First Space-Based View of the Ozone Hole

First Space-Based View of the Ozone Hole, a photo by NASA Goddard Photo and Video on Flickr.
At an August 1985 meeting in Prague, atmospheric scientist Pawan Bhartia presented this satellite-based image that revealed for the first time the size and magnitude of the Antarctic ozone hole. The discovery ultimately led to the 1987 Montreal Protocol, a landmark international treaty designed to phase out ozone-depleting substances. Yesterday, Sept. 16,2012, marked 25 years since the treaty was opened for signatures.

NASA satellites continue to provide clear snapshots of a generally stabilized Antarctic ozone hole as it cycles toward and away from its annual maximum depth by late September or early October.

To read a Q&A about the discovery with NASA's Pawan Bhartia, visit:
www.nasa.gov/topics/earth/features/bhartia-qa.html
 

Study: Tourism not a factor in Antarctic penguin decline

Posted on September 15, 2012 by Bob Berwyn 

  

Steep drops in chinstrap, Adélie penguin populations linked with global warming, decline of krill

A lone chinstrap penguin on an ice floe near Brown Bluff, Antarctica. Photo by Bob Berwyn.

By Bob Berwyn

FRISCO — Chinstrap penguin populations around Antarctica — including a major colony at Baily Head on Deception Island — are dwindling, and some have even blinked out in what scientists are calling colony collapse.

But tourism is not a big factor in the decline, according to researchers who compared penguin population trends at heavily visited sites with other spots that aren’t on the Antarctic tourism circuit.
Adélie penguin populations are also dropping regionally. Both species are offshore foragers, so loss  of sea ice and changes in krill populations — driven by global warming — are suspected be the primary causes. The Antarctic Peninsula, including the South Shetland archipelago, is warming faster than almost any other part of the planet.

It’s also possible that rebounding humpback whale populations, as well as commercial fishing, are affecting krill distribution to some degrees, but researchers haven’t yet been able to pinpoint those impacts accurately.


New study

In one of the most recent penguin studies, ecologist Heather Lynch, of Stony Brook University, teamed up with other researchers to make a detailed count of breeding chinstrap penguins at Deception Island, including the colony at Baily Head. The scientists worked from a private yacht (not a US research vessel) chartered with grant money from the Tinker Foundation to count nests and also used satellite images for their census.

Comparing the numbers with earlier surveys done in the 1980s, the scientists estimated that the number of breeding chinstrap penguins at Baily Head has dropped by 50 percent since the 1980s, and by as much as 39 percent just in the past seven years.

“For people that have been going down there for decades, it takes their breath away to see how few there are … they say it’s like a ghost town,” Lynch said. “The evidence for a significant decline is very strong. It didn’t surprise anybody … people could see these changes happening, but it was mostly from anecdotal reports.”

It’s difficult to quantify historic chinstrap penguin populations before the 1980s, but the trend from the past 25 years, coinciding with rapid warming in the region, is clear, she said.

“We now know that two of the three predominant penguin species in the Peninsula — chinstrap and Adélie — are declining significantly in a region where, in the last 60 years, it’s warmed by 5 degrees annually and by 9 degrees in winter, said Ron Naveen, founder of the nonprofit science and conservation organization, Oceanites, Inc. “By contrast, gentoo penguins, the third of these species, are expanding both its numbers and range. These divergent responses are an ongoing focus of our inventory work effort,” Naveen said.

Managing tourism

The results of the study should help inform decisions about tourism management at Baily Head and other locations, where previous discussions within the framework of the Antarctic Treaty proceeded without detailed information about penguin population trends.

Deception Island and Baily Head are among the most popular stops for visitors to Antarctica. Last year, about 1,500 tourists visited the chinstrap colony. Because the observed decline in chinstrap penguin numbers coincided with increases in visitation, there was speculation that tourism was impacting the penguins.

But surveys at other sites that are only rarely, or never, visited by tourists showed similar declines. Essentially, the researchers said their study showed no link between tourism and chinstrap penguin population declines.

“We wanted to make sure the Antarctic community didn’t get distracted by tourism and put the focus back on climate change, which seems to be the real issue here,” Lynch said.

There are other concerns related to Antarctic tourism, including a push toward more camping, the continued threat of invasive species, as as the issue of ship collisions and groundings, but at least for now, it appears that visitors aren’t contributing to the decline of the ice-loving sea birds.
Establishing solid baseline data on the penguin populations will also help researchers going forward as they try to determine the exact causes of the decline.

Counting krill

“People have been thinking about Adélies for a long time … they thought chinstrap penguins would benefit, that open-water species would do better,” Lynch said, describing the feeding habits of the various species and explaining that some of the existing models that relied solely on sea ice metrics may not encompass all the possible factors.

“Chinstraps don’t like to forage in sea ice, but they like to eat krill … the thinking is, there’s just not enough krill left to support the populations, but krill are amazingly difficult to survey.”

The decline in sea ice may be hampering the ability of krill populations to recruit new generations, she explained.

“In the juvenile stage of krill, they feed on algae on the underside of ice … that’s what allows them to recruit. It’s this incredibly important bottleneck for them to be able to feed on the underside of the sea ice,” she said, adding that krill populations tend to grow in pulses during “boom years.”

“The concern is, you have to have at least one boom in the life cycle of krill, but the booms are becoming less frequent. There are bigger gaps between years with heavy sea ice,” she said.
The bottom line is that there’s less food available for foraging penguins around the Antarctic Peninsula.

Lynch said she’s a member of an international working group established to try and determine if commercial krill fishing is also a factor.

“We just don’t know yet. Spatially-resolved data on fishing effort are not widely available,” she said.
Based on the fact that the two offshore-foraging species — chinstrap and Adélies — are declining, while gentoo penguins, which forage close to shore are increasing, there’s also a hypothesis that the comeback of humpback whales may be linked with the decline in krill populations, she concluded.

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Plans for giant Antarctic marine sanctuary falter

September 14, 2012 by Nick Perry
Enlarge

In this Dec. 1, 2006 photo released by Fish Eye Films, a small group of emperor penguin stand on the edge of an ice drift in the Ross Sea in the Antarctic. Antarctica's Ross Sea is often described as the most isolated and pristine ocean on Earth, a place where seals and penguins still rule the waves and humans are about as far away as they could be. But even here it has proven difficult, and maybe impossible, for nations to agree on how strongly to protect the environment. (AP Photo/Fish Eye Films, John Weller)

(AP)—Antarctica's Ross Sea is often described as the most isolated and pristine ocean on Earth, a place where seals and penguins still rule the waves and humans are about as far away as they could be. But even there it has proven difficult, and maybe impossible, for nations to agree on how strongly to protect the environment.

 

The United States and New Zealand have spent two years trying to agree on an Alaska-sized marine sanctuary where fishing would be banned and scientists could study climate change. U.S. Secretary of State Hillary Rodham Clinton took a strong interest in the outcome, regularly prodding diplomats, and New Zealand recently sent a delegation to Washington to reach a tentative deal.

That compromise, over a region that accounts for less than 2 percent of New Zealand's fishing industry, flopped this month when senior New Zealand politicians rejected it behind closed doors.
The U.S. and New Zealand have now sent competing plans to the 25 countries that meet annually each October to decide the fate of Antarctica's waters. Their inability to agree greatly increases the chances that nothing will get done.

Evan Bloom, director of the U.S. State Department's Office of Ocean and Polar Affairs, said the U.S. put a great deal of effort into its reserve proposal because it believes the Ross Sea is the best place on Earth for scientists to carry out studies away from the influence of mankind.
"If you can't do it in Antarctica, where can you do it?" said Bloom.

Both countries advocated for marine sanctuaries. The differences between the two plans seem small on a map, but they center on the areas of the sea where marine life is most abundant.

The U.S. does not have fishing interests in the Ross Sea, though fish caught there often end up in high-end American restaurants, marketed as Chilean sea bass.

The species is actually an ugly creature called the Antarctic toothfish. Fishermen from New Zealand, South Korea, Russia and other nations have been catching them in the Ross Sea since the 1990s. They use lines that can stretch more than a mile to catch about 100,000 of them a year.


Enlarge

In this Dec. 1, 2006 photo released by Fish Eye Films, a lone emperor penguin stands on the edge of an iceberg drift in the Ross Sea in the Antarctic. Antarctica's Ross Sea is often described as the most isolated and pristine ocean on Earth, a place where seals and penguins still rule the waves and humans are about as far away as they could be. But even here it has proven difficult, and maybe impossible, for nations to agree on how strongly to protect the environment. (AP Photo/Fish Eye Films, John Weller)

The U.S. aimed to reach an agreement with a nation that fishes the Ross Sea in hopes it would lead to a broader deal to protect marine habitats there.


New Zealand wanted to minimize disruption to its fisheries, but also wanted to burnish its conservation credentials. The country not only prides itself as an environmental leader, but it also makes money by marketing its clean, green image to trading partners and tourists. And it has criticized other nations' environmental records at sea, particularly nations that allow whaling.
Clinton urged diplomats to craft a deal. When she visited the Cook Islands last month, she described the Ross Sea as "one of the last great marine wilderness areas on the planet" and said the U.S. was working with other countries, "in particular New Zealand," to establish protected areas. Murray McCully, New Zealand's foreign affairs minister, echoed her comments.

Late last month, senior New Zealand diplomat Gerard van Bohemen led a team to Washington that spent four days grinding out the details of a compromise. After he brought the proposal back to New Zealand's ruling National Party, its senior Cabinet of lawmakers met in a closed session and rejected it.

Exactly why, they're not saying. Van Bohemen and Cabinet minister Steven Joyce declined to give interviews.

McCully also declined to discuss what happened, although he said in an email that New Zealand will keep working closely with the Americans.

The Ross Sea fishery is small on a global scale, worth about $60 million per year. The New Zealand Seafood Industry Council says New Zealand's Ross Sea catch accounts for just $16 million of a national industry worth over $1 billion.

But council spokesman Don Carson said New Zealand relies on dozens of species being fished in dozens of places. "None of them are huge, but they are very diverse, and we are keen not to lose any of them," he said.

Carson said the Ross Sea is being fished conservatively and sustainably, so further restrictions are unnecessary.

"We fish in a very limited area for a very limited season," he said. "We don't want to be buffeted by the winds of popular sentiment when that sentiment is based on a misapprehension of what's going on."
Antarctic fishing is regulated by the Commission for the Conservation of Antarctic Marine Living Resources, the 25-nation group scheduled to meet next month. Its executive secretary, Andrew Wright, said fishing in the Ross Sea is carefully regulated with quota limits set each year, and that available science points to the fishery being sustainable.

Peter Young, a New Zealander who recently directed an environmental advocacy documentary on the sea titled "The Last Ocean," said an international agreement that protects Antarctic land from exploitation should be extended to its seas.

"Almost every other ocean on earth has been impacted and affected by humanity," he said. "We're down to the last few places, and we've got to protect it and have something to hand on to future generations."

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Picky Penguins: Does Mate Choice Depend On Genes That Help Resist Disease?

 

Magellanic penguins. (Credit: Photo courtesy of J. L. Bouzat) 

 

ScienceDaily (Sep. 4, 2012) — Magellanic penguins have a high level of variation in genes associated with the ability to fight infectious disease, but a recent study found that the mechanism the penguins use to ensure that diversity is far from black and white.

Found exclusively south of the equator in South America, Magellanic penguins assemble in large nesting colonies along the coasts of Argentina, Chile, and the Falkland Islands. They typically mate for life, producing clutches of two eggs that are cared for by both parents. While individual colonies can number in the millions of birds, the species as a whole appears to be in decline, and is therefore classified as "Near Vulnerable" by the IUCN Red List.

A recent study published via Advance Access in the Journal of Heredity tested whether the significant diversity in the Major Histocompatibility Complex (MHC) genome region observed in these birds is attributable to mate choice or genetic selection based on disease exposure.

The study first confirmed that MHC diversity is high in these birds compared to other closely-related penguin species. Gabrielle Knafler, a graduate student at Bowling Green University and the first author of the study, explained, "By looking at the MHC genotypes of 50 breeding pairs of Magellanic penguins, we found considerable levels of genetic variation, detecting a significantly greater number of MHC variants or alleles than those reported for Galapagos penguins and Humboldt penguins." Forty-five alleles were found at the gene locus for the Magellanic penguins, sampled from a wild population in southern Patagonia, compared to 3 for Galapagos penguins and 7 for captive Humboldt penguins.

The authors of this study then investigated two possible mechanisms for maintaining the high MHC diversity in the Magellanic penguins: balancing selection, in which heterozygous individuals are better adapted to combat a wide range of diseases and are therefore more likely to survive to pass on their genes, and disassortative mating, or preferentially choosing a mate with a different MHC genotype.

How might a penguin know that a potential mate has different MHC genes? Smell could tell. Dr. Juan L. Bouzat of Bowling Green University, the lead scientist on the study, said, "In some species in which disassortative mating has been detected, individuals discriminate among potential mates by MHC type on the basis of olfactory cues."

To test the mechanism for maintaining MHC diversity, the authors studied the genetic variation of 50 breeding pairs of penguins. They examined whether MHC diversity was greater between breeding pairs as compared to random mating, and determined whether MHC genotype was correlated with measures of reproductive fitness, such as number of eggs hatched and number of chicks fledged.
Surprisingly, they found no direct evidence for disassortative mating based on the genotypes of the breeding pairs. Incidence of shared alleles between males and females in breeding pairs was not significantly different from what would be expected by chance.

But heterozygosity was found to be associated with increased fitness of adults, as heterozygous females hatched significantly more eggs and fledged significantly more chicks than homozygous females (in fact, none of the homozygous females that hatched eggs actually fledged any chicks). This finding suggests that a mechanism for balancing selection is at work in maintaining MHC diversity, even if it is not promoted by disassortative mating.

Other evidence for balancing selection was also found, including a gene phylogeny for MHC alleles from Magellanic, Humboldt, and Galapagos penguins. This analysis, akin to developing a "family tree" for genes, found that MHC alleles did not group together by species, suggesting that balancing selection has maintained different alleles even as species evolved over millions of years.

"There are likely other mechanisms at work as well," said Bouzat. "Spatial and temporal patterns in exposure to different pathogens may shape which alleles are favored at different times," changing selection pressures on the MHC genes. "The direct association of MHC genes with mechanisms of disease resistance suggests that the maintenance of MHC diversity could be driven by periodic selection due to different pathogens, similar to epidemics in humans."

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Story Source:

The above story is reprinted from materials provided by Journal of Heredity, via EurekAlert!, a service of AAAS.
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. G. J. Knafler, J. Alan Clark, P. Dee Boersma, J. L. Bouzat. MHC Diversity and Mate Choice in the Magellanic Penguin, Spheniscus magellanicus. Journal of Heredity, 2012; DOI: 10.1093/jhered/ess054

Journal of Heredity (2012, September 4). Picky penguins: Does mate choice depend on genes that help resist disease?. ScienceDaily. Retrieved September 6, 2012, from http://www.sciencedaily.com­ /releases/2012/09/120905163708.htm

Rare Find: Feathered Dinosaur Feasted On Flying Food

Holotype of Sinocalliopteryx gigas. (Credit: Xing et al., Abdominal Contents from Two Large Early Cretaceous Compsognathids (Dinosauria: Theropoda) Demonstrate Feeding on Confuciusornithids and Dromaeosaurids. PLoS ONE, 2012; 7 (8): e44012 DOI: 10.1371/journal.pone.0044012)

ScienceDaily (Aug. 29, 2012) — University of Alberta researchers found evidence that a feathered, but flightless dinosaur was able to snag and consume small flying dinosaurs.

The U of A paleontology team found the fossilized remains of three flying dinosaurs in the belly of a raptor-like predator called Sinocalliopteryx. Sinocalliopteryx was about two meters in length and roughly the size of a modern-day wolf.

Sinocalliopteryx's flying meals were three Confuciusornis. Confuciusornis was one of the earliest birds and had a crude version of a modern bird's skeleton and muscles. The researchers say such primitive birds were probably limited to slow take-offs and short flights.
According to the researchers, this is the first time a predator has been linked to the killing of multiple flying dinosaurs.

Scott Persons, a U of A paleontology student and research coauthor, says Sinocalliopteryx may have used stealth to stock the flyers. "Sinocalliopteryx didn't have wings or the physical tools needed to be an adept tree climber," said Persons.

Persons explains Sinocalliopteryx had feathers or hair-like fuzz covering its body creating a level of insulation that helped maintain a warm body temperature and high metabolism that required a lot of food to fuel.

"The fact that this Sinocalliopteryx had, not one, but three undigested birds in its stomach indicate it was a voracious eater and a very active hunter," said Persons.

This find was made in China's Liaoning province, and U of A researchers analyzed stomach contents of a second Sinocalliopteryx fossil discovery from that area. The researchers identified this Sinocalliopteryx's last meal as a Sinornithosaurus, a small feathered meat-eater about the size of a house cat that may have been able to fly or glide short distances.

"Sinornithosaurus is a relative of Velociraptor which means this is the first direct evidence of a raptor becoming another predatory dinosaur's meal," said Persons.

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Story Source:

The above story is reprinted from materials provided by University of Alberta, via EurekAlert!, a service of AAAS.
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. Lida Xing, Phil R. Bell, W. Scott Persons, Shuan Ji, Tetsuto Miyashita, Michael E. Burns, Qiang Ji, Philip J. Currie. Abdominal Contents from Two Large Early Cretaceous Compsognathids (Dinosauria: Theropoda) Demonstrate Feeding on Confuciusornithids and Dromaeosaurids. PLoS ONE, 2012; 7 (8): e44012 DOI: 10.1371/journal.pone.0044012

University of Alberta (2012, August 29). Rare find: Feathered dinosaur feasted on flying food. ScienceDaily. Retrieved August 30, 2012, from http://www.sciencedaily.com­ /releases/2012/08/120829171943.htm

Decline in Breeding Chinstrap Penguins in Antarctic Peninsula Confirmed

Chinstrap penguins at Baily Head, Deception Island. (Credit: Copyright Thomas Mueller)

 

ScienceDaily (Aug. 29, 2012) — In a paper published this week in the journal Polar Biology, researchers from the Antarctic Site Inventory confirm significant declines in the breeding population of chinstrap penguins in the vastly warming Antarctic Peninsula, where it's warming faster than, or as fast as, any other place on Earth.

New results and analyses stem from fieldwork conducted in December 2011 at Deception Island, one of the most frequently visited locations in Antarctica.

Overseen by Ron Naveen, founder of the nonprofit science and conservation organization, Oceanites, Inc., the Deception Island census effort analyses were undertaken by Dr. Heather Lynch, Assistant Professor of Ecology and Evolution at Stony Brook University, and chief scientist of the Antarctic Site Inventory project.

The Inventory has been collecting and analyzing Antarctic Peninsula-wide penguin population data since 1994, and these new findings have important implications both for the advancement of Antarctic science and the management of Antarctica by the Antarctic Treaty nations.

"Our Deception Island work, using the yacht Pelagic as our base, occurred over 12 days and in the harshest of conditions -- persistent clouds, precipitation, and high winds, the latter sometimes reaching gale force and requiring a lot of patience waiting out the blows," said Naveen. "But, in the end, we achieved the first-ever survey of all chinstraps breeding on the island."

The other Inventory researchers on the team were Steven Forrest (Oceanites, Inc.), Dr. Thomas Mueller (Biodiversity and Climate Research Centre), and Dr. Michael Polito (now at Woods Hole Oceanographic Institute). The scientific effort of the Inventory is supported by the U.S. National Science Foundation and public contributions, and the project's on-the-ground fieldwork at Deception Island was specifically supported by a grant from The Tinker Foundation. The Inventory is the only publicly supported science project working in Antarctica and the only science project tracking penguin populations throughout the entire Antarctic Peninsula region.

The scientific effort of the Inventory is supported by the U.S. National Science Foundation and public contributions, and the project's on-the-ground fieldwork at Deception Island was specifically supported by a grant from The Tinker Foundation. The Inventory is the only publicly supported science project working in Antarctica and the only science project tracking penguin populations throughout the entire Antarctic Peninsula region.

Deception Island is frequently visited and there has been speculation that tourism may have a negative impact on breeding chinstrap penguins -- especially, at Deception Island's largest chinstrap colony known as Baily Head. Previously, Antarctic Treaty-level discussions regarding the management of visitors at Baily Head proceeded in the absence of concrete site-wide census data.

The results and analyses, according to Dr. Lynch, shed new light on the massive changes occurring in this region.

"Our team found 79,849 breeding pairs of chinstrap penguins at Deception, including 50,408 breeding pairs at Baily Head. Combined with a simulation designed to capture uncertainty in an earlier population estimate, there is strong evidence to suggest a significant (>50%) decline in the abundance of chinstraps breeding at Baily Head since 1986/87.

"The decline of chinstrap penguins at Baily Head is consistent with declines in this species throughout the region, including at sites that receive little or no tourism; further, as a consequence of regional environmental changes that currently represent the dominant influence on penguin dynamics, we cannot ascribe any direct link in this study between chinstrap declines and tourism."

The Baily Head analysis was abetted by Dr. Lynch's cutting-edge analyses of high-resolution satellite imagery. Images were available for the 2002/03 and the 2009/10 seasons that suggest a 39% decline over that seven-year period, and which provide independent confirmation of this population decline. Via assistance from the U.S. National Science Foundation and a cooperative effort the University of Minnesota's Polar Geospatial Center, the Inventory continues to demonstrate the use of satellite imagery to analyze and describe environmental change in sensitive habitats.

"We now know," says Naveen, "that two of the three predominant penguin species in the Peninsula -- chinstrap and Adélie -- are declining significantly in a region where, in the last 60 years, it's warmed by 3˚ C. (5˚ F.) annually and by 5˚ C. (9˚ F.) in winter. By contrast, gentoo penguins, the third of these species, are expanding both its numbers and range. These divergent responses are an ongoing focus of our Inventory work effort."

Adds Lynch: "While there has been considerable focus in the policy and management community about the potential impact of tourism on these penguin populations, we cannot forget the overwhelming evidence that climate is responsible for the dramatic changes that we are seeing on the Peninsula. If tourism is having a negative impact on these populations, it's too small an effect to be detected against the background of climate change."

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Story Source:

The above story is reprinted from materials provided by Stony Brook University.
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. Ron Naveen, Heather J. Lynch, Steven Forrest, Thomas Mueller, Michael Polito. First direct, site-wide penguin survey at Deception Island, Antarctica, suggests significant declines in breeding chinstrap penguins. Polar Biology, 2012; DOI: 10.1007/s00300-012-1230-3

Stony Brook University (2012, August 29). Decline in breeding chinstrap penguins in Antarctic Peninsula confirmed. ScienceDaily. Retrieved August 30, 2012, from http://www.sciencedaily.com­ /releases/2012/08/120829103413.htm

Six-ton feathered dinosaurs once flocked in Denali region

Numerous tracks of therizinosaurs were found over the summer.

By MIKE DUNHAM
Anchorage Daily News

Published: August 21st, 2012 

 

Therizinosaurs weighed six tons, had a giraffe-length neck, claws like scimitars -- and feathers. Alaska once had a lot of them, said paleontologist Anthony Fiorillo. 

Anthony Fiorillo --->

Fiorillo, curator of earth sciences at the Perot Museum of Nature and Science in Dallas, and his colleague Thomas Adams published a paper in the June online edition of the scholarly journal Palaios identifying a single track found in Denali National Park as belonging to the odd plant-eating dinosaur related to Tyrannosaurus rex and the modern chickadee.

In an interview last week, Fiorillo said several more therizinosaur tracks were found in the park over the course of this summer.

Scientists have been baffled by this family of dinosaurs, originally thinking they were something like turtles. The first incomplete specimens came from Mongolia. More fossils were then found in China and North America. The Denali tracks are the first evidence that they were among the ancient reptiles that lived in high latitudes, sometimes called "polar dinosaurs." 

 

Perot Museum of Nature and Science

Anthony Fiorillo, curator of earth sciences at the Perot Museum of Nature and Science in Dallas, works to recover the remains of a horned pachyrhinosaur on the North Slope in 2006.

The biggest Therizinosaurus is estimated to have stretched 40 feet. Even the smallest member of the family was 7 feet from the tip of its tail to its tiny head. They walked on their hind legs -- very well, as it turns out. Despite those ferocious front-limb talons, which could be a yard long, they seem to have come from a meat-eating species that turned vegetarian. 

The purpose of the Edward Scissorhands-like claws is something of a mystery. They could have been used to scythe leaves or stalks, Fiorillo said. Therizinosaur is Greek for "reaping lizard."

Likewise, "The feathers are the source of a lot of speculation," Fiorillo said. Perhaps they were for display. Perhaps they helped the animal control its body temperature.

For purposes of identifying the Alaska animal as a therizinosaur, however, the important feature is its feet.

In their paper, Fiorillo and Adams document the configuration of the original Denali track, saying, "Four-toed theropod tracks are decidedly uncommon." Theropods are the suborder of dinosaurs to which therizinosaurs belonged. Only two groups have all four toes facing forward, the researchers note as they meticulously eliminate other possibilities. 

In the case of therizinosaurs, all four toes bear some weight. It's a design not unlike the human foot, built for walking rather then springing, perching, swimming or other things feet do.

And walk they did. The Palaios article includes a map showing a possible therizinosaur highway from Lake Baikal in Central Asia to central Canada by way of the Bering Land Bridge. It likely took generations for the clan to travel that far.

The Denali region, on the other hand, may have been a major seasonal migration corridor, similar to those used by the birds and fish that swarm into Alaska during the summer nowadays. It was a place where different species fed and mingled; the therizinosaur tracks were found in the same layer of "bedding plains" as a number of duck-billed dinosaur tracks. It was a family place; different-size prints show adults and juveniles traveling together.

The abundant signs of various dinosaurs and prehistoric birds in Denali suggest to Fiorillo a scene not unlike the African savannah, with the Cretaceous versions of wildebeest and zebra herds eying each other across the plain.

"Alaska is the best place on the planet to study a high latitude ecosystem in deeper geologic time," he said. "We have something we can contribute to the discussion of what a warming Arctic might look like."

"There's so much (paleontological) potential in this state," Fiorillo said. "You never know what's around the corner."

The Denali footprints supply something like a photograph of what was happening in the far North 70 million years ago or more, he said. "We don't have bones. But the tracks give us a component to the biodiversity of the area that we didn't have before."

The therizinosaur isn't the first feathered dinosaur found in Alaska. That honor probably belongs to the small, wide-eyed, big-brained carnivore Troodon, fossils of which were previously found on the North Slope. 

source 

Become an Antarctic explorer with panoramic imagery

Become an Antarctic explorer with panoramic imagery

July 17, 2012

In the winter of 1913, a British newspaper ran an advertisement to promote the latest imperial expedition to Antarctica, apparently placed by polar explorer Ernest Shackleton. It read, "Men wanted for hazardous journey. Low wages, bitter cold, long hours of complete darkness. Safe return doubtful. Honour and recognition in event of success." While the ad appears apocryphal, the dangerous nature of the journey to the South Pole is certainly not—as explorers like Roald Amundsen, Robert Falcon Scott and Shackleton himself discovered as they tried to become the first men to reach it.

Back in September 2010, we launched the first Street View imagery of the Antarctic, enabling people from more habitable lands to see penguins in Antarctica for the first time. Today we’re bringing you additional panoramic imagery of historic Antarctic locations that you can view from the comfort of your homes. We’ll be posting this special collection to our World Wonders site, where you can learn more about the history of South Pole exploration.

With the help of the Polar Geospatial Center at the University of Minnesota and the New Zealand Antarctic Heritage Trust, we’ve added 360-imagery of many important spots, inside and out, such as the South Pole Telescope, Shackleton's hut, Scott’s hut, Cape Royds Adélie Penguin Rookery and the Ceremonial South Pole.

The ceremonial South Pole (View Larger Map)

The interior of Shackleton’s Hut demonstrates the host of supplies used in early 20th century Antarctic expeditions—everything from medicine and food to candles and cargo sleds can be found neatly stored inside. (View Larger Map)

With this technology, you can go inside places like Shackleton’s Hut (pictured above) and the other small wooden buildings that served as bases from which the explorers launched their expeditions. They were built to withstand the drastic weather conditions only for the few short years that the explorers inhabited them, but remarkably, after more than a century, the structures are still intact, along with well-preserved examples of the food, medicine, survival gear and equipment used during the expeditions. Now anyone can explore these huts and get insight into how these men lived for months at a time.

The landscape outside of Robert Falcon Scott’s supply hut conveys just how desolate the area is. For these early explorers, the supply huts were an oasis of warmth and comfort in a cold and inhospitable landscape. (View Larger Map)

This new imagery was collected with a lightweight tripod camera with a fisheye lens—equipment typically used to capture business interiors through the Business Photos program. We worked with this technology because of its portability, reliability and ease-of-use (our Street View trikes wouldn’t be much use in the snow).

The goal of these efforts is to provide scientists and travel (or penguin) enthusiasts all over the world with the most accurate, high-resolution data of these important historic locations. With this access, schoolchildren as far as Bangalore can count penguin colonies on Snow Hill Island, and geologists in Georgia can trace sedimentary layers in the Dry Valleys from the comfort of their desks. Feel free to leave your boots and mittens behind, and embark on a trip to Antarctica.

Posted by Alex Starns, Technical Program Manager, Street View

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Bare Feet: Why So Warm (Download Great Podcast)

Bare Feet: Why So Warm

By Eric Sonstroem

Posted April 12, 2012

E

What keeps penguin's feet from freezing? Penguins' feet don't freeze because of the blood circulating in them.

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Photo: Bruce McAdam (Flickr)

The circulatory system of a penguin's legs and feet has evolved to lose as little heat as possible.

What keeps penguin’s feet from freezing?
Penguins’ feet don’t freeze because of the blood circulating in them.

The circulatory system of a penguin’s legs and feet has evolved to lose as little heat as possible, while keeping the penguin’s feet just above freezing. One way a penguin’s feet hold onto heat is by restricting the flow of blood in really cold weather. Actually, humans can do this too. That’s why your hands turn whiter in cold weather, there’s less blood in them.

Also, the tops of penguins’ legs work like a kind of natural heat-exchanger, cooling the blood from their bodies on the way to their feet, and heating the blood as it returns to their bodies. The arteries and veins here become very fine and interwoven. That way the feet only get pre-cooled blood, so there’s less heat to lose.

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Antarctica at Risk from Human Activities

 

 Penguins nest. (Credit: © Goinyk Volodymyr / Fotolia)

ScienceDaily (July 12, 2012) — The continent of Antarctica is at risk from human activities and other forces, and environmental management is needed to protect the planet's last great wilderness area, says an international team of researchers, including a Texas A&M University oceanographer, in a paper published in the current issue of Science magazine.

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Mahlon "Chuck" Kennicutt II, professor of oceanography who has conducted research in the area for more than 25 years, says Antarctica faces growing threats from global warming, loss of sea ice and landed ice, increased tourism, over-fishing in the region, pollution and invasive species creeping into the area. One of the longer-term concerns that may present the greatest threat overall is the potential for oil, gas and mineral exploitation on the continent and in the surrounding ocean, the authors note.
Kennicutt says the Antarctic Treaty System that governs the continent has worked well since it was established in 1962 and that 50 countries currently adhere to the treaty, but it is under pressure today from global climate changes and the ever-present interest in the area's natural resources, from fish to krill to oil to gas to minerals.

"Many people may not realize that Antarctica is a like a 'canary in a coal mine' when it comes to global warming, and Antarctica serves as a sort of thermostat for Earth," he points out. "The polar regions are the most sensitive regions on Earth to global warming, responding rapidly, so what happens in Antarctica in response to this warming affects the entire Earth system in many ways that we barely understand," Kennicutt explains. "Antarctica contains over 90 percent of the fresh water in the world, locked up as solid water in its massive ice sheets. Research that develops fundamental knowledge and understanding of these complex systems conducted in and from Antarctica is critical to understanding many of the challenges facing Earth today."

In addition to conducting research in the area, Kennicutt is also president of the Scientific Committee for Antarctic Research (SCAR), formed in 1958 to coordinate international research in the region.
More than twice the size of the United States, Antarctica has no cities, no government and no permanent residents. All who go to Antarctica are short-time visitors, whether they are scientists, personnel that support scientists or tourists. Antarctica is the coldest, driest and windiest location on Earth and is the only continent with no time zones.

"The Antarctic Treaty has worked well for the past 50 years, but we need to rethink how best to protect the continent from a range of growing of threats," Kennicutt adds.

"The treaty forbids oil or gas development, but it's possible that could be challenged in the years to come. Until now, energy companies have shown little interest in exploring the southern reaches of our planet because of the harsh conditions, the distance to market and the lack of technologies make it a very expensive commercial proposition.

"In the 1960s, most believed that drilling on the North Slope of Alaska was not economical, and in less than 30 years, it became one of the world's major sources of oil. Deep-water drilling today is practiced worldwide and subfloor completion technologies are rapidly advancing, so barriers in the past may soon be overcome increasing the threat to Antarctica in the not-so-distant future."
Another problem -- melting ice from several areas of Antarctica -- is a very real concern today, Kennicutt adds.

"A report in the news last week shows that sea-level rise on the east coast of the U.S. is occurring much faster than predicted," he notes.

"As the planet warms and the massive ice sheets break apart and melt, sea levels could continue to rise dramatically, not only in the U.S. but around the world. The ice sheets of Antarctica are known as the 'sleeping giants' in the ongoing debates about climate change and sea level rise. Scientists have only rudimentary understanding of how and when these 'giants' will contribute to sea level in the future."

He adds that the first explorers to Antarctica more than 100 years ago would be surprised to see how things have changed in the region.

For instance, it has been proven there are more than 300 sub-glacial lakes in Antarctica, some of them as big as the Great Lakes, and the huge ice sheets in the area flow like rivers to the ocean. He adds that growing tourism in the area and numerous scientific expeditions suggest that the prospect of permanent human settlements is not out of the question.

"All of these concerns pose serious challenges to conservation and protection efforts in Antarctica," Kennicutt notes.

"The bottom line is that we need to make sure that existing agreements and practices that address and respond to these threats are robust enough to last for the next 50 years, and that they truly provide the necessary protection of Antarctica that we all wish for and that we owe to future generations."

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Story Source:

The above story is reprinted from materials provided by Texas A&M University, via Newswise.
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. S. L. Chown, J. E. Lee, K. A. Hughes, J. Barnes, P. J. Barrett, D. M. Bergstrom, P. Convey, D. A. Cowan, K. Crosbie, G. Dyer, Y. Frenot, S. M. Grant, D. Herr, M. C. Kennicutt II, M. Lamers, A. Murray, H. P. Possingham, K. Reid, M. J. Riddle, P. G. Ryan, L. Sanson, J. D. Shaw, M. D. Sparrow, C. Summerhayes, A. Terauds, and D. H. Wall. Challenges to the Future Conservation of the Antarctic. Science, 13 July 2012: 158-159 DOI: 10.1126/science.1222821

Texas A&M University (2012, July 12). Antarctica at risk from human activities. ScienceDaily. Retrieved July 13, 2012, from ­source

Fossil Egg Links Dinosaurs to Modern Birds

Researchers have discovered a series of dinosaur eggs with a unique characteristic: they are oval in shape. The discovery supports the theory that birds and non-avian theropods, dinosaurs from the Cretaceous Period, could have a common ancestor. (Credit: Image courtesy of Universitat Autònoma de Barcelona)

ScienceDaily (July 12, 2012) — Researchers have discovered a series of dinosaur eggs with a unique characteristic: they are oval in shape. The discovery supports the theory that birds and non-avian theropods, dinosaurs from the Cretaceous Period, could have a common ancestor.

Before her death in December 2010, Nieves López Martínez, palaeontologist of the Complutense University of Madrid, was working on the research of dinosaur eggs with a very peculiar characteristic: an ovoid, asymmetrical shape. Together with Enric Vicens, palaeontologist of the Universitat Autònoma de Barcelona, the two scientists conducted an exhaustive analysis of their discovery, recently published in the journal Palaeontology.

The new type of dinosaur egg has been given the scientific name of Sankofa pyrenaica. The eggs were discovered in the Montsec area of Lleida, in two sites located on either side of the Terradets pass in Spain.

The South Pyrenean area is rich in dinosaur egg sites, most of which correspond to sauropod eggs from the upper Cretaceous, dating back more than 70 million years ago. During that period, the area was a coastal area full of beaches and deltas which won land from the sea through sediment accumulation. Sand and mud from that period gave way, millions of years later, to the sandstone and marl where dinosaur remains now can be found. On the beach ridges and flat coastal lands is where a large group of dinosaurs laid their eggs.

The sites where the discoveries were made correspond to the upper Cretaceous, between the Campanian and Maastrichtian periods, some 70 to 83 million years ago. The fossils found belong to small eggs measuring some 7 centimeters tall and 4 cm wide, while the eggshell was on average 0.27mm thick. Most of the eggs found were broken in small fragments, but scientists also discovered more or less complete eggs, which can be easily studied in sections. The eggs found at the sites all belong to the same species. The main difference when compared to other eggs from the same period is their asymmetrical shape, similar to that of chicken eggs. The more complete samples clearly show an oval form rarely seen in eggs from the upper Cretaceous period and similar to modern day eggs.
Their shape is a unique characteristic of theropod eggs from the upper Cretaceous period and suggests a connection with bird eggs. Non avian dinosaur eggs are symmetrical and elongated.

Asymmetry in bird eggs is associated to the physiology of birds: they take on this shape given the existence of only one oviduct which can form only one egg at a time. In this case the isthmus, the region in the oviduct creating the eggshell membrane, is what gives the egg its asymmetrical shape.

Thanks to this shape, the wider end contains a bag of air which allows the bird to breathe in the last stages of its development. This evolutionary step was still relatively underdeveloped in dinosaurs.
Thus, the egg discovered by UCM and UAB researchers may represent the missing link between dinosaurs and birds. Only one other egg, discovered in Argentina and corresponding to a primitive bird from the same period, has similar characteristics. The discover supports the theory that non avian theropods, the dinosaurs of the Cretaceous period, and birds could have had a common ancestor.

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Story Source:

The above story is reprinted from materials provided by Universitat Autònoma de Barcelona.
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. Nieves López-Martínez, Enric Vicens. A new peculiar dinosaur egg, Sankofa pyrenaica oogen. nov. oosp. nov. from the Upper Cretaceous coastal deposits of the Aren Formation, south-central Pyrenees, Lleida, Catalonia, Spain. Palaeontology, 2012; 55 (2): 325 DOI: 10.1111/j.1475-4983.2011.01114.x

Universitat Autònoma de Barcelona (2012, July 12). Fossil egg links dinosaurs to modern birds. ScienceDaily. Retrieved July 13, 2012, from source­ 

King Penguin Colony Getting Used to Humans

Jeanna Bryner, LiveScience Managing Editor

The researchers aren't sure if the king penguins are acclimating to humans and so don't get stressed when in their presence or if human presence weeded out those stress-sensitive penguins, leaving the copers behind. CREDIT: Vincent Viblanc View full size image

 
Updated Wednesday, July 11

Scientists studying king penguins on a sub-Antarctic island, along with tourists, may be stressing the waddling, flightless birds, new research suggests. However, it seems the penguins are getting used to their human visitors.

The new study reveals how more than 50 years of human presence, or the time since a permanent research station was set up, on Possession Island, has impacted a major colony of breeding king penguins (Aptenodytes patagonicus), called the "Baie du Marin" colony. Research reported last year on these penguins found that flipper tagging was linked with fewer chicks and a lower survival rate for the birds compared with untagged king penguins.


Turns out, according to the new study, penguins that are used to humans being around didn't get too upset by noise and human-presence stressors, though capturing these penguins for scientific measurements did cause a stress surge, according to the study published this week in the journal BMC Ecology.


"A central question for ecologists is the extent to which anthropogenic disturbances (e.g. tourism) might impact wildlife and affect the systems under study," lead researcher Vincent Viblanc of the University of Lausanne in Switzerland said in a statement. "One of the major pitfalls of such research is in forgetting that, from the perspective of the wildlife studied, tourism and scientific research are not two worlds apart."

In some ways, this island is perfect for studying stress in penguins. That's because some parts of the Baie du Marin colony have been exposed more intensely to humans than others, Viblanc told LiveScience. In disturbed parts of the colony scientists and tourists, sometimes in groups of tens, come into the presence of the penguins. A small number, about 50 birds, in this area are captured and handled by scientists one to five times each year. Meanwhile, another part of the colony is relatively undisturbed, Viblanc said, with one to two visits per week by scientists.

 

The king penguins come ashore on the sub-antarctic island to breed each year. Hundreds of the penguins waddle onto land to find a mate, and hopefully, make some chicks.
CREDIT: Pierre Bize

Viblanc and his colleagues compared 15 breeding penguins in these disturbed areas with 18 undisturbed penguins. All of the penguins were brooding a chick between 2 days and a month old.
To get a sense of the penguins' stress levels, the researchers measured their heart rates in response to three stressors: two low-intensity stressors that included a human approach to about 33 feet (10 meters) and a loud noise, meant to mimic tourists, scientists and noises from machines operating on the outskirts of the colony. The high-intensity stressor involved capturing a penguin to simulate what happens when scientists take direct measurements.

Compared with penguins from undisturbed areas, the disturbed penguins were less stressed by noise and approaching humans; the increase in heart rate above resting levels was much lower, 81 percent and 74 percent lower, in birds used to humans when they heard stressful sounds and saw humans approaching, respectively.

However, following capture, the human-acclimated penguins' maximum relative heart rate increased 42 percent higher than it did for undisturbed birds, though it recovered faster afterwards.
"Penguins habituate to the distant presence of human observers in disturbed areas, whereas they do not habituate to being captured," Viblanc wrote in an email to LiveScience. "This makes sense, as from an adaptive perspective, stress responses enable the organism to deal with life-threatening situations. Captures may indeed be assimilated as predation events from the birds, whereas the distant presence of observers poses no immediate threat."

Their findings can't tease out whether the lower heart-rate numbers in the highly disturbed areas are a result of penguins becoming habituated to human presence or if they are the result of a selection process. For instance, have penguins whose "animal personalities" are more susceptible to stress deserted these areas, leaving behind those that are better at coping, the researchers wonder.

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