Tag Archives: arctic

In life, ivory gull draws crowd—and in death, will contribute to science

Ivory gull flying ovef water

(Elliot Nelson; 17 March 2017)

On the evening of March 9, 2017, Lauren LaFave, 16, was walking across a bridge over the Flint River on the campus of the University of Michigan-Flint. LaFave noticed an unusually white bird resting on the bridge and was able to snap a few quick pictures on her phone. After those photos were shared among a number of Facebook groups it was confirmed that the bird photographed was, in fact, one of the rarest birds in all of North America, an ivory gull.

To understand the rarity of finding an ivory gull in downtown Flint, one must understand a bit about the species. The ivory gull is a bird rarely found south of the Arctic Circle. In North America, ivory gulls breed in the high arctic regions of Canada on bare rocks exposed only during the summer months. Unlike most arctic birds that head south for the winter, the ivory gull spends its winters remaining in the arctic. It can be found foraging on pack ice in the Bering Sea as well as the ice edge region between 50°–65° north latitude around Labrador and Greenland. The bird research database Birds of North American Online notes that only 2000-3000 of these birds breed in North America. It is listed in the 2014 State of the Birds report as being a species that will most likely become threatened or endangered unless conservation actions are taken. The species decline is due in part to declining sea ice associated with climate change as well as high mercury levels that accumulate in their tissue.

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Antarctic penguin numbers double previous estimates: scientists

(Physorg; 15 March 2017)

Almost six million Adelie penguins are living in East Antarctica, more than double the number previously thought, scientists said Wednesday in findings that have implications for conservation.

Research by an Australian, French and Japanese team used aerial and ground surveys, tagging and resighting data and automated camera images over several breeding seasons, which allowed them to come up with the new figure.

They focused on a 5,000 kilometre (3,100 mile) stretch of coastline, estimating it was home to 5.9 million birds—some 3.6 million more than previously thought. On this basis, they estimate a likely global population of 14 to 16 million.

Before, population estimates only took into account breeding pairs, said Australian Antarctic Division seabird ecologist Louise Emmerson.

“Non-breeding birds are harder to count because they are out foraging at sea, rather than nesting in colonies on land,” she said.

“However, our study in East Antarctica has shown that non-breeding Adelie penguins may be as, or more, abundant than the breeders.

“These birds are an important reservoir of future breeders and estimating their numbers ensures we better understand the entire population’s foraging needs.”

Adelie penguins, slick and efficient swimmers, live on the Antarctic continent and on many small, surrounding coastal islands. They spend the winter offshore in the seas surrounding the pack ice.

Seabird ecologist Colin Southwell said the research had implications for conservation, with more birds potentially interacting with humans in Antarctica and the Southern Ocean than previously thought.

He said the rocky, ice-free areas preferred by penguins for nesting were also favoured by research stations due to ease of resupply.

“There are currently nine permanently occupied research stations in the ice-free areas of East Antarctica and we found over one million birds breed within 10 kilometres of a station,” he said.

“By identifying significant penguin breeding populations near stations we can better identify which areas may need enhanced protection into the future.”

The study also estimated the amount of krill and fish needed to support the Adelie penguin population, prey that is also sought after by seals and whales.

“An estimated 193,500 tonnes of krill and 18,800 tonnes of fish are eaten during the breeding season by Adelie penguins breeding in East Antarctica,” Emmerson said.

This information will now be used by the Commission for the Conservation of Antarctic Marine Living Resources to set sustainable krill fishery catch limits.

How Will an Arctic-Breeding Songbird Respond to Taller Shrubs and Warmer Temperatures?

(Heather McFarland, 1 Feb, 2017)

How will songbirds that nest in tundra respond as the Arctic transforms into a warmer and shrubbier environment? This is the question that drove us to study a small songbird known as the Smith’s Longspur. Endemic to North America, this songbird breeds in only a few remote mountain valleys in Canada and Alaska, making it particularly susceptible to changes at northern latitudes. Smith’s Longspur’s are also unique in that they are polygynandrous. This is a rare mating strategy where both sexes are polygamous, and birds of either sex may mate with up to three individuals each breeding season. Rather than a single male and female establishing a territory, Smith’s Longspurs usually form larger groups called neighborhoods which contain many inter-mated individuals. Since this mating strategy is poorly understood and so different from other tundra nesting songbirds, it is difficult to predict how breeding Smith’s Longspurs may respond to climate change. Therefore, prior to further change, baseline information about breeding requirements is needed. To fill this void, we monitored more than 250 Smith’s Longspur nests between 2007 and 2013 in the Brooks Range of Alaska. All of the nests were found in open tundra areas, and females never placed their nests in tall vegetation.

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High Mercury Levels Pose Another Setback for Arctic Birds

(Katie Valentine, July 22, 2016)
Gone unchecked, the element can lead to sickness, sterility, or even death in breeding shorebirds.

Life in the Arctic has its challenges. The shorebirds that breed there each summer have to complete some of the longest migrations on record. Once they arrive, they’re forced to deal with harsh living and foraging conditions—made worse by the ill effects of a changing climate.

Now scientists are adding another hardship to the list: mercury poisoning. A new study by researchers at McGill University and the U.S. Fish and Wildlife Service shows that Arctic shorebirds are exhibiting high levels of mercury, which could be dangerous for their population numbers. “The concentrations in some were much higher than we would have ever expected for small birds that are foraging on insects,” says Marie Perkins, a PhD candidate at McGill and lead author of the study.

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Arctic-Breeding Shorebird Populations Are Plummeting, with No Single Culprit

(Margaret Munro, 06 January 2017)
There are almost 30 species of shorebirds that breed in the Canadian Arctic, and all are strongly migratory. Surely the longest of their migrations must count among the most impressive feats in the natural world. Red Knots, for instance, are only nine inches long. And yet, every year, they fly some 9,000 miles from their summertime Arctic nesting territories to their South American vacation hideaways—and then another 9,000 miles back again.

Unfortunately, shorebird population are hurting across the globe. In North America alone, shorebird populations have plummeted by 70 percent since 1973, and among those, birds that breed in the Arctic are especially threatened, writes journalist Margaret Munro in a recent Nature feature. But a workable solution is hard to come by because the birds face a multitude of threats as they make their way across the Western Hemisphere.

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