Melting Sea Ice Threatens Emperor Penguins

At nearly four feet tall, the Emperor penguin is Antarctica’s largest sea bird. Unlike other sea birds, Emperor penguins breed and raise their young almost exclusively on sea ice. If global temperatures continue to rise, the Emperor penguins in Terre Adélie in East Antarctica may eventually disappear. (Credit: Photo courtesy Glen Grant, U.S. Antarctic Program, National Science Foundation)

 

ScienceDaily (June 20, 2012) — At nearly four feet tall, the Emperor penguin is Antarctica's largest sea bird -- and thanks to films like "March of the Penguins" and "Happy Feet," it's also one of the continent's most iconic. If global temperatures continue to rise, however, the Emperor penguins inTerre Adélie, in East Antarcticamay eventually disappear, according to a new study by led by researchers from the Woods Hole Oceanographic Institution (WHOI).

The study was published in the June 20th edition of the journal Global Change Biology.
"Over the last century, we have already observed the disappearance of the Dion Islets penguin colony, close to the West Antarctic Peninsula," says Stephanie Jenouvrier, WHOI biologist and lead author of the new study. "In 1948 and the 1970s, scientists recorded more than 150 breeding pairs there. By 1999, the population was down to just 20 pairs, and in 2009, it had vanished entirely." Like in Terre Adélie, Jenouvrier thinks the decline of those penguins might be connected to a simultaneous decline in Antarctic sea ice due to warming temperatures in the region.

Unlike other sea birds, Emperor penguins breed and raise their young almost exclusively on sea ice. If that ice breaks up and disappears early in the breeding season, massive breeding failure may occur, says Jenouvrier. "As it is, there's a huge mortality rate just at the breeding stages, because only 50 percent of chicks survive to the end of the breeding season, and then only half of those fledglings survive until the next year," she says.

Disappearing sea ice may also affect the penguins' food source. The birds feed primarily on fish, squid, and krill, a shrimplike animal, which in turn feeds on zooplankton and phytoplankton, tiny organisms that grow on the underside of the ice. If the ice goes, Jenouvrier says, so too will the plankton, causing a ripple effect through the food web that may starve the various species that penguins rely on as prey.

To project how penguin populations may fare in the future, Jenouvrier's team used data from several different sources, including climate models, sea ice forecasts, and a demographic model that Jenouvrier created of the Emperor penguin population at Terre Adélie, a coastal region of Antarctica where French scientists have conducted penguin observations for more than 50 years.

Combining this type of long-term population data with information on climate was key to the study, says Hal Caswell, a WHOI senior mathematical biologist and collaborator on the paper.

"If you want to study the effects of climate on a particular species, there are three pieces that you have to put together," he says. "The first is a description of the entire life cycle of the organism, and how individuals move through that life cycle. The second piece is how the cycle is affected by climate variables. And the crucial third piece is a prediction of what those variables may look like in the future, which involves collaboration with climate scientists."

Marika Holland of the National Center for Atmospheric Research is one such scientist. She specializes in studying the relationship between sea ice and global climate, and helped the team identify climate models for use in the study.

Working with Julienne Stroeve, another sea ice specialist from the National Snow and Ice Data Center, Holland ultimately recommended five distinct models. "We picked the models based on how well they calculated the sea ice cover for the 20th century," she says. "If a model predicted an outcome that matched what was actually observed, we felt it was likely that its projections of sea ice change in the future could be trusted."

Jenouvrier used the output from these various climate models to determine how changes in temperature and sea ice might affect the Emperor penguin population at Terre Adélie. She found that if greenhouse gas emissions continue to rise at levels similar to today -- causing temperatures to rise and Antarctic sea ice to shrink -- penguin population numbers will diminish slowly until about 2040, after which they would decline at a much steeper rate as sea ice coverage drops below a usable threshold.

"Our best projections show roughly 500 to 600 breeding pairs remaining by the year 2100. Today, the population size is around 3000 breeding pairs," says Jenouvrier.

The effect of rising temperature in the Antarctic isn't just a penguin problem, according to Caswell. As sea ice coverage continues to shrink, the resulting changes in the Antarctic marine environment will affect other species, and may affect humans as well.

"We rely on the functioning of those ecosystems. We eat fish that come from the Antarctic. We rely on nutrient cycles that involve species in the oceans all over the world," he says. "Understanding the effects of climate change on predators at the top of marine food chains -- like Emperor penguins -- is in our best interest, because it helps us understand ecosystems that provide important services to us."
Also collaborating on the study were Christophe Barbraud and Henri Weimerskirch of the Centre d'Etudes Biologiques de Chizé, in France, and Mark Serreze of the National Snow and Ice Data Center in the United States.

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Story Source:

The above story is reprinted from materials provided by Woods Hole Oceanographic Institution.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Stephanie Jenouvrier, Marika Holland, Julienne Stroeve, Christophe Barbraud, Henri Weimerskirch, Mark Serreze, Hal Caswell. Effects of climate change on an emperor penguin population: analysis of coupled demographic and climate models. Global Change Biology, 2012; DOI: 10.1111/j.1365-2486.2012.02744.x

Woods Hole Oceanographic Institution (2012, June 20). Melting sea ice threatens emperor penguins. ScienceDaily. Retrieved June 21, 2012, from http://www.sciencedaily.com­ /releases/2012/06/120620113342.htm ­ /

36% of Chinstrap Penguins Missing from Antarctic Island

Jeanna Bryner, LiveScience Managing Editor

Date: 19 June 2012


A population of chinstrap penguins is feeling the heat, with more than one-third of a breeding colony lost in the past 20 years, new research finds.

A warming planet, which is causing sea ice in Antarctica (and elsewhere) to melt, may ultimately be to blame for the plummeting penguin population, the researchers said. That's because the chinstraps' main food, shrimplike creatures called krill, depend on algae that attaches to that ice.

"Actually, in the '90s it was thought that the climate change would favor the chinstrap penguin, because this species prefers sea waters without ice, unlike the Adélie penguin, which prefers the ice pack," study researcher Andres Barbosa told LiveScience. He added that at the time, chinstraps, named for the thin black facial line from cheek to cheek, seemed to increase in numbers, with some new colonies being established.


The sea-ice decline in the winter, however, has become so big that it is now impacting krill populations, said Barbosa, of the National Museum of Natural Sciences in Madrid.

Counting chinstraps

Barbosa and his colleagues tallied chinstrap penguins (Pygoscelis antarctica) in the Vapour Col colony of Deception Island, in the Antarctic's South Shetland Islands in 1991-92 and 2008-09. They photographed nests in 19 subcolonies, mainly in December when chicks were hatching.


Results, which ended up including just 12 of the subcolonies due to availability of data, showed the occupied nests had declined by 36 percent between 1991 and 2008.

Barbosa and colleagues ruled out research activity as the cause for the loss since both studied populations and those used as controls showed similar patterns of decline.

Tourism is also not a likely culprit. Deception Island, built on a volcano, is one of the most visited places in Antarctica; the 2007-08 year saw some 25,000 visitors, according to the International Association of Antarctica Tour Operators (IAATO). Meanwhile, the nearby chinstrap penguin colony of Bailey Head, which is usually visited by 2,000 to 3,500 people every season, showed a decline of about 50 percent.

Rather, a dip in the krill population may be to blame, an idea supported by the fact that Adélie penguin population (P. adeliae) in the region is also declining, while the gentoo penguin population (P. papua), which has a more variable diet, is not.

(The chinstrap, gentoo and Adélie penguins are the three pygoscelid species (in the Pygoscelis genus) that inhabit the Antarctic Peninsula, the region of the Antarctic continent where the effects of climate change are more evident, the researchers noted.)

Saving penguins

But Barbosa says the chinstraps aren't a lost cause.

"This is an example of how the human activity far from the poles can affect the life at thousands of kilometers far from our homes," Barbosa told LiveScience. "Therefore, a more responsible use of the energy and the fossil fuels is necessary to preserve the planet and then the Antarctica."

In addition, he said, to protect the organisms that call the Antarctic home, we need to reduce human impact by reducing overfishing, tourism and even research activity.

The research was detailed online May 22 in the journal Polar Biology.

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Chin StrapCredit: Andres BarbosaNamed for the thin black band of feathers that extends from ear to ear under their heads, chinstrap penguins grow to about 2.2 feet (68 centimeters) tall, with males being larger and heavier than females.  

Two ChicksCredit: Andres BarbosaThe female usually lays two eggs in a shallow nest in late November, with each of the pair participating in incubation duties. The chicks hatch after about 33 to 35 days.  

Deception IslandCredit: Andres BarbosaAndres Barbosa of the National Museum of Natural Sciences in Madrid and his team have been studying the chinstrap penguins of Deception Island since 1999. Its volcanic origins have shaped the island into a horseshoe shape, with the volcano's caldera at the center. The island is one of the most visited of Antarctica, drawing some 25,000 visitors in the year 2007-08.  

Find the MateCredit: Andres BarbosaMonogamy between chinstrap penguin couples often persists from year to year, with pairs even using the same nesting sites in successive years. To make sure they've got the right mate, the penguins use certain mate-recognition behavior, seen here between a pair of chinstraps, which involves the penguins pumping their chests and stretching their heads upward. 

Little NestsCredit: Andres BarbosaFemale chinstrap penguins form a circular platform nest with a shallow interior. The nests are roughly about 16 inches (40 cm) across and up to 6 inches (15 cm) high.  

Chick HuddleCredit: Andres BarbosaTypically, fledgling occurs at about 7 to 8 weeks, with the chinstrap penguin chicks eventually forming crèches, or groups of young penguins that huddle together for warmth and protection. Then, at about 50-60 days old, once the chicks have molted, they head out to sea. 

Penguin TeamCredit: Andres BarbosaThe penguin team, including Barbosa, shown here with chinstrap penguins on Deception Island. 

Nest ChecksCredit: Andres BarbosaThe researchers tallied the occupied nests on the island in 1991-92 and 2008-09. Here they are checking chinstrap nests. (They also used photographic evidence for nest counts.) 

Main FoodCredit: Andres BarbosaThe culprit for the decline is likely a loss of their main prey, tiny shrimplike creatures called krill. The krill eat algae that attach to the sea ice, so without sea ice the krill plummet, followed by a decline in chinstrap penguins. 

Little BeaksCredit: Andres BarbosaResearchers measure the beak of a chinstrap penguin on Deception Island. 

Penguins PlummetCredit: Andres BarbosaThe researchers found occupied nests on the island have declined by about 36 percent between 1991 and 2008. 

Sea IceCredit: Andres BarbosaSea ice around the Antarctic's Deception Island. "Actually, in the 90's it was thought that the climate change would favor the chinstrap penguin, because this species prefers sea waters without ice unlike the Adelie penguin which prefers the ice pack," study researcher Andres Barbosa told LiveScience. The sea-ice decline in the winter, however, has become so big that it is now impacting krill populations, said Barbosa, of the National Museum of Natural Sciences in Madrid.  

Icy IncubationCredit: Andres BarbosaA chinstrap penguin nesting in the snow. 

Saving ChinstrapsCredit: Andres BarbosaBut Barbosa says the chinstraps aren't a lost cause. "This is an example of how the human activity far from the poles can affect the live at thousands of kilometers far from our homes," Barbosa told LiveScience. "Therefore, a more responsible use of the energy and the fossil fuels is necessary to preserve the planet and then the Antarctica." 

Penguin ProtectionCredit: Andres BarbosaIn addition, he said, to protect the organisms that call the Antarctic home we need to reduce human impact by reducing overfishing, tourism and even research activity. source 

Ancient Warming Greened Antarctica, Study Finds

This artist's rendition created from a photograph of Antarctica shows what Antarctica possibly looked like during the middle Miocene epoch, based on pollen fossil data. (Credit: NASA/JPL-Caltech/Dr. Philip Bart, LSU)

ScienceDaily (June 17, 2012) — A new university-led study with NASA participation finds ancient Antarctica was much warmer and wetter than previously suspected. The climate was suitable to support substantial vegetation -- including stunted trees -- along the edges of the frozen continent.

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The team of scientists involved in the study, published online June 17 in Nature Geoscience, was led by Sarah J. Feakins of the University of Southern California in Los Angeles, and included researchers from NASA's Jet Propulsion Laboratory in Pasadena, Calif., and Louisiana State University in Baton Rouge.

By examining plant leaf wax remnants in sediment core samples taken from beneath the Ross Ice Shelf, the research team found summer temperatures along the Antarctic coast 15 to 20 million years ago were 20 degrees Fahrenheit (11 degrees Celsius) warmer than today, with temperatures reaching as high as 45 degrees Fahrenheit (7 degrees Celsius). Precipitation levels also were found to be several times higher than today.

"The ultimate goal of the study was to better understand what the future of climate change may look like," said Feakins, an assistant professor of Earth sciences at the USC Dornsife College of Letters, Arts and Sciences. "Just as history has a lot to teach us about the future, so does past climate. This record shows us how much warmer and wetter it can get around the Antarctic ice sheet as the climate system heats up. This is some of the first evidence of just how much warmer it was."

Scientists began to suspect that high-latitude temperatures during the middle Miocene epoch were warmer than previously believed when co-author Sophie Warny, assistant professor at LSU, discovered large quantities of pollen and algae in sediment cores taken around Antarctica. Fossils of plant life in Antarctica are difficult to come by because the movement of the massive ice sheets covering the landmass grinds and scrapes away the evidence.

"Marine sediment cores are ideal to look for clues of past vegetation, as the fossils deposited are protected from ice sheet advances, but these are technically very difficult to acquire in the Antarctic and require international collaboration," said Warny.

Tipped off by the tiny pollen samples, Feakins opted to look at the remnants of leaf wax taken from sediment cores for clues. Leaf wax acts as a record of climate change by documenting the hydrogen isotope ratios of the water the plant took up while it was alive.

"Ice cores can only go back about one million years," Feakins said. "Sediment cores allow us to go into 'deep time.'"

Based upon a model originally developed to analyze hydrogen isotope ratios in atmospheric water vapor data from NASA's Aura spacecraft, co-author and JPL scientist Jung-Eun Lee created experiments to find out just how much warmer and wetter climate may have been.

"When the planet heats up, the biggest changes are seen toward the poles," Lee said. "The southward movement of rain bands associated with a warmer climate in the high-latitude southern hemisphere made the margins of Antarctica less like a polar desert, and more like present-day Iceland."

The peak of this Antarctic greening occurred during the middle Miocene period, between 16.4 and 15.7 million years ago. This was well after the age of the dinosaurs, which became extinct 64 million years ago. During the Miocene epoch, mostly modern-looking animals roamed Earth, such as three-toed horses, deer, camel and various species of apes. Modern humans did not appear until 200,000 years ago.

Warm conditions during the middle Miocene are thought to be associated with carbon dioxide levels of around 400 to 600 parts per million (ppm). In 2012, carbon dioxide levels have climbed to 393 ppm, the highest they've been in the past several million years. At the current rate of increase, atmospheric carbon dioxide levels are on track to reach middle Miocene levels by the end of this century.

High carbon dioxide levels during the middle Miocene epoch have been documented in other studies through multiple lines of evidence, including the number of microscopic pores on the surface of plant leaves and geochemical evidence from soils and marine organisms. While none of these 'proxies' is as reliable as the bubbles of gas trapped in ice cores, they are the best evidence available this far back in time. While scientists do not yet know precisely why carbon dioxide was at these levels during the middle Miocene, high carbon dioxide, together with the global warmth documented from many parts of the world and now also from the Antarctic region, appear to coincide during this period in Earth's history.

This research was funded by the U.S. National Science Foundation with additional support from NASA. The California Institute of Technology in Pasadena manages JPL for NASA.

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Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Sarah J. Feakins, Sophie Warny, Jung-Eun Lee. Hydrologic cycling over Antarctica during the middle Miocene warming. Nature Geoscience, 2012; DOI: 10.1038/ngeo1498

NASA/Jet Propulsion Laboratory (2012, June 17). Ancient warming greened Antarctica, study finds. ScienceDaily. Retrieved June 18, 2012, from  http://sciencedaily.com/releases/2012/06/120617170307.htm

Anthropomorphism is Dangerous in Science

9 June 2012 

'Depraved' sex acts by penguins shocked polar explorer

By Matt McGrath Science reporter, BBC World Service

 Scientists now understand the biological reasons for behaviour Dr Levick considered to be "depraved"

Accounts of unusual sexual activities among penguins, observed a century ago by a member of Captain Scott's polar team, are finally being made public.

Details, including "sexual coercion", recorded by Dr George Murray Levick were considered so shocking that they were removed from official accounts.
However, scientists now understand the biological reasons behind the acts that Dr Levick considered "depraved".

The Natural History Museum has published his unedited papers.
Dr Levick, an avid biologist, was the medical officer on Captain Scott's ill-fated Terra Nova expedition to the South Pole in 1910. He was a pioneer in the study of penguins and was the first person to stay for an entire breeding season with a colony on Cape Adare.
He recorded many details of the lives of adelie penguins, but some of their activities were just too much for the Edwardian sensibilities of the good doctor.

He was shocked by what he described as the "depraved" sexual acts of "hooligan" males who were mating with dead females. So distressed was he that he recorded the "perverted" activities in Greek in his notebook.

Graphic account

 

  On his return to Britain, Dr Levick attempted to publish a paper entitled "the natural history of the adelie penguin", but according to Douglas Russell, curator of eggs and nests at the Natural History Museum, it was too much for the times.
"He submitted this extraordinary and graphic account of sexual behaviour of the adelie penguins, which the academic world of the post-Edwardian era found a little too difficult to publish," Mr Russell said.

Pages from Dr Levick's notebook with some sections coded in Greek

 

The sexual behaviour section was not included in the official paper, but the then keeper of zoology at the museum, Sidney Harmer, decided that 100 copies of the graphic account should be circulated to a select group of scientists.
Mr Russell said they simply did not have the scientific knowledge at that time to explain Dr Levick's accounts of what he termed necrophilia.

"What is happening there is not in any way analogous to necrophilia in the human context," Mr Russell said. "It is the males seeing the positioning that is causing them to have a sexual reaction.
"They are not distinguishing between live females who are awaiting congress in the colony, and dead penguins from the previous year which just happen to be in the same position."
Sexual coercion

  Only two of the original 100 copies of Dr Levick's account survive. Mr Russell and colleagues have now published a re-interpretation of Dr Levick's findings in the journal Polar Record.
Mr Russell described how he had discovered one of the copies by accident.
"I just happened to be going through the file on George Murray Levick when I shifted some papers and found underneath them this extraordinary paper which was headed 'the sexual habits of the adelie penguin, not for publication' in large black type.

"It's just full of accounts of sexual coercion, sexual and physical abuse of chicks, non-procreative sex, and finishes with an account of what he considers homosexual behaviour, and it was fascinating."
The report and Dr Levick's handwritten notes are now on display at the Natural History Museum for the first time. Mr Russell believes they show a man who struggled to understand penguins as they really are.

"He's just completely shocked. He, to a certain extent, falls into the same trap as an awful lot of people in seeing penguins as bipedal birds and seeing them as little people. They're not. They are birds and should be interpreted as such."

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Gay, straight or necrophiliac, a penguin isn't a human being

By Tim Stanley Science
 June 9th, 2012

All ages of man have tried to understand penguin sexuality in human terms

An Edwardian notebook has gone on display at the Natural History Museum that describes the sexual activities of the Antarctic penguin. Read it and you’ll never look at Pingu the same way again.
The text was compiled by George Murray Levick, a scientist with the Scott Antarctic Expedition, and it contains details of homosexuality, pederasty, necrophilia and rape. In the Antarctic summer of 1911-1912, Levick observed the breeding cycle of the Adélies colony at Cape Adare. To his horror, he witnessed male penguins attempting to make love to the long-dead bodies of females, males getting it on with other males, and coercive sex acts with females and chicks that sometimes led to violence and death. It was Sodom in the snow.

It’s hardly news that penguins are motivated entirely by their loins, but what reports have seized upon is the charming way in which Levick processed this information. Being an Edwardian gentleman, he blamed the orgy on the male “hooligans,” perhaps believing that the lady penguins were incapable of bad behaviour. Describing what he saw as “astonishing depravity,” he recorded it all in Greek code and his findings were suppressed for many years. Reading Levick’s work, it’s hard not to spot traces of Judeo-Christian morality that seem inappropriate in the context of zoological study. Anything that an animal does cannot be depraved because they don’t have morals, or a rational soul.

But the temptation towards Anthropomorphism (the identifying of human characteristics among animals) didn’t stop in the Edwardian era. We still do it today – rationalising animal sexual behaviour in a different, yet still heavily politicised, way.

Take the case of the gay penguins. Inca and Rayas met at the Faunia Park in Madrid and seemed so devoted to each other that the zookeepers gave them their own egg. The pair have been dubbed “gay” and elevated to the status of the Elton and David of the animal kingdom. They are proof, for those seeking it, that gay monogamy finds a template in nature.

The problem is that the term “gay” is as inappropriate to describe what’s going on here as is Levick’s use of “depravity.” Gay is a term that has only been in use since the rights revolution of the 1960s and which describes far more than just homosexual activity; it denotes a politicised identity that makes no sense unless it is self-aware and publicly understood. Levick’s penguins face no moral choices, so they cannot be depraved. Inca and Rayas cannot conceptualise sexual category or identity, so they can’t be gay in the sense that a human being is. They certainly can't go through the rite of passage associated with being gay, "coming out." The thought of them waddling up to their parents – flipper in flipper – and telling them to prepare themselves for a shock is absurd.

Indeed, their zookeeper insists that they are not even homosexual – just “the best of friends.” There’s every expectation that they will, eventually, mate with a female. That’s happened in Tornoto, where the star “gay” couple, Buddy and Pedro, was paired off with females. The “bromance” was over when Buddy made it with a girl called Farai. Pedro chased the luscious Thandiwey for several weeks, but got nowhere. Buddy and Pedro’s relationship was never sexual, but instead social. That didn’t stop people asking if it was “homophobic” to separate them, as if some fundamental human right was being broken.

And what is happening here is the projection of human values onto a different species. At the same time that we more ruthlessly exploit animals than ever before, we also seem determined to find qualities within them that we can empathise with. We want to turn them into mirrors of ourselves. Sometimes – as with the Dachshund UN – the result is unbelievably cute. But in most instances it misleads about the nature of animals and blurs the lines between man and nature. Humanity shouldn’t judge its moral code by the sexual standards of the penguins. It should be guided by the uniquely human qualities of reason and compassion.

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