Friday, October 26, 2012

The Peruvian Red Bellied Penguin


The Peruvian Red-bellied Penguin, one of the giant South American penguins, is easily recognizable for it's long beak and reddish-brown belly. It is more aggressive than usual for penguins, and it's big size (up to 1.5m) makes it a rather dangerous animal to handle.

PENGUIN PANIC: Is this volcano on Heard Island exploding?

  • Heard Island is a tiny speck of Australian territory near Antarctica
  • NASA says there are "signs of an eruption on Heard Island"
  • There is no one there, except for the penguins
Heard Island
Although not definitive, this NASA Earth Observatory image by Robert Simmon suggests an ongoing eruption. The dark summit crater is partially snow-free and the darker area could be lava flow within.
RELAX. Stay calm. Everything's almost certainly going to be OK. Unless you're a penguin. If you're a penguin, it may just pay to panic like hell. 

A volcano on Heard Island, a tiny uninhabited speck of Australian territory near Antarctica, may just be erupting.

It also may not be erupting. Nobody really knows. We contacted the Australian Antarctic Division in Hobart this afternoon, and they didn’t know.

So why would we think that a massive volcano could this minute be spewing poisonous fumes across pristine penguin colonies?

One word: NASA.

The US government space agency has a website called NASA Visible Earth, which publishes pictures taken by a range of satellites.

On October 23, after cobbling together a series of images dating back to October 13, NASA declared there were “signs of an eruption on Heard Island”.

It then stated:

“Although not definitive, this natural-color satellite image also suggests an ongoing eruption. The dark summit crater - much darker than Mawson [Peak]’s shaded southwestern face - is at least partially snow-free.

“There is also a faint hint of an even darker area - perhaps a lava flow - within. Shortwave infrared data shows hot surfaces within the crater, indicating the presence of lava in or just beneath the crater. Heavy cloud cover camouflaged what may have been a plume that erupted less than an hour after the image above was captured.”

Now you might think someone would have worked out by now whether there was in fact an eruption and whether that eruption is still happening. Well, not necessarily.

Not only is Heard Island uninhabited, but its unremarkable fauna and flora mean that it is often years between scientific visits.

No one is there, almost nobody is nearby, and pretty much no one cares whether one of the only two active volcanoes in Australian territory is blowing its top.

Except, of course, the penguins, who as you read this may well be lava-surfing using seals as surfboards.

Or not.


Fossils of First Feathered Dinosaurs from North America Discovered: Clues On Early Wing Uses


This is an artistic reconstruction of feathered ornithomimid dinosaurs found in Alberta. (Credit: Julius Csotonyi)
ScienceDaily (Oct. 25, 2012) — The ostrich-like dinosaurs in the original Jurassic Park movie were portrayed as a herd of scaly, fleet-footed animals being chased by a ferocious Tyrannosaurus rex. New research published in the journal Science reveals this depiction of these bird-mimic dinosaurs is not entirely accurate -- the ornithomimids, as they are scientifically known, should have had feathers and wings.

The new study, led by paleontologists Darla Zelenitsky from the University of Calgary and François Therrien from the Royal Tyrrell Museum of Palaeontology, describes the first ornithomimid specimens preserved with feathers, recovered from 75 million-year-old rocks in the badlands of Alberta, Canada.

"This is a really exciting discovery as it represents the first feathered dinosaur specimens found in the Western Hemisphere," says Zelenitsky, assistant professor at the University of Calgary and lead author of the study. "Furthermore, despite the many ornithomimid skeletons known, these specimens are also the first to reveal that ornithomimids were covered in feathers, like several other groups of theropod dinosaurs."

The researchers found evidence of feathers preserved with a juvenile and two adults skeletons of Ornithomimus, a dinosaur that belongs to the group known as ornithomimids. This discovery suggests that all ornithomimid dinosaurs would have had feathers.

The specimens reveal an interesting pattern of change in feathery plumage during the life of Ornithomimus. "This dinosaur was covered in down-like feathers throughout life, but only older individuals developed larger feathers on the arms, forming wing-like structures," says Zelenitsky. "This pattern differs from that seen in birds, where the wings generally develop very young, soon after hatching."

This discovery of early wings in dinosaurs too big to fly indicates the initial use of these structures was not for flight.

"The fact that wing-like forelimbs developed in more mature individuals suggests they were used only later in life, perhaps associated with reproductive behaviors like display or egg brooding," says Therrien, curator at the Royal Tyrrell Museum and co-author of the study.

Until now feathered dinosaur skeletons had been recovered almost exclusively from fine-grained rocks in China and Germany. "It was previously thought that feathered dinosaurs could only fossilize in muddy sediment deposited in quiet waters, such as the bottom of lakes and lagoons," says Therrien. "But the discovery of these ornithomimids in sandstone shows that feathered dinosaurs can also be preserved in rocks deposited by ancient flowing rivers."

Because sandstone is the type of rock that most commonly preserves dinosaur skeletons, the Canadian discoveries reveal great new potential for the recovery of feathered dinosaurs worldwide.
The fossils will be on display this fall at the Royal Tyrrell Museum in Drumheller, Alberta.

Story Source:
The above story is reprinted from materials provided by University of Calgary.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:
  1. D. K. Zelenitsky, F. Therrien, G. M. Erickson, C. L. DeBuhr, Y. Kobayashi, D. A. Eberth, F. Hadfield. Feathered Non-Avian Dinosaurs from North America Provide Insight into Wing Origins. Science, 2012; 338 (6106): 510 DOI: 10.1126/science.1225376

University of Calgary (2012, October 25). Fossils of first feathered dinosaurs from North America discovered: Clues on early wing uses. ScienceDaily. Retrieved October 26, 2012, from ­­ /releases/2012/10/121025150357.htm

Monday, October 8, 2012

Cut in half - Researchers document steep decline in chinstrap population at iconic site

Penguins on an island.
Photo Credit: ©Ron Naveen/Oceanites Inc.
Chinstrap penguins at Baily Head, Deception Island, off the Antarctic Peninsula. Researchers have documented at least a 50 percent decline in the population over the last 20 years. Various factors may be involved, but scientists don't believe tourism is a contributing factor.

An iconic chinstrap penguin colony on Deception Island, a popular stop for tourists to the Antarctic Peninsula, has declined by more than 50 percent in the last 25 years.

That’s the conclusion published last month in the journal Polar Biology by a team of researchers that spent 12 days in December 2011 counting individual penguin nests on the remote Antarctic island. The census found nearly 80,000 breeding pairs, with about 50,000 at a location called Baily Head.
The results were compared against a 1986-87 survey, refined with a simulation designed to capture uncertainty in the earlier population estimate by British Antarctic Survey (BAS) External Non-U.S. government site scientists.
It had already been known that the colony was in steady decline but no one had been able to quantify the plummet in population until now.

Patchy-looking island.
Photo Credit: ©Ron Naveen/Oceanites Inc.
An aerial view of chinstrap penguin colony at Baily Head, Deception Island.
Satellite image of an island.
Photo Credit: ©DigitalGlobe Inc.; Image provided by National Geospatial-Intelligence Agency Commercial Imagery Program
A satellite image shows chinstrap penguin colonies at Baily Head, Deception Island, in 2003.
“It was really nice to be able to put a number on the decline, since so many people were tossing around estimates that were not based in data,” said Heather Lynch External Non-U.S. government site, an assistant professor at Stony Brook University External Non-U.S. government site and co-author on the paper. “Now we at least know exactly the status of Deception, which is important both scientifically and for tourism.”

There has been concern by nations party to the Antarctic Treaty System External Non-U.S. government site that the population crash at Baily Head was due largely to tourism. During the 2010-11 season, 1,354 tourists visited Baily Head, a massive amphitheater of breeding chinstrap penguins on the island’s eastern shore. The common name for Pygoscelis antarctica comes from the thin black line that runs around the penguin’s head.

However, the drop in the chinstrap population at Baily Head is consistent with population declines of the species at other locations, including sites that receive little or no tourism, according to Ron Naveen, founder of Oceanites Inc. External Non-U.S. government site, a nonprofit organization that since 1994 has conducted the Antarctic Site Inventory, an ongoing census of the seabird populations around the Antarctic Peninsula.
Previously, the researchers had published results from surveys of 29 chinstrap colonies that found significant declines at 16 sites and increases at only seven. Another one of the so-called brushtailed penguins, Adélie numbers are also crashing along the northwestern Antarctic Peninsula. The third brushtailed species, gentoos, appears to be increasing in numbers. [See previous story — The big picture: Broad-scale study suggests sea ice not driving changes in penguin populations.]

Pressures from climate change are believed to be hurting the Adélie and chinstrap colonies off the Antarctic Peninsula, where temperatures have increased by about 3 degrees Celsius in the summer and almost double that in the winter. In particular, the Adélies rely on sea ice as a key habitat. And while subantarctic chinstraps aren’t as reliant on the seasonal pack ice, which is also shrinking in duration and extent, food sources such as krill graze on the algae that grow under the ice. Other factors may also be in play.

The team backed up its census data with a comparison of satellite imagery between the 2002-2003 and 2009-2010 summer seasons. During that seven-year period, the chinstrap population dropped by an estimated 39 percent, though there was a larger degree of uncertainty because of the difficulty involved in estimating nest density from the satellite imagery.

Chinstrap Penguin
Photo Credit: ©Ron Naveen/Oceanites Inc.
A chinstrap penguin at Baily Head, Deception Island.
Chinstrap adults with chick.
Photo Credit: ©Ron Naveen/Oceanites Inc.
Chinstrap penguin breeding pair with chick at Baily Head, Deception Island.
Chinstrap penguins walk up hill.
Photo Credit: ©Ron Naveen/Oceanites Inc.
Chinstrap penguins return to their nests from the small cove on the southwestern side of Baily Head, Deception Island.
“We do not yet have very sophisticated models for nesting density, but we are working on them, and these will fit nicely into everything we have developed to date and will allow us to shrink those error bars substantially,” Lynch said.

Despite the uncertainty, there was a remarkable correspondence between the field census and the satellite image counts, according to Lynch.

“The two census estimates were completed entirely independently using separate ‘pools’ of information,” she explained. “We were completely shocked at how close the two census estimates were to one another. I think this is a really incredible validation that the high-resolution satellite imagery can produce census data of the same quality as can be obtained in the field and, potentially, over a much larger scale.”

Lynch is a proponent of remote-sensing conservation, a growing field that uses satellite imagery to monitor wildlife populations. The technique has been used in the Antarctic to assess seal populations as well as penguin colonies. [See previous story — Eyes in the sky: Scientists use satellites to track health of seal, penguin populations in Antarctica.] She is also an advisory member of the Polar Geospatial Center (PGC) External U.S. government site, based at the University of Minnesota External Non-U.S. government site. PGC has access, through the National Geospatial-Intelligence Agency External U.S. government site, to high-resolution commercial satellite imagery.
Fortunately, for seasoned and enthusiastic field hands like Naveen, there’s still a need to visit and census the animals on the ground.
“The reason that we were able to use the satellite imagery so successfully is because we have a lot of ground truthing data — density estimates, photo-documentation, personal experience — and as we start expanding this approach, our investment in regional-scale census work is going to pay major dividends,” Lynch said.

Of course, the fieldwork isn’t as romantic as it sounds. The 12-day stint on Deception Island was as much a function of nasty weather — persistent clouds, precipitation and at times gale-force winds — as the desire to fill in a key gap in the Oceanites dataset, according to Naveen.

“Deception [has] never been fully censused in one season, let alone 12 days. Unfortunately, the weather was such that we never left Deception,” he said. “I wanted to make sure we had those data in hand and this coming season we’ll be doing more ‘gap’-filling work.”

In 18 years, Oceanites teams have conducted more than 1,200 census visits at 169 locations over an area covering more than 100,000 square kilometers. Naveen said he is eager to continue the census work, especially with the more sophisticated analytical tools employed by Lynch and her lab.
“Assessing and analyzing the changes now occurring in the peninsula is an engrossing and thoroughly complex undertaking,” he said. “The statistics and photo-analytical resources we have available, and the new ones that we’re developing, particularly in regard to using satellite photo-documentation … will give all of us a better understanding of what’s driving change in the vastly warming peninsula ecosystem.”


Thursday, October 4, 2012

Ecologists Start New Antarctic Season Comparing Animals' Handling of Adversity

A mother Weddell seal with her pup in front of Mt. Erebus in the Ross Sea, Antarctica. The tagged mother and pup are both part of MSU's long-term study of population dynamics in Weddell seals in Erebus Bay, Antarctica. (Credit: Photo by Jay Rotella, ecology department, Montana State University)
ScienceDaily (Oct. 3, 2012) — Montana State University ecologists who are about to return to Antarctica for another season had to adapt to dramatic changes in the sea ice last year.

Now they have published a paper that says the Weddell seals they monitor had to deal with some dramatic changes in ice in recent years, too. In fact, the seals handled the adverse conditions well and suffered less than the Emperor penguins in that region.

The paper was published Sept. 26 in the international journal, Proceedings of the Royal Society B: Biological Sciences. Lead author was Thierry Chambert, a doctoral student supervised by co-authors Bob Garrott and Jay Rotella in the MSU ecology department. Rotella and Garrott have just received a National Science Foundation grant for $867,272 that will extend their long-term study by five more years.

Last year, the researchers encountered unusually thin ice that was three feet thick instead of the usual 12 to 16 feet, Garrott said. Large cracks and active breaks threatened snowmobile travel. As a result, the faculty members and students moved their base camp to a safer spot and set up emergency camps around their study area. When they couldn't cross the ice on snowmobiles, they flew by helicopter.
In the course of their work, Rotella said the researchers saw how the Weddell seals faced their own challenges from massive icebergs that broke off and dramatically changed sea-ice conditions in a number of recent years.

Using data from 29 years, the team was able to compare seal numbers, as well as rates of pup production and adult survival, from before, during, and after the iceberg event, to learn how the seals fared. The number of seals they observed and the number of pups that were born during the peak of the iceberg event were down to unprecedented low numbers, but monitoring showed that, "the seals, in fact, handled the event quite well," Rotella said.

He explained that the seals were able to maintain high survival rates by lowering their breeding efforts during the years of iceberg presence. They tended to avoid breeding colonies when sea-ice conditions were particularly unfavorable.

The Emperor penguins, however, continued their normal activities during the worst of the iceberg event. The result was dramatic with dying penguins, as well as breeding failures, Rotella said. He noted that moving ice crushed eggs and even some adults at the peak of the iceberg event. Exhaustion and starvation might also have been an issue for penguins that walked across the ice from open water to their nesting colonies.

"These results reveal that, depending on their ecology, different species can suffer different impacts from an extreme environmental disturbance," said Rotella, the new leader of the Weddell seal study.
"The results also reveal the importance of having long-term data to evaluate possible effects," Rotella continued. "Without the data, we couldn't have known whether this extreme environmental event had extreme consequences for the seals or not. Fortunately for the seals, it did not. We learned that the seals were quite capable of riding out the massive changes in ice conditions as long as they didn't persist too long."

Rotella said the relationship between thinner ice and icebergs is outside of his field of expertise, but he said that ice provides protection from predators like orcas and leopard seals. It also serves as a platform for Weddell seals in the first few weeks of their lives when they have little fat for staying warm in the water and can't swim well yet. When the ice is thinner, predators have better access to the breeding areas used by penguins and Weddell seals for rearing their young. It is also easier for storms to shatter the ice sheets and for the area to have open water.

No one knows what this season will bring for sea-ice conditions, but the MSU researchers said they hope it isn't a repeat of last year.

"That was very challenging," Garrott said. "We really don't know what the ice conditions are like this year until we get down there."

This year's field season will run from about Oct. 10 to mid-December, with Rotella going down for the first half of the season and Garrott for the second half. Mary Lynn Price, a video journalist who has joined the group for the past two seasons, will be there for three weeks in the middle, with her stay overlapping Rotella's and Garrott's.

Price will again produce a variety of videos and other materials that will be available to the public.
This will be the 45th season for the study that Garrott and Rotella took over around 2001 from Don Siniff at the University of Minnesota. Initiated by Siniff, the study is one of the longer running animal population studies and the longest marine mammal study in the southern hemisphere. It not only focuses on changes in the Weddell seal population, but it yields broader information about the workings of the marine environment. The study incorporates information on sea ice, fish, ecosystem dynamics, climate change, and even the Antarctic toothfish, which is marketed in U.S. restaurants as Chilean sea bass.

The MSU study concentrates on pups and adult breeding females that live in the Ross Sea, which is the most pristine ocean left in the world and the only marine system whose top predators -- including the Weddell seal -- still flourish.

The researchers start the season by weighing and tagging every pup when it's about two days old. Later in the season, they visit every colony in their study, collecting genetic samples and recording every tag they find. Weddell seals are relatively gentle for being a top predator in the ecosystem, but they can weigh over 1,000 pounds and have a set of teeth like a bear's, Garrott has said in the past.

Story Source:
The above story is reprinted from materials provided by Montana State University.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:
  1. T. Chambert, J. J. Rotella, R. A. Garrott. Environmental extremes versus ecological extremes: impact of a massive iceberg on the population dynamics of a high-level Antarctic marine predator. Proceedings of the Royal Society B: Biological Sciences, 2012; DOI: 10.1098/rspb.2012.1733

Montana State University (2012, October 3). Ecologists start new Antarctic season comparing animals' handling of adversity. ScienceDaily. Retrieved October 4, 2012, from­ /releases/2012/10/121003132414.htm