Wednesday, December 23, 2009

First Report of Venom in Bird Lineage

This image of fossilized Sinornithosaurus shows the raptor's long, grooved fangs. It lived in prehistoric forests of northeastern China that were filled with a diverse assemblage of animals including other primitive birds and dinosaurs. (Credit: David A. Burnham, PhD, University of Kansas, Biodiversity Institute)

Poisonous Prehistoric 'Raptor' Discovered in China

ScienceDaily (Dec. 22, 2009) — A group of University of Kansas researchers working with Chinese colleagues have discovered a venomous, birdlike raptor that thrived some 128 million years ago in China. This is the first report of venom in the lineage that leads to modern birds.

"This thing is a venomous bird for all intents and purposes," said Larry Martin, KU professor and curator of vertebrate paleontology at the Natural History Museum and Biodiversity Institute. "It was a real shock to us and we made a special trip to China to work on this."

The KU-China team's findings will be published in the early edition of the Proceedings of the National Academy of Sciences during the week of Dec. 21. "We think it's going to make a big splash," said Martin.
The article's authors are Enpu Gong, geology department at Northeastern University in Shenyang, China, and researchers Martin, David Burnham and Amanda Falk at the KU Natural History Museum and Biodiversity Institute.

The dromaeosaur or raptor, Sinornithosaurus (Chinese-bird-lizard), is a close relative to Velociraptor. It lived in prehistoric forests of northeastern China that were filled with a diverse assemblage of animals including other primitive birds and dinosaurs.

"This is an animal about the size of a turkey," said Martin. "It's a specialized predator of small dinosaurs and birds. It was almost certainly feathered. It's a very close relative of the four-winged glider called Microraptor."
The venom most likely sent the victim into rapid shock, shrinking the odds of retaliation, escape or piracy from other predators while the raptor manipulated its prey.

"You wouldn't have seen it coming," said Burnham. "It would have swooped down behind you from a low-hanging tree branch and attacked from the back. It wanted to get its jaws around you. Once the teeth were embedded in your skin the venom could seep into the wound. The prey would rapidly go into shock, but it would still be living, and it might have seen itself being slowly devoured by this raptor."

The genus had special depressions on the side of its face thought by the investigators to have housed a poison gland, connected by a long lateral depression above the tooth row that delivered venom to a series of long, grooved teeth on the upper jaw. This arrangement is similar to the venom-delivery system in modern rear-fanged snakes and lizards. The researchers believe it to be specialized for predation on birds.
"When we were looking at Sinornithosaurus, we realized that its teeth were unusual, and then we began to look at the whole structure of the teeth and jaw, and at that point, we realized it was similar to modern-day snakes," Martin said.

Sinornithosaurus is represented by at least two species. These specimens have features consistent with a primitive venom-delivery system. The KU-China research team said it was a low-pressure system similar to the modern Beaded lizard, Heloderma, however the prehistoric Sinornithosaurus had longer teeth to break through layers of feathers on its bird victims.

The discovery of features thought to be associated with a venom-delivery system in Sinornithosaurus stemmed from a study of the anatomy and ecology of Microraptor by the joint Chinese-KU team. They now are seeking to discover if Microraptor may have possessed a similar poison-delivery system.

Story Source:
Adapted from materials provided by University of Kansas, via EurekAlert!, a service of AAAS.

University of Kansas. "Poisonous Prehistoric 'Raptor' Discovered in China." ScienceDaily 22 December 2009. 23 December 2009 <­ /releases/2009/12/091221212630.htm>.

Monday, December 14, 2009

Scientists make penguin DNA discovery

Scientists make penguin DNA discovery at ZSL 

Monday, 14, Dec 2009 12:01

By Sarah Garrod.

Scientists have developed a new penguin DNA profiling technique which is being used for the first time to study how they migrate between colonies.

Researchers from the Zoological Society of London (ZSL) and the University of Sheffield have identified genetic markers that can be used to track the movement of penguins.

They say ultimately the discovery could determine whether Antarctica's changing climate is driving penguins from their favoured breeding sites.

ZSL's own penguinologist, Tom Hart said: "Knowing how penguins are responding to climate change is vital to conservation efforts.

"If we understand how their populations are changing, we can do something about it, such as making sure that our protected areas are in the right place for penguins in 100 years time."

The researchers say penguins are not only threatened by climate change, but are also under increasing pressure from direct competition with fisheries.

Studying them is notoriously difficult because they live in very harsh environments and are hard to track, therefore this new monitoring tool enables scientists to follow their populations and address the threats that they face.


Tuesday, November 17, 2009

Penguins and Sea Lions Help Produce New Atlas

Southern elephant seals were fitted with GPS collars to help provide data for the new atlas. (Credit: Valeria Falabella/Wildlife Conservation Society)

Penguins and Sea Lions Help Produce New Atlas

ScienceDaily (Nov. 16, 2009) — Recording hundreds of thousands of individual uplinks from satellite transmitters fitted on penguins, albatrosses, sea lions, and other marine animals, the Wildlife Conservation Society (WCS) and BirdLife International have released the first-ever atlas of the Patagonian Sea -- a globally important but poorly understood South American marine ecosystem.

The atlas contains the most accurate maps ever assembled for this ecosystem revealing key migratory corridors that span from coastlines to deep-sea feeding areas off the continental shelf hundreds of miles away.

Data for the atlas was gathered by a team of 25 scientists working over a 10-year period -- many of them supported by the National Research Council of Argentina (CONICET). The team tracked 16 species of marine animals, which produced some 280,000 individual uplinks of data over the Patagonian Sea, a huge area ranging from southern Brazil to southern Chile.

Called Atlas of the Patagonian Sea: Species and Spaces, the 300-page book was edited by Valeria Falabella and Claudio Campagna of the Wildlife Conservation Society, and John Croxall of Birdlife International.

The atlas, which is in English and Spanish, will be used to help inform potential policy decisions in the region such as managing fisheries and charting transportation routes of oil tankers. This vast region, which spans 3 million square kilometers (1.1 million square miles), is becoming increasingly threatened by burgeoning development and overfishing.

"This unprecedented atlas was essentially written by the wildlife that live in the Patagonian Sea," said Dr. Claudio Campagna who runs the Wildlife Conservation Society's "Sea and Sky" initiative. "The atlas helps fill in many gaps of knowledge and should serve as a blueprint for future conservation efforts in this region."

"This is an exceptional collaborative achievement; now that we know where some of the region's most important marine areas are, they need to receive appropriate protection and management," said John Croxall, Chair of BirdLife's Global Seabird Programme.

The atlas underscores the need to establish a new network of marine protected areas that would include open-sea environments that are linked to key coastal areas. Many of the species tracked travel vast distances between coastal breeding grounds and feeding areas. For example, satellite data revealed that southern elephant seals travel more than 10,000 kilometers (6,200 miles) during an average season at sea, and an additional 10,000 kilometers in repeated vertical dives for food.

"The Patagonian Sea is a remarkable intersection of global physics, marine biodiversity, and climate and economic change," said Dr. Steven E. Sanderson, President and CEO of the Wildlife Conservation Society. "The Atlas of the Patagonian Sea will advance conservation of this region and can serve as a roadmap for the creation and management of future marine protected areas -- of which there are precious few worldwide."

The list of species tracked for the atlas includes five species of albatross, three species of petrel, four varieties of penguin, two fur seal species, the South American sea lion, and the southern elephant seal.

The completion of the Atlas of the Patagonian Sea is due in large part to the generosity and long-standing support of the Liz Claiborne and Art Ortenberg Foundation for the WCS "Sea and Sky" initiative. Additionally, WCS's conservation work in this region has been supported by the Mitsubishi Foundation for the Americas and Mr. and Mrs. James M. Large, Jr.
Adapted from materials provided by Wildlife Conservation Society, via EurekAlert!, a service of AAAS.

Wildlife Conservation Society. "Penguins and sea lions help produce new atlas." ScienceDaily 16 November 2009. 17 November 2009 .

Thursday, November 12, 2009

News: Penguin DNA

Adelie penguins have survived in Antarctica for thousands of years and are invaluable for genetic research. (Credit: Image courtesy of Oregon State University)

Ancient Penguin DNA Raises Doubts About Accuracy Of Genetic Dating Techniques

ScienceDaily (Nov. 10, 2009) — Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been routinely underestimating the age of many specimens by 200 to 600 percent.

In other words, a biological specimen determined by traditional DNA testing to be 100,000 years old may actually be 200,000 to 600,000 years old, researchers suggest in a new report in Trends in Genetics, a professional journal.

The findings raise doubts about the accuracy of many evolutionary rates based on conventional types of genetic analysis.

"Some earlier work based on small amounts of DNA indicated this same problem, but now we have more conclusive evidence based on the study of almost an entire mitochondrial genome," said Dee Denver, an evolutionary biologist with the Center for Genome Research and Biocomputing at Oregon State University.

"The observations in this report appear to be fundamental and should extend to most animal species," he added. "We believe that traditional DNA dating techniques are fundamentally flawed, and that the rates of evolution are in fact much faster than conventional technologies have led us to believe."

The findings, researchers say, are primarily a challenge to the techniques used to determine the age of a sample by genetic analysis alone, rather than by other observations about fossils. In particular, they may force a widespread re-examination of determinations about when one species split off from another, if that determination was based largely on genetic evidence.

For years, researchers have been using their understanding of the rates of genetic mutations in cells to help date ancient biological samples, and in what's called "phylogenetic comparison," used that information along with fossil evidence to determine the dates of fossils and the history of evolution. The rates of molecular evolution "underpin much of modern evolutionary biology," the researchers noted in their report.

"For the genetic analysis to be accurate, however, you must have the right molecular clock rate," Denver said. "We now think that many genetic changes were happening that conventional DNA analysis did not capture. They were fairly easy to use and apply but also too indirect, and inaccurate as a result."

This conclusion, researchers said, was forced by the study of many penguin bones that were well preserved by sub-freezing temperatures in Antarctica. These penguins live in massive rookeries, have inhabited the same areas for thousands of years, and it was comparatively simple to identify bones of different ages just by digging deeper in areas where they died and their bones piled up.

For their study, the scientists used a range of mitochondrial DNA found in bones ranging from 250 years to about 44,000 years old.

"In a temperate zone when an animal dies and falls to the ground, their DNA might degrade within a year," Denver said. "In Antarctica the same remains are well-preserved for tens of thousands of years. It's a remarkable scientific resource."

A precise study of this ancient DNA was compared to the known ages of the bones, and produced results that were far different than conventional analysis would have suggested. Researchers also determined that different types of DNA sequences changed at different rates.

Aside from raising doubts about the accuracy of many specimens dated with conventional approaches, the study may give researchers tools to improve their future dating estimates, Denver said.

Collaborators on the research included scientists from OSU, Griffith University in Australia, the University of Auckland in New Zealand, Massey University in New Zealand, University of North Carolina in Wilmington, the Scripps Research Institute, and Universita' di Pisa in Italy.

The studies were supported by the National Science Foundation, National Geographic Society, and other agencies.
Adapted from materials provided by Oregon State University.

Oregon State University. "Ancient Penguin DNA Raises Doubts About Accuracy Of Genetic Dating Techniques." ScienceDaily 10 November 2009. 12 November 2009 <­ /releases/2009/11/091110135411.htm>.

Monday, November 2, 2009

Changing Diet

Cape Adare is home to the largest Adélie penguin colony in Antarctica. Until about 200 years ago, when humans decimated whale and seal populations, the penguins subsisted mainly on fish. But the ensuing surplus of krill created by the dearth of top predators caused a shift in diet. Photo Credit: Steve Emslie

Photo Credit: Michael Polito
Adélie penguins march along Brown Bluff at the northern end of the Antarctic Peninsula.

Changing diet
Krill surplus 200 years ago may have caused penguins to shift prey preferences
By Peter Rejcek, Antarctic Sun Editor
Posted October 30, 2009

Most of us have heard the oft-repeated phrase, “You are what you eat.” Turns out it’s not just a way for your mother to nag you about your poor eating habits.

By studying the tissue remains of penguins in Antarctica, scientists are not only learning more about the modern diet of the continent’s iconic seabird but also what was on the menu thousands of years ago. And that information can provide insight into past climate and penguin behavior, as well as how the species could respond to future climate changes.

Steve Emslie External Non-U.S. government site, a marine ornithologist in the Department of Biology and Marine Biology External Non-U.S. government site at the University of North Carolina Wilmington External Non-U.S. government site, and his team are in the midst of a five-year grant from the National Science Foundation (NSF) External U.S. government site to determine how changes in climate and penguin prey dynamics have influenced the seabird population.

Much of their work involves collecting tissue samples, such as eggshells and feathers, from existing penguin colonies and long-extinct ones around the Antarctic Peninsula and the Ross Sea regions. Then they analyze the samples in the lab, looking at the ratios of carbon and nitrogen stable isotopes, which can provide important clues to what’s been on the dinner plate throughout the year.

“It’s mainly based on the fact that you are what you eat,” explained Emslie, who will return to McMurdo Station External U.S. government site and Ross Island this summer season to continue his fieldwork as the principal investigator (PI) on the project. “Whenever you eat something, you’re absorbing the carbon and nitrogen isotopes that are stored in that food. That ratio of carbon and nitrogen isotopes will be a part of your tissues as long as you’re eating that food.”

For example, shifts in carbon isotope ratios can indicate if a bird feeds inshore or in the marine environment. Nitrogen isotope ratios indicate how far up or down an animal feasts on the food chain.

“We look at that as a way to assess diet and how it has shifted through time as well with the Pygoscelis penguins, and also through space by the different colonies in the different regions of the Antarctic,” Emslie said.

In a study published two years ago in the journal Proceedings of the National Academy of Sciences, Emslie and collaborator William Patterson suggested that the krill-centric diet of today’s Adélie penguin is a recent phenomenon, a shift that occurred maybe 200 years ago. Their suggestion is based on a change in the nitrogen stable isotope ratio in penguin tissue.

Two hundred years ago is about the time when whalers began decimating the waters around Antarctica of krill-eating whales and seals, creating what Antarctic scientists in the 1960s and 1970s labeled as a “krill surplus,” Emslie said.

“It makes sense,” he said. “Krill per gram are just as rich in protein as fish but during a krill swarm, you can gather a lot more food a lot more quickly than you could in a school of fish. We think that’s probably why they did that switch — when krill became more abundant — even though fish were probably still available.”

Now the scientists are testing the idea further by looking at gentoos, another Pygoscelis penguin, a mostly subantarctic bird that is pushing its way across the northern end of the Antarctic Peninsula as the climate there warms and the Adélie population declines.

“We’re not sure it will show up because gentoos are known to eat a lot more fish and squid in their diet anyway compared to Adélies,” Emslie said.

The scientists know the shift in diet for the Adélies in the Ross Sea region is relatively recent because tissue samples dating back at least 40,000 years from extinct colonies in the region suggest a diet richer in fish. “Surprisingly, there weren’t any noticeable shifts [in diet] between warm and cold [periods] that are known from ice core records,” Emslie said.

“That was kind of a surprise as to why there would be a sudden shift in diet historically that wasn’t related with these climate intervals,” he said, referring to the krill surplus that resulted from whaling.

Emslie said it’s difficult to pin down an exact date on when Adélies began to prefer krill, but it was certainly happening by the beginning of the 20th century based on an analysis of Adélie eggs stored in explorer Robert F. Scott’s Hut on Cape Evans that were collected from a nearby colony sometime between 1911-1917.

“They became a nice historical sample to run isotope analysis on to see if the dietary switch had occurred by the early 1900s, and the data suggest that it had,” Emslie said. “On the peninsula you would expect it to occur first because it was hit hard first by the sealers and whalers.”

Research suggests modern Adélie diet not as krill-centric as scientists once thought

Michael Polito External Non-U.S. government site, a graduate student in Emslie’s lab External Non-U.S. government site and co-principal investigator on the project, has been working around the Antarctic Peninsula collecting penguin tissue samples from extant, or existing, colonies. By comparing the data from the stable isotope analysis to what other penguin researchers have found by physically looking at the stomach contents of the penguins, Polito hopes to refine the isotope methodology.

“They’re both useful, especially when you can use them together you can get more information than you could get just by one method alone,” he said.

For instance, it’s possible to determine the exact species of fish from stomach contents, but underestimate the mass of fish consumed, as fish digest rapidly in a penguin’s stomach, Polito said. In contrast, the stable isotope method can’t readily determine what fish species the penguins are eating, but it can provide a good estimate on how much fish the penguins consume versus krill and other prey in the ocean.

In addition, stomach content data are limited to when the penguins are on land rearing their chicks. The isotope method can also provide information about penguin diets outside of the breeding season.

And based on early results, it appears the Adélies aren’t always as reliant on krill as one might suppose from looking at what’s in their bellies during the austral summer.

“We’re definitely finding that the isotopes in general do predict a higher composition of fish in the diet than the stomach content do. It still looks like during the chick-rearing period krill are still dominant,” Polito said. “Based on the isotope data, fish appear to be relatively more important to penguins during the pre-breeding period than the breeding period.”

That finding is important but puzzling. Researchers working along the Antarctic Peninsula have reported that Adélie colonies are disappearing, their fate apparently linked to the diminishing sea ice in the region from warming temperatures. Krill also use sea ice as a key habitat. Hence, the Adélies face a double climate whammy — loss of their sea ice habitat and loss of a primary prey.

But if fish still remain a staple, why are Adélie numbers declining so dramatically? Scientists don’t really have an answer at this point. Emslie noted that part of the problem is that fish have become highly depleted as well from fisheries. “That means they have no other choices left,” he said of the Adélies.

Polito’s work to improve the isotope methodology also involves determining what other variables may be at work influencing the carbon and nitrogen ratios. For example, it turns out the size of the krill — from the juvenile stage to the adulthood — might affect their stable isotope ratio.

“Once we know how variable krill is and why it’s variable, that’s going to allow us to predict with greater accuracy the penguin diet itself.

“The modern work that we do is really designed to gain more insight about the past as well as the future,” Polito added. “We want to know how penguins respond to changes in their environment, be it climate or food availability.”

NSF-funded research in this story: Steven Emslie, Michael Polito and William Patterson, University of North Carolina Wilmington, Award No. 0739575


Penguins on the Edge

Scientists use screens to sift through dirt on Beaufort Island, searching for remains of ancient penguin colonies. Ornithologist Steve Emslie has found remains as old as 40,000 years on Beautfort Island.

A scientist examines molt layers in a glacial moraine on Beaufort Island.

Penguins on the edge
Location of ancient colonies follow the ebb and flow of Antarctic ice
By Peter Rejcek, Antarctic Sun Editor
Posted October 30, 2009

Location, location, location. For marine ornithologist Steve Emslie External Non-U.S. government site, the long-abandoned homes of Adélie penguins in Antarctica are markers in time that help define how far the continent’s ice sheets advanced and retreated for the last 45,000 years.

“The whole pattern of the colonies coming in and out of the Ross Sea fits really nicely with the forward and backward movement of the ice sheet,” said Emslie, the principal investigator on a National Science Foundation External U.S. government site grant to study how population dynamics of the three Pygoscelis penguin species in Antarctica relate to changes in prey availability and climate.

Scientists have a pretty good idea of what the climate in Antarctica was like over the last 45 millennia thanks largely to the atmospheric record from ice cores. Less well known is the location of the ice sheet edge as the atmosphere alternately warmed and cooled.

By locating and dating Adélie penguin colonies, mainly in the Ross Sea region, Emslie has been able to interpret how the ice moved. That’s because penguins re-establish their seasonal colonies in the same ice-free areas every year unless conditions force them to move.

For instance, in a study published in Geology in 2007, Emslie and his colleagues, geologists Larry Coats and Kathy Licht, determined from the existence of former colonies along the Victoria Land coast that open water existed in the southern Ross Sea from about 40,000 to 27,000 years ago. Then the ice began to advance, reaching as far as Coulman Island, about 300 kilometers north of the current edge of the Ross Ice Shelf External U.S. government site.

The climate pendulum began to swing the other away about 13,000 years ago with the start of the warmer Holocene. As the ice retreated back south, the penguins returned and re-colonized the coast, especially the Scott Coast in the southern Ross Sea, Emslie said.

Then, about 2,000 years ago, a cold snap or perhaps the presence of too much sea ice, caused the penguins to leave their colonies for a thousand years, most apparently retreating to Cape Adare far to the north, where radiocarbon dates indicate that occupation began there at that time.

“Cape Adare is now the largest Adélie penguin colony in the Antarctic, but it is definitely not the oldest,” Emslie noted.

Even after ice conditions became more favorable for the Adélies to return south, they didn’t, except for some apparently intrepid birds that founded the large colonies around Ross Island today, according to Emslie.

“So far, the data indicate that Adélie penguins, even though they’re super abundant on Ross Island today, that only occurred in the last 500 years,” he said. “They still have not reoccupied the Scott Coast, probably because of persistent annual sea ice that blocks access to that shoreline.”

Emslie and members of his research team, including a geologist from China, will revisit previous sites at Cape Bird and Cape Crozier to collect more tissue samples such as feathers, eggshells and even mummified bodies. The scientists use the organic material for radiocarbon dating — measuring the radioactive decay of radioisotope carbon-14 — to determine the age of the remains.
Molt layers in a glacial moraine.
Photo Credit: Steve Emslie
A scientist examines molt layers in a glacial moraine on Beaufort Island.

The field plan also calls for searching for more remains on Beaufort Island, which hosts the oldest samples, dating back more than 40,000 years.

Emslie’s group is one of very few using the historical location of animals like penguins to interpret ice conditions in the past. Another team, led by Brenda Hall External Non-U.S. government site with the University of Maine External Non-U.S. government site, has done similar work in the region using abandoned elephant seal colonies. [See previous article: Cradle to grave.]

Any differences? Well, it sounds like it’s much easier to locate lost penguin colonies than elephant seal colonies, where there are no definite signs to mark the remains, requiring the researchers to get down on hands and knees to search for bits of tissue from skin and hair.

Not so with Adélie penguin colonies, where the birds stack pebbles into little mounds to make a nest.

“Once you have an eye for what an abandoned colony looks like, they stand out pretty well. You can often see them from a distance away,” Emslie said. “I scan large areas with binoculars and tell whether or not abandoned sites are possible.”

Then it’s a matter of digging into the ground in tightly controlled increments, screening for samples. “You excavate them like an archaeological site,” he explained.

“There’s no other place in the world where you can have such good preservation of the same species through time that is also a good indicator of environmental change like the Adélie penguin. There’s nothing in the Arctic that we can use like that,” Emslie said.

“I think it’s pretty remarkable, pretty unique to be able to do this in the Antarctic with these preserved, ancient colonies, some as old as 40,000 years looking like they were abandoned yesterday.”


Wednesday, October 14, 2009

Penguin Food: How 'superswarms' of krill gather

Krill swarm from above
An extraordinary gathering

Antarctic krill (Euphausia superba)

How 'superswarms' of krill gather
By Matt Walker
Editor, Earth News

When krill come together, they form some of the largest gatherings of life on the planet.

Now scientists have discovered just how these small marine crustaceans do it.

Huge 'superswarms' containing trillions of krill are formed by juveniles not adults, and these swarms are even denser than experts supposed.

That suggests that all krill in the Southern Ocean are more vulnerable to overfishing than previously thought, the scientists warn.

Krill are small shrimp-like crustaceans that gather in huge numbers.

Previous research has found that some gatherings of Antarctic krill (Euphausia superba) can stretch for tens of kilometres.

It was astonishing how much biomass could be concentrated into such a small area
British Antarctic Survey scientist Dr Geraint Tarling

But while huge swarms are known to exist, scientists did not really understand why some swarms are bigger than others, and what drives krill to gather in this way.

So researchers working for the British Antarctic Survey (BAS) decided to investigate the phenomenon.

Led by Dr Geraint Tarling, a BAS researcher based in Cambridge, UK, the research team studied the composition and structure of 4525 separate krill swarms in the Scotia Sea, a vast expanse of water in the Southern Ocean.

The team used echo-sounding equipment, which works much like underwater radar, to find the krill across an area of water equivalent to the eastern half of the Atlantic Ocean.

What they found surprised them.

Krill tend to gather into two distinct types of swarm.

Some krill gather into smaller swarms, no longer than 50m long and up to 4m deep.

These swarms are not very tightly packed, with just ten individual krill per cubic metre, on average.
Antarctic krill (Euphausia superba)
A lone shrimp

However, other much bigger swarms also occur.

Dubbed "superswarms", these are an order of magnitude larger in area, often stretching over one kilometre in length, and averaging almost 30m deep.

What is more, these superswarms are much more densely packed, containing up to ten times greater density of animals.

"I was coming at it thinking there might be small swarms tightly packed, and then large swarms that were a bit more diffuse," says Dr Tarling.

"But what we actually found was the opposite. There were small swarms that were quite diffuse and large swarms that were tightly packed."

That means that the majority of krill living in the Antarctic Ocean at any one time will exist within a few, huge superswarms.

"We talking trillions of krill in one aggregation," explains Dr Tarling.

"Ten or 12 swarms could explain 60 or 70% of the biomass in an area the size of the eastern Atlantic."

"It was astonishing how much biomass could be concentrated into such a small area."

Youthful gathering

The scientists then searched for reasons why such superswarms form.

Certain factors made superswarms more likely.

"The factors we identified included whether there was more likely to be a lot of food around or not, and when there wasn't that much food around, they tended to form larger swarms," says Dr Tarling.
Acoustic image of krill swarm
A superswarm of krill located by echosounder (swarm shown in red)

The small, diffuse swarms are usually formed by mature, adult krill, the researchers discovered.

However, the huge superswarms are formed by juvenile krill.

"Where the animals were less mature, they were more likely to form the larger swarms," says Dr Tarling.

"Why they do that I don't know."

Nightime mystery

One possible explanation could be that swarming together offers individual krill protection against marine predators such as whales or seals.

"All types of swarms are probably to a greater or lesser extent an antipredator response. There is safety in numbers, the predator confusion affect," Dr Tarling says.

But swarming comes at a cost, as each individual shrimp has to compete with millions of others for food.

Adult krill are quite negatively buoyant, and have to keep swimming to stay afloat. That takes a lot of energy, which must be supplied by food, so adult krill likely want to avoid competing with millions of others for their next meal.

But juvenile krill are more buoyant, and need to eat less. So they can afford to gather into huge superswarms for protection.

Another reason could be that researchers have previously shown it is more energetically efficient to be in swarm than be isolated.

"For a juvenile that wants to grow very quickly, saving energy could be a bonus for them," says Dr Tarling.

One mystery to emerge from the research, which is published in the journal Deep Sea Research I, is that superswarms are more likely to gather at night.

"That is more puzzling for us to explain," says Dr Tarling.

"Up until this point, most polar biologists believed that the swarms dispersed [at night], because that's the time they feed."

"When daylight comes they get back into the swarm again for the antipredator benefit. But we found the opposite to that."

Vulnerable to overfishing

The discovery that most krill in the Southern Ocean can be found gathered into just a few superswarms has significant implications for how the animals are fished, Dr Tarling warns.

Fishing fleets can efficiently locate and scoop up whole swarms of krill.

But by fishing out just a few huge superswarms, they may be removing the majority of krill living in the entire ocean.

"Focusing on large swarms can have a much larger effect on the environment than you would predict."


Saturday, October 10, 2009

Archaeopteryx Was Not Very Bird-like

Archaeopteryx Was Not Very Bird-like: Inside The First Bird, Surprising Signs Of A Dinosaur

ScienceDaily (Oct. 9, 2009) — The raptor-like Archaeopteryx has long been viewed as the archetypal first bird, but new research reveals that it was actually a lot less "bird-like" than scientists had believed.

In fact, the landmark study led by paleobiologist Gregory M. Erickson of The Florida State University has upended the iconic first-known-bird image of Archaeopteryx (from the Greek for "ancient wing"), which lived 150 million years ago during the Late Jurassic period in what is now Germany. Instead, the animal has been recast as more of a feathered dinosaur -- bird on the outside, dinosaur on the inside.

That's because new, microscopic images of the ancient cells and blood vessels inside the bones of the winged, feathered, claw-handed creature show unexpectedly slow growth and maturation that took years, similar to that found in dinosaurs, from which birds evolved. In contrast, living birds grow rapidly and mature in a matter of weeks.

Also groundbreaking is the finding that the rapid bone growth common to all living birds but surprisingly absent from the Archaeopteryx was not necessary for avian dinosaur flight.

The study is published in the Oct. 9, 2009, issue of the journal PLoS ONE. In addition to Erickson, an associate professor in Florida State's Department of Biological Science and a research associate at the American Museum of Natural History, co-authors include Florida State University biologist Brian D. Inouye and other U.S. scientists, as well as researchers from Germany and China.

"Living birds mature very quickly," Erickson said. "That's why we rarely see baby birds among flocks of invariably identical-size pigeons. Slow-growing animals such as Archaeopteryx would look foreign to contemporary bird-watchers."

Erickson said evidence already confirms that birds are, in fact, dinosaurs. "But just how dinosaur-like -- or even bird-like -- was the first bird?" he asked. "Almost nothing had been known of Archaeopteryx biology. There has been debate as to how well it flew, if at all. Some have suggested that early bird physiology may have been very different from living birds, but no one had tested fossils that were close to the base of bird ancestry."

Fossilized remains of Archaeopteryx were found in Germany in 1860, one year after Charles Darwin's "Origin of Species" was published. With its combination of bird-like features, including feathers and a wishbone, and reptilian ones -- teeth, three-fingered hands, a long bony tail -- the skeleton made evolutionary theory more credible. The 1860s evolutionist Thomas Henry Huxley saw the Archaeopteryx as a perfect transition between birds and reptiles. Erickson calls it "the poster child for evolution."

"For our study, which required tremendous collaboration, we set out to determine how Archaeopteryx grew and compare its growth to living birds, closely related non-avian dinosaurs, and other early birds that came after it," Erickson said. "I went to Munich with my colleague Mark Norell from the American Museum of Natural History, and we met with Oliver Rauhut, curator of the Bavarian State Collection for Palaeontology and Geology, which houses a small juvenile Archaeopteryx that is one of 10 specimens discovered to date. From that specimen, we extracted tiny bone chips and then examined them microscopically."

Surprisingly, the bones of the juvenile Archaeopteryx were not the highly vascularized, fast-growing type, as in other avian dinosaurs. Instead, Erickson found lizard-like, dense, nearly avascular bone.

"It led us to ask, 'Did Archaeopteryx grow in a unique way?'" he said.

To explain the strange bone type, the researchers also examined different-size species of dinosaurs that were close relatives of Archaeopteryx, including Deinonychosaurs, the raptors of "Jurassic Park" fame. They then looked to colleagues in China for specimens of two of the earliest birds: Jeholornis prima, a long-tailed creature, and the short-tailed Sapeornis chaochengensi, which had three fingers and teeth.

"In the smallest dinosaur specimens, and in an early bird, we found the same bone type as in the juvenile Archaopteryx specimen," Erickson said.

Next, the research team plugged bone formation rates into the sizes of the Archaeopteryx femora (thigh bones) to predict its rate of growth.

"We learned that the adult would have been raven-sized and taken about 970 days to mature," Erickson said. "Some same-size birds today can do likewise in eight or nine weeks. In contrast, maximal growth rates for Archaeopteryx resemble dinosaur rates, which are three times slower than living birds and four times faster than living reptiles.

"From these findings, we see that the physiological and metabolic transition into true birds occurred millions of years after Archaeopteryx," he said. "But, perhaps equally important, we've shown that avians were able to fly even with dinosaur physiology."

Inouye added, "Our data on dinosaur growth rates and survivorship are bringing modern physiology and population biology to a field that has historically focused more on finding and naming fossil species."

Funding for the study came from the National Science Foundation (NSF); Germany's Deutsche Forschungsgemeinschaft (DFG); and The Major Basic Research Projects of the Ministry of Science and Technology of China.

In addition to Gregory Erickson (first author) and Brian Inouye of Florida State University's Department of Biological Science in Tallahassee, Fla., co-authors of the PLoS ONE paper are Oliver W. M. Rauhut, Bavarian State Collection for Palaeontology and Geology, LMU Munich, Munich, Germany; Zhonghe Zhou, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China; Alan Turner, Department of Anatomical Sciences, Stony Brook University, Stony Brook, N.Y.; Dongyu Hu, Paleontological Institute, Shenyang Normal University, Shenyang, China; and Mark Norell, Division of Paleontology, American Museum of Natural History, New York, N.Y.

Journal reference:

1. Erickson et al. Was Dinosaurian Physiology Inherited by Birds? Reconciling Slow Growth in Archaeopteryx. PLoS ONE, 2009; 4 (10): e7390 DOI: 10.1371/journal.pone.0007390

Adapted from materials provided by Florida State University, via EurekAlert!, a service of AAAS.

Florida State University. "Archaeopteryx Was Not Very Bird-like: Inside The First Bird, Surprising Signs Of A Dinosaur." ScienceDaily 9 October 2009. 10 October 2009 <­ /releases/2009/10/091009090436.htm>.

Wednesday, September 30, 2009

Feathery Four-winged Dinosaur Fossil Found In China Bridges Transition To Birds

Feathery Four-winged Dinosaur Fossil Found In China Bridges Transition To Birds

ScienceDaily (Sep. 29, 2009) — A fossil of a bird-like dinosaur with four wings has been discovered in northeastern China. The specimen bridges a critical gap in the transition from dinosaurs to birds, and reveals new insights into the origin evolution of feathers.

The transition from dinosaurs to birds is poorly understood because of the lack of well-preserved fossils, and many scientists argue that bird-like dinosaurs appear too late in the fossil record to be the true ancestors of birds.

In the journal Nature this week, Xing Xu and colleagues describe an exceptionally well-preserved fossil of Anchiornis huxleyi from the province of Liaoning, China. Long feathers cover the arms and tail, but also the feet, suggesting that a four-winged stage may have existed in the transition to birds.

Anchiornis huxleyi was previously thought to be a primitive bird, but closer inspection reveals that it should be assigned to the Troodontidae — a group of dinosaurs closely related to birds.

The authors date the fossil to the earliest Late Jurassic, meaning that it is the oldest bird-like dinosaur reported so far, and older than Archaeopteryx, the earliest known bird.

They conclude that the presence of such a species at this time in the fossil record effectively disputes the argument that bird-like dinosaurs appeared too late to be the ancestors of birds.

Journal reference:

1. Dongyu Hu, Lianhai Hou, Lijun Zhang, Xing Xu. A pre-Archaeopteryx troodontid theropod from China with long feathers on the metatarsus. Nature, 2009; DOI: 10.1038/nature08322

Adapted from materials provided by Nature.

Nature. "Feathery Four-winged Dinosaur Fossil Found In China Bridges Transition To Birds." ScienceDaily 29 September 2009. 30 September 2009 <­ /releases/2009/09/090928205415.htm>.

Monday, September 28, 2009

King penguins make a comeback

Posted Mon Sep 28, 2009 5:34am AEST

King Penguins re-populating in Southern Ocean

King Penguins were virtually wiped out on Macquarie Island about 100 years ago.

Scientists are celebrating the re-colonisation of king penguins on Macquarie Island in the Southern Ocean.

When Macquarie Island was discovered in 1810, it was teeming with king penguins, but by the turn of the century, hundreds of thousands of birds had been slaughtered for blubber oil.

Only a small colony of the birds survived at Lusitania Bay on the island.

Almost 100 years later, John van den Hoff from the Australian Antarctic Division says he is surprised to find King Penguins at the Macquarie Island isthmus where a century ago they had been exterminated.

"Without having read the historical accounts, we had no idea there were ever birds on the isthmus," he said.

He believes the population at Lusitania Bay has grown to the point that penguins are looking for more real estate.

"There are now 250 chicks in that colony and growing," he said.

"We hope it will continue to grow and perhaps the numbers will reach such a point on the isthmus that they'll have to move on to colonise other parts of the island as well."

Penguin biologist Barbara Wienecke says finding the population has recovered is a rare occurrence.

"There are only very few documented examples where colonies have popped up again," she said.

"All species have an extraordinary affinity to the colonies from which they would have left as fledglings, so to hear that a brand new colony is popping up on an island ... is really fantastic news."


Tuesday, September 15, 2009

Dee Boersma wins Heinz Award

September 15, 2009
Dee Boersma wins Heinz Award

Dee Boersma is among 10 recipients of the Heinz Family Foundation awards given to people whose achievements have fostered a cleaner, greener and more sustainable world.

Each recipient will receive $100,000 and a medallion inscribed with the image of the late Sen. John Heinz, R-Pa., whose environmental legacy is commemorated by the awards.

Boersma, a UW biology professor, and holder of the Wadsworth Endowed Chair in Conservation Science is being honored for her extensive field study of penguins and other sea birds to promote conservation and understanding human impact on marine environments. In an effort to better communicate issues of the natural world to the public, she launched Conservation Magazine a publication for cutting -edge science and smarter conservation ( For more than 25 years she and her students, working with the Wildlife Conservation Society, have studied Magellanic penguins at the Punta Tombo reserve in Argentina. She has dubbed the penguins "marine sentinels" for their warning signs about the ocean environment. Her recent work has shown that, because of climate change and other factors, during the critical period of egg incubation the penguins at Punta Tombo must swim an average of 25 miles further in search of food than they did just 10 years ago.

The awards, announced Sept. 15, were established in 1993 to honor Heinz's legacy on environmental issues.

Learn more at the Heinz Awards website:


Saturday, July 18, 2009

How Penguins & Seals Survive Deep Dives

How Penguins & Seals Survive Deep Dives
By Jessica Meir , Scripps Institution of Oceanography (UCSD)

posted: 17 July 2009 08:48 am ET

(1)Juvenile northern elephant seals on the beach at Ano Nuevo. Credit: Jessica Meir, Scripps Institution of Oceanography at UCSD

(2)Jessica Meir scanning for the radio transmission of a seal Jessica Meir scanning for the radio transmission of a seal in our study that has returned from sea (Ano Nuevo Island). Credit: Jessica Meir, Scripps Institution of Oceanography at UCSD
Emperor penguins diving

(3)Emperor penguins diving beneath the dive holes at the Penguin Ranch. Credit: Kathi Ponganis, Scripps Institution of Oceanography at UCSD
emperor penguin colony

(4)Self portrait at the Cape Crozier emperor penguin colony. Credit: Jessica Meir, Scripps Institution of Oceanography at UCSD

This Behind the Scenes article was provided to LiveScience in partnership with the National Science Foundation.

My main research interest is physiology in extreme environments, particularly those with low levels of oxygen.

Animals that thrive in such "hypoxic" environments are ideal species to investigate for how their physiology responds. In addition, studying adaptations to hypoxia in animals at high altitude, during hibernation, or in diving environments may provide insight for understanding and treating human medical issues, such as heart attack and stroke.

My recent Ph.D. dissertation focused on the diving physiology of some of the most accomplished diving animals: emperor penguins and elephant seals. Emperor penguins can dive for almost 30 minutes on a single breath, and the record dive of a northern elephant seal is almost two hours!

Both species can dive to great depths — greater than 1,500 feet for the emperor penguin — and almost 5,000 feet (nearly a mile!) for the elephant seal. It is well-documented that animals that can dive well have enhanced oxygen-storage capability in their bodies, a feat accomplished by increased blood volumes and higher levels of the proteins that carry oxygen in the blood and muscle (hemoglobin and myoglobin).

In the lab of my thesis advisor, Paul Ponganis of the Scripps Institution of Oceanography at UC San Diego, we use various approaches to study how these animals manage their oxygen stores to achieve such extraordinary dives.

In the Antarctic, we set up the Penguin Ranch on the sea-ice of McMurdo Sound. During our study, we drilled two dive holes in the ice at our camp site, enabling the emperor penguins to dive freely in the ocean below.

In northern California, we study elephant seals while they are diving at sea. We deploy backpack-style recorders on these animals to document their physiological responses while diving.

Our work, funded by the National Science Foundation (NSF), has revealed extraordinary physiological responses and adaptations that contribute to the diving ability of these animals.

For example, one study revealed that diving emperor penguins have heart rates significantly lower than that of their heart rates at rest. During one emperor penguin’s impressive 18-minute dive, its heart rate decreased to as low as three beats per minute, with a rate of six beats per minute lasting for over five minutes during the dive. As heart rate is a very good indicator of how much oxygen is utilized, decreased heart rates during dives correspond to conservation of oxygen, enabling the animals to dive for a longer time.

To provide a direct look at oxygen depletion, we also measured the levels of oxygen in the blood during the dive using an oxygen electrode. This electrode continuously measured the amount of oxygen in the blood, documenting the rate and extent of oxygen depletion during the dive and providing us with knowledge of how these animals manage their oxygen stores.

Both emperor penguins and elephant seals can tolerate exceptionally low levels of oxygen in their blood, far below the limits of humans and other animals. This assists them in managing oxygen efficiently and contributes to their ability to dive and obtain food. Combined with their enhanced oxygen stores, other physiological responses like reduced heart rates, and factors such as swimming styles and their hydrodynamic body shape, these animals are well adapted to flourish in underwater environments.

Now that I have completed my Ph.D. work with diving animals, I will embark upon studies with another remarkable species: the high-flying bar-headed goose. This bird accomplishes the extraordinary feat of flying directly over the Himalayan mountain range during its semi-annual migration from wintering grounds in India to breeding grounds in Tibet.

Although other migratory birds use alternative, lower altitude routes through mountain passes, flocks of these exceptional high-flying geese have been sighted above the summits of Mt. Everest (29,000 feet) and Annapurna I (26,500 feet). Exercise at these altitudes during the migration may be completed in a single, non-stop flight, with no allowance for acclimatization, flying from near sea level in India to altitudes approaching 9,000 meters in less than one day.

Oxygen levels at this altitude are only about one fifth that at sea level, yet the bar-headed goose increases its oxygen consumption 10- to 20-fold during flight. Birds are generally more tolerant of high altitude than mammals, but sustained flight at these reduced levels of oxygen is certainly exceptional.

The goal of this project is to explore the physiological adaptations in this species, with the overarching purpose of understanding tissue and cellular hypoxia tolerance in an animal that has evolved specifically to maintain performance in hypoxia.

With support of an NSF International Research Fellowship, I will initiate this work in the fall of 2009 in collaboration with researchers at the University of British Columbia in Vancouver, Canada. We will investigate oxygen transport from the respiratory system to the tissue during flight in the bar-headed goose, with specific focus on delivery to the heart.

The next natural question after documenting what these impressive physiological responses are in any of these species, is of course to ask how they are achieved. We will address the mechanisms of hypoxia tolerance in the heart of the bar-headed goose using a variety of physiological, morphological and intracellular approaches.

This work may also provide clues about adaptations in these animals that could benefit humans in the future. For example, tolerance to hypoxia has implications for better methods of harvesting and preserving organs for transplant, and treatment of heart attack and stroke victims.

These animals somehow withstand seriously low levels of oxygen in the blood and tissues that are catastrophic to humans. The issue of reperfusion injury — tissue damage caused by oxygen free radicals when blood flow resumes to an organ which has been deprived of blood — is also relevant. This is applicable to a variety of issues in human medicine, though diving animals appear immune to such concerns.

A complete understanding of the physiology of these organisms is also essential to interpreting their role within ecosystems. Such knowledge has clear ecological and conservation implications and is particularly relevant in the face of global climate change.

Editor's Note: This research was supported by the National Science Foundation (NSF), the federal agency charged with funding basic research and education across all fields of science and engineering. See the Behind the Scenes Archive.


Thursday, July 16, 2009

Adelie Penguins Annual Breeding Rituals

Penguin parenting: Adelie penguins reunite for their annual breeding rituals
Animals, July-August, 1997 by Michelle Alten

Near Antarctica's Ross Sea, a bitter wind rips across ice-covered beach. In the blizzard, Adelie penguins hunker 'clown on their nests, covering their newly laid eggs. It is November, and another rigorous breeding season is under way.

Life in Antarctica is a challenge. In the winter, coastal temperatures can drop to minus 22 degrees Fahrenheit; in the summer, they may climb only slightly above freezing. But despite seemingly unbeatable odds, Adelie populations flourish here with a breeding strategy finely tuned to this tempestuous polar region. Adelies are so well adapted to this frigid climate that, while most southern penguins breed in the subantarctic, on outer islands, or on the Antarctic Peninsula, Adelies have colonies all along the Antarctic coast. Emperor penguins also breed in the coldest regions of Antarctica, but Adelies are far more numerous, estimated at 2,465,800 pairs, compared with 195,400 pairs of emperors.

In late October, after a winter on the sea's pack ice, Adelies journey back to their breeding grounds. It is the austral spring, and a frozen sea means Adelies may travel across 60 miles of ice as they return to their colony. First the male arrives, then the female. Each recognizes its mate's call and nesting site from previous years, and perhaps even its partner's physical features. Unless one of the mates fails to return, a pair may reunite for many consecutive breeding seasons.

After a long winter apart, the two penguins thrust their beaks in the air, wave their heads, and let out a raucous call. After this display and renewed bonding, the birds ramble along the barren shore, gathering pebbles in their beaks. Then they strut back to the rookery and place them gingerly around their stone nests.

With the breeding season under way, the penguin colony is alive with activity. At the edge of the rookery, young males, three and four years old, stretch their bills toward the sky and cry out as they stake out their territory and attempt to attract a mate.

The female Adelie penguin lays two eggs. The male, in charge of the first stint of incubation, steps over the eggs and tucks them beneath two protective flaps of skin on his belly. These brood patches keep the eggs secure and warm. The female, free to feed, scampers through the colony down to the beach, pads over a stretch of ice, then disappears into the sea.

For the male, incubation is an endurance test. The father-to-be has not eaten since his arrival, and it may be weeks before his partner returns. This extensive fasting period, which may last as long as 40 days, can cause the penguin to lose a third of his weight.

After a boisterous greeting, the female returning from sea steps behind her partner and scoots into position to take over the job of incubation. Relieved of duty, the male toboggans down a snow-covered hillside and slips off to sea to feed on krill, small shrimplike creatures that are the keystone of Antarctica's complex food chain.

"Adelies capitalize on a huge food source by breeding in the Antarctic," explains Frank Todd, founder of Sea World's Penguin Encounter and author of numerous books on penguins. "They eliminate competition with birds that nest farther north, and even though emperors, which also nest in the Antarctic, include krill in their diet, they also feed extensively on fish and squid."

Penguins must keep careful watch over their eggs. At the rookery's edge, a sheathbill, a white scavenger with a fleshy pink wattle, pushes a penguin egg from its nest. Repeatedly the bird retreats, approaches, and pecks at the shell. Finally it shatters a hole in the egg and begins to eat. Other sheathbills gather for a share, until one flies off with the egg in its beak. Nearby, skuas, black gull-like birds, hover, also hoping to snatch an unguarded egg.

After about 36 days, the faint peeping of a newly hatched chick is heard amid the chatter of adult penguins. The charcoal chick taps at its shell with its egg tooth, gradually poking a way out. After a time, the hungry chick pecks at the parent's bill, begging for food. The adult reaches down, opens its beak, and regurgitates a meal of krill into the tiny, gaping bill.

While the chicks are being reared, pack ice can present a survival challenge, forcing the birds to walk rather than swim to the sea. While Adelies walk about three miles per hour, they can swim almost twice as fast. "The pack ice reduces the frequency that they can feed their chicks," notes David Ainley, an ornithologist and author of The Breeding Biology of the Adelie Penguin. "As a result, chicks can be smaller in weight. This gives them less of a time cushion in which to learn how to catch their own food."

Around the age of four weeks, Adelie chicks leave their parents' protection and gather to form a creche, a group of up to 100 or more youngsters. The chicks huddle together for warmth and for defense against skuas. Now both parents feed at sea, nourishing themselves and gathering food for their growing youngster.

Gradually the chicks lose their fuzzy down and gain their mature black and white feathers. After 56 days, many leave the creche behind. Now larger in size, they return to their nests, no longer fearing the assaults of skuas.

A cluster of adults forms at the water's edge. A few penguins peer over the ice. No leopard seals. One bird pauses, then dives into the icy ocean. The next one follows, then the next. Finally all the penguins tumble into the sea, like a chain of dominoes. In the water, penguins take no chances with leopard seals, which are ferocious predators. A seal will grab hold of a penguin, whip it inside out, removing its skin, and swallow it whole.

In Antarctica the Adelies face constant hazards. During the austral summer, storms with savage gales and freezing temperatures often rush in without warning. A layer of blubber and tightly packed feathers help adults withstand the cold. Young chicks are often not as lucky. If they are not sheltered by a parent or the creche, they may freeze or be buried in snow.

By February many Adelie juveniles have made it through the breeding season and are ready to fledge. Despite the rigors of Antarctic life, studies in the Ross Sea have shown that about 75 to 85 percent of chicks that hatch usually survive to the fledgling stage.

"The number of Adelie penguins has been increasing in the high-latitude areas of the Ross Sea," Ainley points out. "The changes may be due to decreases in the amount of pack ice, caused by global warming."

Meanwhile, at the close of each breeding season winter steals in, covering the continent with darkness. Antarctica's "ice birds" leave behind their colonies and head out on the frozen sea.
Bibliography for: "Penguin parenting: Adelie penguins reunite for their annual breeding rituals"

Michelle Alten "Penguin parenting: Adelie penguins reunite for their annual breeding rituals". Animals. 16 Jul, 2009.

Image: Flickr Uploaded on January 28, 2007 by mark van de wouw

Wednesday, July 8, 2009

New Message from Dr. Dee Boersma

Hello Penguin Fans,

The 2009 Spring update is here! Learn how the 2008-09 season went and what is new at the Penguin Project. The 2009 Spring Newsletter text can be found below or I have attached the newsletter with pictures as a pdf. We also recently renovated our website ( to include up-to-date penguin news from around the world as well as anything and everything Magellanic Penguin. You can find all of our newsletters, including this most recent one, on the website under 'Publications'. Additionally, Turbo is now on Facebook so make sure to search for 'Turbo the Penguin' and add yourself as a fan to see exciting pictures, videos and stories all about Turbo!



Spring 2009 Penguin Update
by Dee Boersma

Five consecutive years of successful chick rearing is in many ways a hopeful sign. Despite a storm that likely killed 16% of the chicks, adults raised 3/4 of a chick per nest, which is well above the 25 year average of a 1/2 chick per nest (most pairs don't raise any chicks). In the areas we call the Canada and Sea we checked 181 nests and 32 pairs fledged both chicks. But in spite of another successful year, the number of active nests in the colony is down 23.1% from 1987. Winters still are tough on the penguins. Only about 2 to 5% of the penguins on the beach this year were juveniles, so few chicks from last year apparently survived. Getting penguins to breed at Punta Tombo requires that they survive several winters, but last winter many juveniles swam to northern Brazil where they eventually starved. Penguins also encountered an oil spill in their winter grounds. There are several dozen groups dedicated to rehabilitation of penguins in northern Argentina, Uruguay and south Brazil, so we need your help to turn our attention to solving this problem. Penguins with petroleum in Chubut are nearly as rare as hen's teeth. We saw one penguin with some petroleum at Punta Tombo, but that was it. Moving the shipping lanes in 1994 and a decrease in illegal dumping of ballast water has helped the penguins. In March, when Esteban Freres and I walked 25 km of beach along the Chubut coast, we found no penguins either dead or alive with petroleum. Penguins are still getting oiled in the north (northern Argentina, Uruguay and southern Brazil), however.

For the second year in a row, we found featherless or ‘naked’ chicks at Punta Tombo. The chicks hatched with an initial layer of down but failed to grow in their second layer of down. They then remained ‘naked’, resembling plucked chickens, until they grew in their juvenile plumage when they were approximately one month old. We speculate that a virus may be the culprit, and our newest graduate student, Olivia Kane, will be investigating this problem.

We deployed 27 satellite tags at Punta Tombo and 10 at Cabo dos Bahìas this season. Penguins are traveling farther to find their food since we began satellite tracking 12 years ago. This year, they swam a mean distance of 430 km from Punta Tombo during incubation, nearly the same as in 2007 (431 km), but approximately 40 km farther than in 2006 (394 km), and almost 100 km farther than the distances traveled prior to 2001.

We had several unexpected and amazing visitors this year. A young man from Ireland, Keith Norris, who suffers from cystic fibrosis, and whose wish was to see penguins in the wild visited thanks to the Make-A-Wish Foundation. We taught him how to measure the volume of a (plastic) egg, and showed him the weigh scale, and walked with him through the penguin colony to give him a sense of how we keep track of all the penguins. In November and again on December 25th, the cormorant colony at the tip of the point had a visitor from southern Africa, a Cape Gannet (Morus capensis). Cape Gannets are rarely seen in Argentine waters. This is the second year we saw a Cape Gannet at Punta Tombo, and it's likely the same one from last year.

Our third visitor, a King Penguin, arrived for a day in December. The beautiful giant preened and made contact calls while resting on the beach. When no King penguins answered he left, but seeing him was a pleasant surprise for everyone except the Magellanic penguins, which seemed to think he was weird.

In 2007, we implanted radio identification tags (similar to those implanted into dogs and cats by veterinarians) in approximately 150 birds, and put out two reading pads that recorded tag numbers, time of day, and direction of travel when penguins cross them. This year we put out a scale to weigh penguins as they walked over it. We got over 10,000 readings and are in the process seeing if we can translate those light and heavy footsteps into weights. We are designing a system to tell use who, when and what direction a penguins was going and its weight. If and when our system works, we can determine the effect of opening and closing of the fisheries on adult penguin fishing success and chick growth. The penguins continue to be a challenge as they pull out cords and walk around the pads, and some only put one foot on the scale. The penguins and technology are a constant challenge, but we hope to win the battle and get accurate and reliable data this coming season.

On April 4, 2009 we celebrated the 25th Anniversary of the Penguin Project by unveiling the U of WA Center for Penguins as Ocean Sentinels. The Penguin Project, The International Penguin Society, Conservation magazine, and volunteer student research and education programs are the four pillars of the Center. The Penguin Project will continue to follow individual penguins, monitor the colony and develop the data needed to plan effective conservation efforts. The International Penguin Society, launched with a Pew Fellowship to Dr. Pablo Borboroglu, an Argentine conservationist, will develop and advocate solutions for sustainable marine activities and management, drawing on penguins as a charismatic, keystone species. Conservation magazine, started in 2001, is the voice for the science behind conservation. The magazine’s mission is to raise the bar on environmental thinking and writing. The Center is dedicated to educating the next generation of conservation leaders. We believe the new University Center will increase our ability to make a positive contribution to the lives of penguins, people, and conservation. As always we are honored by and welcome your support. These are challenging times and it is your support that makes it possible to continue our satellite work: $5,000 allows you to name a penguin that we will follow closely and provide you with maps and its life story each year.

Best wishes,

P.S. If you would like to accompany me and other wildlife enthusiasts on the trip of a lifetime. there is still room on the University of Washington expedition to the Galápagos (October 31 through November 8, 2009) . If you are interested please contact Olivia Kane at

Friday, July 3, 2009

Penguin Parents Won’t Chip In to Help Handicapped Spouse

Penguin Parents Won’t Chip In to Help Handicapped Spouse

* By Hadley Leggett Email Author
* July 2, 2009 |

Tired of your partner not helping out with the kids after you’ve had a tough day at work? At least you’re not a handicapped penguin parent trying to fish with a Plexiglas box strapped to your back.

Penguin pairs are known for their elaborate collaboration in raising chicks under harsh Antarctic conditions. But it turns out penguins will take teamwork only so far. When French scientists handicapped one bird from each of 46 pairs of Adélie penguins, partners of the unlucky birds didn’t step up to help out their mates, or to provide extra food for their chicks.

“In Adélie penguins, when one mate was handicapped, no compensatory care was observed from the partner,” researchers from the Institut Pluridisciplinaire Hubert Curien reported Tuesday in Animal Behaviour. “As a consequence, handicapped individuals and offspring both supported the whole additional breeding cost of the handicap.”

box1After a female penguin lays one or two eggs, she leaves the nest to forage for food while dad guards the eggs. Once the chicks hatch, mom and dad share equal responsibility for baby-rearing, with one parent enduring long periods of fasting to care for chicks while the other parent hunts at sea.

To study the effects of a handicap on pair cooperation, the researchers chose one unlucky bird from each penguin pair and attached a small Plexiglas box to its middle-back feathers. Similar to the first-generation tracking devices used by penguin researchers in the 1990s, the boxes were designed to increase underwater drag during diving and fishing, but not to interfere with the penguins’ other activities.

“According to previous studies, we could guess what the potential effects of the dummy devices would be on handicapped penguins, but not on their partner or their chicks,” animal ecologist Michael Beaulieu, a co-author on the study, wrote in an e-mail.

As expected, the handicapped penguins spent more time hunting at sea and came back with less food for their chicks. But instead of helping out, partners of the handicapped birds essentially ignored the plight of their unlucky mates. Partner penguins didn’t compensate by spending more time foraging for food or bringing back extra fish. And at the end of the study, while both handicapped birds and their chicks weighed less than their unhindered counterparts, the handicap-free partners stayed fat and happy.

It’s tempting to blame penguin partners for their negligence and insensitivity, especially because similar handicap studies in other species have shown that some birds, including passerines and great tits, do compensate for their mate’s deficiencies.

But Beaulieu has a different explanation: Because penguins are long-lived birds, it doesn’t make evolutionary sense for them to invest too much effort in any single reproductive season.

“Short-lived birds have only a few breeding attempts during their lifetime while long-lived birds have a lot,” he said. “As a result, short-lived birds are expected to give the maximum during one breeding season to increase the probability of survival of their current chicks.” Long-lived birds, on the other hand, should prioritize their own long-term survival over the outcome of individual chicks.

“Consequently, when the investment of the partner decreases,” Beaulieu said, “short-lived birds are expected to compensate while long-lived birds are expected to keep a fixed level of parental investment.”

The evolutionary explanation makes sense, but there’s one other possible explanation: It appears that male penguins don’t have great communication skills. Handicapped dads didn’t convey their distress to females after returning from a hunt, and when mom came back squawking about her feeding troubles, dad didn’t listen.

“If you do not ask for help, I will not help you,” Beaulieu said. “That may also explain why they did not compensate.”


Wednesday, July 1, 2009

Scientists find extinct penguin

Scientists find extinct penguin


WELLINGTON — The Associated Press Last updated on Tuesday, Mar. 31, 2009 09:13PM EDT

Researchers studying a rare and endangered species of penguin in New Zealand have uncovered a previously unknown species that disappeared about 500 years ago.

The research suggests that the first humans in New Zealand hunted the newly found waitaha penguin to extinction by 1500, about 250 years after their arrival on the islands. But the loss of the Waitaha allowed another kind of penguin to thrive – the yellow-eyed species, which that now also faces extinction, Philip Seddon of Otago University, a co-author of the study, said Wednesday.

The team was testing DNA from the bones of prehistoric modern yellow-eyed penguins for genetic changes associated with human settlement when it found some bones that were older and had different DNA.

Tests on the older bones “lead us to describe a new penguin species that became extinct only a few hundred years ago,” the team reported in a paper in the biological research journal Proceedings of the Royal Society B: Biological Sciences.

Polynesian settlers reached New Zealand around 1250 and are known to have hunted species such as the large, flightless moa to extinction.

Dr. Seddon said dating techniques used on bones pulled from old Maori trash pits revealed a gap in time between the disappearance of the Waitaha and the arrival of the yellow-eyed penguin.

The gap indicates the extinction of the older bird created the opportunity for the newer to colonize New Zealand's main islands about 500 years ago, said Sanne Boessenkool, an Otago University doctoral student who led the team of researchers, including some from Australia's Adelaide University and New Zealand's Canterbury Museum.

Competition between the two penguin species may have previously prevented the yellow-eyed penguin from expanding north, the researchers noted.

David Penny of New Zealand's Massey University, who was not involved in the research, said the waitaha was an example of another native species that was unable to adapt to a human presence.

“In addition, it is vitally important to know how species, such as the yellow-eyed penguin, are able to respond to new opportunities,” he said. “It is becoming apparent that some species can respond to things like climate change, and others cannot. The more we know, the more we can help.”

The yellow-eyed penguin is considered one of the world's rarest. An estimated population of 7,000 in New Zealand is the focus of an extensive conservation effort.


Friday, June 19, 2009

Beaked, Bird-like Dinosaur Tells Story Of Finger Evolution

This image shows a reconstruction of Limusaurus; there is no evidence of feather structures. (Credit: Portia Sloan)

Beaked, Bird-like Dinosaur Tells Story Of Finger Evolution

ScienceDaily (June 18, 2009) — Scientists have discovered a unique beaked, plant-eating dinosaur in China. The finding, they say, demonstrates that theropod, or bird-footed, dinosaurs were more ecologically diverse in the Jurassic period than previously thought, and offers important evidence about how the three-fingered hand of birds evolved from the hand of dinosaurs.

The discovery is reported in a paper published in the June 18 edition of the journal Nature.

"This work on dinosaurs provides a whole new perspective on the evolution of bird manual digits," said H. Richard Lane, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research.

"This new animal is fascinating, and when placed into an evolutionary context it offers intriguing evidence about how the hand of birds evolved," said scientist James Clark of George Washington University.

Clark, along with Xu Xing of the Chinese Academy of Science's Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, made the discovery. Clark's graduate student, Jonah Choiniere, also was involved in analyzing the new animal.

"This finding is truly exciting, as it changes what we thought we knew about the dinosaur hand," said Xu. "It also brings conciliation between the data from million-year-old bones and molecules of living birds."

Limusaurus inextricabilis ("mire lizard who could not escape") was found in 159 million-year-old deposits located in the Junggar Basin of Xinjiang, northwestern China. The dinosaur earned its name from the way its skeletons were preserved, stacked on top of each other in fossilized mire pits.

A close examination of the fossil shows that its upper and lower jaws were toothless, demonstrating that the dinosaur possessed a fully developed beak. Its lack of teeth, short arms without sharp claws and possession of gizzard stones suggest that it was a plant-eater, though it is related to carnivorous dinosaurs.

The newly discovered dinosaur's hand is unusual and provides surprising new insights into a long-standing controversy over which fingers are present in living birds, which are theropod dinosaur descendants. The hands of theropod dinosaurs suggest that the outer two fingers were lost during the course of evolution and the inner three remained.

Conversely, embryos of living birds suggest that birds have lost one finger from the outside and one from the inside of the hand. Unlike all other theropods, the hand of Limusaurus strongly reduced the first finger and increased the size of the second. Clark and Xu argue that Limusaurus' hand represents a transitional condition in which the inner finger was lost and the other fingers took on the shape of the fingers next to them.

The three fingers of most advanced theropods are the second, third and fourth fingers-the same ones indicated by bird embryos-contrary to the traditional interpretation that they were the first, second and third.

Limusaurus is the first ceratosaur known from East Asia and one of the most primitive members of the group. Ceratosaurs are a diverse group of theropods that often bear crests or horns on their heads, and many have unusual, knobby fingers lacking sharp claws.

The fossil beds in China that produced Limusaurus have previously yielded skeletons of a variety of dinosaurs and contemporary animals described by Clark and Xu.

These include the oldest tyrannosaur, Guanlong wucaii; the oldest horned dinosaur, Yinlong downsi; a new stegosaur, Jiangjunosaurus junggarensis; and the running crocodile relative, Junggarsuchus sloani.

This research was also funded by the National Geographic Society, the Chinese National Natural Science Foundation, the Jurassic Foundation and the Hilmar Sallee bequest.
Adapted from materials provided by National Science Foundation.

National Science Foundation. "Beaked, Bird-like Dinosaur Tells Story Of Finger Evolution." ScienceDaily 18 June 2009. 19 June 2009 .

Friday, June 12, 2009

Could Antarctica Have Been Where Modern Avian Species Originated?

Photo Credit: Judd Case
Sandwich Bluff on Vega Island, northern Antarctic Peninsula, where the Vegavis specimen and many other late Cretaceous, Antarctic bird specimens, have been recovered. The specimens here range in age from 70 to 67.5 million years ago.
Antarctic bird nest?

Discovery of avian fossils suggests Antarctica may have been origin of modern species
By Peter Rejcek, Antarctic Sun Editor
Posted June 5, 2009

Julia Clarke External Non-U.S. government site has good reason to believe fossils collected from islands along the Antarctic Peninsula could yield new insights into the evolutionary history of modern birds.

After all, about five years ago, she and her U.S. and Argentine colleagues found proof from a rock specimen, which contained avian vertebrae and pelvic bones among other bits of skeleton, that close relatives of at least one order of modern birds co-existed with dinosaurs.

The discovery of the new species, Vegavis iaai, collected in 1992 by scientists from Argentina on Vega Island and re-examined by Clarke and her U.S. and Argentine team more than a decade later, using high-resolution X-ray computed tomography (CT) technology, resulted in a paper in the journal Nature in 2005. Based on the data, Vegavis iaai fell within the order Anseriformes, which includes ducks, geese and swan.

Vegavis lived more than 65 million years ago, well before Antarctica turned into an icehouse. It also existed just before the mass extinction that swept the dinosaurs from the Earth along with up to three-quarters of all species.

The find was important because it offered some of the best fossil evidence to date that linked modern bird divergence, the spread of today’s species, before the K-T boundary — when geologic time turned the page from the Cretaceous to the Tertiary period after the mass extinction.

On one side of the controversy are scientists who argue that molecular evidence and modern distribution of living bird groups suggest that their ancestors existed alongside non-avian dinosaurs well before the K-T extinction, perhaps tens of millions of years earlier. Others have claimed the fossil record shows no real evidence of living bird lineages in the Cretaceous. Only after the extinction, they say, did modern bird evolution take flight.

“It’s still really extraordinarily contentious five years later what lineages are present in the Cretaceous prior to the K-T boundary,” said Clarke, associate professor in the Department of Geological Sciences at the University of Texas at Austin External Non-U.S. government site. “We propose you have the beginnings of this radiation supported [by the Vegavis specimen]. We don’t see any evidence yet of [all extant bird radiation] having happened so much earlier in the fossil record.”

Clarke and her colleagues believe they may find additional information on what lineages date before the K-T boundary by examining additional fossils collected from Antarctica over the last 20 years.
Growing evidence

Clarke is the principal investigator (PI) on a Small Grant for Exploratory Research (SGER) from the National Science Foundation (NSF) External U.S. government site to pull together the data and experts from the United States and Argentina to see what the fossil record from the Antarctic Peninsula says about the evolutionary history of other orders of birds, most of which fall into the superorder Neoaves. (It was a separate SGER project that led to the discovery that Vegavis was closely related to modern waterfowl, Anseriformes, which fall into the superorder Galloanserae.)

Julia Clarke
Photo Credit: North Carolina State University
Julia Clarke holds a penguin skull related to separate avian fossil research.

“The partial skeletons … from Antarctica are the best candidates for being part of that extant radiation,” Clarke said. “The nice thing about getting this team together is we’re sharing information, we’re sharing data, and hopefully coming to a consensus view of what diversity is represented,” Clarke said.

Her co-PI on the project is Judd Case, dean of Eastern Washington University’s College of Science, Health and Engineering External Non-U.S. government site. He made several expeditions to Vega and James Ross islands between 1997 and 2004 on the northern tip of the Antarctic Peninsula to hunt for vertebrate fossils. The goal of those expeditions was to put together a more complete picture of dinosaur, mammal and reptile geographic distribution and evolution between 80 and 65 million years ago.

Case said the material from those finds has further bolstered the hypothesis of the earlier radiation of modern birds, with at least four lineages emerging before the K-T extinction based on the evidence the scientists are assembling.

“We’ve got a good amount of material to make the judgment,” he said. “We’ve got good documented, late Cretaceous deposits,” including specimens from the major clade, or group, Neoaves.

“The fossil data, along with the molecular data, continue to point to this older origination, and it’s providing a location where this … may have occurred,” Case said.

Ground zero for bird originationVegavis iaai concretion, left, and the CT scan of the rock and bird fossils. CT scans offer a noninvasive way for peering into solid objects and for obtaining digital information on their 3-D geometries and properties.

In fact, the paleontologists believe this region may have been ground zero for modern bird evolution, or at least a major hotspot. The hypothesis is based largely on the biogeography, the distribution of existing bird groups, an idea that dates back to the 1970s, according to Clarke.

“That idea has been around for a long time,” she said, but the fossil evidence hasn’t been collected and evaluated in a systematic fashion, as she and her team proposes to do, to put it to the test.

Case said evidence is mounting for such a scenario, especially given the Southern Hemisphere origination of lineages for penguins and ratites (such as ostriches and emus). “If you throw those lines in with [the other pre-K-T boundary lineages], it clearly begins to allow for the hypothesis, and add some strength to the idea, that somewhere deep in Gondwana, modern birds originated.”

Gondwana is the southern supercontinent that at one time included Antarctica, South America, Africa, Madagascar, Australia-New Guinea and New Zealand. By the late Cretaceous, Antarctica had moved into its current position, though still tenuously connected to Australia and South America.

The climate would have been quite moderate, according to Case. “Where today [Antarctica] seems pretty stark … back in this timeframe, it was a very rich, vibrant place,” he said. “The contrast of what it was to what it is today is pretty dramatic. I can’t think any place else on the Earth as dichotomous.

“We’re looking at cool, temperate waters, certainly not much different than what we see off the west coast of the United States, at least until you get to southern California,” he added. “We don’t expect marine reptiles to have a lot of blubber, like marine mammals do, so it’s got to be warm enough that the young with small body sizes can survive comfortably.”

Clarke said that while there appears to be good evidence emerging from the Antarctic Peninsula fossil record to suggest a Southern Hemisphere origination, she cautioned that the sampling size is still relatively small.

“We’re going to be able to be able to offer more data than has ever been put forward on what’s really in Antarctica during this time period, but we’re not going to be able to answer this question definitively,” she said.
Breaking rocks digitally

Clarke’s expertise is phylogenetic analysis from morphological data, meaning she studies the evolutionary relatedness among birds by comparing the physical changes that occur over time. A very useful tool in acquiring the data she needs for the research is a high-resolution X-ray CT scanner.

CT scans offer a noninvasive way for peering into solid objects and for obtaining digital information on their 3-D geometries and properties. High-resolution X-ray CT differs from conventional medical CAT-scanning in its ability to provide details down to the tens of microns — less than the width of a hair. The NSF supports the High-Resolution X-ray Computed Tomography Facility External Non-U.S. government site at the University of Texas at Austin (UTCT).

Clarke said the scans save time and allow scientists to manipulate the data in new ways. “CT scans are really useful in this case because a lot of the rocks in which these remains are preserved are incredibly hard,” she explained. “It’s months and months and months of moving individual sand grains to prepare these things. You can see the interiors of elements. You could see morphologies that would never be exposed even if you didn't have those tools.

“There were bones that were discovered in that Vegavis specimen that we had no idea were in there,” she added. In addition, one of her students is digitally extracting individual bones from the original Vegavis scan, which appears online like the silvery half of an oversized grapefruit, with the ancient bird bones prominently sticking out.

Work has already begun on the fossils from Argentina, Texas Tech, the South Dakota School of Mines and elsewhere. Eventually, the team plans to publish a monograph, a sort of comprehensive essay, which describes the Antarctic materials, with a photo library of all the remains with preliminary identifications, according to Clarke.

“We’re making progress,” she said.

Case said the researchers would propose further fieldwork to look specifically at bird fossils and the question of whether that part of Gondwana was indeed the cradle for modern birds.

“It’s one of the biggest questions out there right now,” he said.

NSF-funded research in this story: Julia Clarke, University of Texas at Austin, and Judd Case, Eastern Washington University, Award No. 0731404 External U.S. government site.