Arctic wildlife uses extreme method to save energy

Date: April 28, 2020

Source: Lund University

The extreme cold, harsh environment and constant hunt for food means that Arctic animals have become specialists in saving energy. Now, researchers at Lund University in Sweden have discovered a previously unknown energy-saving method used by birds during the polar night.

Researchers from Lund University and the University of Tromsø have examined the immune system strength of the Svalbard rock ptarmigan in the Arctic. This bird lives the farthest up in the Arctic of any land bird, and the researchers have investigated how the immune response varies between winter and late spring.

"We have discovered that the birds reduce how much they spend on keeping their own immune defence system up and running during the five months of the year when it is dark around the clock, probably to save energy. Instead, they use those resources on keeping warm and looking for food. When daylight returns, their immune response is strengthened again," says Andreas Nord, researcher at Lund University.

The researchers found that when the birds become ill in mid-winter, their energy consumption drops compared to when they are healthy. However, when the birds become ill in late spring, their energy consumption increases instead.

"A weaker immune system is probably a part of all the adaptations that Arctic animals use to save energy in winter. The risk of being infected by various diseases so far north is less in winter than when it becomes warmer towards summer," says Andreas Nord.

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The Unsettling Reason Why We're Seeing More Snowy Owls

Lorraine Chow Dec. 20, 2018 01:46PM EST

For birders and fans of Hedwig from the Harry Potter series, spotting a snowy owl in the wild is a special treat as these great white raptors spend most of their lives in the Arctic.

But sightings further south have become more common in North America in recent winters. As the Ottawa Citizen reported this week, sightings of the charismatic owl have soared in Eastern Ontario for the last six years.

This "irruption"—an influx of a species to areas they aren't usually found—could be a sign that there's not enough food for the snowies around their usual home.

Because of climate change, the Arctic is warming at twice the rate of the rest of the planet, causing dramatic shifts to ecosystems. This warmth has caused the region to become more green.

As a result, rodents have more vegetation to graze on, thus increasing the prey base for snowy owls. This abundance in prey, a bird expert suggested to Ottawa Citizen, has resulted in successful breeding seasons for the snowy owls. But with more owls hunting in the same area, the less successful hunters end up traveling south in search of food.

Read on

In a warming climate, Arctic geese are rushing north

Date:  July 19, 2018

Source:  Cell Press

Summary:

As Arctic temperatures continue to rise, migratory barnacle geese have responded by speeding up their 3,000-kilometer migration in order to reach their destination more quickly with fewer stops along the way, according to new evidence. Unfortunately, the birds' earlier arrival isn't making as much of a difference as one might expect.

As Arctic temperatures continue to rise, migratory barnacle geese have responded by speeding up their 3,000-kilometer migration in order to reach their destination more quickly with fewer stops along the way, according to new evidence reported in Current Biology on July 19. Unfortunately, the birds' earlier arrival isn't making as much of a difference as one might expect. That's because, when the geese reach their Arctic breeding grounds after an accelerated marathon flight, they must take extra time to refuel their own bodies before laying eggs.

As a result of this recovery period, barnacle goose chicks continue to hatch too late to take advantage of early spring foraging opportunities. The new study shows that fewer of them are surviving long enough to leave their mothers' sides and make the trek on their own. The findings suggest that the birds are in trouble unless they start heading north for the Arctic earlier in the year, as opposed to speeding up their travel along the way, the researchers say.

Read on 

'Worrying alarm call' for world's birds on brink of extinction

By Helen Briggs

BBC News

12 December 2017

Overfishing and changing sea temperatures are pushing seabirds to the brink of extinction, according to new data on the world's birds.

Birds that are now globally threatened include the kittiwake and the Atlantic puffin, which breed on UK sea cliffs.

Meanwhile, on land, the Snowy Owl is struggling to find prey as ice melts in the North American Arctic, say conservation groups.

The iconic bird is listed as vulnerable to extinction for the first time.

"Birds are well-studied and great indicators of the health of the wider environment,'' said Dr Ian Burfield, global science coordinator at BirdLife International, the IUCN Red List authority on birds.

''A species at higher risk of extinction is a worrying alarm call that action needs to be taken now. ''

He added that success in kiwi and pelican conservation had shown that, when well-resourced and supported, conservation efforts do pay off.

Worldwide, over a quarter of more than 200 bird species reassessed by the International Union for the Conservation of Nature have been moved to higher threat categories while a similar number have been downgraded.

Read on 

Can barnacle geese predict the climate?

Unpredictable warming spells 'problems' for Arctic-breeding migratory birds

Date: April 18, 2017

Source: Netherlands Institute of Ecology (NIOO-KNAW)

The breeding grounds of Arctic migratory birds such as the barnacle goose are changing rapidly due to accelerated warming in the polar regions. They won't be able to keep up with this climate change unless they can somehow anticipate it. A research team from the Netherlands Institute of Ecology (NIOO-KNAW) employed computer models to assess the future of the geese and their young. Results are being published online by the scientific journal Global Change Biology.

It's the time of year when barnacle geese and many other migratory birds prepare to depart for their breeding grounds above the Arctic Circle. From their wintering grounds in the Netherlands, the geese fly all the way up to the Barentsz Sea in northern Russia, where they should arrive just as the snow has melted. But in the polar regions, the climate is warming much more rapidly than in more temperate areas like the Netherlands -- a phenomenon known as 'Arctic amplification'.

It's hard enough for humans to get to grips with the accelerated warming, let alone for barnacle geese, as an earlier NIOO-led study showed. After all, how can they tell from their wintering grounds if the snow has begun to melt thousands of kilometres away? So is it possible for the barnacle geese to advance their spring migration nonetheless, to predict climate change?

Read on

90 million year old bird fossils found in the Arctic

By Helen Clark on 2016-12-24 Science


A new prehistoric species of 90 million years old bird had been identified in the Canadian Arctic, media reports said.

John Tarduno, professor and chair of the Department of Earth and Environmental Sciences at the University of Rochester and leader of the expedition with his team had unearthed three bird bones: part of the ulna and portions of the humerus, which, in birds, are located in the wings. Along with these bones they found the bones of some vertebrates on Axel Heiberg Island in Nunavut, Canada, said CBC News.

From the bone features, as well as its thickness and proportions, the team’s paleontologist, Julia Clarke of the University of Texas, was able to determine the evolutionary relationships of the new birds as well as characteristics that indicate whether it likely was able to fly or dive.

“The bird would have been a cross between a large seagull and a diving bird like a cormorant, but likely had teeth,” said Tarduno.

From the bone features, as well as its thickness and proportions, the team’s paleontologist, Julia Clarke of the University of Texas, was able to determine the evolutionary relationships of the new birds as well as characteristics that indicate whether it likely was able to fly or dive.

These physiological characteristics were still assumptions, Tarduno emphasized, but he said the bird’s environment gives clear indications as to why the bird fossils were found in this location.

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Scientists map migration paths of Arctic breeding birds

Results help identify rapidly disappearing staging and wintering grounds

Date: August 22, 2016

Source: Wildlife Conservation Society

Conservation of intertidal habitat -- 65 percent of which has been lost over the last 50 years -- is critical to the survival of countless birds during migration on the East Asian Australasian Flyway.

In an effort to understand the threats and inform conservation of these areas, scientists from The Institute of Biological Problems of the North (Russian Academy of Sciences) and WCS (Wildlife Conservation Society) have collaborated to identify vital stopover areas for the dunlin, a shorebird known to migrate up to 7500 km (4700 miles) to reach its destination.

Arctic shorebirds breeding in Chukotka and Alaska depend upon key coastal intertidal sites along their migratory route to find food to supply energy on their flights. Such intertidal habitats are rapidly being lost to human development, resulting in marked declines of all species that have been studied on this flyway. Some, like the spoon-billed sandpiper, are now at critical risk of extinction, while 23 other species are now threatened, endangered, or vulnerable to extinction. Many others are in rapid decline, losing up to 10 percent of their numbers each year. A key driver of these losses is thought to be associated with development projects along the Yellow Sea coastline that convert intertidal mudflats to dry ground.

To better understand the nuanced threats to shorebird species that breed in Chukotka and nearby Alaska, Russian and American scientists have collaborated on a number of studies, including an assessment of nesting densities and factors influencing nest survival on breeding grounds in Russia. Most recently they have charted the migratory movements, timing, and wintering ground locations of a sub-species of dunlin, a relatively common shorebird that breeds in Chukotka.

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Birds on top of the world, with nowhere to go

Date: July 20, 2016

Source: University of Queensland

Climate change could make much of the Arctic unsuitable for millions of migratory birds that travel north to breed each year, according to a new international study published today in Global Change Biology.

The University of Queensland School of Biological Sciences' researcher Hannah Wauchope said that suitable breeding conditions for Arctic shorebirds could collapse by 2070.

"This means that countries throughout the world will have fewer migratory birds reaching their shores," Ms Wauchope said.

Arctic breeding shorebirds undertake some of the longest known migratory journeys in the animal kingdom, with many travelling more than 20,000 kilometres per year to escape the northern winter.

The bar-tailed godwit flies from Alaska to New Zealand in a single flight of 12,000 kilometres without landing.

The study predicts that, in a warming world, migratory birds will become increasingly restricted to small islands in the Arctic Ocean as they retreat north.

This could cause declines in hard-hit regions and some birds could even completely change migratory pathways to migrate closer to suitable habitat.

"Climate change is also opening up the Arctic to threats such as mining and tourism, and we must make sure we protect key places for all Arctic species, including these amazing migratory birds," Ms Wauchope said.

UQ's Associate Professor Richard Fuller from the ARC Centre of Excellence for Environmental Decisions (CEED) said most migratory populations followed well-defined migratory routes.

"This makes shorebirds an excellent group to investigate how climate change might impact breeding grounds and conservation actions that could address these impacts," Associate Professor Fuller said.

The research modelled the suitable climate breeding conditions of 24 Arctic shorebirds and projected them to 2070.

The researchers also examined the impact on Arctic birds of the world's last major warming event about 6000 to 8000 years ago.

"Climatically suitable breeding conditions could shift and contract over the next 70 years, with up to 83 per cent of Arctic bird species losing most of their currently suitable area," Ms Wauchope said.

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Shifting bird distribution indicates a changing Arctic

Posted on June 28, 2016 by Vetscite

Shifts in the distribution of Spectacled Eiders, a predatory bird at the top of the Bering Sea’s benthic food web, indicate possible changes in the Arctic’s marine ecosystem, according to new research in The Condor: Ornithological Applications.

Matt Sexson of the USGS Alaska Science Center and his colleagues compared recent satellite telemetry data from molting eiders with data from the mid-1990s. They found that in two of the species’ four primary molting areas, the birds have shifted their range significantly in the intervening decades, and the researchers interpret this as an indicator of ecosystem change–eiders go where their prey is, and their movements could indicate big changes in the community of bottom-dwelling, cold-water-dependent invertebrates they eat.

It’s easier to track marine predators than it is to track their prey, explains Sexson. “It’s tough to speculate on the connection with climate change because the data are so sparse, but we know that the north Pacific is changing,” he says. “There’s a lot of corresponding evidence that together all says something big is happening here, and eiders provide a readily available indicator that changes are occurring.”

Read more …

Shifting bird distribution indicates a changing Arctic

CENTRAL ORNITHOLOGY PUBLICATION OFFICE

Shifts in the distribution of Spectacled Eiders, a predatory bird at the top of the Bering Sea's benthic food web, indicate possible changes in the Arctic's marine ecosystem, according to new research in The Condor: Ornithological Applications.

Matt Sexson of the USGS Alaska Science Center and his colleagues compared recent satellite telemetry data from molting eiders with data from the mid-1990s. They found that in two of the species' four primary molting areas, the birds have shifted their range significantly in the intervening decades, and the researchers interpret this as an indicator of ecosystem change--eiders go where their prey is, and their movements could indicate big changes in the community of bottom-dwelling, cold-water-dependent invertebrates they eat.

It's easier to track marine predators than it is to track their prey, explains Sexson. "It's tough to speculate on the connection with climate change because the data are so sparse, but we know that the north Pacific is changing," he says. "There's a lot of corresponding evidence that together all says something big is happening here, and eiders provide a readily available indicator that changes are occurring."

Sexson and his colleagues spent months at a time in the remote Arctic to catch eiders on land during their breeding season, luring them into nets before making a two-hour trek back to base camp with each bird to surgically implant a satellite transmitter. "It's a lot of hard work, but it's a lot of fun," Sexson says. "I used to just flip past the eiders in bird field guides, thinking I'd never see any of these. Now five years later I'm catching them and holding them. I've really developed a love for this group of birds--how unique they are, how beautiful they are. I've just become attached."

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Uncovering the secrets of Arctic seabird colonies

Nearly two million seabirds nest along the Norwegian coast north of the Arctic Circle. How do they decide where to nest?

Date: May 13, 2016

Source: Norwegian University of Science and Technology

Seabirds nest by the hundreds of thousands in colonies along the Norwegian coast. By combining an ocean current model with fish larvae transport modeling and bird population numbers, researchers have uncovered the factors that help determine the location of seabird nesting colonies.

Ninety per cent of Norway's two million pairs of cliff-nesting seabirds are located in nesting colonies above the Arctic Circle.

But why are these colonies located exactly where they are? Much of the 1200-km stretch of coastline from the Arctic Circle to Norway's easternmost point, on the Russian border, has features that ought to be attractive to birds that nest in colonies, mainly steep, protected cliffs that are essentially inaccessible to terrestrial predators.

Using computer models to describe ocean currents and the transport of floating fish larvae, researchers were able to show that bird colonies are located in areas where currents and the shape of the coastline cause fish larvae to concentrate.

More simply stated, "the birds are where the food is," said Hanno Sandvik, a biologist from the Centre for Biodiversity Dynamics at the Norwegian University of Science and Technology (NTNU) and first author of a paper published inNature Communications on Friday.

This may seem like a self-evident fact, but the research team is the first ever to be able to essentially predict where seabird colonies should be, based on fish larvae "hot spots" that show up in computer models of how fish larvae are transported along the coast.

"We are starting from where the prey is," Sandvik said. "We know where the prey is (because of the computer models). Then, based on what we know about where their prey is, where should the colonies be?"

Spotting a pattern in hot spots

The idea for the study came about several years ago, when researchers met to discuss a different project for which oceanographers from the Norwegian Institute of Marine Research (IMR) had created a coastal current and fish larvae transport model.

Read more …

Shrinking bird pays the bill for Arctic warming

By Helen Briggs

BBC News

A migratory bird has shrunk in stature as temperatures warm at its Arctic breeding ground, according to research.

As a consequence of climate change, the red knot may have a lower survival chance on a different continent, say scientists.

The shore bird breeds in the Arctic in the summer and flies to tropical habitats in winter.

Scientists believe shrinkage in body size is a response to climate change in different animals.

The latest research, published in the journal, Science, looked at the red knot (Calidris canutus).

The wading bird is one of the record-breakers for long distance flight, being able to cover about 5,000 km without stopping.

An international team studied the bird over 30 years at its stop-off point in Russia.

"We see a change in body size and also a change in body shape," said lead researcher Dr Jan van Gils of the Royal Netherlands Institute for Sea Research and Utrecht University.

He told the BBC's Science in Action programme: "What is peculiar about this is that we have strong evidence that this is an effect of climate change and people have seen in other species changes in body size in response to climate change."

The study was the first to show that shrinking in response to climate change was a disadvantage to an animal, because the smaller birds had a lower survival rate, he added.

Paying the bill

The scientists found that over the course of 30 years, the date of the snow melt in the Arctic had advanced by more than two weeks.

Meanwhile, the birds produced smaller and smaller offspring - probably because the chicks missed the main food supply at the time of the thaw.

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Arctic-nesting birds may struggle with climate change

CENTRAL ORNITHOLOGY PUBLICATION OFFICE

Songbird nestlings in the Arctic struggle in cold, wet years, but the changes forecast by climate models may lead to even more challenging conditions, according to new research in The Auk: Ornithological Advances.

Jonathan Pérez of the University of California, Davis, and his colleagues compared the growth rates of the nestlings of White-crowned Sparrows, which have a broad breeding range, with those of Lapland Longspurs, which are an Arctic breeding specialist. They predicted that nestlings would grow faster in warmer, drier conditions, that clutches laid earlier would do better, and that the nestlings of specialist longspurs would grow faster than the generalist sparrows.

They found that growth rates were higher overall in 2013 than in 2014, when the weather was colder and wetter. There were also fewer arthropods, the birds' food source, available in 2014. Longspur nestlings grew faster than sparrow nestlings both years, but sparrows were unaffected by temperature, perhaps because sparrows nest in shrubs rather than on the open tundra. Nestlings from clutches that were laid earlier did grow faster than those from later clutches, since birds that arrived on their breeding grounds early could claim the best territories for raising young.

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Giant flightless bird wandered the Arctic 50 million years ago

A single toe bone found on Ellesmere Island in the 1970s is described for the first time

Date: February 12, 2016

Source: University of Colorado at Boulder

It's official: There really was a giant, flightless bird with a head the size of a horse's wandering about in the winter twilight of the high Arctic some 53 million years ago.

The confirmation comes from a new study by researchers from the Chinese Academy of Sciences in Beijing and the University of Colorado Boulder that describes the first and only fossil evidence from the Arctic of a massive bird known as Gastornis. The evidence is a single fossil toe bone of the 6-foot tall, several-hundred-pound bird from Ellesmere Island above the Arctic Circle. The bone is nearly a dead ringer to fossil toe bones from the huge bird discovered in Wyoming and which date to roughly the same time.

The Gastornis (formerly Diatryma) fossil from Ellesmere Island has been discussed by paleontologists since it was collected in the 1970s and appears on a few lists of the prehistoric fauna there, said Professor Thomas Stidham of the Chinese Academy of Sciences in Beijing. But this is the first time the bone has been closely examined and described, he said. Gastornis fossils also have been found in Europe and Asia.

"We knew there were a few bird fossils from up there, but we also knew they were extremely rare," said Eberle, an associate professor in geological sciences who conducts research on fossil mammals, reptiles and fishes. In addition to the Gastornisbone from Ellesmere, another scientist reported seeing a fossil footprint there, probably from a large flightless bird, although its specific location remains unknown, Eberle said.

A paper by Stidham and Eberle appears in the most recent issue of Scientific Reports, an open access, weekly journal from the publishers of Nature.

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Loon chicks grow fast, fledge early to give parents a break

Date:

June 8, 2015

Source:

Central Ornithology Publication Office

Summary:

Raising healthy chicks is always a challenge, but in a cold, fish-free Arctic lake, it's an enormous undertaking. Red-throated Loon parents must constantly fly back and forth between their nesting lakes and the nearby ocean, bringing back fish to feed their growing young, and a new study suggests that the chicks grow fast and fledge while they're still small so that they can reach the food-rich ocean themselves and give their parents a break.

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97% of Northwest Alaska bird, mammal species could experience habitat change from warming climate

Date:

April 3, 2015

Source:

USDA Forest Service - Pacific Northwest Research Station

Summary:

Of the 201 bird and mammal species that call northwest Alaska's arctic and subarctic region their home, 195 of them -- or, roughly, 97 percent -- could experience some form of habitat loss or gain stemming from climate change, a new study has found.

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Mercury pollution poses threat to Arctic birds

By Tim Sandle 16 hours ago in Environment

Research indicates that mercury pollution has risen around 50-fold in the feathers of a rare Arctic bird over the past 130 years. Conservationists are concerned for the bird’s future.

The bird at risk is the ivory gull. The ivory gull (Pagophila eburnea) is a small gull (17 inches tall) which breeds in the high Arctic. In non-breeding seasons the bird can be found in Greenland, Canada, and Eurasia. Unusually for a gull, the bird has a totally white plumage.

There are around 20,000 birds in existence. The species is said, by the International Union for Conservation of Nature, to be in rapid decline and the status is “threatened.”

As well as habitat loss and risk from predators, the ivory gull has a new threat: mercury poisoning. New research, based on a review of museum specimens, indicates high mercury levels in the gulls. The analysis spanned the time period from 1877 to 2007. Here the increase in mercury levels was over fifty times, with the greatest rises occurring over the past thirty years.

The finding with the gulls is consistent with rising mercury levels in other Arctic birds, fish and mammals. The source of the mercury probably relates to atmospheric pollution. The gull is a good indicator of mercury levels due to the absorption of the toxin into its feathers. The direct concern with the gulls is that, in time, this will affect the bird’s reproduction.

Read more:

Arctic warming upsetting birds' breeding calendar, study warns

2,500 nests in Alaska show that nesting is taking place up to seven days earlier, reports 

Tim Radford for Climate News Network, part of the Guardian Environment Network

theguardian.com, Tuesday 8 July 2014 15.13 BST

Arctic migrants are nesting up to seven days earlier as the world warms. The sandpiper makes a beeline for the Alaskan shores, to join the phalarope on the beach and the songbirds in the woods − and all because the winter snows are melting earlier.

Conservation scientists Joe Liebezeit and Steve Zack – both then of the Wildlife Conservation Society (WCS) – and colleagues report in the journal Polar Biology that they looked into nearly 2,500 nests of four shorebird species in Alaska – two sandpipers, two phalaropes − and a songbird called the Lapland songspur over a nine-year period.

They recorded when the first eggs were laid. And they also assessed snow melt in nesting plots at different times in the early spring, and took note of predator abundance and the seasonal flush of vegetation − both of which can affect nest timing − to see what mattered most in terms of breeding.

“It seems clear that the timing of the snow melt in Arctic Alaska is the most important mechanism driving the earlier and earlier breeding dates we observed in the Arctic,” said Liebezeit, now of the Audubon Society of Portland, Oregon.

“The rates of advancement in earlier breeding are higher in Arctic birds than in other temperate bird species, and this accords with the fact that the Arctic climate is changing at twice the rate.”

During the nine years in which the scientists conducted their study, they found that nesting advanced by between four and seven days.

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