Emperor Penguins are now endangered, warn biologists

A new study has estimated that by 2100, at least two-thirds of Emperor penguin colonies will have dramatically declined by more than half if temperatures rise at the rate predicted by the Intergovernmental Panel on Climate Change (IPCC)

Emperor Penguins on frozen sea ice in Antarctica. Photo: Paul Souders / Barcroft Media

 

By Sarah Knapton, Science Correspondent

 29 Jun 2014

Emperor penguins should be classed as an endangered species because the majority of colonies will have lost half their populations by the end of the century, biologists have warned.

The flightless birds which inhabit Antarctica are threatened by changes to sea ice which are being driving by climate change.

Emperor penguins are heavily dependent on sea ice as it provides krill, one of their primary food sources.

A new study has estimated that by 2100, at least two-thirds of emperor penguin colonies will have dramatically declined by more than half if temperatures rise at the rate predicted by the Interngovernmental Panel on Climate Change (IPCC)

The study was conducted by lead author Stephanie Jenouvrier, a biologist with the Woods Hole Oceanographic Institution (WHOI).

Researchers have been returning to Terre Adélie, which lies across the Southern Ocean from New Zeland, every year to chart populations, monitoring their their mating, foraging, chick-rearing patterns, and following marked individuals. "If sea ice declines at the rates projected by the IPCC climate models, and continues to influence emperor penguins as it did in the second half of the 20th century in Terre Adélie, at least two-thirds of the colonies are projected to have declined by greater than 50 percent from their current size by 2100," said Jenouvrier. "None of the colonies, even the southern-most locations in the Ross Sea, will provide a viable refuge by the end of 21st century.
"We propose that the emperor penguin is fully deserving of endangered status due to climate change, and can act as an iconic example of a new global conservation paradigm for species threatened by future climate change.” 

 

^{Stephanie Jenouvrier with an emperor penguin chick}

 
The emperor penguin is currently under consideration for inclusion under the US Endangered Species Act. In 2012 the status of the birds was changed from ‘least concern’ to ‘near threatened’ by the International Union for Conservation of Nature. (IUCN), but they are not on the ‘red list.’

Emperor penguins are heavily dependent on sea ice for their livelihoods, and, therefore, are sensitive to changes in sea ice concentration "The role of sea ice is complicated Too much ice requires longer trips for penguin parents to travel to the ocean to hunt and bring back food for their chicks,” said Jenouvrier. “But too little ice reduces the habitat for krill, a critical food source for emperor penguins. Our models take into account both the effects of too much and too little sea ice in the colony area."

Listing the species as endangered would kick-start conservation efforts and prevent the animals being further disturbed through bad fishing practices or habitat loss. "When a species is at risk due to one factor – in this case, climate change – it can be helped, sometimes greatly, by amelioration of other factors,” said Hal Caswell, a scientist emeritus at WHOI and professor at the University of Amsterdam. “That's why the Endangered Species Act is written to protect an endangered species in a number of ways – exploitation, habitat, disturbance, etc. – even if those factors are not the cause of its current predicament."

The research was published in the journal Nature Climate Change.

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Journal article

Is Global Warming Creating Penguin Winners And Losers?

Researchers look to ancient melts to predict which species might survive in the present

By

Emily Gertz

Posted 06.26.2014 

Adélie penguins

The species is found only in Antarctica.

PLOS Biology via Wikimedia Commons 

Planetary temperatures warmed up naturally thousands of years ago, at the end of the last Ice Age. Some Antarctic penguin populations flourished under the changes. 11,000 years later, however, some Adélie and chinstrap colonies are turning from winners into losers: As temperatures around the western Antarctic Peninsula increase at some of the fastest rates on Earth, their population numbers are falling quickly, while gentoo penguins appear to holding their own.

What's the difference between then and now?

Looking the past to learn more about how different species might fare under today's anthropogenic climate change, researcher Gemma Clucas of the University of Southhampton, U.K., and her team collected samples of feathers and blood from 537 individual Adélie, chinstrap, and gentoo penguins, which live and breed near each other on the Antarctic Peninsula, and sequenced DNA from the samples.

By calculating the rate of genetic diversification revealed in the DNA, Clucas and her team were able to project how the different species' populations changed over time, and draw some tentative conclusions about why. Their findings are published in the June 12, 2014 edition of the open-access journal Scientific Reports.

Their findings suggest that while a certain absence of ice is important to improving the welfare of penguins, too little can tip things against them.

During the last Ice Age, the amount of ice covering land and water around the Antarctic Peninsula limited the growth of these penguin populations, because all three species need access to the sea to feed, and ice-free land for breeding. When snow and ice cover on both water and land decreased, the penguins were able to get at increased amounts of krill, minute shrimp which feed on algae growing beneath the ice. There was also more ice-free land available for nesting and raising chicks. Gentoo, chinstrap, and Adélie penguins all appear to have flourished for thousands of years under these conditions.

But with sea-ice further melting over the last half-century, krill habitat has also decreased. Most colonies of chinstraps and Adélie, which have krill-heavy diets, are losing numbers fast, while gentoo penguins, which eat a wider array of fish and squid in addition to krill, seem to be showing greater resilience to the shifting environment. Clucas and her colleagues think the more varied diet is a key:

This ‘reversal of fortunes’ for two former climate change ‘winners’ has resulted from anthropogenic impacts outside the range of natural variation that has occurred in the past. Rapid warming trends in the Antarctic Peninsula over the past 50 years has led to decreased sea ice, loss of winter habitat, and a reduction in krill stocks that is negatively affecting Adélie and chinstrap penguins, but not gentoo penguins5, 18, which apparently are not as reliant on krill17. While we know of no other examples of ‘reversal in fortunes’ as documented here, we expect many more will be identified as global warming proceeds and biodiversity declines.

The researchers don't want the findings to be taken as a sign that global warming is nothing to worry about, however. Says one report co-author in a statement, "We are not saying that today's warming climate is good for penguins. In fact, the current decline of some penguin species suggests that the warming climate has gone too far for most penguins."

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Penguin Research Update from South Georgia Newsletter

Baby King Penguins, Where Do They Go?

Little was known about where king penguin chicks go when they fledge and first head to sea, or why some survive their first year when many don’t, so researchers have been trying to answer these questions with fieldwork based in South Georgia and the Falkland Islands.

To discover where newly fledged king penguin chicks go researchers put small satellite tags on chicks in two colonies in December 2007. The study sites in South Georgia and the Falklands contrasted, being located on different sides of the Antarctic Polar Front (APF) and having a different climate. The APF is a key oceanographic feature generally thought to be important for king penguin foraging success.

Of the fledglings tracked, eight penguins were tracked for periods greater than120 days; seven of these (four from South Georgia and three from the Falkland Islands) migrated into the Pacific. Results showed that birds from both sites foraged predominantly in the vicinity of the APF. Only one bird, from the Falkland Islands, moved into the Indian Ocean, visiting the northern limit of the winter pack-ice; three others from the Falkland Islands migrated to the eastern coast of Tierra del Fuego before travelling south. The birds usually swam no more than 10km in a day, though they could travel more than 100km in 24 hrs. The tracks of the tagged birds from the two colonies can be seen in the figure below.

Though migratory behaviour from both sites was broadly similar, the young birds from the Falkland Islands spent more time in comparatively shallow waters whilst the new fledeged birds from South Georgia spent more time in deeper waters. The satellite tracks also showed that, to start with, the young birds stayed clear of areas being used by adult birds. King penguins usually spend four or five years “exploring the Southern Ocean” before they settle down and start breeding, the researchers noted.

A paper on the study entitled ‘Post-fledging dispersal of king penguins (Aptenodytes patagonicus) from two breeding sites in the South Atlantic’ was published in PLOS ONE on May 14th by authors Kelmens Putz, Phil Trathan, Martin Collins, Sally Poncet and Benn Luthi.

The satellite tracks obtained from the South Georgia juvenile king penguins. The breeding site is marked by a yellow asterisk over South Georgia. Track colours represent a monthly time scale, with positions in pink (December 2007), blue (January 2008), yellow-green (February), orange (March), golden (April), red (May), olive (June), violet (July) and green (August 2008). The black line indicates the approximate position of the Antarctic Polar Front.

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Ten Year Study Of Bird Island Macaroni Penguins

Scientists at Bird Island have been studying macaroni penguins for over ten years. The BAS-led team of scientists studied the birds during a period that their numbers were declining. The macaroni penguin population on South Georgia has declined by almost 70% since the early 1980s.

The electronically tagged macaroni penguins are recorded by a sensor as they pass through this gate at the entrance to their colony on Bird Island. Photo BAS.

Since 2003 birds that had been fitted with small electronic tags have passed an electronic scanner at the entrance to the colony, which records the birds as they come and go. The resultant data was analysed to determine survival rates. The results have now been presented in a paper.

The penguins’ survival rates are influenced by both environmental and predation pressures. The scientists found penguins were particularly vulnerable to predation by other seabirds such as giant petrels. The macaroni chicks were found to be particularly vulnerable, with only a third surviving their first fledgling year.

Catharine Horswill, from BAS, said: “Penguins are facing rapid changes in their environment, but at South Georgia we found compelling evidence that predators are the most important factor influencing the survival of chicks as they leave the colony for the first time. This is a big leap forward as we had no idea that predation could be such a strong driving force. Knowing what drives survival rates of penguins puts us in a much better place to predict how these populations may change in the future.”

The research paper, ‘Survival in macaroni penguins and the relative importance of different drivers; individual traits, predation pressure and environmental variability.’ is published by the Journal of Animal Ecology.
Info BAS

This very short video shows the macaroni penguins crossing the recording bridge.

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A call to better protect Antarctica: Human activity threatening continent

Date:

June 18, 2014

Source:

Monash University

Summary:

With visitor numbers surging, Antarctica's ice-free land needs better protection from human activities, leading environmental scientists say. The new study found that all 55 areas designated for protection lie close to sites of human activity. Antarctica has over 40,000 visitors a year, and more and more research facilities are being built in the continent's tiny ice-free area. Most of the Antarctic wildlife and plants live in the ice-free areas -- and this is also where people most visit.

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Antarctic view from land.

Credit: Photo credit: Aleks Terauds

With visitor numbers surging, Antarctica's ice-free land needs better protection from human activities, leading environmental scientists say.

The new study, published in the journal PLoS Biology, found that all 55 areas designated for protection lie close to sites of human activity. Seven are at high risk for biological invasions, and five of the distinct ice-free eco regions have no protected areas.
Antarctica has over 40,000 visitors a year, and more and more research facilities are being built in the continent's tiny ice-free area. Most of the Antarctic wildlife and plants live in the ice-free areas -- and this is also where people most visit.

One of the researchers from the collaborative study, Professor Steven Chown from the School of Biological Sciences at Monash University, said the ice-free area contains very simple ecosystems due to Antarctica's low species diversity. This makes its native wildlife and plants extremely vulnerable to invasion by exotic species. "Antarctica has been invaded by plants and animals, mostly grasses and insects, from other continents. The very real current and future threats from invasions are typically located close to protected areas," Professor Chown said. "Such threats to protected areas from invasive species have been demonstrated elsewhere in the world, and we find that Antarctica is, unfortunately, no exception."
 
Dr Justine Shaw of the National Environmental Research Program's Environmental Decisions Hub at the University of Queensland said the 'last wilderness on Earth' is one of the planet's least-protected regions "Most of Antarctica is covered in ice, with less than one per cent permanently ice-free. Only 1.5 per cent of this ice-free area belongs to Antarctic Specially Protected Areas under the Antarctic Treaty System, yet ice free land is where the majority of biodiversity occurs," Dr Shaw said.

The study shows that protected areas in Antarctica currently fall well short of the Aichi Biodiversity Targets -- an international biodiversity strategy that aims to reduce threats to biodiversity, and protect ecosystems, species and genetic diversity.The team compared Antarctica's protected area system with the protected areas of nations round the world, and found that Antarctica ranks in the lowest 25 per cent of assessed countries.
 
Dr Shaw said many people think that Antarctica is well protected from threats to its biodiversity because it's isolated and no one lives there, however the study clearly shows threats to Antarctic biodiversity. "We need to establish protected areas that are representative of Antarctic biodiversity to protect a diverse suite of native insects, plants and seabirds, many of which occur nowhere else in the world," Dr Shaw said. "We also need to ensure that Antarctic protected areas are not going to be impacted by increasing human activities, such as pollution, trampling or invasive species," she added.
 
Professor Hugh Possingham of the National Environmental Research Program's Environmental Decisions Hub at the University of Queensland said Antarctica is one of the last places on Earth that has no cities, agriculture or mining. "It is unique in this respect -- a true wilderness. If we don't establish adequate and representative protected areas in Antarctica this unique and fragile ecosystem could be lost," Professor Possingham said. "Although we show that the risks to biodiversity from increasing human activity are high, they are even worse when considered together with climate change. This combined effect provides even more incentive for a better system of area protection in Antarctica," he said.
 

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Story Source:
The above story is based on materials provided by Monash University. Note: Materials may be edited for content and length.

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Journal Reference:

1. Justine D. Shaw, Aleks Terauds, Martin J. Riddle, Hugh P. Possingham, Steven L. Chown. Antarctica’s Protected Areas Are Inadequate, Unrepresentative, and at Risk. PLoS Biology, 2014; 12 (6): e1001888 DOI: 10.1371/journal.pbio.1001888

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Monash University. "A call to better protect Antarctica: Human activity threatening continent." ScienceDaily. ScienceDaily, 18 June 2014. <www.sciencedaily.com/releases/2014/06/140618100620.htm>.

Are some penguins benefiting from climate change? J

 June 13, 2014

Climate change is usually thought of as a great menace to the world’s ecology, but the truth is that climate change isn’t a death sentence for everyone. The rest of the animal kingdom will produce a set of “winners” – those for whom climate change has a positive or negligible impact – and a set of “losers,” for whom climate change means certain doom.

Is there any way to know which species will be winners and which will be losers? Short of a magic crystal ball, the answer is basically no. But we can, at least, make some good guesses. One way in which we might generate predictions is to understand how past climate change has impacted animal populations. While the rate of warming, thanks to human culture, is fairly unprecedented the overall level of warming is not. The last 50 million years has seen periodic oscillations between epochs of relative cold and relative warmth.

By combining geological information with molecular genetics, researcher Gemma V. Clucas of the University of Southampton, and colleagues, set out to see whether historical population shifts in Antarctic penguins could reveal any clues for how they might respond to the current anthropogenic warming. They collected feathers and blood samples from 537 penguins and extracted their DNA. Using their genetic information, the researchers could better understand how the penguin populations changed over time to result in the genetic diversity that we see today.

The researchers focused on the three Pygoscelis species: Adélie, Chinstrap, and Gentoo penguins. They all live in the same parts of Antarctica’s “Scotia Arc,” and have overlapping breeding colonies. As a group, the Pygoscelis penguins live at an important position in the food chain. They’re “meso-predators,” who do quite a bit of predation themselves, but can also get gobbled up by other predators. Thus, the health of their populations reveals important information about the effects of environmental change.

Adélie, Chinstrap, and Gentoo penguins all require ice-free land on which to lay their eggs, and liquid seawater in order to forage for food. As ice retreated at the end of the last Ice Age, oceans opened, non-frozen land became available, and all three penguin species benefited. They expanded their populations, eventually splitting to colonize new breeding sites.

At first glance, the good fortunes of ancestral Pygoscelis might seem like good news for modern penguins. But today’s warming is already showing that all is not well. Adélies and Chinstraps rely on Antarctic krill for a majority of their diets, while the Gentoos also feed on fish and squid. And krill require the underside of sea ice, which serves as a sort of nursery for their young. Decreases in sea ice over the last half century have therefore led to reductions in krill. And that’s a problem, especially for the Adélies and Chinstraps. Gentoos, on the other hand, already seem to be benefitting from climate change, exploring new territories and establishing new breeding colonies.

“What we are seeing is a ‘reversal of fortunes’ where increased warming is no longer good for two out of the three species of Antarctic Peninsula penguins. This research shows quite clearly how a single environmental change, in this case warming, can have different consequences over time,” said study co-author Michael Polito, a Woods Hole Oceanographic Institute post-doctoral researcher, in a statement.

After the last Ice Age, all three species benefited from the increase in available breeding habitats, but this time around, it is only the Gentoos who seem to be in the “winners” circle. Clucas and colleagues suspect that’s because of their more balanced diet. “It seems that climate warming is…only benefitting the more opportunistic and generalist Gentoo penguin, whose diverse and flexible foraging niche likely make this species relatively less sensitive to declines in krill,” they write.
That doesn’t mean that climate change isn’t a problem, of course, just that some species stand to benefit. Only by placing current trends into their historical contexts, though, can scientists begin to make educated guesses as to what the future holds for other animals. 

– Jason G. Goldman | 13 June 2014

Source: Clucas G.V., Dunn M.J., Dyke G., Emslie S.D., Naveen R., Polito M.J., Pybus O.G., Rogers A.D. & Hart T. (2014). A reversal of fortunes: climate change ‘winners’ and ‘losers’ in Antarctic Peninsula penguins., Scientific reports, PMID: 24865774

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Antarctic species dwindle as icebergs batter shores year-round

Date:

June 16, 2014

Source:

Cell Press

Summary:

As the planet has warmed, massive losses of sea ice in winter have left icebergs along the Antarctic free to roam for most of the year. As a result, boulders on the shallow seabed -- once encrusted with a rich assemblage of species in intense competition for limited space -- now mostly support a single species. The climate-linked increase in iceberg activity has left all other species so rare as to be almost irrelevant.

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The Antarctic shore is a place of huge contrasts, as quiet, dark, and frozen winters give way to bright, clear waters, thick with algae and peppered ...

Credit: British Antarctic Survey

The Antarctic shore is a place of huge contrasts, as quiet, dark, and frozen winters give way to bright, clear waters, thick with algae and peppered with drifting icebergs in summer. But as the planet has warmed in the last two decades, massive losses of sea ice in winter have left icebergs free to roam for most of the year. As a result, say researchers reporting in the Cell Press journal Current Biology on June 16, boulders on the shallow seabed -- once encrusted with a rich assemblage of species in intense competition for limited space -- now mostly support a single species. 

The climate-linked increase in iceberg activity has left all other species so rare as to be almost irrelevant. "The Antarctic Peninsula can be considered an early warning system -- like a canary in a coal mine," says David Barnes of the British Antarctic Survey. "Physical changes there are amongst the most extreme and the biology considered quite sensitive, so it was always likely to be a good place to observe impacts of climate change -- but impacts elsewhere are likely to be not too far behind. A lot of the planet depends on the near-shore environment, not least for food; what happens there to make it less stable is important."

Earlier studies had noted an increase in mortality of the pioneer species, Fenstrulina rugula, a rather unremarkable suspension feeder that belongs to a group sometimes referred to as moss animals. Barnes and his colleagues suspected that those losses would be more widespread. Indeed, a 2013 survey dive at a nearby spot showed large areas where no live animals could be found, the first time that had ever been reported, despite frequent diving in the area.


In the new study, the researchers detail the first assemblage-level changes coincident with increased scouring. Not one species present in 1997 has disappeared entirely, they found, yet many have become so rare as to play little role in the community. In 2013, almost all interactions (96 percent, to be exact) involved just one species, F. rugula, making it one of the simplest seabed systems to be found anywhere. In almost all of those competitive interactions, there was no clear winner or loser, because F. rugula individuals battle against each other.


Barnes says he and his colleagues were surprised to see such a large effect so quickly, given that climate change is expected to be a slowly evolving, long-term process. On that note, the losses in complexity observed along the Antarctic shores are surely the beginning of more shifts to come.
"Warming is likely to increase ice scour mortality and reduce assemblage complexity and could aid establishment of nonindigenous species," the researchers write in conclusion. "We expect the deeper seabed to become richer in benthic colonisation with more ice shelf collapses and fast ice losses, but hard surfaces in the shallows are likely to become deserts dominated by rapidly colonising pioneers and responsive scavengers -- with little role for spatial competition or even predation in shaping the structure of such assemblages."

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Story Source:
The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.

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Journal Reference:

1. Barnes et al. Climate-linked iceberg activity massively reduces spatial competition in Antarctic shallow waters. Current Biology, 2014 DOI: 10.1016/j.cub.2014.04.040

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Cell Press. "Antarctic species dwindle as icebergs batter shores year-round." ScienceDaily. ScienceDaily, 16 June 2014. <www.sciencedaily.com/releases/2014/06/140616130859.htm>.

Penguin population declines on Marion Island: Study

Wednesday 11 June 2014

Lebo Tshangela

Penguins walk over a data logger which picks up information stored in passive integrated transponders implanted under their skin. (SABC)

The Nelson Mandela Metropolitan University, Zoology, Senior Lecturer, Pierre Pistorius says rockhopper penguin population has gone down by over 70% since the mid-1990s on Marion Island and this has a negative consequence on the eco-system.

A team from the university returned recently from a five-week research trip to island, where there is an on-going trend of declining numbers among several of the seabirds that breed on the island.


Pierre Pistorius and Makabongwe Sigqala implant special microchips into penguins on Marion Island. (Photo courtesy of the Nelson Mandela Metropolitan University)


Marion Island is the most pristine area in the world, located 1 200 km south of Port Elizabeth. It is between South Africa and Antarctica.

Speaking to SABC Digital News, Pistorius says the reason for the decline has to do with the geographical changes currently taking place in the Southern Ocean and this is related to increasing temperatures and global warming.

He says the other reason for the decline is that seabirds have to move long distances to find food for their offspring. “They have to work harder to find food, this results in breeding success being low or possible adult survival being low. That is why the seabirds are declining.”

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Rise and fall of prehistoric penguin populations charted

14 hours ago

A pair of Gentoo penguins. Credit: Gemma Glucas

A study of how penguin populations have changed over the last 30,000 years has shown that between the last ice age and up to around 1,000 years ago penguin populations benefitted from climate warming and retreating ice. This suggests that recent declines in penguins may be because ice is now retreating too far or too fast.

An international team, led by scientists from the Universities of Southampton and Oxford, has used a genetic technique to estimate when current genetic diversity arose in penguins and to recreate past population sizes. Looking at the 30,000 years before human activity impacted the climate, as Antarctica gradually warmed, they found that three species of penguin; Chinstrap, Adélie and southern populations of Gentoo penguins increased in numbers. In contrast, Gentoo penguins on the Falkland Islands were relatively stable, as they were not affected by large changes in ice extent.
A report of the research is published in the journal Scientific Reports.

Lead author of the paper, Gemma Clucas, from Ocean and Earth Sciences at the University of Southampton comments: "Whereas we typically think of penguins as relying on ice, this research shows that during the last ice age there was probably too much ice around Antarctica to support the large populations we see today. The penguins we studied need ice-free ground to breed on and they need to be able to access the ocean to feed. The extensive ice-sheets and sea ice around Antarctica would have made it inhospitable for them.

A Chinstrap penguin. Credit: Dr Tom Hart

"What is particularly interesting is that after the ice age, all of these penguin populations were climate change 'winners', that is to say the warming climate allowed them to expand and increase in number. However, this is not the pattern we're seeing today. Adélie and Chinstrap penguins appear to be declining due to climate change around the Antarctic Peninsula, so they've become 'losers'. Only the Gentoo penguin has continued to be a 'winner' and is expanding its range southward."

Dr Tom Hart of the University of Oxford's Department of Zoology, an author of the paper, continues: "We are not saying that today's warming climate is good for penguins, in fact the current decline of some penguin species suggests that the warming climate has gone too far for most penguins. "What we have found is that over the last 30,000 years different penguin species have responded very differently to a gradually warming world, not something we might expect given the damage current rapid warming seems to be doing to penguins' prospects."

A group of Adélie penguins. Credit: Dr Tom Hart

To estimate changes in penguin genetic diversity, the researchers collected feathers and blood samples from 537 penguins in colonies around the Antarctic Peninsula. The scientists then sequenced a region of mitochondrial DNA that evolves relatively quickly. Using the rate of mutation of this region of DNA as a calibration point, the researchers were able to chart how the size of these populations has varied over time. The team working on the project included scientists from the British Antarctic Survey and also US scientists from Oceanites Inc, Woods Hole Oceanographic Institution, and the University of North Carolina, Wilmington. "During the last ice age Antarctica was encircled by 100 per cent more winter sea ice than today," says Dr Tom Hart. "As ice retreated, these penguins had access to more breeding sites and more open ocean to feed."

 
Explore further: Researchers use genome analysis to understand how King Penguins came to breed on Crozet Islands

More information: A reversal of fortunes: climate change 'winners' and 'losers' in Antarctic Peninsula penguins, Scientific Reports, 2014.

Journal reference: Scientific Reports
Provided by University of Southampton  

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Penguins That Weathered Past Climate Change Suffer This Time

Three penguin species tolerated a warming climate quite well about 15,000 years ago, but it's a very different story for two of them now.

Adélie penguins, seen here on an ice floe, are in decline because retreating sea ice and commercial fishing have reduced the penguins' main food source: krill.

PHOTOGRAPH BY BILL CURTSINGER, NATIONAL GEOGRAPHIC CREATIVE

Jane J. Lee

National Geographic

Published June 12, 2014

Despite their pot-bellied profile and waddling gait, Antarctic penguins have weathered the challenges of one of the harshest climates on Earth for millennia. Three of those species—the Adélie, chinstrap, and gentoo—were also able to tolerate, if not flourish under, a warming event that came as ice sheets began to shrink, says a new study.

They were climate change "winners," the authors write. About 15,000 to 20,000 years ago, the retreating ice exposed expanses of bare ground that the penguins could build nests on, allowing them to expand their populations.

This historical perspective is helping researchers to understand the penguins' current situation in western Antarctica. (See "West Antarctic Glaciers Collapsing, Adding to Sea-Level Rise.")

The warming that researchers are now measuring on the Antarctic Peninsula is approaching the limits of what these penguin species experienced in the past, says Gemma Clucas, a doctoral student at the University of Southampton in the United Kingdom and lead author of the new paper. "We're seeing a very different response [from them now.]"

Genetic analysis of 249 gentoo, 166 chinstrap, and 122 Adélie penguins showed that all three populations expanded after the last glacial maximum—when the ice sheets were at their greatest extent—the researchers report today in the journal Scientific Reports. But only gentoo penguins seem to be holding their own against current warming trends in the western Antarctic. The other two species are in decline.

Too Much and Not Enough

"You can have too little ice and too much ice, and both of these are bad," says Jefferson Hinke, an ecologist with the U.S. National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center in La Jolla, California.

In the past, the problem was a lack of real estate. During the last glacial maximum, there was 100 percent more ice in the sea surrounding Antarctica, severely restricting access to the ocean, which penguins depend on for food. Glaciers also covered the bare ground, where they lay their eggs and raise their young. It wasn't until the ice started melting that the penguin populations began to do better.

"Now we have too little ice," says Hinke, who was not involved in the study, "and the ecological consequences of that are that species like Adélie and chinstraps aren't doing too well." However, unlike the past, the problem for penguins now is a dwindling food supply.

Adélie and chinstrap penguins rely mainly on krill, which has been declining due to retreating sea ice, which the shrimplike animals need to grow. Commercial fishing for krill, along with a resurgence of whales that prey on the tiny animals, have further reduced krill populations.  Gentoo penguins are likely doing better because they have a more flexible diet, which includes fish and some squid, in addition to krill. (See also "Penguin Numbers Plummeting—Whales Partly to Blame?")

Nothing Lasts Forever

"These species are a lot more robust than we sometimes give them credit for," says Heather Lynch, a population ecologist at Stony Brook University in New York who contributed data to the study. Researchers worry when species are forced to shift their ranges, she says, but this paper shows that these penguin species can come through those changes.

However, "there have been reversals of fortune in the past," Lynch says. The Adélie and chinstrap penguins are evidence of that. Even though the gentoo penguins seem to be doing OK now, "there's no guarantee that that will last forever."

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King Penguins' Genes Explain Ancient Island-Hopping

By Tia Ghose, Staff Writer   |   June 10, 2014

 A singing king penguin on South Georgia Island.Credit: Lieutenant Philip Hall, NOAA Corps

King penguins colonized a string of islands north of Antarctica about 15,000 years ago, after glaciers melted and the climate warmed, according to a new genetic study. The balmier weather gave the penguins two things they needed to thrive: ice-free pockets of land on which to raise their chicks, and food within swimming range for feeding those chicks, the study found. "When you have these two conditions, these two parameters that are met, then the population can just explode," said study co-author Emiliano Trucchi, an evolutionary biologist at the University of Vienna in Austria.

Island living

King penguins (Aptenodytes patagonicus) are the second-largest penguins in the world and live on temperate islands that are closest to Antarctica, such as South Georgia, Tierra del Fuego and the Falkland Islands. But the biggest breeding grounds for king penguins are on the Crozet Islands, a string of islands in the southern reaches of the Indian Ocean.

In the summer, the penguins dive for tiny lanternfishes about 250 miles (400 kilometers) from the archipelago, returning every three to five days to feed their chicks. The lanternfishes congregate in an ocean region called the polar front, where cold polar water meets the warmer tropical water, creating a sharp temperature gradient. In the winter, the penguins venture about 621 miles (1,000 km) to the fringes of Antarctica to forage for food, though exactly what they eat is a mystery, said study co-author Céline Le Bohec, a polar ecologist at the Centre Scientifique de Monaco.

Penguin-egg swap

To understand how the flightless birds first reached the Crozet Islands, Le Bohec and her colleagues snuck onto the edges of the penguins' breeding colonies, quietly taking two- to three-week-old chicks from right under their parents' noses and replacing them with fake eggs. "This is really weird," Le Bohec told Live Science. "If you are delicate enough and quick enough, really the adult doesn't notice what you are doing."

Outside the colony, the researchers measured the baby penguins' weights, as well as the beaks, flippers and feet. Then, the team took a few drops of blood from the chicks to test their DNA. (Past studies have shown that the king penguin colonies have adjusted to these human intrusions.)

Migration history

The team analyzed about 65,000 snippets of DNA from eight king penguins. Because the base pairs, or letters in DNA, mutate at a slow but somewhat predictable rate over time, calculating how many of these stretches of DNA contain the same letter sequence can reveal how long ago the population expanded.

The team found that most of the genetic regions were very similar in the penguins, indicating that they originated from a very small initial population. Furthermore, the population began expanding about 15,000 years ago — right after the last ice age was ending and the glaciers were retreating from the islands. "Just as soon as the breeding sites were available, then the population just skyrocketed," Trucchi told Live Science.

Future bleak

The new model underscores conditions the penguins need to thrive, which could help researchers predict how penguins will adapt to climate change. But the future doesn't look so hot for the blubbery birds. Current models predict that unmitigated climate change will push the polar front south, taking the penguins' summer staple of lanternfishes farther from the islands.

This will make it hard for the penguins to live on the islands, as they need to feed their chicks frequently in the summer, and can only swim so far to do that, Le Bohec said. "If we don't change our human behavior, I think in 200 years, it will be quite nasty for king penguins," Le Bohec said.
The study was published today (June 10) in the journal Proceedings of the Royal Society B.

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Virus found among Adélie penguin population on Ross Island

June 6, 2014

 

It seems that research into Antarctic penguins and viruses has gone, well, viral.

A team of researchers funded by the National Science Foundation has reported finding a novel papillomavirus among the Adélie penguins on Ross Island, joining another group led by Australian scientists who also recently announced they found a new strain of avian flu amongst a population of Adélie penguins around the Antarctic Peninsula.

The former finding, published in the Journal of General Virology earlier this year, is the first report of a papillomavirus associated with a penguin species. Only three papillomaviruses have previously been identified in birds, though there are hundreds of types, including many that infect humans. “I was not expecting to find an avian papillomavirus to be honest,” said lead author Arvind Varsani , an expert in virology at the University of Canterbury in New Zealand. Varsani has worked two seasons in Antarctica on a long-term project studying the population dynamics of Adélie penguins in the Ross Sea region. “I thought what we’d find would be novel viruses that are highly divergent from any known viruses,” he explained via e-mail. “The Antarctic ecosystem is quite unique, and hence I imagined that the viruses found there would probably require the establishment of new viral families to accommodate these viruses.”

Papillomaviruses (PV) typically infect the skin or mucus membranes in most vertebrate species. Human PV types can cause benign warts, though types that are more serious can become cancerous.
Varsani said the scientists have no idea if the Adélie papillomavirus is benign or not. “To be honest, I’d say we [know] extremely little about viruses associated with penguins,” Varsani said.

The handful of previous studies on viruses associated with penguin species relied on serology, using blood samples to identify the specific antibodies associated with certain types of viruses. The current studies rely on genetic techniques. In the research led by Varsani, the team used a noninvasive technique, collecting fecal matter, and then extracted the total viral DNA, followed by DNA sequencing and database searches to determine the entire genome of the virus.

Varsani said there are several important reasons for studying viruses in penguins, not least of which is to establish a baseline on virology in Antarctica, which is the least studied of the continents in this field. Research will also allow scientists to identify emerging viruses, especially those that may appear as the climate changes. “Viruses are everywhere and infect organisms in every domain of life,” Varsani said. “With habitat loss we are bound to see a higher incidence of emerging viruses that will spill over from well-established ecosystems to ‘altered’ ecosystems.”

Varsani is also collaborating with other U.S. Antarctic Program researchers working on permafrost melt in the McMurdo Dry Valleys and the potential for discovering new viruses locked in the ice since the last glacial period. “This opens up some important questions about pathogens in the Antarctic, including flow of pathogens from sled dogs to seals,” Varsani said, referring to a real concern that led to the eventual banishment of canines from Antarctica in 1994, “or as a matter of fact from any organism to another. [It] also raises a serious question with climate change: are the current ecosystems being seeded with pathogens trapped in the last glacial ice age?”

During the 2011-12 season, before Varsani joined the team, researchers had noted a high incidence of what looked like “beak-and-feather” disease, according to David Ainley, principal investigator on the long-term population dynamics study in the Ross Sea region.

The suspected virus, which is known to affect parrots, caused the loss of feathers mainly around the birds’ faces and bills across about 10 percent of the penguins. The next year, it was mostly gone, said Ainley, senior ecologist at a San Francisco Bay Area ecological consulting firm, H.T. Harvey and Associates.

Tests on blood samples collected from the birds for other studies related to the individual fitness and breeding success of some Adélies over others were inconclusive. “There has been evidence of very low presence of whatever it was since,” Ainley added, saying less than 1 percent of the population still seems to be affected.

In the study that discovered avian influenza among the Adélie penguins of the Antarctic Peninsula – published in mBio, the online open-access journal of the American Society for Microbiology External Non-U.S. government site – researchers echoed the same concerns voiced by Varsani. “We found that this virus was unlike anything else detected in the world,” said lead author Aeron Hurt External Non-U.S. government site, a senior research scientist at the World Health Organization Collaborating Centre for Reference and Research on Influenza External Non-U.S. government site in Melbourne, Australia, in a press release External Non-U.S. government site.

Like the rapidly evolving viruses themselves, the study of virology in the Antarctic appears to be evolving rapidly. A preprint version of a paper in the journal Infection, Genetics and Evolution by Peyman Zawar-Reza et al, a study led by Varsani, reported identifying eight novel viruses from algal mats found in a freshwater pond on the McMurdo Ice Shelf sampled in 1988 by Paul Broady External Non-U.S. government site at the University of Canterbury.

Varsani said more papers are forthcoming on other novel viruses discovered among the penguin populations and melting permafrost in the Dry Valleys. “We are living in a rapidly changing environment, as a result of climate change and human activities (some of our negative impacts on ecosystems including deforestation, over fishing, pollution, etc.),” Varsani said. “These have huge implications on pathogen evolution and spread.”

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