Big thaw projected for Antarctic sea ice: Ross Sea will reverse current trend, be largely ice free in summer by 2100

Emperor Penguins: Changes in the extent and duration of Ross Sea ice will significantly impact marine life in what is one of the world’s most productive and unspoiled marine ecosystems, where rich blooms of phytoplankton feed krill, fish, and higher predators such as penguins.

Credit: Photo courtesy of Walker Smith

Date:

February 27, 2014

Source:

Virginia Institute of Marine Science

Summary:  A new modeling study suggests that a recent observed increase in summer sea-ice cover in Antarctica's Ross Sea is likely short-lived, with the area projected to lose more than half its summer sea ice by 2050 and more than three quarters by 2100. These changes will significantly impact marine life in what is one of the world's most productive and unspoiled marine ecosystems.

Antarctica's Ross Sea is one of the few polar regions where summer sea-ice coverage has increased during the last few decades, bucking a global trend of drastic declines in summer sea ice across the Arctic Ocean and in two adjacent embayments of the Southern Ocean around Antarctica.
 

Now, a modeling study led by Professor Walker Smith of the Virginia Institute of Marine Science suggests that the Ross Sea's recent observed increase in summer sea-ice cover is likely short-lived, with the area projected to lose more than half its summer sea ice by 2050 and more than three quarters by 2100.

These changes, says Smith, will significantly impact marine life in what is one of the world's most productive and unspoiled marine ecosystems, where rich blooms of phytoplankton feed krill, fish, and higher predators such as whales, penguins, and seals.

Smith, who has been conducting ship-based fieldwork in the Ross Sea since the 1980s, collaborated on the study with colleagues at Old Dominion University. Their paper, "The effects of changing winds and temperatures on the oceanography of the Ross Sea in the 21^st century," appears in the Feb. 26 issue of Geophysical Research Letters. Smith's co-authors are Mike Dinniman, Eileen Hofmann, and John Klinck.

Smith says "The Ross Sea is critically important in regulating the production of Antarctica's sea ice overall and is biologically very productive, which makes changes in its physical environment of global concern. Our study predicts that it will soon reverse its present trend and experience major drops in ice cover in summer, which, along with decreased mixing of the vertical column, will extend the season of phytoplankton growth. These changes will substantially alter the area's pristine food web."

Researchers attribute the observed increase in summertime sea ice in the Ross Sea -- where the number of days with ice cover has grown by more two months over the past three decades -- to a complex interplay of factors, including changes in wind speed, precipitation, salinity, ocean currents, and air and water temperature.

But global climate models agree that air temperatures in Antarctica will increase substantially in the coming decades, with corresponding changes in the speed and direction of winds and ocean currents. When Smith and his colleagues fed these global projections into a high-resolution computer model of air-sea-ice dynamics in the Ross Sea, they saw a drastic reduction in the extent and duration of summer sea ice.

The modeled summer sea ice concentrations decreased by 56% by 2050 and 78% by 2100. The ice-free season also grew much longer, with the mean day of retreat in 2100 occurring 11 days earlier and the advance occurring 16 days later than now.

Also changed was the duration and depth of the "shallow mixed layer," the zone where most phytoplankton live. "Our model projects that the shallow mixed layer will persist for about a week longer in 2050, and almost three weeks longer in 2100 than now," says Smith. "The depth of the shallow mixed layer will also decrease significantly, with its bottom 12% shallower in 2050, and 44% shallower in 2100 than now."

For Smith, these changes in ice, atmosphere, and ocean dynamics portend major changes in the Antarctic food web. On the bright side, the decrease in ice cover will bring more light to surface waters, while a more persistent and shallower mixed layer will concentrate phytoplankton and nutrients in this sunlit zone. These changes will combine to encourage phytoplankton growth, particularly for single-celled organisms called diatoms, with ripples of added energy potentially moving up the food web.

But, Smith warns, the drop in ice cover will negatively affect several other important species that are ice-dependent, including crystal krill and Antarctic silverfish. A decrease in krill would be particularly troublesome, as these are the major food source for the Ross Sea's top predators -- minke whales, Adélie and Emperor penguins, and crabeater seals.

Overall, says Smith, "our results suggest that phytoplankton production will increase and become more diatomaceous. Other components of the Ross Sea food web will likely be severely disrupted, creating significant but unpredictable impacts on the ocean's most pristine ecosystem."

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Story Source:
The above story is based on materials provided by Virginia Institute of Marine Science. The original article was written by David Malmquist. Note: Materials may be edited for content and length.

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Journal Reference:

1. Walker O. Smith, Michael S. Dinniman, Eileen E. Hofmann, John M. Klinck. The effects of changing winds and temperatures on the oceanography of the Ross Sea in the 21stcentury. Geophysical Research Letters, 2014; DOI: 10.1002/2014GL059311

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Virginia Institute of Marine Science. "Big thaw projected for Antarctic sea ice: Ross Sea will reverse current trend, be largely ice free in summer by 2100." ScienceDaily. ScienceDaily, 27 February 2014. <www.sciencedaily.com/releases/2014/02/140227115512.htm>.

Waterbirds' hunt aided by specialized tail: Swimming birds evolved rudder-like tail to dive for food

Date:

February 26, 2014

Source:

PLOS

Summary:

The convergent evolution of tail shapes in diving birds may be driven by foraging style. Birds use their wings and specialized tail to maneuver through the air while flying. It turns out that the purpose of a bird's tail may have also aided in their diversification by allowing them to use a greater variety of foraging strategies. To better understand the relationship between bird tail shape and foraging strategy, researchers examined the tail skeletal structure of over 50 species of waterbirds, like storks, pelicans, and penguins, and shorebirds, like gulls and puffins. They first categorized each species by foraging strategy, such as aerial, terrestrial, and pursuit diving, and then compared the shape and structure of different tails.

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This is a contrast of the typical elongate pygostyle of a diving bird (A), the Adélie Penguin (Pygoscelis adeliae, specimen AMNH 623439) to the typical short, dorsally deflected pygostyle of a non-diving bird (B), the Northern Fulmar (Fulmarus glacialis, specimen AMNH 20697).

Credit: Ryan Felice; CC-BY

The convergent evolution of tail shapes in diving birds may be driven by foraging style, according to a paper published in PLOS ONE on February 26, 2014 by Ryan Felice and Patrick O'Connor from Ohio University.

Birds use their wings and specialized tail to maneuver through the air while flying. It turns out that the purpose of a bird's tail may have also aided in their diversification by allowing them to use a greater variety of foraging strategies. To better understand the relationship between bird tail shape and foraging strategy, researchers examined the tail skeletal structure of over 50 species of waterbirds, like storks, pelicans, and penguins, and shorebirds, like gulls and puffins. They first categorized each species by foraging strategy, such as aerial, terrestrial, and pursuit diving, and then compared the shape and structure of different tails.

Scientists found that foraging style groups differed significantly in tail skeletal shape, and that shape could accurately "predict" foraging style with only a small amount of mismatch. In particular, underwater foraging birds, such as cormorants, penguins, puffins, gannets, and tropicbirds, have separately evolved a similarly specialized elongated tail structure, whereas aerial and terrestrial birds have a short, dorsally deflected tail structure. Moreover, each underwater foraging group, such as foot propelled, wing propelled, or plunge diving, had a distinctive tail-supporting vertebrae shape. 
According to the authors, the probable separate evolution of the specialized tail in underwater-diving birds may suggest that body structure adapted to the demand, or the need to move the tail as a rudder during underwater foraging. In contrast, the authors found no conclusive results when looking at the relationship between tail shape and flight style.

Mr. Felice adds, "Previous research has shown that diving birds evolve specializations in wing and leg morphology to facilitate underwater locomotion. This study puts a necessary focus on the tail, finding that this region of the body also evolves in response to the demands of underwater movement."

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

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Journal Reference:

1. Ryan N. Felice, Patrick M. O’Connor. Ecology and Caudal Skeletal Morphology in Birds: The Convergent Evolution of Pygostyle Shape in Underwater Foraging Taxa. PLoS ONE, 2014; 9 (2): e89737 DOI: 10.1371/journal.pone.0089737

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PLOS. "Waterbirds' hunt aided by specialized tail: Swimming birds evolved rudder-like tail to dive for food." ScienceDaily. ScienceDaily, 26 February 2014. <www.sciencedaily.com/releases/2014/02/140226174546.htm>.

New insights into origin of birds focuses on key characteristics that preceded flight: Body size, forelimb length

Date:

February 23, 2014

Source:

University of Bristol

Summary:

The key characteristics of birds which allow them to fly -- their wings and their small size -- arose much earlier than previously thought, according to new research that examined closely the Paraves, the first birds, and their closest dinosaurian relatives which lived 160 to 120 million years ago. Researchers investigated the rates of evolution of the two key characteristics that preceded flight: body size and forelimb length. In order to fly, hulking meat-eating dinosaurs had to shrink in size and grow much longer arms to support their feathered wings.

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Ruby Throated Hummingbird in flight. Being small and light is important for a flyer, and it now seems a whole group of dozens of little dinosaurs were lightweight and had wings of one sort or another. Most were gliders or parachutists, spreading their feathered wings, but not flapping them.

Credit: © gregg williams / Fotolia

The key characteristics of birds which allow them to fly -- their wings and their small size -- arose much earlier than previously thought, according to new research from the Universities of Bristol and Sheffield into the Paraves, the first birds and their closest dinosaurian relatives which lived 160 to 120 million years ago.

Mark Puttick and colleagues investigated the rates of evolution of the two key characteristics that preceded flight: body size and forelimb length. In order to fly, hulking meat-eating dinosaurs had to shrink in size and grow much longer arms to support their feathered wings. "We were really surprised to discover that the key size shifts happened at the same time, at the origin of Paraves," said Mr Puttick of Bristol's School of Earth Sciences. "This was at least 20 million years before the first bird, the famous Archaeopteryx, and it shows that flight in birds arose through several evolutionary steps."

Being small and light is important for a flyer, and it now seems a whole group of dozens of little dinosaurs were lightweight and had wings of one sort or another. Most were gliders or parachutists, spreading their feathered wings, but not flapping them. "Out of all these flappers and gliders, only the birds seem to have been capable of powered flight," said co-author Mike Benton, Professor of Vertebrate Palaeontology at Bristol. "But you wouldn't have picked out Archaeopteryx as the founder of a remarkable new group."

The study applied new numerical methods that calculate the rate of evolution of different characteristics across a whole evolutionary tree, and identify where bursts of fast evolution occurred. "Up to now you could only have guessed roughly where the major evolutionary transitions occurred," said Dr Gavin Thomas of the University of Sheffield, "but the new methods pinpoint the size changes. The small size of birds and their long wings originated long before birds themselves did."

Birds owe their success to their flight, wings and feathers. Until the 1990s, when the first feathered dinosaurs were found in China, birds were thought to have originated rapidly, marking a major transition from dinosaurs. Now, we know that Archaeopteryx was only one of a large number of small, flying dinosaurs. "The origin of birds used to be seen as a rapid transition," said Mark Puttick, "but now we know that the key characteristics we associate with them arose much earlier."

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

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Journal Reference:

1. Mark N. Puttick, Gavin H. Thomas, Michael J. Benton. HIGH RATES OF EVOLUTION PRECEDED THE ORIGIN OF BIRDS. Evolution, 2014; DOI: 10.1111/evo.12363

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University of Bristol. "New insights into origin of birds focuses on key characteristics that preceded flight: Body size, forelimb length." ScienceDaily. ScienceDaily, 23 February 2014. <www.sciencedaily.com/releases/2014/02/140223215134.htm>.

Yellow-eyed penguins forage in trawlers' wake

Wednesday Feb 12, 2014

A yellow-eyed penguin. Photo / Thinkstock

 

New Zealand's endangered yellow-eyed penguin have been found to follow the line of swooping seabirds - literally - when it comes to reaping the food stirred up by trawlers.

An Otago University research team have discovered the penguins, of which there were around 500 estimated pairs left on mainland New Zealand, forage in straight lines for several kilometres by following furrows in the seafloor scoured out by fishing trawlers.

Using GPS dive loggers the researchers monitored the penguins' movements over three years showing the birds use furrows scoured on the seabed by otter boards from trawl nets to find food, particularly blue cod. "This research is unique as it shows for the first time that not only do flying seabirds follow fishing vessels, but also penguins, with the latter foraging after a trawler has gone through a particular area," lead research Professor Philip Seddon said.

The researchers said blue cod and other bottom feeders were likely to forage around the seafloor lines because they were attracted to the marine life stirred up and exposed by the action of the nets being dragged behind fishing trawlers. The lines made by the otter boards, which keep the mouth of the trawl net open, are up to 15cms wide and two centimetres in depth on a north-east to south-west axis.

They can remain on the sea floor for a year or more and are clearly visible. GPS dive loggers were attached to the back of the birds to determine the depth the penguins dive, their locations and line of travel and how far they swim in one foraging trip. Lines on the seafloor were located by using video footage taken by a remote operated vehicle launched from the university's research vessel Polaris II.

Many penguins swim to a depth of between 60 and 70 metres to feed during multiple dives - up to 80 - over several hours before returning to shore. The penguins can travel up to 120 kilometres in one trip, while foraging in the mid-shelf fishing grounds some 20 kilometres off the Otago Peninsula.

The study shows that the birds also revisit the lines on subsequent occasions and might develop a visual memory of the area, researchers say. "It appears that using the lines for foraging is particularly related to bad breeding years when penguins are more likely to go further out to sea to find blue cod and other bottom feeders. This might also be due to the individual preference of some birds though," said Dr Thomas Mattern, the first author of the paper reporting the results. But the researchers say that one of the downsides of foraging around the trawl lines might be that an exclusive diet of blue cod, which tends to be low in nutritional value, could affect breeding.

As yet, there was no confirmation of this hypothesis and further research was needed to determine if there is any relationship between foraging patterns, diet quality and breeding success in the penguin population.

The research was published in the journal PloS ONE and supported by the Yellow-Eyed Penguin Trust.

source

Rains Spurred by Climate Change Killing Penguin Chicks

By Laura Poppick, Staff Writer   |   January 29, 2014

Three chicks suffer from hypothermia and die after a rainstorm. Credit: D. Boersma/U of Washington View full size image

Penguin-chick mortality rates have increased in recent years off the coast of Argentina — a trend scientists attribute to climate change and expect to worsen throughout the century, a new study finds.

From 1983 through 2010, researchers based at the University of Washington in Seattle monitored a colony of roughly 400,000 Magellanic penguins living halfway up the coast of Argentina on a peninsula called Punta Tombo. Each year, the researchers visited penguin nests once or twice a day from mid-September through late February to assess the overall status of the colony and the health of the chicks once they hatched in late November or early December. [Gallery of Magellanic Penguin Colony]

The resulting data set provides one of the longest-ever records of a single penguin colony. It revealed that starvation and predation were the most common and consistent chick killers over the years, but that hypothermia was the leading cause of death during years with heavy rainstorms, which became more prevalent throughout the study period — a trend that is consistent with climate models projecting the effects of climate change in the region.

This chick has found refuge in a burrow, where the water is still shallow enough to not wet its  

        downey plummage . Credit: D. Boersma/U of Washington

Young chicks between 9 and 23 days old were particularly vulnerable to hypothermia, as they were too young to have fully grown their waterproof plumage but already too big to seek shelter under their parents' bodies, the team reports today (Jan. 29) in the journal PLOS ONE. "They have to have waterproof feathers to survive," study co-author Dee Boersma told LiveScience. "If chicks don't have waterproof plumage, they are going to die as soon as they end up in the water."

Extreme heat — another component of climate change expected to worsen throughout the century — also challenged chicks' temperature-regulation systems and resulted in deaths, though not as many as hypothermia did, the team reports.

David Ainley, a senior wildlife ecologist at ecological consulting firm H.T. Harvey & Associates who studies Antarctic penguin colonies, says that, aside from giving Magellanic chicks the chills, rain can also damage the burrows that they live in during their early days. "I think that [penguin] pairs that have good burrows probably wouldn't suffer much of an effect, but it might be harder for pairs that have not competed successfully for where to make their burrow," Ainley, who was not involved in this study, told LiveScience. "Shallow burrows, or no burrow at all — those would be the ones that are most affected by rain."

Climate-change connection

The team noted that not all rainstorms killed the chicks. Of the 233 storms that occurred over the course of the study period, only 16 resulted in chick deaths. Still, the researchers pointed out that the types of heavy storms that did result in mortalities are projected to become more frequent, with some climate models predicting an increase in extreme precipitation in the Southern Hemisphere summer by 40 to 70 percent between 2076 and 2100, compared with that seen between 1951 and 1976.

Though the researchers only analyzed a single Magellanic colony in the study, they expect that colonies of the same species elsewhere along the coasts of Chile and Argentina likely react similarly to changes in weather patterns.

Wayne Trivelpiece, an Antarctic penguin researcher with the National Oceanographic and Atmospheric Administration's Southwest Fisheries Science Center, based in La Jolla, Calif., agrees that climate change is a serious threat to these and other penguin populations around the world. He has spent nearly the past 40 years studying penguins in Antarctica, and said he has also seen a decline in populations that he feels comfortable attributing to the indirect effects of climate change. "I don't think it is a real stretch to make that kind of connection," Trivelpiece told LiveScience. "But the actual hard evidence will come many decades down the road."

source

Hope for Antarctic Emperor Penguins Amidst Changing Climate (New Paper)

SustainableBusiness.com News
January 8, 2014
 

Among the great tragedies associated with climate change is that it is causing one of the greatest species extinctions of all time - a majority of plants and animals won't be able to adapt fast enough to the changing climate.

But there's some hope for Antarctic Emperor Penguins as a new study shows they may be adapting to environmental changes.

 

Satellite observations reveal that penguin colonies are actually moving away from traditional breeding grounds when there's not enough ice.

“These charismatic birds tend to breed on sea ice because it gives them relatively easy access to waters where they hunt for food.  Satellite observations captured of one colony in 2008, 2009 and 2010 show that the concentration of annual sea ice was dense enough to sustain a colony. But this was not the case in 2011 and 2012 when sea ice didn't form until a month after the breeding season began. During those years the birds moved up onto the neighbouring floating ice shelf to raise their young," says Peter Fretwell, lead author of the research and from the British Antarctic Survey.

 

“What’s particularly surprising is that climbing up the sides of a floating ice shelf – which at this site can be up to 30 metres high – is a very difficult manoeuvre for emperor penguins.  Whilst they are very agile swimmers they have often been thought of as clumsy out of the water,” he adds.

Reporting this week in the online journal, PLOS ONE, a team of scientists from British Antarctic Survey, the Australian Antarctic Division and the Scripps Institution of Oceanography at UC San Diego in California, describe this extraordinary change in behaviour.   

 

Because emperor penguins rely on sea ice as a breeding platform coupled with concerns about changing patterns of sea ice, the species is designated as ‘near threatened’ on the International Union for Conservation of Nature (IUCN) red list.

Scientific models suggest that levels of sea ice around Antarctica will decline over coming decades. Some forecasts predict Emperor Penguin numbers will halve before 2052 and more northerly colonies could be lost.

 

Barbara Wienecke from the Australian Antarctic Division says, “These new findings are an important step forward in helping us understand what the future may hold for these animals, however, we cannot assume that this behaviour is widespread in other penguin populations.  The ability of these four colonies to relocate to a different environment – from sea ice to ice shelf - in order to cope with local circumstances, was totally unexpected.  We have yet to discover whether or not other species may also be adapting to changing environmental conditions.” 

Whereas sea-ice is frozen salt water, ice shelves are made up of glacial ice that has flowed from the land into the sea.  Ice cliffs can form at the outer edge of an ice shelf and they can be up to 60 metres high. 

source 

You can download the Emperor Penguin study here:

Website: http://dx.plos.org/10.1371/journal.pone.0085285

Mosaic of Antarctica

Mosaic of Antarctica, a photo by NASA Goddard Photo and Video on Flickr.

Traffic Jams Lend Insight Into Emperor Penguin Huddle

Emperor penguins maintain the tight huddle that protects them from the harsh conditions of an Antarctic winter with stop-and-go movements like cars in a traffic jam, a new study has shown. (Credit: Daniel Zitterbart)

 

Dec. 16, 2013 — Emperor penguins maintain the tight huddle that protects them from the harsh conditions of an Antarctic winter with stop-and-go movements like cars in a traffic jam, a new study has shown.

 

By using a mathematical model that recreated the positions, movements and interactions of individual penguins in a huddle, researchers have revealed that an individual penguin only needs to move 2 cm in any direction for its neighbour to react and also perform a step to stay close to it. 

 

These movements then flow through the entire huddle like a travelling wave and play a vital role in keeping the huddle as dense as possible to protect the penguins from the cold; the wave also helps smaller huddles merge into larger ones.

The results have been published today, 17 December, in the Institute of Physics and German Physical Society's New Journal of Physics and are accompanied by a video abstract. An advanced set of videos can be viewed here -- http://www.youtube.com/playlist?list=PLx-sGUtkV82eZJHWNyJ4uxPCBtb1GlWgw
In a previous study, the same group of researchers studied time-lapse videos and showed that instead of remaining static, penguins in a huddle actually move every 30-60 seconds, causing surrounding penguins to move with them.

Co-author of the study Daniel Zitterbart, from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), said: "Our previous study showed how penguins use travelling waves to allow movement in a densely packed huddle, but we had no explanation as to how these waves propagate and how they are triggered."

To investigate this, the researchers used a mathematical model, which has previously been used to study traffic jams, and compared the results with an analysis of video recordings of a real-life penguin huddle.
Unlike a traffic jam, the researchers found that the waves of movements in a penguin huddle can originate from any single penguin and can propagate in any direction as soon as a sufficient gap, known as a "threshold distance," develops between two penguins.

This threshold distance was estimated to be around 2 cm, which is twice the thickness of a penguin's compressive feather layer, suggesting the penguins touch each other only slightly when standing in a huddle without compressing the feather layer so as to maximize huddle density without compromising their own insulation.

"We were really surprised that a travelling wave can be triggered by any penguin in a huddle, rather than penguins on the outside trying to push in," continued Zitterbart. "We also found it amazing how two waves, if triggered shortly after each other, merged instead of passing one another, making sure the huddle remains compact."

The emperor penguin is the only vertebrate species that breeds during the severe conditions of the Antarctic winter. At this time of year temperatures can get as low as -50°C and winds can reach speeds of up to 200 km/h.

To cope with the harsh conditions, the male penguins form dense huddles, often consisting of thousands of individuals, to maintain their body temperatures. Unlike other species of penguin, the male emperors are solely responsible for incubating their single egg during the winter, covering it in an abdominal pouch above their feet while the female returns to sea to feed.

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Story Source:

The above story is based on materials provided by Institute of Physics, via EurekAlert!, a service of AAAS.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. R C Gerum, B Fabry, C Metzner, M Beaulieu, A Ancel, D P Zitterbart. The origin of traveling waves in an emperor penguin huddle. New Journal of Physics, 2013; 15 (12): 125022 DOI: 10.1088/1367-2630/15/12/125022

Institute of Physics (2013, December 16). Traffic jams lend insight into emperor penguin huddle. ScienceDaily. Retrieved December 17, 2013, from http://www.sciencedaily.com­ /releases/2013/12/131216204020.htm

2 Profs Head to Antarctica for Penguin Studies

Penguin study

Posted: Dec 12, 2013
  San Diego, California News Station - KFMB Channel 8 - cbs8.com

By Natasha Stenbock, Weather

SAN DIEGO (CBS 8) - Funding is a dilemma researchers always face. Luckily for one local scientist, private funding paved the way from San Diego to the South Pole, with the benefit of using new technology that's cutting down on time in the field with better accuracy. In this week's earth 8 we bring you part 2 of the science behind this penguin study.
Senior research scientist Dr. Brent Stewart hopes to answer many important questions about several penguin species living on the South Pole.

When you're surrounded by hundreds of thousand of birds, the only way to get a better count is to fly high above them. As we showed you in part one of this series, a drone-like aircraft was used to collect more precise scientific data.
"What I really like about it is it can be a stable platform rather than flying over very quickly, we can hover. We can quickly move it in one direction, spin it around to get different perspectives," Stewart said. "But it's going to take another month, two months to count each bird at the two colonies. The big ones, the king penguins St. Andrews Bay, Salsbury Plains, they're probably 200,000 to 300,000 birds at each one of those colonies."

Although it looks crowded, Stewart says some colonies are not doing as well as others.
"Adelie penguins on the peninsula, we know that their populations are changing very rapidly as the climate there changes very rapidly. But other species are coming in and doing very well, so there are local colonies which are sustaining and are vital and other colonies are declining," he said.

Aside from a variable climate, penguins will always have natural predators.
"For Antarctic penguins, leopard seals are predators, they eat them. Particularly in the peninsula, killer whales, I think the ultimate predators are parasites which they're always dealing with. Infectious disease is a key issue in their population, biology. But it's really leopard seals and killer whales are their primary predators other than humans used to be.

"We're starting to plan for the next season next year for the Antarctic trip. Locally it's elephant seal season that's coming up in December, so I spend a lot of time out in San Nicholas & San Miguel Islands to study populations there, and we're trying to use the same kind of tools to help us with that," Stewart said.

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Citadal professor headed to Antarctica to study penguins

• Diane Knich
• Posted: Thursday, December 12, 2013

 

 

ProvidedA rockhopper penguin warms its young chick and guards against predators during Citadel professor Paul Nolan's 2006 research trip to the Falkland Islands.

Penguins are the proverbial canary in a coal mine when it comes to gauging climate change, says Citadel biology professor Paul Nolan.

So he packed his freezing-weather gear and is headed to Antarctica Friday to study them.

• Citadel biology professor Paul Nolan packs cold-weather gear for a research trip to Antarctica to study penguins.

Nolan, who studies animal behavior focusing mostly on birds, said he's been studying penguins for more than a decade, including taking several trips south of the equator to observe the waddling black and white creatures in their natural habitats.

He'll be working on the penguin study with Oxford University professor Tom Hart. People can learn more about the work, at PenguinLifelines.org.

Nolan, who also runs the nonprofit group CharlestonAudubon.org,said The Citadel Foundation gave him a $3,000 grant to help him with his research. He expects to share much of what he experiences with his students in future classes.

Jay Dowd, the foundation's chief executive officer, said Nolan's research is one of many ground-breaking projects conducted on campus by faculty, graduate students, and cadets to which the foundation contributes.

Nolan said it's important to go to Antarctica because "ongoing climate change is most pronounced at the poles." In Antarctica, there's been a 5- to 6-degree temperature increase in the past 100 years," he said.

The researchers plan to study the birds in two major ways. They will collect and analyze feathers that drop from the birds, he said, because feathers contain stress hormones, an indicator of environmental change.

They also will place cameras in penguin colonies that snap pictures every hour. The cameras will remain in place for about a year, he said, then researchers will go back and collect the cards from the cameras and study the photos. "The big idea behind this is that we want to monitor the behavior without bothering the birds."

A huge number of photographs will be collected, Nolan said, and members of the public can volunteer to help annotate them. The photographs will be available on April 25, which is International Penguin Day, he said.

Nolan said his unique role in the project is to study the color and color changes of the birds, especially in their beaks and feet. Color can reveal a great deal about an animal's health, he said.

Temperatures in Antarctica this time of year range from 0 to 20 degrees, he said, but he's ready for the cold.

The research team will travel on a cruise ship, and take Zodiac boats to various penguin colonies each day, he said. It's very difficult to find a way to travel in that part of the world, he said, but cruise ships work well. The researchers will make some presentations on penguins to other travelers, he said.

source 

 

A Penguin's Tale: Diet Linked to Breeding Failure

 

The Little Penguin 

 

Dec. 12, 2013 — A study on a Victorian penguin colony has revealed new insight into the link between seabird diet and breeding success.

In a study published in Functional Ecology, Nicole Kowalczyk and Associate Professor Richard Reina of Monash University's School of Biological Sciences, in collaboration with Andre Chradia from Phillip Island Nature Parks, studied Melbourne's St Kilda little penguin colony over two years.

They detailed how changes to prey abundance or food sources influenced reproductive success, tracking the penguins' nesting and feeding behaviour during the 2010 and 2011 breeding season.

Given previous data had shown that the colony fed mainly on anchovy which accounted for up to 78 per cent of their diet between years 2004 and 2008, the researchers predicted that changes in abundance would impact on the reproductive success of the colony -- but they were surprised to find the little penguins were resilient to changing conditions only if alternative prey such as sardines could be found.

Ms Kowalczyk said breeding failure in seabirds has been associated with declines in prey abundance, and the quality and diversity of prey -- but identifying which aspect of diet was responsible was challenging.
"The St Kilda little penguin colony has a short foraging range and displays narrow dietary diversity so this gave us the unique ability to identify how changes in food supply influence their reproduction," Ms Kowalczyk said.

"We found that a sharp decline of anchovy in 2010 had a negative impact on little penguin reproduction. However, in 2011, despite the relatively low anchovy abundance, their breeding success was extremely high.
"We believe the decrease of anchovy itself was not the only cause for low breeding success in 2010 but in combination with the scarcity of alternative prey. Our results show that little penguins are resilient to changes in their preferred prey but their ability to adapt to these changes is limited by the availability of alternative prey species."

Ms Kowalczyk said understanding seabird diet was integral to their conservation and management.
"Our results highlight that resource abundance and the availability of a variety of prey are critical factors in enabling this inshore seabird to adjust to changes in environmental conditions and fluctuations in their primary source of prey," Ms Kowalczyk said.

"Dietary changes have been linked to population declines and provide information about foraging conditions, particular prey species and foraging locations that require protection."

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Story Source:

The above story is based on materials provided by Monash University.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Nicole D. Kowalczyk, Andre Chiaradia, Tiana J. Preston, Richard D. Reina. Linking dietary shifts and reproductive failure in seabirds: a stable isotope approach. Functional Ecology, 2013; DOI: 10.1111/1365-2435.12216

Monash University (2013, December 12). A penguin's tale: Diet linked to breeding failure. ScienceDaily. Retrieved December 13, 2013, from http://www.sciencedaily.com­ /releases/2013/12/131212103351.htm

The mystery of Captain Scott's penguin eggs

Posted by GrrlScientist, Thursday 21 November 

 

Specimens for scientific study can be extremely difficult to collect, as Captain Robert Falcon Scott learned on his last expedition to Antarctica.

During the past few days, I've been sorting and organising the photographs from my recent trip to London, and shared the above image on twitter. In this photograph, you see a rather large eggshell with a more-or-less rectangular window cut into the shell. According to the museum label that accompanies this specimen, this is one of three emperor penguin eggs that had been collected -- fresh -- by Captain Scott on his last expedition to Antarctica.

But because I had copied the tweet to the Natural History Museum, and because a knowledgeable person was monitoring their twitter feed, I soon learned that the museum tag accompanying this egg shell was not-quite-correct: in fact, Bill Wilson, Apsley Cherry-Garrard and Henry "Birdie" Bowers actually collected this egg in 1911. These three men were part of Captain Scott's last Antarctic expedition.

But that is only a small part of the story. Since emperor penguins breed in the middle of the Antarctic winter, this meant the explorers had to hike 70 miles from Scott's base camp on Ross Island to the penguin breeding colony on Cape Crozier, locate and collect these eggs during the worst possible time: not only was it perpetually dark, but they faced extreme cold, powerful winds and intense blizzards. Why would three well-educated humans knowingly subject themselves to the worst weather imaginable on Earth to collect five fresh penguin eggs -- two of which they accidentally broke during their return journey? Were these guys mad?

These three men might have been mad, but the reason for their five-week-long expedition was not. Penguin eggs were important at that time because they were thought to be integral to confirming a scientific hypothesis popularised by Ernst Haeckel. This hypothesis, famously known as "ontogeny recapitulates phylogeny", proposed that development from a fertilised egg through adulthood re-enacts evolution via stages that resemble the ancient ancestors that gave rise to that particular species:

 

"Ontogeny recapitulates phylogeny." George Romanes' 1892 copy of Ernst Haeckel's controversial -- allegedly fraudulent -- embryo drawings. Romanes' version is often attributed incorrectly to Haeckel. [Romanes, G. J. (1892). Darwin and After Darwin. Open Court, Chicago.] This image is in the public domain due to its age.

This was a controversial hypothesis, but at least some scientists of that time thought they could watch the evolution of bird feathers from reptilian scales by documenting various stages of embryonic development of a primitive bird. At the time, penguins were thought to be the most primitive of birds (actually, this is not true) so this was the rationale for collecting penguin eggs for study instead of, say, chicken eggs.

Eventually, these eggs were added to the collection at the Natural History Museum. Twenty-three years after they had been collected -- after the "ontogeny recapitulates phylogeny" hypothesis had been discredited -- a study was published by zoologist CW Parsons, who concluded that "they did not greatly add to our understanding of penguin embryology."

Although Wilson, Cherry-Garrard and Bowers miraculously managed to return to Scott's base camp with three of the five eggs intact, perhaps most remarkable aspect of this adventure was the mystery that the intrepid explorers had missed: they never noticed that each bird's single precious egg, which was balanced on the parent's feet, was actually being incubated by the father.
Here's a video of Douglas Russell, curator of eggs at the Natural History Museum, telling us a little more of the story about this particular egg:


The pencil drawing of the penguin embryo (above right) is by Dorothy Thursby-Pelham.

NOTE [23 November 2013, Saturday, 0830]: this piece incorrectly stated that the NHM tag on this egg was incorrect. In fact, although captain Scott did not personally collect the penguin eggs, he did make it possible for this to happen by providing access to Antarctica and some information to Wilson, Cherry-Garrard and Bowers about the colony's location. This piece has been amended to correct that inaccuracy.

GrrlScientist can also be found here: Maniraptora. She's very active on twitter @GrrlScientist and sometimes lurks on social media: facebook, G+, LinkedIn, and Pinterest.

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A Heat Map Of Penguins Explains How They Stay Warm

Mac Irvine, Popular Science
Nov. 23, 2013,

courtesy Université de Strasbourg and Centre National de la Recherche Scientifique (CNRS), Strasbourg, France

As if their home in Antarctica weren’t cold enough, emperor penguins allow their exteriors to drop at least 7°F below their surroundings. The change helps the penguins stay warm, a recent paper showed. When the outer layer of feathers radiates heat to the sky, it becomes colder than its immediate environment, so heat flows back in. The cycle keeps the temperature underneath the plumage constant—and the penguin alive.

This article originally appeared in the December 2013 issue of Popular Science.
This article originally appeared on Popular Science

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