SHEARWATERS ON ABACO: SAD TALES FROM THE SEA
We do not generally do sad or sombre at Rolling Harbour. It’s a beautiful and happy place, and the Delphi Club is a haven of good fellowship and good craic (stemming no doubt from its Irish connections). But I have to report on a sad occurrence on the beach at Delphi and, as it turns out, at many other Abaco locations (and beyond) during June – a notable number of shearwaters being found dying or dead on beaches or else in the sea, their bodies in due course being washed in on the tide.
There are quite a few species of shearwater worldwide, of which 5 are recorded for Abaco. The only permanent breeding resident is the Audubon’s Shearwater, a bird that is quite commonly seen out at sea though not, I imagine, on land. We never managed to obtain a photo of one for “The Birds of Abaco”. I presume there are breeding colonies on Abaco, but not that I have heard about.
My first inkling that something unusual was occurring came a week ago from a FB post by Melissa Maura, whose wonderful parrot and flamingo photos feature elsewhere in these pages. She said “…on my rugged Abaco ocean beach last week, were many dead magnificent seabirds – greater shearwaters (about 5) and a couple of Frigate birds… They didn’t appear to wash in on the waves, but appeared to have perished perhaps from exhaustion on the beach”. Various later comments suggested that this phenomenon had been noted periodically in the past, the last time 4 or 5 years ago.
This was followed a couple of days later by evidence from well-known birding maestro Woody Bracey that living great shearwaters were in Abaco waters, perhaps confirming that they are in mid-migration at the moment. The one in #2 was “caught” 3 miles off Great Guana Cay.
Then a couple of days ago Jane Mantle emailed me with photos of some dead birds on the beach at Delphi saying that “half- dead birds are washing up on the beach ‘only for the vultures to finish off’. We must have over 20 with more to come”. I circulated these to the ‘usual suspects’ for ID and comment.
I also posted the photos on my RH FB to see if others had seen anything similar. Many thanks to all those who ‘liked’, shared or commented on the post. Here is a summary of the responses, from which a pretty clear picture emerges of widespread recent shearwater deaths on Abaco mainland and Cays.
- Delphi Club Beach – 20 plus
- Bahama Palm Shores – ‘many many’ dead birds washed up on the shore
- Casuarina Beach – 1
- Cherokee (Watching Bay) – 3 or 4
- Cherokee (Winding Bay) – 4
- Marsh Harbour area – about 5
- Great Guana Cay, southern end – 1 (possibly a gull)
- Tilloo Cay – 13 at least on Junk Beach, more than ever seen (see photos below)
- Elbow Cay – 2 + 1 Atlantic side beach near Abaco Inn
- Elbow Cay – 2, North End
- Green Turtle Cay beach – 2
- Green Turtle Cay, offshore – “a lot in the water”
- Man-o-War Cay – 1 by the roadside
- Ocean 20m from HT Lighthouse – 2 in the sea
also Exuma Sound (5 birds), Briland Beach Harbour Island (“some”) and Shroud Cay (gull?”)
Shearwaters at Tilloo Cay (Janie Thompson)
Shearwaters on Elbow Cay (Rudolf Verspoor)
WHAT SORT OF SHEARWATERS ARE THESE?
In the main it looks and sounds as though these are migrating great shearwaters. Woody Bracey has identified several dead birds as ‘greats’ from photos, and one as an alive Cory’s shearwater swimming in the sea off the Delphi Beach. ID is not easy, and a few of the birds found may be gulls. It’s possible that there are some Audubon’s shearwaters among the stricken birds, although since they are resident to Abaco that would go against the theory of an exhausted migratory species that has been blown of course en masse.
WHAT DO THE EXPERTS THINK?
There are a few obvious contenders for the solution to the riddle of the shearwaters, ranging from the frontrunner migration exhaustion to disease and trash ingestion. The evidence of mass deaths over a wide geographical area during a short time probably rules out trash ingestion – although I’m sure the poor creatures must have plenty of plastic bits inside them. Mass disease striking suddenly over one area is seems unlikely. Once those two possibilities are ruled out, the primary cause, covering most instances of the sad and upsetting phenomenon, becomes clearer.
Lynn Gape of BNT posted the view of William Mackin, a seabird biologist who looked at some of the photos and wrote “The five birds look like greater shearwaters. They breed at Gough Island in the South Atlantic. The young begin life by flying 10000 miles to Newfoundland in the North Atlantic. Some do not make it. They wash up on eastern US and Bahamian beaches. It is sad. We should monitor the numbers. The frequency is variable but possibly increasing.”
Tony White, the omniscient Recorder of Bahamas Birds and compiler of the comprehensive and authoritative checklist for the area, writes:
“The dead birds on the beach (and in the water) is a phenomenon that happens every five to ten years. According to the late Dave Lee these are young Great Shearwaters migrating from their natal home in the South Atlantic to their feeding grounds off the US and Canada, Combination of poor food supply and wind conditions in the doldrums lead to their expending all their energy and expiring. It is a normal event for this species and has been recorded many times The Great Shearwater population appears to weather the bad years and do well in the good years. Relevant articles are: Lee, D.S. 2009. Mass die-offs of Greater Shearwater in the Western North Atlantic: Effects of weather patterns on mortality of a trans-equatorial migrant. Chat 73(2):37; Seabird Ecological Assessment Network. 2007. Greater Shearwater Die-off in the Atlantic: June-July 2007. Volunteer Newsletter 3(2):2; and Watson, George. 1970. A Shearwater Mortality on the Atlantic Coast. Atlantic Naturalist 25(2):75-80.
Woody Bracey has now left an informative and perceptive comment: “It’s amazing how far(10,000 miles) these young birds have to travel to their feeding grounds so soon after being fledged. Breeding colonies are on isolated subantarctic islands of the southern hemisphere. Breeding begins in October. Incubation of the single egg lasts 55 days and it is another 105 days until the chick is ready to fly. Each loss of a bird represents much time and effort of a pair to produce a single chick which then has to fly the gauntlet through the windless, often foodless doldrums to reach its northern feeding grounds. So many hazards, so few birds! It’s sad to witness these die-offs but the species still survives. Global warming cannot be helping this species on its journey to the colder, nutrient rich more northern briny destinatioin. Lets stop setting our dumps and forests on fire here in the Abacos. Eventually it will not only affect the Great Shearwaters but us as well”.
I should add that it is reassuring to be able to confirm that, at least at present, the great shearwater is IUCN-listed “Least Concern”
Tony has asked for all available information Bahamas-wide: “It would be very useful if someone could collect some hard data on the die-off, e.g. when was it first noted and how many birds are found along a given stretch of beach? Check for other species and take a few wings as samples of the desiccated birds. In past events the number of dead birds was much greater on Crooked and Acklin Islands than Abaco. Eleuthera too should be checked if possible”.
Lynn has also asked “Please photograph and count birds found on your beaches and send images and the number counted to me at firstname.lastname@example.org. We will send on to William Mackin and Tony White who are keeping records of these occurrences The image with this post is a Greater Shearwater in flight…” (see above, as we would all like to think of these magnificent birds)
Or by all means contact me at email@example.com and I’ll pass on any info
STOP PRESS An update to this post written the following week, detailing new sightings and reporting the passing of a sad fortnight of shearwater fatalities in the Bahamas, can be found HERE