Seabirds Can Spy Fishing Boats From 7 Miles Away

A northern gannet points toward the sky before taking flight in Scotland's Shetland Islands. PHOTOGRAPH BY ANDREW PARKINSON, NATIONAL GEOGRAPHIC CREATIVE

A northern gannet points toward the sky before taking flight in Scotland’s Shetland Islands.

A type of seabird can zero in on fishing boats from a distance of about 7 miles (11 kilometers) away, a new study says.

Northern gannets, North Atlantic seabirds with a 70-inch (178-centimeter) wingspan, likely use their binocular vision to determine the boat’s speed and fishing activities—and the presence of other birds—before deciding to fly over to investigate.

Once gannets arrive at the boat, they often catch fish that have been thrown overboard, plunge-diving into the water at speeds of up to 60 miles (96 kilometers) an hour. Continue reading

Climate Change Threatens N.E. Coastal Birds

Rising sea levels brought on by climate change are threatening some of New England’s signature coastal birds, according to a new study.

07042007_04birds.JPGThe National Wildlife Federation recently released “Shifting Skies”, a large study accompanied by a more local report by the Natural Resources Council of Maine, detailing the adverse effects climate change is having on Northeastern birds such as Piping Plovers, Roseate Terns, and Saltmarsh Swallows.

“We are already seeing New England’s birds … at risk from Climate Change,” says Hector Galbraith, staff scientist for the Northeast office of the National Wildlife Federation. Terns especially are “inundated by sea level rise or extreme weather.” One of these species, the federally endangered Roseate Tern, is especially affected.

Just under one-half of the North American Roseate Tern population nests on two small islands in Buzzard’s Bay which are being swallowed by rising seas.

“Because so many of the terns live on Ram and Bird Islands, they’re particularly susceptible to climate change,” says Molly Sperduto of the U.S. Fish and Wildlife Service New England Field Office. As sea level rises “those islands will become over-washed,”
she said.

Sperduto said the frequency of major storm events, such as Hurricane Sandy, increasing with climate change, also harms the birds by destroying habitat.

Many of the islands, beaches, and marshes that terns, plovers, and swallows occupy are mere feet above sea level, and as the polar ice caps melt and warmer waters expand, the rising ocean waters encroach on valuable habitat. This can be seen in places like Scituate and Plum Island, Mass., where beach erosion continues to wipe out plovers’ nesting grounds, as well as on tiny islets which, at high tide, are little more than barren rocks in an unforgiving, ever-rising sea.

On Ram Island, a small rock off of Mattapoisett, almost all of the birds’ nests are fewer than three feet in elevation above the mean high water mark, according to Sperduto.

Both studies list several ways by which climate change can be combatted in the long term, including investment in clean energy, a carbon dioxide cap for industry, restoration of farms and forests for CO2 sequestration, and conservation of habitat.

Meanwhile, more immediate, local action is being taken to protect the Roseate Tern, according to Carolyn Mostello, a Coastal Waterbird Biologist with the Natural Heritage and Endangered Species Program of the Mass. Division of Fisheries and Wildlife.

Armed with $4.2 million, largely from multiple government sources, the State Natural Heritage program “has been working with the Army Corps of Engineers on plans to rebuild the … deteriorating seawall and add fill to [Bird] Island to help increase nesting habitat for the Terns,” Mostello said.

No specific project has yet been decided upon on Ram Island, though Mostello says various options have been explored. There is $534,000 set aside for the island from damages paid in relation to the 2003 Bouchard oil spill in Buzzards Bay. Mostello’s agency had also requested federal funding for Ram Island after Superstorm Sandy, but no monies have yet been awarded.

These immediate fixes, maintain the study’s authors at the NWF and the NRCM, are not enough. Says N.H. Audubon’s Pam Hunt, “We must not only protect … habitat, but also curb climate change in order to ensure that super storms and extreme weather events don’t wipe out [our coastal birds] altogether.”


Fish Nets Found to Kill Large Numbers of Birds

Gill net fishing vessels in Alaska. Eighty-one types of birds have been reported killed by the nets.

Gill net fishing vessels in Alaska. Eighty-one types of birds have been reported killed by the nets.

Fishing vessels that deploy gill nets snare and drown at least 400,000 seabirds every year, and the actual figure could be considerably higher, according to research published in the June edition of an academic journal devoted to conservation.

The study, in the journal Biological Conservation, uncovered reports of 81 species of birds killed by gill nets, including penguins, ducks and some critically endangered ones like the waved albatross. One of its three authors, Cleo Small, called the estimated toll a bare minimum, saying that data on the deaths from many areas were either nonexistent or too old to be useful.

“It’s quite startling,” said Dr. Small, who heads the global seabird program at the British conservation group BirdLife International, which sponsored the study. “In Japan, for example, some populations have already been extirpated on islands. Some colonies have disappeared where there is gill net fishing, and in other areas they have dramatically declined.”

Other academic studies have estimated that a minimum of 160,000 additional birds are killed each year by longline fishing, she said. Longlines, which dangle baited hooks from lines that can stretch for miles, are widely used in commercial fishing.

Gill nets, mesh nets that are much smaller, are used both by commercial and small local fishermen. Anchored in the water by weights and buoys, they are designed to snare fish by their gills, but they can catch any creature that is too large to swim through the mesh. Conservationists say that includes large numbers of sea turtles and mammals like porpoises, seals and even whales.

Nearly half of the seabirds killed by gill nets were in a section of ocean stretching from the northern tip of Africa to north of Greenland and Scandinavia. The bird catch was said to be especially high around Iceland, a prolific seabird habitat, where researchers estimated that 100,000 birds die every year.

But at least 140,000 die annually in the northwest Pacific, an area extending from the Aleutian Islands west and south to Russia and China, the study said.

Losses in United States coastal fisheries appeared to be smaller. In a 2011 survey of 28 coastal fisheries using data from 2005, the National Oceanic and Atmospheric Administration counted fewer than 7,800 birds caught in all types of nets, although some academic studies suggest that gill nets may kill tens of thousands of one species, the marbled murrelet.

Seabird populations are falling faster than other types of birds, and gill nets have long been identified as a main reason, the researchers said. Huge drifting gill nets were estimated to be killing 500,000 birds annually before a United Nations moratorium on large driftnets took effect in 1992.

Most of the gill net toll involves seabirds that dive into the ocean in search of fish. Many birds were once able to see the nets from above and avoid them, but modern nets made of monofilament are all but invisible.

Reducing seabird deaths is hard, as there are few proven ways to deter them. California has sharply cut the toll by banning gill nets in some shallow waters. Other efforts, like setting gill nets at night and placing lights and sonar-style “pingers” on them, have shown some success.

But many of the options are either too expensive or unworkable for local fishermen, who are major users of gill nets, said George Wallace, a vice president at the American Bird Conservancy. And there are so many small fishing enterprises that merely reaching and educating the proprietors is a monumental task, he added.

Most fishermen, nevertheless, want to reduce bycatches if it is economically possible, Mr. Wallace said. “Fishermen want to catch fish,” he said. “That’s what they can sell. They don’t want to tie up their lines with seabirds and sea turtles.”


A First in 73 Years: Endangered Birds Nesting Again at Malibu Lagoon


The revitalization efforts over at Malibu Lagoon seem to be paying off. A colony of endangered birds, the California least tern, have been documented nesting at the beach, a first for the state park in 73 years.

The terns are migratory seabirds that breed primarily along the California coast, but their population has declined as habitat was lost to development and recreational spots, as well as predation by other animals, native and non-native alike. In Los Angeles County, only two other nesting sites exist: Venice Beach and the Port of L.A.

California State Parks staff will be monitoring the nesting site and keeping beachgoers out of the fenced exclosure that has been set up to protect the birds. Particular attention will be paid to keeping all dogs off the beach because the nests are extremely vulnerable to trampling and predation.

The presence of the birds come nearly a month after the public unveiling of the new lagoon, an $8 million effort that has attracted lawsuits and angry protests. The 31-acre bay sits at the end of Malibu Creek at Malibu’s Surfrider Beach, which gets about 1.5 million visitors a year.

Read more about Malibu Lagoon at KCET Departures.

Channel Island birds observed for renewable energy study

Previous research has indicated there are more than 7,000 gannets in and around Alderney

Previous research has indicated there are more than 7,000 gannets in and around Alderney

Habits of Channel Island seabirds will be monitored for three years as part of an investigation into renewable energy.

The Alderney Wildlife Trust is looking into the feeding and foraging patterns of shags and gannets.

Both wind and tidal power generation are being investigated by Channel Island governments.

A study by the University of Liverpool published in 2012 found that Alderney’s gannet population could be adversely affected by renewable energy.

The birds will be tracked using GPS technology. Roland Gauvin from the trust said it was an important project.

He said: “The idea is that over a three year period to study the movements of shags and gannets around the island to see where they feed, forage, how deep they go and what they are catching.

“It would give us an idea of what our seabirds are doing in relation to what might be about to happen and where generators could go.”

The Alderney Wildlife Trust said it picked the shag and gannet to monitor because they are both common in the islands and forage in different ways.

The shag tends to feed close to its nesting site and the gannet can travel well over 200km on a single foraging trip.

Both birds fly between roosting and feeding sites and capture their prey by diving in the water column.

Mr Gauvin said: “This means that they could encounter wind turbines while flying above the water and tidal turbines while foraging below the water.”


Behaviour of seabirds during migration revealed

London: The behaviour of seabirds during migration – including patterns of foraging, rest and flight – has been revealed in new detail using novel computational analyses and tracking technologies.


Using a new method called ‘ethoinformatics’, described as the application of computational methods in the investigation of animal behaviour, scientists have been able to analyse three years of migration data gathered from miniature tracking devices attached to the small seabird the Manx Shearwater (Puffinus puffinus).

The Manx Shearwater is currently on the ‘amber’ list of UK Birds of Conservation Concern. Up to 80% of the world population breeds in the UK, travelling 20,000km each year in their migrations to South America and back.

In a continuing long-term collaboration, researchers at UCL and the University of Oxford collected data over three consecutive years. In this study, published in the Royal Society journal Interface, they show that the migration of the Manx Shearwater contains a complex pattern of three behavioural states; rest, flight and foraging.

Results indicate that in winter, birds spend much less time foraging and in flight than in breeding season. Also, a much larger proportion of birds’ time in the southern hemisphere was spent at rest – probably a reflection of their release from the demands of reproduction and also the increased costs of flight during the winter.

Dr Robin Freeman, from the UCL COMPLEX (Centre for Mathematics and Physics in the Life Sciences and Experimental Biology), and first author of the study, said: “Understanding the behaviour of these birds during migration is crucial for identifying important at-sea locations and for furthering conservation efforts. By tracking the movements, foraging behaviour and environmental drivers of such species, and developing new techniques to do so is critical as they continue to be subject to environmental and anthropogenic pressure.”

He added: “Methods to understand animal behaviour from complex data series – what we’re calling ‘ethoinformatics’ – are increasingly important as we continue to gather large amounts of data about animals in the wild.”

Professor Tim Guilford, who leads the team at the University of Oxford, said: “At the Oxford navigation group, we have been able to gather an unprecedented amount of information about these elusive ocean wanderers. We trying to understand the processes that govern the behaviour seabirds at sea, and the decisions they must make during migration and foraging.”

During the study, birds were fitted with miniature geolocators and lightweight GPS loggers. The geolocation devices have been developed by the British Antarctic Survey and record salt-water immersion and light levels. Using behaviours identified from GPS tracking during the breeding season, the team demonstrated that these behaviours could be predicted solely from data collected by the much smaller immersion-loggers.

Unlike other devices that limit broad use because of their mass, cost and longevity (life span), these devices can record continuously for many years and weigh less than two grams.

During the birds’ migratory journey the team identified areas of high foraging behaviour, with concentrations off south-eastern Brazil during the southbound journey and in the Western Atlantic during the return. Rest also occurs throughout migration, with greater concentration towards the very end of the route in both directions. This could reflect distinct stopover types, like foraging stopovers to take advantage of the high prey availability or rest stopover to recover from long flight periods.

The researchers also discovered that the birds’ behaviour responded to different environmental conditions. There was a significant relationship between behaviour and environmental variables such as net primary production (the rate at which all the plants in an ecosystem produce net useful chemical energy), chlorophyll and sea surface temperature. During migration, resting behaviour was found to occur in much more productive waters than other behaviours.

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