The postmortem adventures of a gull

31 03 2011

First off–a renewed call to any Seanetters available on April 12 around 5pm for a field trip to Revere Beach in Massachusetts! An undergraduate class from Tufts will be heading out with us to learn a bit about citizen science, beachwalking with a purpose, and the curious lives of dead birds. We would love to have some of you folks come and give your first hand accounts of what SEANET has meant to you. If you think you might be able to make it, please get in touch!

Now, to today’s thrilling content: a study of decay and decomposition.

Since we introduced individually numbered cable ties on a few beaches, we have reaped unexpected benefits. In addition to being able to track a specific carcass from week to week and month to month, we have also been able to observe the degradation of carcasses over time until little is left but a bone and feather pile. Here is a photo journal of the postmortem progress of Great Black-Backed Gull 1943, first seen and tagged by Dennis Minsky in October 2010.

While most Seanetters don’t have the opportunity to observe a carcass for so long a timeframe, this should serve as a justification for photographing even previously seen carcasses. This is an education for us all, and helps us understand how long it takes a carcass to break down, and what parts tend to persist. Perhaps the most valuable is being able to watch a known species degrade to almost unrecognizable parts. These images can make all the difference when we get difficult cases of mangled wings and bones.

October 2010: the month the bird was initially tagged.

November 2010

December 2010

February 2011

March 2011

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South Atlantic oil spill threatens more than the oiled penguins

30 03 2011

The isolated Tristan da Cunha archipelago

Many of you have likely already heard about the oil spill in the Tristan da Cunha islands in the south Atlantic. The remote archipelago is smack in the middle of the ocean, 1700 miles from the nearest port in South Africa. The spill occurred on March 16th when the M.S. Oliva, a cargo ship carrying soya beans from Brazil to Singapore, ran aground on Nightingale Island. The crew were rescued, but by Friday, the 18th, the ship’s hull had split, and oil was spilling into the waters around Nightingale. A salvage tug was deployed from Cape Town, South Africa the day the ship ran aground, and another ship was chartered to carry oil spill clean up personnel and equipment when it became clear that an environmental disaster was inevitable.

The islands are home to over half of the world’s threatened Northern Rockhopper Penguin population, and observers reported seeing between 10,000 and 20,000 oiled individuals on the island. Britain’s Royal Society for the Protection of Birds is coordinating the spill response, and set up shop on Tristan da Cunha, the largest island in the archipelago of the same name. They began accepting oiled birds on March 24th and started stabilizing the birds, administering fluids, warming them, and preparing them for the rigorous washing process. Penguins are generally quite hardy and resilient and a good percentage of them survive to be released after having been oiled.

The swimming pool on Tristan was filled with non-cholrinated water and pressed into penguin service. (BBC photo)

As if the spill weren’t bad enough, the greater potential threat in this disaster may be harder to detect right away: if rats aboard the Oliva make it to the shores of Nightingale  (one of two islands in the archipelago that are currently rodent-free), they will threaten the very survival of the seabirds breeding there. Many seabirds evolved to raise their young on islands where eggs and young on the open ground would not be at risk from opportunistic rodents. When rats arrive on such an island, the birds are entirely without defense. Given the stakes, conservation officers stationed on the islands have been searching for any evidence of rat arrivals, and have set traps along the island’s shores to attempt to intercept any interlopers.

SEANET will be watching the situation on Tristan with interest and hope that the damages may be limited. We will keep you updated as the cleanup continues.





Dead Bird Quiz answers

24 03 2011

Thank you to Mary Wright for yet another correct answer, though Mary also was stumped by the red kite-like object that was “Bird” C.
As for our first two specimens, however, Mary nailed the id: Bird A is a Black Guillemot, and Bird B a Brown Pelican.

The Black Guillemot tends to reside in nearshore waters, especially in comparison with other alcids, which are much more common on the open ocean. The breeding grounds of the Black Guillemot are not substantially different from its wintering grounds, and the birds typically don’t stray far from their breeding sites unless sea ice forces them to in winter. The birds can often be seen foraging at the edges of said sea ice.

Field marks of note include those evident in the photo in the previous post: adult birds have bright red feet, and in breeding plumage, large white patches on black wings are distinctive. Also worth noting: the underwing of the Black Guillemot is almost entirely white. This is in comparison with our other alcids, which show much more black on the underwing.

The underwing of this murre shows a lot more black than our Black Guillemot.

Perhaps you can appreciate on this photo that the black on the underwing of the guillemot is limited to the margins.

As for our Bird B, I chose this specimen since Pelicans with heads are so obvious and this headless one offered more subtlety. How to i.d. a pelican without that preposterous pouchy bill? Here are some pointers: Brown Pelicans are big. The wing chord of Brown Pelicans ranges from 48-56cm or so. The only other species that large commonly encountered by Seanetters is the Northern Gannet, and indeed the Gannet is in the same, pouchbill family with pelicans and cormorants. Without the head, the best indication that one is looking at a pouchbill are the feet. All four toes are webbed in pouchbills.

So, a big bird with four web toes is a pouchbill. But how to tell if it’s a gannet or a pelican? Adults of both species are rather distinctive, so let us focus on the youngsters. Subadult gannets start out quite dark, with a lighter belly. However, the bird has the look of a starry sky, with white spangles all over its handsome self. Brown pelican subadults, on the other hand, have a rather plain belly with a paler brown back and wings. So, no head? Don’t despair! We can overcome such minor handicaps.

And if any of you ever figure out what that red contraption is, let me know.

The star-spangled subadult Northern Gannet. Compare to the rather more plain subadult pelican.

The rather more plain subadult Brown Pelican.

Pouchbill feet: even the backward facing toe (the hallux) is incorporated in the web.





Dead Bird Quiz: headless or not a bird edition

22 03 2011

Bird A: Found by Sue Bickford in Wells, ME earlier this month.

Time for a dead bird quiz! I tried to be equal opportunity this time and include something from our southern friends. And please, if you have any idea what the non-bird mystery object is, tell me!

Answers (to the extent I have any) will be revealed in the next post, as per our usual arrangement.

Bird B: Found by Rick Kurz on Hunting Island, SC in February.

"Bird" C: contraption. Found by Dick Jordan in Wellfleet, MA this month.





Albatross weather the tsunami on Midway Atoll

16 03 2011

Midway atoll located at the far northwestern reaches of the Hawaiian archipelago.

Though clearly outside the usual purview of decidedly Atlantic-looking SEANET, the story of the Laysan and black-footed albatross nesting on the small sand islands of Midway atoll merits the attention of seabird enthusiasts everywhere. Midway is about one third of the distance between Honolulu and Tokyo and is the breeding grounds for millions of seabirds, including 71% of all breeding Laysan albatross in the world. It is also the second largest breeding colony of Black-footed albatross. Following the earthquake off Japan, observers on Midway braced for a tsunami, and reported watching a five foot wave wash over the low-lying islands, submerging 20% of some of the larger islets and completely swamping at least one smaller one.

A series of the waves swept over the terrain, tumbling albatross chicks and their attentive parents among sand, rocks, and uprooted vegetation. When the waves receded, fish and wildlife workers headed out to dig the survivors out of the sand and gravel. Pete Leary, who works on Midway, provided an incredible account on his blog of the scene out there.

We’ve had a few readers of the SEANET blog asking if we’ve heard anything about the fate of Wisdom, a 60-something Laysan albatross who had been nesting on Midway. The BBC reported today that Wisdom was known to be among the tsunami’s survivors but gave no further details on her condition or the fate of her chicks. Current estimates are that 10s of thousands of albatross chicks were killed, and some thousands of adults, though firm numbers are hard to come by. The birds are at a point in their breeding cycle where the adults spend a great deal of time away from the nest foraging for food to bring back. Unfortunately though, the waves hit in the middle of the night, when the birds were less likely to be foraging and more likely to be attending the nest. Biologists say the birds would have stayed on the nest even in the face of the waves, unwilling to abandon their young.

Albatross chicks half-buried by sand deposited by the tsunami. Photo: P. Leary.

Facing a fate even more grim than the albatross, thousands of Bonin petrels which nest in subterranean burrows, were buried alive by the sand and debris.

Biologists studying the birds report that while these losses are severe, the relative impact of the deaths of so many chicks is far less than it would be for a comparable number of adults. Albatross are exceedingly long-lived (exhibit A: Wisdom), and the loss of one year’s chicks makes little difference in their lifetime productivity. Wildlife officials are optimistic that the population will bounce back from this event.





NH sewage treatment plant discharges filtration discs

15 03 2011

Sewage filtration discs found on Seabrook Beach in New Hampshire.

Seanetter Stephen Brezinski in Maine was the first to notify me of the appearance of thousands of small, perforated plastic discs on Seabrook beach in New Hampshire this weekend. After his report, Seanetter Linda McCallum who walks on Plum Island in Massachusetts, and Alicia Lenci, who walks Crane Beach a bit farther south on Massachusetts’ North Shore, both reported that their beaches were closed due to “a potential health risk.” While the discs themselves had not yet appeared as far south as Alicia’s beach, officials there have chosen to err on the side of caution based on the origin of the mysterious objects:

The discs have been traced back to a sewage treatment plant in Hooksett, NH, where heavy rains and melting snow overwhelmed the plant’s discharge systems and caused the small plastic filters to spill into the Merrimack River north of Manchester. Normally, the discs are contained in large tubs where they aid in the digestion of sewage. Not surprisingly then, the discs have tested positive for E. coli and Enterococcus, common bacteria inhabiting the human intestinal tract.

The path of the discs. Orange markers represent reports of beach closures.

After the release a week ago, the discs traveled south and then east along the course of the Merrimack River, which meets the Atlantic just south of the New Hampshire border. They began appearing on Seabrook beach on Thursday. Officials in Massachusetts have criticized their counterparts in New Hampshire for failing to notify their neighbors downstream about the accidental discharge, and it remains unclear who will ultimately pay for the cleanup of the thousands of discs. It is not known how many of the objects escaped into the river, but plant officials say the facility may have contained 9-10 million in total, and it is unclear what portion of those were released.

In the interim, beachgoers who encounter the discs are warned not to touch the objects without gloves, and to wash their hands thoroughly after visiting the beach.

New Hampshire DES officials are requesting that anyone who finds the discs call them at 603-271-3710, so they can track where they are going. Your SEANET blogger also requests that you notify us if you find them.

 

 





Gull banding in Maine; wanna join?

10 03 2011

The children are always underfoot on Appledore Island.

Our own Julie Ellis has been working since pre-history on a gull banding project out on Appledore Island in southern Maine. Her study, involving both Herring Gulls and Great Black-Backed Gulls, requires a couple rounds of bird capture and banding each breeding season. Adults are banded in May when they are incubating eggs, and fledglings are caught and banded in July before they are particularly adept at flying escapes.

This year, Julie has invited yours truly (SEANET blogger, Sarah Courchesne) to assist her in directing these efforts. In addition to the two of us, we will be capably assisted by a team of experienced gull wranglers who come back every year for more abuse. But even given that crack team, we are looking for more recruits. The Shoals Marine Laboratory, a joint venture of Cornell University and the University of New Hampshire) administers courses and programs on the island for children through college undergrads through retirees. The gull banding study is being offered this year as an Adult Education opportunity, so anyone over the age of 18 is invited to join us! There is a fee to cover your room and board and to support the “course faculty”, and life on the island is not glamorous, but the rewards are great and the company is passable.

Typical evening view from your front porch if you join us on Appledore this year.

You can get more information on the adult banding session in May, and the fledgling banding session in July at the Shoals Marine Lab website. No prior experience handling birds is required; we can teach you everything you need to know. Hope to see some Seanetters (and anyone else who might be interested) out there this season!