will thus alight, and, during their stay about the weeds, dive, flutter, and swim, with all the gaiety of a flock of Ducks newly alighted on a pond. Many Gulls of different kinds hover over the spot, vociferating their anger and disappointment at not being so well qualified for supplying themselves with the same delicate fare. No sooner have all the fishes disappeared than the Petrels rise, disperse, and extend their flight in search of more, returning perhaps in awhile to the same spot. I heard no sound or note from any of them, although many came within twenty yards of the ship and alighted there. Whenever an individual settled in a spot, many others flew up directly and joined it. At times, as if by way of resting themselves, they alighted, swam lightly, and dipped their bills frequently in the water, in the manner of Mergansers.

I preserved the skins of the four specimens procured. One of them I sent to the Academy of Natural Sciences of Philadelphia, by Captain JOHN R. BUTLER, of the ship Thalia, then bound from Havana to Minorca. Two others were presented to my excellent friend Dr. TRAILL, on my first becoming acquainted with him at Liverpool.

I found the wings of this species strong and muscular for its size, this structure being essentially requisite for birds that traverse such large expanses of water, and are liable to be overtaken by heavy squalls. The stomach resembles a leather purse, four inches in length, and was much distended with fishes of various kinds, partially digested or entire. The oesophagus is capable of being greatly expanded. Some of the fishes were two and a half inches in length, and one in depth. The flesh of this Petrel was fat, but tough, with a strong smell, and unfit for food; for, on tasting it, as is my practice, I found it to resemble that of the porpoises. No difference is perceptible in the sexes.

While on board the United States revenue cutter Marion, and in the waters of the Gulf Stream opposite Cape Florida, I saw a flock of these birds, which, on our sailing among them, would scarcely swim off from our bows, they being apparently gorged with food. As we were running at the rate of about ten knots, we procured none of them. I have also seen this species off Sandy Hook.

Audubon’s Range Map for the species
Audubon's-Shearwater_map (audubon.org)

Credits: thanks to those on Abaco who have been reporting this sad event over the last few days, and to Woody Bracey for his views; Dominic Sherony (wiki) for the header image; Keith Kemp for photos from Casuarina; Audubon.org for images, quote & range map; Richard Crossley / Crossley Guides for the composite picture; Audubon, wiki and random pickings for info about these birds