Coastal Birds Carry Toxic Ocean Metals Inland

A collaborative research team led by Queen's University biologists has found that potent metals like mercury and lead, ingested by Arctic seabirds feeding in the ocean, end up in the sediment of polar ponds.

"Birds feeding on different diets will funnel different 'cocktails' of metal contaminants from the ocean back to terrestrial ecosystems, which can then affect other living organisms," says lead author Neal Michelutti, a research scientist at Queen's Paleoecological Environmental Assessment and Research Lab (PEARL).
The study will be published on-line the week of May 24 in the Proceedings of the National Academy of Sciences USA.
The team collected sediment cores from two ponds on a small island in the Canadian Arctic that is home to the nests of two kinds of seabirds: Arctic terns, which feed primarily on fish, and common eider ducks which feed mainly on mollusks. The researchers analyzed the pond sediment for metals and other indicators of the birds' activity.
They found significant differences between the samples that aligned with the birds' diets. There were higher concentrations of metals such as mercury and cadmium in the sites inhabited by terns, while the nearby eider site recorded higher amounts of lead, manganese, and aluminum. The patterns of metals in the sediment cores matched those recorded in the different bird species' tissues.
Queen's biology professor John Smol says the findings can be applied to other locations. "The High Arctic is an excellent 'natural laboratory' to undertake such studies, due to the lack of local industries," notes Dr. Smol, Canada Research Chair in Environmental Change, and winner of the 2004 NSERC Herzberg Gold Medal as Canada's top scientist. "However, the presence of seabirds on every continent suggests similar processes are operating along coastlines worldwide.
"Our concern is that these areas of elevated metals and other contaminants occur exactly where biological activity is greatest," he adds.
"The seabirds are obviously not directly to blame for the elevated metal concentrations in the ponds," says team member Jules Blais, a biology professor from the University of Ottawa. "They are simply carrying out their natural behaviours and lifecycles, but have become unwitting vectors of pollutants in an increasingly industrial age."
Other members of the multidisciplinary team include Queen's biology undergraduate student Jaclyn Brash and PhD candidate Joshua Thienpont, Linda Kimpe from the University of Ottawa, Marianne Douglas (University of Alberta) and Mark Mallory (the Canadian Wildlife Service).
This research was funded primarily by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Polar Continental Shelf Program (PCSP).

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Queen's University.

Wandering Albatross: Is Foraging Efficiency a Key Parameter in Aging?

The male wandering albatross, which can live more than 50 years, modifies its foraging behavior with age. CNRS researchers, working with the Université de Bourgogne, have for the first time shown such changes by studying aging in these birds under natural conditions.

The scientists have discovered that old males forage in different waters from younger males, and are less active at the sea surface. However, none of the classic markers of human aging are altered in old albatrosses, which underlines the importance of taking account of foraging efficiency in studies on aging.
The work, carried out with the backing in particular of IPEV1 and the Prince Albert II of Monaco Foundation, has been published online on the website of the journal Proceedings of the National Academy of Sciences (USA).
Aging in animals, the causes of which are increasingly well understood in laboratory conditions, is hardly ever studied in a natural environment. Researchers from the 'Marine Predator' group at CNRS's Chizé Center for Biological Studies, working with the 'Biogeosciences-Dijon' Unit (CNRS / Université de Bourgogne), studied wandering albatrosses, which stand out among other birds because they are exceptionally long-lived2 (over 50 years). With a life expectancy close to that of humans, they therefore make exceptional models for the study of aging in the natural environment. Wandering albatrosses travel huge distances. During their lifetime, they fly millions of kilometers across the Southern Ocean, only returning to dry land to breed once every two years. Their reproductive performance declines from the age of thirty, but the reasons for this decline were unknown until now.
The scientists undertook the first multidisciplinary study ever carried out on the aging of these seabirds under natural conditions. They did this by observing around a hundred albatrosses aged 6-49 years breeding on Possession Island in the Crozet islands (French Southern and Antarctic Territories). By using miniature devices (Argos transmitters and activity loggers), they were able to analyze foraging trips by the birds during the egg incubation stage.
The researchers discovered that the older male albatrosses foraged in areas of ocean that were somewhat different from those favored by younger birds. For reasons that remain unclear, during the incubation period they undertake very long foraging trips to the cold waters of the Antarctic, at a distance of over 3000 km from their nest. They are less active at the sea surface and return to dry land with elevated levels of stress hormone, which suggests a fall in foraging efficiency (a parameter which is very hard to measure except under natural conditions). Only males appear to modify their foraging strategy with age. No difference was observed between females aged over 30 and younger birds.
At the same time, the researchers measured seven physiological parameters naturally associated with aging in humans, including stress hormone (corticosterone) levels, parental hormone (prolactin) levels, the amount of oxidative stress, the ability of plasma to respond to attack by free radicals, and humoral immunity levels. Quite unexpectedly, no variation in these parameters was detected for the older albatrosses (30-49 years old) within this population. The older birds therefore appear to maintain a 'normal' physiological level.
This study is the first to directly show that, under natural conditions, several aspects of foraging behavior decline with age, without this resulting from a deterioration in their physiological state. As a result, a fall in foraging efficiency may be one of the first signs of aging.
Notes
(1) Institut polaire français Paul-Emile Victor
(2) Life expectancy of birds varies considerably from one species to another, from three or four years for some passerines to over 50 years for albatrosses and shearwaters, exceeding 60 years for large species of albatross.

Vincent Julien Lecomte, Gabriele Sorci, Stéphane Cornet, Audrey Jaeger, Bruno Faivre, Emilie Arnoux, Maria Gaillard, Colette Trouvé, Dominique Besson, Olivier Chastel, and Henri Weimerskirch. Patterns of aging in the long-lived wandering albatross. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.0911181107

Warmer Summers Could Create Challenges for Nesting Arctic Seabirds

Warmer, wetter weather in the Canadian Arctic could create problems for nesting seabirds, say a team of Canadian scientists who, between them, have spent over 7,000 days observing birds in the North.

Arctic birds are uniquely adapted to survive in the cold, dry summers that mark the high Arctic. However, warmer temperatures are bringing more storm events, including incidents of heavy fog, rain, freezing rain, wet snow and stronger winds.
"It's not really a surprise," says Mark Mallory, a biologist with the Canadian Wildlife Service in Iqaluit. "If a bird is adapted to cold conditions and you make things warmer, predictably they'll find things harder."
Mortality studies in seabirds typically focus on birds in tropical or temperate regions where 'normal' causes of death include population declines due to fishery collapse, ecto-parasites like ticks, introduced predators such as rats, and storms at sea.
Mallory and two other Canadian scientists decided to combine 33 years of observation into a paper that was released in Arctic, the journal of the Arctic Institute of North America. In it, the trio track the unusual ways Arctic seabirds die and they predict that a warming climate could have serious consequences for these birds. The study is based on observations of six species of birds on 11 different seabird colonies in the eastern Arctic ranging from northern Hudson Bay to Devon Island.
Typical causes of death include crashing into each other or cliffs during heavy fog, being slammed into the ocean by Katabatic winds or, perhaps most grizzly of all, dying from a combination of heat stress and blood loss due to mosquito attacks.
"I was working at a fulmar colony and after a couple of days of fog we'd see fulmars on the sea ice, alive but with their wings broken. These birds are phenomenal flyers, but you take away their visibility to a meter or two and maybe that causes problems. In talking to my Inuit guides, they told me that they had seen this a lot, and thought that the birds flew into each other in low visibility," says Mallory.
Few birds winter in the Arctic because of the harsh climate conditions. But in the spring, there is a veritable explosion as millions of birds return to nest. Seabirds in Mallory's study area tend to spend the winter months floating in the North Atlantic ocean. When they return in the spring, conditions are often still very harsh. Mallory has seen fulmars and thick-billed murres incubate eggs with only their heads visible above the snow.
The preferred nesting sites of many seabirds are cliffs, which often prove to be very dangerous. Falling rocks and chunks of ice, as well as slides kill great numbers of birds. In fact, the authors cite one incident in which over 800 murres and kittiwakes died almost instantly when the ledges on which they were nesting collapsed. Mallory suspects cliffs could become unstable as temperatures rise, with more freeze-thaw action of ice.
And not all cliffs provide a safe haven from predators. Cliff-dwelling birds are, of course, easily accessible by other predatory birds. But Arctic foxes and even polar bears have been observed on cliff sides eating eggs, chicks or adult nesting birds.
"It's always shocking to see a polar bear on a cliff," says Mallory adding, "I saw Arctic foxes down what appeared to be effectively a vertical wall. And the Inuit report seeing more polar bears on cliffs. So these birds think they are safe, but they are not."
The Arctic has been getting warmer and increased temperatures create stronger storm fronts and bring more precipitation to what is essentially a desert region. For birds adapted to a cold, dry climate, these changes could be very challenging.
"Arctic seabirds don't do well in really heavy, wet snowfall. Chicks hatch in early August and they expect it to be dry and cool. They can't handle soaking wet for very long, even if it is warmer," says Mallory.
These birds have adapted to past climate shifts, but the changes occurred over long periods of time. It might be difficult for them to adjust to the rapid changes now underway.
"They can deal with cold and wind and storms, but within the range of what has occurred over the past decades or centuries. If you suddenly change that range, make things warmer and wetter with a different type of precipitation, that's a scenario these populations aren't adapted to."

Fishing Discard Ban Could Damage Sea Bird Success, Scientists Warn

A proposed EU ban on throwing unwanted fish overboard from commercial boats could put one of the North Sea's most successful sea birds at risk, say researchers at the University of Leeds.

New research led by Dr Keith Hamer will assess the extent to which gannets rely on unwanted fish and offal thrown from fishing boats to successfully breed and raise their chicks.
"The North Sea has undergone massive environmental changes over the last twenty years, which has put pressure on nearly all sea bird species," said Dr Hamer, from Leeds' Faculty of Biological Sciences. "Only gannets have consistently bred successfully, partly because they can travel as far as South West Norway to feed, but also because they are able to target food thrown overboard by fishing boats.
"Although discards should be stopped to protect marine biodiversity, research is needed on the impact of a ban, so policy makers can understand the best way to implement it."
Dr Hamer will work with colleagues at the universities of Exeter and Plymouth to fit GPS tracker devices on breeding pairs of gannets from twelve colonies around the UK. The gannets will also be fitted with miniaturised, fast-acting depth recorders, so the researchers can see how deep the birds dive and how they pursue prey underwater -- both indicative of the kinds of food they are targeting.
Blood and feather samples from the gannets will be analysed to determine their diet and their nests monitored to check how well they are feeding their chicks.
The data will be plotted against the location of fishing vessels in the North Sea to calculate how many of the birds are relying on discards to breed successfully.
The researchers believe that gannets may have specialised feeding habits, with some individuals relying heavily on discards while others focus on finding sand eels or diving for mackerel and herring. If this theory is correct, a ban would disproportionately affect some breeding pairs, rather than impacting to a lesser degree on the whole colony.
The research builds on more than 10 years of research on gannets by Dr Hamer in addition to work by research team members Stephen Votier in the Marine Biology & Ecology Research Centre, University of Plymouth, and Stuart Bearhop, University of Exeter, published this month in the Journal of Applied Ecology.
"We think gannets have different aptitudes and specialities and for some, that skill might be finding and following fishing boats," said Dr Hamer. "If our hypothesis is wrong and gannets are in fact generalists, with all of them making occasional use of discards, that has a different implication for policy."
There is increasing pressure on the EU to ban discards and legislation is likely in the near future. The three-year, £700,000 research project, funded by the Natural Environment Research Council (NERC), will help inform policy makers of how to ensure new regulations minimise potential impact on the gannets. It could also help the UK government decide where to impose marine protected areas in the North Sea.
"Although the long-term benefits of a ban will be positive, we need to accurately predict short-term impacts as well," says Dr Hamer. "If gannets have specialised to the extent we believe, rather than cut off a crucial food source overnight, a gradual phasing in of the ban would allow them time to retrain to find food elsewhere."

Seabirds' Movement Patterns Tied to What Fishermen Toss Away

Humans and human activities have clearly altered the Earth's landscape and oceans in countless ways, often to the detriment of other plants and animals. But a new report published online on January 28th in Current Biology, a Cell Press publication, shows just what a tangled food web we've woven.

Two species of Mediterranean seabirds change their every move based on the activities of local fisheries and, in particular, the fish that people toss away. The seabirds' shifting movement patterns can be seen at the regional scale.
"We show that human activities in the natural environment can promote critical transitions in the spreading properties of foraging animals by locally changing the predictability and availability of their resources," said Frederic Bartumeus of Princeton University and Institut Català de Ciències del Clima in Spain. "Our study suggests an elementary but often disregarded connection between human local resource exploitation and global movement patterns of organisms."
The findings may have important implications for conservation biology and the study of invasive species, the researchers said. The work also provides a solid statistical framework for quantifying movement patterns across ecological scales, which can now be applied to other species and other circumstances.
Bartumeus' team took advantage of existing satellite data on the Cory's shearwater and the Balearic shearwater, which tracked the seabirds' movement over multiple foraging trips. Each trip typically lasts less than two days and covers distances anywhere from 10 to 1000 kilometers. Because the fisheries don't operate on holidays and weekends, the researchers were able to characterize the birds' activities in the presence and in the absence of the fisheries' trawling activities.
When the fisheries don't operate, seabirds essentially combine local searching with very large traveling distances, Bartumeus explained. Such a multiscale search pattern generates what he calls superdiffusive movement properties, meaning that the birds spread out from one another at a rate that accelerates over time. "Such a movement pattern allows for efficient explorations when the birds are looking for their natural prey of small fish and squid, which are highly mobile and unpredictably distributed in space and time," he said.
In contrast, when fishermen are discarding fish, seabirds perform local searches around the boats, which act as an "attracting force." As a result of such confined movement, the spreading of scavenging seabirds in the seascape decelerates with time, and movement patterns involve well-defined spatial scales related to the fishery activity.
In a nutshell, says Bartumeus: "Fishery activities impact the foraging ecology of seabirds at much larger spatiotemporal scales than one might expect intuitively. The macroscopic spreading properties of seabirds through the seascape are directly influenced by the presence of fishermen's boats discarding fish."

Complex Life of Marsh Birds: Coots Foil Nest Invaders, Reject Impostors

The American coot is a drab, seemingly unremarkable marsh bird common throughout North America. But its reproductive life is full of deception and violence.

According to biologists at the University of California, Santa Cruz, coots have evolved a remarkable set of cognitive abilities to thwart other coots that lay eggs in their neighbors' nests. In 2003, the researchers showed that coots can count their own eggs and reject ones laid in their nests by other coots. Their latest findings, published this week in Nature, show that coot parents can tell the difference between their own chicks and any impostors that manage to hatch in their nest, and they will violently reject most impostor chicks.

The findings are particularly striking because so many birds seem to be unable to recognize the chicks of species such as cowbirds and cuckoos, which always lay their eggs in the nests of other birds. This behavior is called brood parasitism, and its success has posed a longstanding challenge to evolutionary theorists.

"When you see a little songbird struggling to feed an enormous cowbird chick, you have to wonder why it can't recognize the parasitic chick when it is so obvious to us," said Bruce Lyon, professor of ecology and evolutionary biology at UCSC and coauthor of the paper. "The coot study shows that chick recognition can evolve, even when the chicks are the same species and all look the same to us."

The researchers found that coots learn to recognize their own chicks each year by using the first-hatched chicks as a template to which other chicks are compared. This learning mechanism may explain why it is so hard for chick recognition to evolve among the hosts of cowbirds and cuckoos, said Dai Shizuka, a UCSC graduate student and first author of the paper.

"Cuckoo and cowbird chicks tend to hatch before the host chicks, so their hosts can't use hatching order as a cue for chick recognition," Shizuka said. "As long as recognition has to be learned, you run the risk of learning incorrectly, and that could be the bottleneck."

These findings provide indirect support for a theory proposed by Arnon Lotem of Tel Aviv University, who attributed the absence of chick recognition in most cuckoo hosts to the high cost of mistaken imprinting. By experimentally causing mistaken imprinting in coots, Shizuka and Lyon confirmed that learned chick recognition does have potential costs.

Lotem assumed a classic imprinting mechanism that would occur only once, during the adult bird's first breeding season. Coots, however, seem to "imprint" on their first-hatched chicks each year. Coots reliably imprint on their own chicks because the first-laid eggs are the first to hatch, and parasitic eggs are deposited only in nests that already have eggs in them.

"It's not that coots are exceptionally smart. They just have reliable information that allows them to do what we expect all hosts 'should' be doing to defend themselves against parasitism," Shizuka said.

The common cuckoo and brown-headed cowbird are specialists in brood parasitism, shifting the burden of parental care onto other species rather than building their own nests. In coots, brood parasitism seems to be an optional component of a reproductive strategy based on laying large numbers of eggs. Depositing a few eggs in a neighbor's nest is just another way to increase the number of potential offspring.

The chances of survival in a neighbor's nest may be slim, but coots habitually lay more eggs than are likely to survive, Lyon said. Only in the best of years is there enough food for all of the chicks; in a typical year, about half of the chicks in each brood starve to death, he said. If a parasitic chick survives, another chick in the brood must die, which explains why coots have evolved such strong defenses against parasitism.

"We actually set out to study how coots bring their brood size into alignment with the availability of food, and what role hatching order plays in the culling process. But we kept seeing anecdotal evidence in the field that something else was going on," Lyon said. "With the parasitic chicks, they don't just let them starve, they attack them with a viciousness we hadn't seen before."

The researchers got a one-year extension to their grant, funded by the National Science Foundation, to study chick recognition at their study site in British Columbia. The experiment required removing eggs from the nests at the pipping stage (when the chick starts trying to break the shell) and hatching them in incubators. This allowed the researchers to tag the chicks and record which eggs they came from before returning them to the nests in a controlled sequence.

In one set of nests, the parents got their own chicks back on the first day. After that, chicks were returned to the nests in pairs consisting of an unrelated chick and a chick that belonged to the parents. The unrelated chicks were all siblings. In a second set of nests, the first chicks returned were not related to the parents, after which chicks were returned in pairs as in the first set of nests.

In all cases, a chick's chances of survival were highest if it was returned to the nest on the first day or was a sibling of the first chicks. If the first chicks were unrelated to the parents, the parents would favor them and their siblings and drive off their own chicks. "The parents learn the first chicks they start taking care of as their own, and base their decisions about later chicks on that," Shizuka said.

Using first-hatched chicks as the basis for recognition will be adaptive only if there is a low probability of parasitic chicks hatching first, he said. In a search of the scientific literature, Shizuka found two recent examples of birds, both in Australia, that appear to be able to recognize and reject cuckoo chicks. He said he hopes to learn more about those species and find out how they compare to coots.

The researchers also want to find out what cues coot parents use to recognize their chicks. The possibilities include smell, vocal calls, and visual cues such as plumage. "Those birdall plausible hypotheses, but we don't know yet," Shizuka said.

Trying to crack an ocean mystery: What caused killer algal blooms?

Mary Sue Brancato, a marine biologist with the Olympic Coast National Marine Sanctuary, checks the tags on dead seabirds caught in the algal bloom that were found on Hobuck Beach on the Makah Reservation last month. The mysterious bird-killing algae that coated Washington's ocean beaches this fall with slimy foam was the biggest and longest-lasting harmful algal bloom to hit the Northwest coast.Now the phenomenon that killed at least 10,000 seabirds — more than any known event of its kind — has scientists consumed by questions: Was it a rogue occurrence, rarely if ever to be repeated, or a sign of some fundamental marine-world shift?And did we cause it?Answers may come slowly. "You can think of it as a jigsaw puzzle with 500 pieces, but we only have about 50," said Julia Parrish, a University of Washington fisheries and oceans professor.This much is known: Toxic blooms of microscopic phytoplankton sometimes called red tides are exploding worldwide, even along pristine waters like the Northwest coast.And the organisms behind these blooms can behave unpredictably, revealing how little we know about the sea.The culprit this fall was a mushroom-shaped single-celled species, Akashiwo sanguinea, that has bloomed in Puget Sound, Chesapeake Bay and saltwater from Europe to Australia and Japan without incident.But something here this time caused the cells to multiply rapidly and break open in a toxic foam. It's been recorded happening only once before — on a smaller scale, in Monterey Bay in California, in 2007.Researchers are trying to gauge whether warming surface waters or more corrosive seas might have played a role in the two blooms, or whether they were caused by a collision of shifting currents and natural atmospheric and weather cycles like El Niño. Or maybe it's all of the above — or something else."We haven't ever seen this before and now we've had two events in two years," said Raphael Kudela, an ocean-sciences professor and toxic-algae expert at the University of California, Santa Cruz. "If it happens again, I'll be concerned. Four times and I'll be really concerned."Soaplike frothThe incident this fall played like something out of a Hitchcock movie: White-winged scoters and surf scoters staggered and collapsed on Olympic Peninsula beaches in September. Then over the next six weeks, loons, grebes and murres were found dead from Neah Bay to Oregon. Just as in Monterey, a soaplike froth coated the natural oils that protect the birds from hypothermia.Researchers are still unearthing its effects: Surfers and kayakers who rode through the foam near Westport, Grays Harbor County, complained of sinus problems and a lingering loss of taste and smell; a pathologist inspecting dead birds found a few whose guts lacked any trace of normal bacteria, raising the possibility they ingested something damaging.Most disturbing to algae experts: The whole incident was unexpected. Akashiwo sanguinea isn't even among the species scientists considered harmful, said Mary Sue Brancato, a marine biologist with the Olympic Coast National Marine Sanctuary.Toxic tides aren't new to the Pacific. A crewman on Capt. George Vancouver's Voyage of Discovery died in 1793 after eating poisoned mussels.The blooms are produced by two classes of microalgae — dinoflagellates and diatoms, tiny creatures that help fuel the marine-food web.In Puget Sound, the most problematic is a type of dinoflagellate that produces a neurotoxin that can reside in shellfish. When ingested by humans, it can cause paralysis and even death.On the coast, the bigger problem is a diatom that blows in from off shore. It can produce domoic acid, which can cause seizures and death in humans.Since being detected in Washington in 1991, this diatom algae has shown up more frequently, shutting down razor-clam harvests in 1998-99 and 2002-03, and appearing in a giant swath offshore in 2004. Some scientists suspect a diatom bloom caused thousands of birds to spiral and crash into cars in California in 1961, an incident that helped inspire Hitchcock's film "The Birds."Along the East Coast and the Gulf of Mexico, as in much of the world, blooms like these are becoming more common, getting bigger and lasting longer.Pollution is believed to influence some events as nutrients drain into the coasts in rivers and as runoff from parking lots and highways. That likely plays a role in the abundant growth of harmful blooms in Puget Sound since the 1950s — but it doesn't appear to be the case along the coast."We haven't polluted our coastal waters to the same extent they have in the East," said William Cochlan, a research scientist at the Romberg Tiburon Center for Environmental Studies at San Francisco State University.But no one disputes that phytoplankton species are showing up in new places or, as the recent bird-killing bloom revealed, responding in new ways. Indeed, no one expected that particular species, a dinoflagellate, to bloom so massively — or disastrously — off the Northwest coast.And no one knows why it did.Broad consequences?Cracking the secret could prove monumental, helping determine whether we can expect greater economic or biological consequences.Vera Trainer, who runs the harmful-algal-bloom program at the Northwest Fisheries Science Center in Seattle, helped produce a new study showing that a toxic diatom bloom that hits beaches and shutters a razor-clam season for a year could cost Washington's coastal economy $22 million. If other harmful blooms start arriving more often, there's no telling what the cost would be.And that's just for starters. New blooms also could signal a significant shift in the bottom of the ocean's food web that could change the distribution of all sorts of marine and seabird species.Figuring out the causes won't be easy.Kudela notes that changes to coastal upwelling patterns, as well as warming ocean-surface temperatures fueled by climate change in response to greenhouse-gas emissions, could alter the West Coast's mix of phytoplankton. And that could allow one type to out-compete others.Ted Smayda, a phytoplankton expert at the University of Rhode Island, pointed out that a similar foam produced by a related phytoplankton species in Norway does best in waters with a low pH.Scientists already have shown that Pacific Northwest waters are becoming more acidic — meaning a lower pH — as the ocean absorbs billions of tons of carbon dioxide.But Smayda also said it's possible that the blooms are part of some natural ocean rhythm we just don't understand — or a combination of all sorts of other factors."What if we're just coming into an era where dinoflagellates are coming into their own?" Smayda said."The bias among investigators, myself included, is that we tend to look for just one factor. But what we have these days is a jumble of events, and we're left asking, 'What the heck is going on?' "

Dining Out In An Ocean Of Plastic: How Foraging Albatrosses Put Plastic On The Menu

The North Pacific Ocean is now commonly referred to as the world's largest garbage dump with an area the size of the continental United States covered in plastic debris. The highly mobile Laysan albatross (Phoebastria immutabilis), which forages throughout the North Pacific, is quickly becoming the poster child for the effects of plastic ingestion on marine animals due to their tendency to ingest large amounts of plastic.

Reporting in the open-access journal PLoS One, Dr. Lindsay Young of the University of Hawaii and her colleagues examined whether Laysan albatrosses nesting on Kure Atoll and Oahu, Hawaii, 2,150 km away, ingested different amounts of plastic by putting miniaturized tracking devices on birds to follow them at sea and examining their regurgitated stomach contents. Surprisingly, birds from Kure Atoll ingested almost ten times the amount of plastic compared to birds from Oahu.
Data from the tracking devices revealed that the birds were distributed over separate areas of the North Pacific during the breeding season and that birds from Kure overlapped considerably with the area of the 'western garbage patch' off of Asia which resulted in their greatly increased plastic ingestion.
"We were very surprised with the results," indicates lead author Lindsay Young. "We suspected that there may be some differences in the amount of plastic that was ingested, but to discover that birds on Kure Atoll ingested ten times the amount of plastic compared to birds on Oahu was shocking. Particularly since the colony on Oahu is less than an hour outside of urban Honolulu, and is much closer to the garbage patch in the Eastern Pacific between Hawaii and California that has received so much attention."
Young indicates that these results were further supported when the plastic items were examined -- virtually all of the plastic pieces recovered from birds on Kure Atoll had Asian characters on them indicating their likely origin, while none of the plastic pieces found in birds on Oahu had similar writing.
While sorting through the polluted stomach contents of albatross chicks was not a particularly pleasant task, the authors found humor in the situation. "We were sorting through these boluses right after Christmas, and there were so many small plastic toys in the birds from Kure Atoll that we joked that we could have assembled a complete nativity scene with them," says Young.
The most common identifiable items they found were paraphernalia from the fishing industry such as line, light sticks, oyster spacers, and lighters. The strangest item that they found? A sealed jar of face lotion with fresh smelling lotion still intact inside the jar. Unfortunately, while the albatross examined in this study were able to purge themselves of the plastic by regurgitating it, thousands of albatross die each year as a result of ingesting plastic debris. Plastic ingestion leads to blockage of the digestive tract, reduced food consumption, satiation of hunger, and potential exposure to toxic compounds to name but a few of its detrimental effects.
This study highlights that garbage generated by human activities on land clearly impacts ocean ecosystems thousands of miles away. And unfortunately there is no easy solution- each person must examine their footprint on the earth and how the lighter or bottle cap they toss into the trash can ultimately end up in the stomach of an albatross, thousands of miles away. Until we learn to do more with less, albatross and other marine animals will continue to dine on our garbage with as of yet unknown consequences.
Funding: LCY was funded by the Hawaii Conservation Alliance, the University of Hawaii Department of Zoology Jessie Kay Fellowship, and several Ecology, Evolution and Conservation Biology research awards as part of NSF grant DGE02-32016 to K.Y. Kaneshiro. SAS was supported in part by grants to the Tagging of Pacific Pelagics (TOPP) program from the Alfred P. Sloan, Gordon and Betty Moore, and David and Lucile Packard Foundations. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Journal reference:
Ropert-Coudert et al. Bringing Home the Trash: Do Colony-Based Differences in Foraging Distribution Lead to Increased Plastic Ingestion in Laysan Albatrosses? PLoS ONE, 2009; 4 (10): e7623 DOI: 10.1371/journal.pone.0007623
Adapted from materials provided by Public Library of Science, via EurekAlert!, a service of AAAS.

'Lost seabird' returns to ocean

Up to eight Fiji petrels were seen over an 11-day periodOne of the world's rarest and most elusive birds has finally been seen flying in its natural habitat.The Fiji petrel, a seabird that once "went missing" for 130 years, has been sighted flying at sea, near the island of Gua in the Pacific Ocean. The culmination of a meticulously planned bird hunt, Birdlife International researchers sighted the birds 25 nautical miles south of Gua. Up to eight individuals were seen and photographed over 11 days. The 30cm tall dark-brown Fiji petrel (Pseudobulweria macgillivrayi) is one of the most elusive of all birds.To see such a little-known bird at such close range was magical Expedition member Mr Tony Pym Originally, the species was known from just a single immature specimen, collected in 1855 on Gau Island, Fiji. But then the bird "went missing" with no further confirmed sightings of it for almost 130 years. Then in 1984, an adult was caught and photographed on Gua, then released. Since then, there have been a handful of reports of "grounded" birds that had crashed onto village roofs on the island. Most were immature birds, of which a few died. Due to the extremely limited number of sightings, the bird is also inferred to be one of the rarest of all bird species. It is one of 192 bird species which are list as Critically Endangered by the International Union for the Conservation of Nature. Stinky lureBut while there have been ten unconfirmed reports of the bird at sea, with the latest a possible Fiji Petrel sighted around 400km north of Bougainville Island, until now there has been no confirmed sightings. That was until in May, when scientists and volunteers working with Birdlife International and NatureFiji-MareqetiViti, a partner conservation organisation based in Fiji, set out to find the bird in its natural habitat. The search for the elusive petrel is described in a paper in the latest Bulletin of the British Ornithologists' Club. The researchers lured the bird with a specially made food, made from finely cut fish offal mixed with very dense fish oil.The Fiji petrel once "went missing" for 130 years These were then frozen into 10kg blocks, which persist for over an hour in the water, creating a pungent oil slick which attracts petrels from some miles away. On the second day of the expedition, the first Fiji Petrel appeared, approaching the chum slick from downwind, slowly zigzagging over the slick, and suddenly changing direction to drop onto a floating morsel. In all, the expedition team believe they saw eight individuals over eleven days of observations. "Finding this bird and capturing such images was a fantastic and exhilarating experience," says ornithologist Hadoram Shirihai, who lead the search team. In 2008, Mr Shirihai also rediscovered the Critically Endangered Beck's Petrel (Pseudobulweria becki) a bird that was also only known from two sightings in the Pacific made in the 1920s. "To see such a little-known bird at such close range was magical," added fellow expedition member Mr Tony Pym, describing his joy at seeing the Fiji petrel flying over the waves. More surveys in 2010 are now planned to to locate the breeding area of the Fiji Petrel, says Dick Watling of NatureFiji-MareqetiViti. "Once we know the location, we can assess what needs to be done to turn around the fortunes of this species," he says. by Matt Walker Editor, Earth News BBC

Scientists In Northern Alaska Spot A Shorebird Tagged 8,000 Miles Away

Wildlife Conservation Society (WCS) scientists studying shorebirds in western Arctic Alaska recently made a serendipitous discovery when they spotted a bar-tailed godwit with a small orange flag and aluminum band harmlessly attached to its legs. Further research revealed that scientists in Australia had banded the bird and attached the flag near Victoria – more than 8,000 miles away.

While banded birds are sometimes seen in the area where they were originally released, it is very rare to see them so far from a release site. The observation was made by WCS biologists Dr. Steve Zack and Joe Liebezeit.
“It’s extremely unusual to find a banded bird that has flown literally thousands of miles from where it was released,” said Steve Zack. “While we know that birds from all over the world come to the Arctic to breed, to see a living example first hand is a powerful reminder of the importance of this region.”
Zack and Liebezeit also sighted a banded dunlin and semipalmated sandpiper both of which were originally marked and released by WCS scientists three years ago in nearby Prudhoe Bay, Alaska for a study testing to see if birds that winter in Asia are carrying highly pathogenic H5N1 Avian Influenza to North America. Semipalmated sandpipers migrate from South America, and dunlins migrate from Asia . So far, shorebirds have not been detected to carry H5N1 into North America .
“These sightings represent direct examples of the importance of Arctic Alaska as an international gathering place for migratory birds,” said Jodi Hilty, Director of WCS’s North America Programs.
“Birds from every continent and every ocean come to Arctic Alaska to breed during the short summer,” said Zack “The immense wetlands of western Arctic Alaska, encompassed almost entirely by the National Petroleum Reserve, are particularly important to migratory birds and worth conserving.”
Zack and Liebezeit have been conducting studies of breeding birds in the Arctic since 2002 for WCS.
“We have worked with the U.S. Fish and Wildlife Service, governmental agencies in the Republic of Korea , and with WCS Global Health staff in capturing shorebirds in Arctic Alaska and in the Republic of Korea to test for the presence of avian flu” said Liebezeit. “It was exciting to see birds we captured three years ago again in the Arctic . Knowing that they have made six long flights back and forth during that time really makes you appreciate their incredible life history.”
Migratory shorebirds of many species are in decline. Both climate change and expanding energy development are affecting these birds, as are habitat loss and other changes to their wintering wetland habitats around the world. The Wildlife Conservation Society is working to understand how best to conserve these international migrants in changing times. There is also a need to create more protection of key wildlife areas in advance of oil development in the National Petroleum Reserve and a need for funding to help highlight and understand those areas.
“Shorebirds like bar-tailed godwits from Australia , dunlin from Asia, and semipalmated sandpipers from South America are affected by different threats in their wintering and summering grounds,” says Zack. “The conservation of this highly migratory group of birds is truly a challenging worldwide issue.”
Adapted from materials provided by Wildlife Conservation Society, via Newswise.

Energetic Bottleneck Factors In Catastrophic Winter Seabird Losses

It's a terrible sight: hundreds of dead seabirds washed up on the seashore. These catastrophic events occur in the winter and are known as winter wrecks. No one knows why the birds perish, and it is almost impossible to study the animals out in stormy winter seas to find out how they meet their fate.

With the birds' tough life style in mind, Jérôme Fort and David Grémillet from the CNRS Centre d'Ecologie Fonctionnelle et Evolutive in France decided to try to estimate the energetic demands placed on two alcid species (little auks and Brünnich's guillemots) by their aquatic lifestyle to find out whether battling the harsh conditions may simply be too energetically demanding for the little seafarers. Fort and his colleagues publish their discovery that winter wreck victims may not be able to eat enough to survive the harsh winter conditions in the Journal of Experimental Biology.
As it is impossible to gain access to the offshore birds in winter to directly measure their energy requirements, Fort and Gremillet teamed up with Warren Porter, who models the effects of environmental conditions on terrestrial animals, to estimate the birds' metabolic demands. Adjusting Porter's Niche MapperTM computational model to take account of the ocean environment and the birds' physiology, the team included environmental data for two regions of the Atlantic Ocean (off Newfoundland and Greenland) occupied by little auks and Brünnich's guillemots. They also detailed the plumage, physiology and behaviour of individual birds and calculated the animals' metabolic demands for the months from September to March.
The results were startling. Both species' energy demands were relatively low during the months of September and October, but rocketed by at least 16% in November and remained high for the rest of the winter. The team realised that an energy demand of 430kJ/day for the tiny, 150g little auks and 1306kJ/day for the Brünnich's guillemots must place the animals under enormous strain as they battle the environment. And when the trio converted the birds' caloric requirements into the amount of food that each animal would have to find and consume daily, it came out at a colossal 289g of zooplankton for the little auks (almost twice their own body weight) and 547g of fish and crustaceans for Brünnich's guillemots (just over half of their body weight).
Fort says 'For seabirds, this is an energetic bottleneck'. He explains that as the winter sets in, increased wind speeds, low temperatures and vicious winter storms all conspire to raise the birds' metabolic demands. At the same time food becomes scarce and more difficult to capture. Coupled with the increase in their energy demands, the birds only carry limited reserves, placing them at an increased risk of starvation.
Given that most winter wrecks occur in November and December, Fort and his colleagues suspect that the energetic bottleneck could be a major contributory factor to the mass loss of life. Having modelled the effects of the climate on individual animals, the team is eager to look at the environment's impact on alcid populations and the effects on the food stocks that the birds depend upon. They are also keen to find out whether other ocean going species suffer the same catastrophic increase in energy demand as little auks and Brünnich's guillemots, raising their risk of succumbing to winter wrecks as the days draw in.
Journal reference:
Fort, J., Porter, W. P. and Grémillet, D. Thermodynamic modelling predicts energetic bottleneck for seabirds wintering in the northwest Atlantic. J. Exp. Biol., 212, 2483-2490
Adapted from materials provided by Journal of Experimental Biology, via EurekAlert!, a service of AAAS. Original article written by Kathryn Knight.

Antibiotics-resistant Gulls Worry Scientists

The resistance pattern for antibiotics in gulls is the same as in humans, and a new study by Uppsala University researchers shows that nearly half of Mediterranean gulls in southern France have some form of resistance to antibiotics. The study is being published June 18 in the journal PLoS One.

Bacteria that develop resistance to antibiotics are one of society’s greatest future threats and are having a major impact on our ability to use various medical treatments. The spread of resistance is no longer a local problem in hospitals; antibiotic-resistant bacteria are also spreading to and throughout the environment.
The research team at the Uppsala University Department of Medical Pathology has studied the occurrence of antibiotics-resistant bacteria in Mediterranean gulls in southern France.
“Gulls have developed behaviors that entail closer and closer contact with us, and opportunities arise for the exchange of bacteria. This is why they are extremely interesting to study,” says Mirva Drobni, who directed the study.
The findings of the study show that nearly half of the birds carry some form of resistance to antibiotics, and a tenth of them carry ESBL-producing bacteria. These bacteria have the capacity to break down some of our most powerful and important antibiotics and furthermore have an ability to spread extremely rapidly. The researchers were able to show that the resistance pattern was the same among gulls and humans, which indicates that human- and bird-borne bacteria and their resistance mechanisms are being mutually exchanged.
“These findings are worrisome as they also indicate a higher degree of resistance in bacteria from gulls than we see in humans in the same region. At present we don’t know whether they constitute merely a reservoir for antibiotics resistance or whether they are moreover a source of further dissemination to humans,” says Mirva Drobni.
Journal reference:
Bonnedahl et al. Dissemination of Escherichia coli with CTX-M Type ESBL between Humans and Yellow-Legged Gulls in the South of France. PLoS ONE, 2009; 4 (6): e5958 DOI: 10.1371/journal.pone.0005958
Adapted from materials provided by Uppsala University.

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Feds want to keep protections for rare Pacific seabird

The marbled murrelet in Washington, Oregon and California should remain protected as a threatened species, the U.S. Fish and Wildlife Service said Wednesday.The agency finished its five-year status review of the small seabird that nests in old-growth timber. Federal biologists found that the birds in the three states are a distinct population that continues to decline and faces a broad range of threats."Our review shows this remarkable bird remains in trouble," said Ken Berg, supervisor of the agency's Washington State Fish and Wildlife Office.It's the latest development in a long-running battle over whether the marbled murrelet deserves protection under the Endangered Species Act. The robin-sized seabird was listed as threatened in 1992.The American Forest Resource Council, based in Portland, Ore., and others have tried to force the bird off the list. Habitat protection for the marbled murrelet, much like such protection for the spotted owl, has meant less logging in Oregon, Washington and Northern California.Last year, the council petitioned the agency to remove protection for the tri-state bird population. A decision on that petition is expected in coming months.The timber group has also sued to delist the birds after the agency's previous status review in 2004 found they were not distinct from birds in Canada and Alaska. The agency later concluded that finding was flawed.On Wednesday, lawyers for the wildlife agency filed a motion in federal appeals court in Washington, D.C., where the case is pending, to dismiss the timber group's lawsuit.Tom Partin, president of the American Forest Resource Council, disagreed with the agency's Wednesday finding and said the West Coast birds are not distinct and shouldn't be protected.He noted that the agency's report found ocean conditions such as gillnetting and changes to the bird's marine prey are also to blame for their decline. "We feel we have the habitat on the ground for them to use," he said.But Kristen Boyles, an attorney with Earthjustice, said the review affirms the need to protect old-growth coastal forest that the birds use to nest and raise their young.It's also an indication that the agency under the Obama administration is following science in its review of the birds, she said.The marbled murrelet population from Northern California to Canada dropped 34 percent between 2001 and 2008, the review found. There were about 18,000 birds in 2008.Federal biologists say the birds face threats from loss of nesting habitat as well as new threats from harmful algae blooms and abandoned fishing gear at sea."The population is still seriously declining," said Joan Jewett, a fish and wildlife spokeswoman in Portland. "We're very concerned, and we'll be closely watching and monitoring them."

Puffin Muffin saved from attack

The puffin has been named Muffin by his rescuers.A puffin is being nursed back to health after being rescued during an attack by seagulls in Moray.The injured bird was rescued by Jennie and John Stewart as they walked their dog in Lossiemouth. They took the puffin, which they named Muffin, home and have been giving him cold baths and feeding him. It is thought the puffin may have been in Lossiemouth after being blown off course. He will be released once back to full strength. 'Running about'Mrs Stewart said the puffin looked stressed when they saved him, and they took him back home wrapped in a scarf. Her husband told the BBC Scotland news website that Puffin was being attacked when they discovered him. He said: "We think the puffin was overcome by storms and was being attacked. It was timely that we found him. "He was quite feisty to start with but is now feeding well. "He is now running about and flapping his wing. He will be released when ready, he would perish otherwise." BBC

FWC to beachgoers: Do not disturb nesting birds

The Florida Fish and Wildlife Conservation Commission (FWC) reminds beachgoers statewide to be mindful of nesting birds. The eggs and chicks of nesting birds are delicate and susceptible to harm from disturbances that cause adults to fly off the nests. "Just approaching a bird is enough to flush it away from its nest," said Ricardo Zambrano, an FWC biologist. "When birds fly off their eggs, it exposes the chicks to predators." Injuries to unprotected eggs or chicks can happen quickly, either from predators or even from the intense heat of direct sunlight. Sun worshipers can help protect the birds by moving parties, picnics or fireworks away from nesting areas. This time of year, a variety of protected birds nest on Florida's beaches, including terns, black skimmers, snowy plovers and Wilson's plovers. The FWC and other agencies posted signs earlier this year around many nesting areas on Florida's beaches. These closed areas protect nesting birds from unnecessary disturbances and prevent humans from stepping on their nests. All of these species nest in the open and lay well-camouflaged eggs directly on the sand, making them nearly invisible to predators and to the untrained human eye. "We need the public's help in protecting these spectacular birds while enjoying the beach," Zambrano said. "Beach-nesting birds are part of Florida's unique natural heritage."

In Chile, the birds are dying, and no one knows why

Chilean scientists are investigating three mysterious ecological disasters that have caused the deaths of hundreds of penguins, millions of sardines and about 2,000 baby flamingos in the past few months.The events started to unfold in March, when the remains of about 1,200 penguins were found on a remote beach in southern Chile. Then came the sardines -- tons of them -- dead and washed up on a nearby stretch of coastline. The stench forced nearby schools to close, and the army was called in to shovel piles of rotting fish off the sand.Farther north, thousands of rare Andean flamingos abandoned their nests on a salt lake in the Atacama Desert. The eggs failed to hatch and, over a period of three months, all 2,000 chicks died. The extent of the damage was discovered in April, during an inspection.

Birds die in unsecured fishing net

Shakespear Park rangers had to pick up 166 dead birds in a set-net last weekend.More than 100 dead birds in a washed-up set-net were found by Shakespear Regional Park visitors last weekend. Duty ranger Steve Burgess was notified of the nets strewn across the park's popular sandy beach Te Haruhi Bay."Tangled in the net were 166 seabirds and 11 kahawai," Mr Burgess says."The birds, which were fluttering shearwaters, were either already dead or close to dying when found and we have had to dispose of them."Dealing with such a significant kill of native wildlife is not a fun task for those of us working on the park, and it can be quite distressing for visitors," he says.Principal ranger Mathew Vujcich says his team alerted the Conservation Department and the Fisheries Ministry. He hopes it does not happen again."This net had no identification and was insecurely anchored," he says.The Auckland Regional Council is appealing to set-netters to act responsibly and follow the set-net code of practice.Set-nets are common on the region's east coast, and poor netting practices can catch seabirds or marine mammals.Poor netting can result in fish wastage, unwanted fish species caught, and lost nets that continue to fish and catch wildlife, like the one found at Shakespear.A set-net ban applies at Arkles Bay on the Whangaparaoa Peninsula and may be extended to other areas if set-netters continue to flout rules.Editor Geoff Dobson and eldest son Eli hit a set-net strung across part of Te Haruhi Bay this summer while snorkelling out to a shipwreck off the bay's eastern point.Set-net codeA set-net code of practice includes:• Any net or nets used either individually or jointly must not extend more than a quarter of the way across any bay, channel, river, stream or sound•Nets must not be set in a way that causes fish to be stranded by the falling tide• The use of stakes to secure nets is prohibited•Each end of a net must have a surface buoy permanently and legibly marked with the fisher's initials and surname• Set-nets must not exceed 60 metres in length•Only one set net up to 60 metres and one bait net up to 10 metres, with a mesh size of 50mm or less, can be carried on a boat at any one time• Nets must not be set within 60 metres of another net. By CARALISE MOORE

Hungry eagles target Maine's coastal seabirds

Bald eagles, bouncing back after years of decline, are swaggering forth with an appetite for great cormorant chicks that threatens to wipe out that bird population in the United States.The eagles, perhaps finding less fish to eat, are flying to Maine's remote rocky islands where they've been raiding the only known nesting colonies of great cormorants in the U.S. Snatching waddling chicks from the ground and driving adults from their nests, the eagles are causing the numbers of the glossy black birds to decline from more than 250 pairs to 80 pairs since 1992."They're like thugs. They're like gang members. They go to these offshore islands where all these seabirds are and the birds are easy picking," said Brad Allen, a wildlife biologist with the Maine Department of Inland Fisheries and Wildlife. "These young eagles are harassing the bejesus out of all the birds, and the great cormorants have been taking it on the chin."The recovery of the bald eagle population has been well-documented, growing from 400 pairs to more than 10,000 pairs in the lower 48 states since the 1960s. But the revival has changed the natural order of things in Maine and other states, threatening other bird species.With more eagles around and fewer fish in the waters than in the past, young eagles are turning to other birds to satisfy their hunger. Eagles are opportunistic feeders and will go after the easiest prey they can find, bird experts say.In Alaska, many eagles have shifted their diet from fish to seabirds. In the Midwest, they've been known to eat baby blue herons. And besides Maine's great cormorants, eagles are also feasting on baby double-breasted cormorants, gulls, eider ducks and even loons.Nobody's raising a stink about the eagles' taste for double-breasted cormorants and gulls because those birds are so numerous and considered nuisances by many.But the great cormorants are another matter, because their numbers in Maine are so small, said John Drury, of Vinalhaven, who's been counting seabirds on Maine islands for more than 25 years. Although the birds are widespread from Europe to eastern Canada, they are uncommon in Maine, which represents their southern range in the Northwest Atlantic.Drury last summer counted only 80 great cormorant nests, the smallest number since 1984, the year after they were first spotted on Maine islands. Without protection, he fears the Maine population could be wiped out.Governmental agencies and conservation groups have put countless hours and dollars toward protecting other seabird populations such as terns — but little has been done for great cormorants, he said."We like to have diversity of species," Drury said. "If we're going to spend all that time and energy to protect terns, then cormorants deserve as much attention."At one time there were an estimated 50,000 pairs of bald eagles in the continental U.S. But their numbers declined from hunting and habitat loss. It was the widespread use of the pesticide DDT that almost did them in. DDT accumulated in fish, a major food source for eagles, which resulted in eagles laying eggs with weakened shells. By 1963, there were only 417 pairs of eagles left in the lower 48 states.The bald eagle began a gradual recovery after it was listed on the federal Endangered Species list in 1967. DDT was banned in the U.S. in 1972.There are now more than 10,000 pairs, according to the U.S. Fish and Wildlife Service. Maine's 500 pairs represent the largest population in the Northeast, up from less than 30 pairs in the 1960s. New Hampshire has about a dozen pairs and Vermont has one. Minnesota, Wisconsin and Florida each have more than 1,000 pairs of bald eagles, the agency said.The bald eagle was taken off the federal endangered species list two years ago; Gov. John Baldacci is set to sign a bill this month taking it off Maine's endangered and threatened species list.But all those eagles need to eat.In the Midwest, eagles have targeted young blue herons, said Jody Millar, the national eagle recovery coordinator for Fish and Wildlife, based in Moline, Ill.And in Alaska, researchers have documented a shift in bald eagles' diet from fish to marine birds that's linked to changes in the coastal ecosystem. A growing number of killer whales caused a chain of ecological events that reduced the number of otters and amount of kelp providing habitat for fish, Robert Anthony reported in the journal Ecology. With fewer fish and baby otters to eat, eagles began raiding nests of other birds. In Maine, eagles have been spotted eating loon chicks and have occasionally been known to carry off adult loons, said Sally Stockwell, director of conservation at Maine Audubon. Off the coast, eagles have taken to eating all types of seabirds on rocky remote islands and ledges where, in years past, the seabirds didn't have any predators. If fish — the eagles' natural diet — were more plentiful, perhaps they wouldn't be so inclined to go after other birds, Drury said. "They'll catch whatever is easiest to catch," he said. "There are more birds now and less fish." Drury was on Seal Island last week to chase bald eagles away from cormorant nests. Besides eating the babies, eagles are driving the adults from their nests, leaving the eggs exposed to other predators, he said. The eggs will hatch in late May or early June, and the chicks will learn to fly by mid-August, he said. Greg Butcher, director of bird conservation for the National Audubon Society in Washington, hasn't heard of the eagle resurgence affecting bird populations elsewhere, but said he wouldn't be surprised if it's happening. Whatever the case, it is sure to generate debate among the nation's millions of birders, he said. "We're in an interesting age where most people think birds are either overabundant or too rare," he said. "It's hard to get it just right."

Seabirds are dying in large numbers yet again

Brandt's Cormorants seem to be the most common victims of this unexplained mortality event. Common Loons, crows and gulls are also being found on beaches. 13 Western Grebes were found dead at Ocean Beach in San Francisco. The San Francisco Bay Area usually supports both Double-crested and Brandt's Cormorants in large numbers.Seabirds are once again dying along the coast from San Francisco as far South as Oxnard, according to WildCare.Brandt's Cormorants, grebes and loons are those that seem to be most commonly found. The largest numbers of dead birds reported so far include 67 Brandt's and 13 grebes at Ocean Beach. This event seems to have coincided with the large wind storms that came through around April 15 but no one knows if that's relevant.So far preliminary necropsy findings show emaciation as the only issue that some of the dead birds had in common BUT many of the dead birds have been within normal healthy body weights.However, IBRRC (the International Bird Rescue and Research Center) reports that of the over 30 live birds they have treated all were emaciated and had very heavy parasite loads and low blood levels. The birds ate well, were treated for the parasites and were banded and released when healthy. Lab results on May 4 were negative for Avian Influenza, West Nile Virus, Newcastle Disease and domoic acid poisoning.

Ecosystem Gone Haywire: Cape Gannet Bird Threatened With Extinction

The ecosystem of the Cape Gannet, a protected bird species, has gone haywire. As a result of overfishing, the birds are no longer able to find enough food to rear their young. Pelicans, kelp gulls and seals are becoming increasing threats – the lack of fish means that these predators are attacking Cape Gannet chicks more often.This has been revealed by research conducted by biologist Ralf Mullers. He will be awarded a PhD by the University of Groningen on 4 May 2009.The Cape Gannet (Morus capensis) is a member of the same family as the pelican. The birds can grow to almost a metre and have a wingspan of nearly two metres. There are only six breeding colonies in the world – three in Namibia and three in South Africa. Since the 1960s, the number of breeding pairs in the colonies in Namibia has been decreasing due to overfishing of sardines and anchovies. In the last ten years, the breeding colonies on the west coast of South Africa have also been getting smaller. This is partly because the schools of anchovies and sardines have moved to the south and east coasts of South Africa.Birds with GPSFor his research, Mullers spent four six-month sessions on the uninhabited islands of Ichaboe (Namibia) and Malgas (South Africa). Here he studied chick development, mapped the parents' behaviour and researched the links between these variables. No fewer than 646 adult gannets were fitted with a GPS logger. This meant that the position of the birds could be precisely followed from minute to minute and it became clear whether they were flying, bobbing up and down on the waves or diving. Never before has the feeding behaviour of the Cape Gannet been so minutely detailed. It turns out that a Cape Gannet flies about 450 kilometres a day in search of food.Destructive pelicansThe decline in the colony on Malgas is due to the dangers the chicks are exposed to, Mullers discovered. Among other things, pelicans are a particular threat. These birds originally only ate fish, but due to the lack of fish they've become accustomed to eating other birds. They've also learnt to eat slaughterhouse waste, present in large amounts at neighbouring pig farms. Mullers: `Pelicans are originally protected birds too. Now one protected bird species needs to be protected against another one. On Malgas you can see entire colonies of gannets being destroyed by pelicans – they can even swallow chicks weighing almost two kilos.'Longer flightsOn Ichaboe (Namibia) chicks have a greater chance of survival. Although their parents have to fly further for food than the Malgas parents, they return with better quality food. Whereas the Malgas parents mainly bring fish waste back to their chicks, those on Ichaboe bring back more mackerel and pike to replace the anchovies and sardines. There are also fewer predators like pelicans, kelp gulls and seals on Ichaboe. It's not yet completely clear why the colonies on this island are also declining in size.Selfish parentsMullers' research has revealed that parents do not risk their own lives to save those of their young. If there is less food available, they do not make longer foraging flights to ensure their young have enough to eat. Mullers: `From an evolutionary point of view that's very sensible. A gannet can live to be twenty-five. If its chicks don't survive one year, it has many more chances to produce descendents. It's not going to risk those chances. It would be interesting to investigate whether the birds will adjust their behaviour if there is too little food for several years in a row.'Fishing quotas neededIf extinction of the gannet is to be prevented, its foraging ranges must be protected. In other words, there must be a limit on the number of sardines and anchovies caught in the bird's foraging range. Mullers: `There are naturally major economic interests involved. It would be great if my research could contribute to the debate on this matter.'