Tuesday, September 16, 2014

Glaciers in northern Antarctic Peninsula melting faster than ever despite increased snowfall


NASA Photo by: Jim Ross - NASA Photo: ED04-0056-137


Date:
September 14, 2014
Source:
University of Royal Holloway London
Summary:
Increased snowfall will not prevent the continued melting of glaciers in the northern Antarctic Peninsula, according to new research. Scientists have discovered that small glaciers that end on land around the Antarctic Peninsula are highly vulnerable to slight changes in air temperature and may be at risk of disappearing within 200 years.
 











Increased snowfall will not prevent the continued melting of glaciers in the northern Antarctic Peninsula, according to new research published in the journal Nature Climate Change. 


An international team of researchers, led by Dr Bethan Davies, from Royal Holloway, University of London, has discovered that small glaciers that end on land around the Antarctic Peninsula are highly vulnerable to slight changes in air temperature and may be at risk of disappearing within 200 years.

Temperatures are currently rising rapidly in the Antarctic Peninsula. Because warmer air holds more moisture, the amount of snowfall has also increased. Some researchers have suggested that this may offset the melting of the glaciers, however this study found that just a small rise in air temperature increased melting so much that even large amounts of extra snowfall could not prevent glacier recession.

"These small glaciers around the edge of the Antarctic Peninsula are likely to contribute most to rising sea levels over the coming decades, because they can respond quickly to climate change," said Dr Davies, from the Department of Geography at Royal Holloway. "This study is the first to show how glaciers in this vulnerable region are likely to respond to climate change in future. Our findings demonstrate that the melting will increase greatly even with a slight rise in temperature, offsetting any benefits from increased snowfall."

The researchers carried out extensive fieldwork on James Ross Island, northern Antarctic Peninsula, to map and analyse the changes to a glacier, which is currently 4km long, over the past 10,000 years. They used a combination of glacier and climate modelling, glacial geology and ice-core data.
Dr Davies added: "Geological evidence from previous studies suggests that the glacier grew by 10km within the last 5,000 years, before shrinking back to its current position. It was argued that this occurred during a warmer but wetter period, suggesting that increased precipitation in the future would offset the melting of the glaciers. However, our study shows that this growth occurred during the colder 'Little Ice Age', reaching its largest size just 300 years ago."

Researcher Dr Nicholas Golledge, from Victoria University of Wellington, in New Zealand, said: "This glacier, though small, is typical of many of the small glaciers that end on land around the Antarctic Peninsula. This research is important, because it helps reduce some of the uncertainties about how these glaciers will react to changing temperature and precipitation over the next two centuries."

Professor Neil Glasser, from Aberystwyth University, added: "We found that this glacier remained roughly the same size for thousands of years until it started to grow again 1,500 years ago. However, it is now melting faster than anything seen before, and over the next 200 years will become far smaller than at any point over the last 10,000 years. This unprecedented glacier recession, in response to climate change, will result in significant contributions to sea level rise from this and similar Antarctic Peninsula mountain glaciers and ice caps."




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



Journal Reference:
  1. Bethan J. Davies, Nicholas R. Golledge, Neil F. Glasser, Jonathan L. Carrivick, Stefan R. M. Ligtenberg, Nicholas E. Barrand, Michiel R. van den Broeke, Michael J. Hambrey, John L. Smellie. Modelled glacier response to centennial temperature and precipitation trends on the Antarctic Peninsula. Nature Climate Change, 2014; DOI: 10.1038/nclimate2369



University of Royal Holloway London. "Glaciers in northern Antarctic Peninsula melting faster than ever despite increased snowfall." ScienceDaily. ScienceDaily, 14 September 2014. <www.sciencedaily.com/releases/2014/09/140914211024.htm>.

Saturday, September 6, 2014

Detection by Dung: Don’t Eat the Brown Snow

2590002176_8c3725fdd8_o
Researchers in Antarctica on a mission to locate penguin colonies found two groups of seabirds, thanks to a little help from satellites, helicopters, and the detection of more “primitive” evidence: penguin poop.

Our favorite tuxedo-clad Emperor penguin is native to Antarctica, but harsh winter conditions and the remoteness of some colonies can make it difficult for biologists to gain a comprehensive population assessment of this “hiding” bird. The first breeding penguin colony was discovered in Antarctica in 1902, and in 1999 thousands of birds were sighted near the Mertz glacier in Antarctica, but for the last century, suspected colonies of Emperor Penguins in the area had yet to be confirmed.

In this recently published PLOS ONE study, the authors used both survey- and satellite-based methods to locate the presence of Emperor penguin colonies on the Mertz glacier, where a previous sighting of thousands of birds had occurred 15 years ago, but a drastic habitat change—the glacier’s “tongue” broke off in February 2010—may have disrupted.

journal_pone_0100404_g002
Aerial surveys captured two new potential breeding grounds for colonies, the Eastern and Western (~7,400 breeding pairs total).  Satellite images from a thousand feet in the sky helped the authors detect the Eastern colony by the presence of fecal marks—or in bird specialist speak, “guano”—in the snow.

The red arrow in the image above points out the lovely brown streak of guano strewn across the ice shelf, which indicates the Eastern colony’s previous breeding ground. The authors used this streak as an indication that the Eastern colony was likely close by. Below the guano-streaked, snow-packed shelf, the presence of the Eastern colony was confirmed by researchers trekking across treacherous terrain to visually confirm the presence of the birds.

Unlike the Eastern colony, who mobilized to a fresh home post-breeding, the Western colony seemingly didn’t mind remaining in their breeding muck. This colony was discovered not by satellite but by chance during helicopter flight operations in Antarctica. Although the authors had difficulties finding the Western colony by aerial footage, as pictured in the below image, these social gatherers appeared to differ from the Eastern colony in that they inhabited a large flat surface, and the colony appeared to be much larger.
journal_pone_0100404_g003
In the cases of both colonies, aerial surveys appeared to be very effective for locating them. So, until humans evolve warmer winter coats, scientists conducting surveys by foot are still limited by frigid conditions and isolated locations in future South Pole endeavors. To obtain a more accurate picture of total penguin counts, the authors suggest taking multiple aerial images during the breeding season and conducting several-year surveys to confirm numbers in suspected Antarctic penguin colonies. But for now, the game of Hide and Go Poop will continue.

Citation: Ancel A, Cristofari R, Fretwell PT, Trathan PN, Wienecke B, et al. (2014) Emperors in Hiding: When Ice-Breakers and Satellites Complement Each Other in Antarctic Exploration. PLoS ONE 9(6): e100404. doi:10.1371/journal.pone.0100404

Image 1: Emperor Penguins by Lin Padgham
Image 2-3: Figures 1 and 2 from article

source

Wednesday, September 3, 2014

Extinctions during human era one thousand times more than before

Date:
September 2, 2014
Source:
Brown University
Summary:
The gravity of the world's current extinction rate becomes clearer upon knowing what it was before people came along. A new estimate finds that species die off as much as 1,000 times more frequently nowadays than they used to. That's 10 times worse than the old estimate of 100 times.









 

Vintage engraving of the Dodo (Raphus cucullatus), a flightless bird endemic to the Indian Ocean island of Mauritius. The dodo has been extinct since the mid-to-late 17th century.

Credit: iStockphoto




The gravity of the world's current extinction rate becomes clearer upon knowing what it was before people came along. A new estimate finds that species die off as much as 1,000 times more frequently nowadays than they used to. That's 10 times worse than the old estimate of 100 times.


It's hard to comprehend how bad the current rate of species extinction around the world has become without knowing what it was before people came along. The newest estimate is that the pre-human rate was 10 times lower than scientists had thought, which means that the current level is 10 times worse.

Extinctions are about 1,000 times more frequent now than in the 60 million years before people came along. The explanation from lead author Jurriaan de Vos, a Brown University postdoctoral researcher, senior author Stuart Pimm, a Duke University professor, and their team appears online in the journal Conservation Biology. "This reinforces the urgency to conserve what is left and to try to reduce our impacts," said de Vos, who began the work while at the University of Zurich. "It was very, very different before humans entered the scene."

In absolute, albeit rough, terms the paper calculates a "normal background rate" of extinction of 0.1 extinctions per million species per year. That revises the figure of 1 extinction per million species per year that Pimm estimated in prior work in the 1990s. By contrast, the current extinction rate is more on the order of 100 extinctions per million species per year.

Orders of magnitude, rather than precise numbers are about the best any method can do for a global extinction rate, de Vos said. "That's just being honest about the uncertainty there is in these type of analyses."

From fossils to genetics

The new estimate improves markedly on prior ones mostly because it goes beyond the fossil record. Fossils are helpful sources of information, but their shortcomings include disproportionate representation of hard-bodied sea animals and the problem that they often only allow identification of the animal or plant's genus, but not its exact species.

What the fossils do show clearly is that apart from a few cataclysms over geological periods -- such as the one that eliminated the dinosaurs -- biodiversity has slowly increased.

The new study next examined evidence from the evolutionary family trees -- phylogenies -- of numerous plant and animal species. Phylogenies, constructed by studying DNA, trace how groups of species have changed over time, adding new genetic lineages and losing unsuccessful ones. They provide rich details of how species have diversified over time.

"The diversification rate is the speciation rate minus the extinction rate," said co-author Lucas Joppa, a scientist at Microsoft Research in Redmond, Wash. "The total number of species on earth has not been declining in recent geological history. It is either constant or increasing. Therefore, the average rate at which groups grew in their numbers of species must have been similar to or higher than the rate at which other groups lost species through extinction."

The work compiled scores of studies of molecular phylogenies on how fast species diversified.
For a third approach, de Vos noted that the exponential climb of species diversity should take a steeper upward turn in the current era because the newest species haven't gone extinct yet.
"It's rather like your bank account on the day you get paid," he said. "It gets a burst of funds -- akin to new species -- that will quickly become extinct as you pay your bills."

By comparing that rise of the number of species from the as-yet unchecked speciation rate with the historical trend (it was "log-linear") evident in the phylogenies, he could therefore create a predictive model of what the counteracting historical extinction rate must have been.

The researchers honed their models by testing them with simulated data for which they knew an actual extinction rate. The final models yielded accurate results. They tested the models to see how they performed when certain key assumptions were wrong and on average the models remained correct (in the aggregate, if not always for every species group).

All three data approaches together yielded a normal background extinction rate squarely in the order of 0.1 extinctions per million species per year.

A human role

There is little doubt among the scientists that humans are not merely witnesses to the current elevated extinction rate. This paper follows a recent one in Science, authored by Pimm, Joppa, and other colleagues, that tracks where species are threatened or confined to small ranges around the globe. In most cases, the main cause of extinctions is human population growth and per capita consumption, although the paper also notes how humans have been able to promote conservation.

The new study, Pimm said, emphasizes that the current extinction rate is a more severe crisis than previously understood. "We've known for 20 years that current rates of species extinctions are exceptionally high," said Pimm, president of the conservation nonprofit organization SavingSpecies. "This new study comes up with a better estimate of the normal background rate -- how fast species would go extinct were it not for human actions. It's lower than we thought, meaning that the current extinction crisis is much worse by comparison."

Other authors on the paper are John Gittleman and Patrick Stephens of the University of Georgia.

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

Journal Reference:
  1. Jurriaan M. De Vos, Lucas N. Joppa, John L. Gittleman, Patrick R. Stephens, Stuart L. Pimm. Estimating the Normal Background Rate of Species Extinction. Conservation Biology, 2014; DOI: 10.1111/cobi.12380


Brown University. "Extinctions during human era one thousand times more than before." ScienceDaily. ScienceDaily, 2 September 2014. <www.sciencedaily.com/releases/2014/09/140902151125.htm>.

Monday, August 25, 2014

Adult survival declines as African Penguin population plummets

Sherley_DSC2401_015_1LR
The African Penguin population is in freefall, with adult survival rates over the last decade desperately low. Urgent management action is required to secure both the prey requirements and future of one of Africa’s most charismatic seabirds.

Richard B Sherley
Animal Demography Unit and Marine Research Institute, University of Cape Town, South Africa

Linked IBIS paper
Age-specific survival and movement among major African Penguin Spheniscus demersus colonies. Sherley, R.B., Abadi, F., Ludynia, K., Barham, B.J., Clark, A.E. & Altwegg, R.


Globally, seabirds are in trouble. With 28% of species listed as globally threatened by the IUCN, no other similarly sized group of birds has a poorer conservation status. Seabirds are susceptible to a wide range of anthropogenic pressures, but some of the most substantial threats they face stem from the deterioration of their marine environment through unsustainable fishing practices and climate change.

Penguins may be particularly sensitive to changes in the oceans that they inhabit compared to flying seabirds, because they must swim to find their food (Boersma 2008). The African Penguin Spheniscus demersus, endemic to South Africa and Namibia, has decreased by more than 90% since the 1930s. In South Africa numbers have dropped by more than 10% a year since 2004, resulting in the species being up-listed to Endangered in 2010. Off the Namibian coast, heavy commercial fishing collapsed the stocks of sardine Sardinops sagax and anchovy Engraulis encrasicolus (the penguins’ main prey) in the 1960s and 1970s. The stocks have never recovered and today penguins in Namibia rely on a diet of junk food (Ludynia et al. 2010).

In South Africa, large-scale changes in the marine environment (possibly linked to global climate change) have caused a change in the spawning grounds of sardine and anchovy. These fish now mostly spawn further east than they did two decades ago and are out of reach of penguin colonies on South Africa’s West Coast for much of the year. However, because many of the fish canning factories are also on the West Coast and fishing vessels, like birds, are limited in how far they can go to find fish, the result has been relatively heavy fishing pressure in areas where the fish have become scarce. This is particularly true for adult sardine, a valuable commercial fish and a key source of energy for African penguins when they need to build up body condition to breed each year (Sherley et al. 2013a).

Sherley (Gaglio) IMG_0231_1
Seabirds will often respond to a scarcity of food by skipping or abandoning breeding, opting not to re-lay after losing clutches of eggs, or reducing the amount of food brought to the chicks leading to slow growth, poor chick condition and mortality through starvation. African penguins have shown all of these responses in recent years. Over time, these behavioural responses can lead to population declines through poor breeding success and juvenile survival, but they usually allow adult seabirds to buffer periods of poor food availability. Although their body condition may fall below a critical threshold needed for breeding, in long-lived animals like seabirds, adult survival is rarely compromised except in cases of extreme food shortage.

Our work, published this week in IBIS (Sherley et al. 2014), demonstrates that this is exactly what has happened with African penguins breeding in South Africa’s Western Cape. Over the course of our study period (1994/95 to 2011/12), we noted substantial decreases in adult survival as the availability of adult sardine decreased on the West Coast. At what was formerly the largest colony, Dassen Island, adult survival dropped from around 80% per year in the late 1990s and early 2000s to a low of 43% in 2007/08 (Figure 1) and a similar decline was noted at nearby Robben Island. During this period, heavy fishing pressure persisted in areas with low fish abundance because of the distribution of land-based processing plants, leading to sardine exploitation rates between 2004 and 2007 which were more than double the long-term average.
R Graphics OutputFigure 1. Time-dependent survival estimates (and 95% confidence intervals) for adult African Penguins from Dassen Island, Western Cape between 1994/95 and 2011/12.

These poor adult survival rates indicate that the population is unsustainable and are, in a large part, the reason for the recent dramatic decline in the number of African penguins breeding in South Africa. Ecologists working in the country have been recommending spatial management of the fishery to offset losses of penguins since 2006 and, in response to the species’ worsening conservation status, the government’s fisheries department has begun to investigate the potential benefits to penguins of spatial closures. Experimental small-scale fishing exclusions have been implemented around several breeding colonies, in the hope that this may take some pressure off of the penguins during the breeding season, allowing them to balance their energy budgets more easily.

However, despite the closures having reduced the energetic costs of foraging at one colony (Pichegru et al. 2012) and encouraging results from a modelling study (Weller et al. 2014), evidence for demographic benefits has been scarce and the experimental closures may be removed at the end of 2014. Even if they remain in place, recent biologging studies have demonstrated that non-breeding and juvenile African penguins travel over hundreds of kilometres and feed in areas far from their breeding colonies (e.g. Sherley et al. 2013b). Thus, these closures as a stand-alone management action will not be adequate to reverse the rapid decline in Africa’s only endemic penguin. Rather, a suite of management measures is encouraged to mitigate the multiple factors contributing to the worrying decline of African penguins (Weller et al. 2014, Ludynia et al. 2014). Impacts on adult survival, such as those noted in our study, make it essential that government organizations rapidly implement effective fisheries management actions over large spatial scales to ensure food security for marine top predators.

References

Boersma, P. 2008. Penguins as marine sentinels. Bioscience 58: 597–607. View
Ludynia, K., Roux, J.-P., Jones, R., Kemper, J. & Underhill, L.G. 2010. Surviving off junk: low-energy prey dominates the diet of African penguins Spheniscus demersus at Mercury Island, Namibia, between 1996 and 2009. African Journal of Marine Science 32: 563–572. View
Ludynia, K., Waller, L.J., Sherley, R.B., Abadi, F., Galada, Y., Geldenhuys, D., Crawford, R.J.M., Shannon, L.J. & Jarre, A. 2014. Processes influencing the population dynamics and conservation of African penguins on Dyer Island, South Africa. African Journal of Marine Science 36: 253–267. View
Pichegru, L., Ryan, P.G., van Eeden, R., Reid, T., Gremillet, D. & Wanless, R. Industrial fishing, no-take zones and endangered penguins. Biological Conservation 156: 117–125. View
Sherley, R.B., Underhill, L.G., Barham, B.J., Barham, P.J., Coetzee, J.C., Crawford, R.J.M., Dyer, B.M., Leshoro, T.M. & Upfold L. 2013a. Influence of local and regional prey availability on breeding performance of African penguins Spheniscus demersus. Marine Ecology Progress Series 473: 291–301. View
Sherley, R.B., Ludynia, K., Lamont, T., Roux, J.-P., Crawford, R.J.M. & Underhill, L.G. 2013b. The initial journey of an endangered penguin: implications for seabird conservation. Endangered Species Research 21: 89–95. View
Sherley, R.B., Abadi, F., Ludynia, K., Barham, B.J., Clark, A.E. & Altwegg, R. 2014. Age-specific survival and movement among major African Penguin Spheniscus demersus colonies. Ibis. DOI: 10.1111/ibi.12189.
Weller, F., Cecchini, L.-A., Shannon, L., Sherley, R.B., Crawford, R.J.M., Altwegg, R., Scott, L., Stewart, T. & Jarre A. 2014. A system dynamics approach to modelling multiple drivers of the African penguin population on Robben Island, South Africa. Ecological Modelling 277: 38–56. View

Sherley Richard_Sherley
About the author
Richard Sherley is a Postdoctoral Researcher with the Animal Demography Unit and Marine Research Institute at the University of Cape Town. He has conducted research on seabirds in southern Africa for the last seven years, focusing on understanding how their productivity, survival and dispersal are influenced by the anthropogenic and environmental changes occurring in their marine ecosystem. In particular, he is interested in research that applies ecological theory to create tangible conservation benefits and in understanding how the conditions that animals experience early in life may influence later fitness and impact on population dynamics.
View full profile

Photo images
TOP: African Penguin © Richard Sherley
BOTTOM: Moulting African Penguin © Davide Gaglio davygaglio.wix.com

source

Marine biologists unlock the secrets of Antarctica

Among the discoveries are crabs that are able to live within the clouds of sulphur emitted by live underwater volcanoes









Marine biologists from across the world have produced an atlas of sea life in the Antarctic Ocean from microbes to whales, finding thousands of new species in the process. Among the discoveries were crabs that are able to live within the clouds of sulphur emitted by live underwater volcanoes and a new type of barnacle that has stems 50 times longer than its head. They also found that climate change had potentially caused changes in the breeding patterns of penguins.

The project was the first of this magnitude since the publication of the Antactic Map Folio Series 45 years ago. Dr Katrin Linse, an expert in Antarctic molluscs at the British Antartic Survey, told The Independent: “Since 1969 there has been no update but lots of science done in that period and lots of species discovered. “We had knowledge of 3,000 or 4,000 species when this process began, but now we know of more like 9,000 -- so it has hugely increased the number of known species.”

She added: “A lot of nations came together and put a lot of information together and specialists were chosen to analyse the data and when you do that you suddenly start to see changes.” The atlas, published this week by the Scientific Committee on Antarctic Research, follows four years work by leading oceanographers and biologists compiling everything they know about ocean species including microbes, fish, mammals and birds. Dr Linse added: “Now if we observe distribution changes or breeding areas, we can say for sure if it represents a change rather than just a year that is different for some reason.”

Claude De Broyer, of the Royal Belgian Institute of Natural Sciences, said: “The data and expert opinions in the atlas will help inform conservation policy, including the debate over whether or not to establish marine protected areas in the open ocean.”

The atlas also gives scientists the ability to predict what effect climate change could have on the distribution of key species, using sophisticated environmental models coupled with the existing species distribution data. The book was a remarkable example of international co-operation. It was produced using data from 147 scientists from 91 different academic institutions in 22 countries.
Huw Griffiths, author and editor of the British Antarctic Survey, said: “The book is unique and contains an amazing collection of information and photos. “It’s been an enormous international effort and will serve as a legacy to the dedicated team of scientists who have contributed to it. “The atlas is a must-read for anyone interested in the animals living at the end of the Earth.”

source 

Friday, August 15, 2014

Little penguins forage together: 40% of studied penguins synchronized underwater movements while foraging

Date: August 13, 2014

Most little penguins may search for food in groups, and even synchronize their movements during foraging trips, according to a study published August 13, 2014 in the open-access journal PLOS ONE by Maud Berlincourt and John Arnould from Deakin University in Australia. 

Little penguins are the smallest penguin species and they live exclusively in southern Australia, New Zealand, and the Chatham Islands, but spend most of their lives at sea in search of food. Not much is known about group foraging behavior in seabirds due to the difficulty in observing their remote feeding grounds.

Scientists aiming to better understand this behavior used GPS-derived location and diving data to track at-sea foraging associations of little penguins during breeding season. Researchers gathered 84 separate foraging tracks and then categorized individual penguin associations into one of three groups: not associating with other penguins; associating when departing from or returning to the colony; or at sea when traveling or diving, including synchronized dives.

The authors found that ~ 70% of little penguins' foraging tracks were in association with other penguins, ~ 50% of individuals dove while associating with other penguins, and ~ 40% exhibited synchronous diving. These behaviors suggest little penguins forage in groups, may synchronize their underwater movements, and potentially cooperate to concentrate their small-schooling prey.

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

Journal Reference:
  1. Maud Berlincourt, John P. Y. Arnould. At-Sea Associations in Foraging Little Penguins. PLoS ONE, 2014; 9 (8): e105065 DOI: 10.1371/journal.pone.0105065


PLOS. "Little penguins forage together: 40% of studied penguins synchronized underwater movements while foraging." ScienceDaily. ScienceDaily, 13 August 2014. <www.sciencedaily.com/releases/2014/08/140813174225.htm>.

Wednesday, August 13, 2014

Penguins Act As Coalmine-Canaries for the Southern Ocean


Miners used to bring caged canaries down into the mines with them. The notion was that if toxic gases like methane or carbon monoxide leaked into the mine, then the canaries would die before the humans, giving the miners a chance to escape. The idea of a sentinel species is the same. Sentinels are groups of animals who are particularly or uniquely sensitive to changes to their ecosystem. If a sentinel species begins to suffer, it might mean that the broader ecosystem is under attack as well, sometimes giving us a brief window of opportunity to try to address the problem. In some ways, penguins are a sentinel species for southern ocean ecosystems.

Seabirds in general are useful indicators of ecosystem health because they are so dependent on having suitable habitats for breeding and on finding sufficient amounts of prey. Penguins in particular reflect local (or regional) conditions perhaps better than any other group of seabirds. That’s according to Head of Conservation Biology at the British Antarctic Survey Phil N. Trathan and colleagues, who reasoned that understanding the threats to penguins might allow us a better understanding of the Southern Oceans more generally.

Seabirds are the most threatened group of birds, and after albatrosses, penguins are the second most threatened group of all the seabirds. Some seabirds can travel quite far to find food; if there isn’t enough nearby, they can fly a little farther, and are therefore better able to withstand certain pressures. But penguins – all 18 species of them – tend to stick close to home. Penguin populations can therefore reflect both natural, seasonal variations in the health of the ecosystems within several hundred kilometers of their colonies, as well as the more artificial changes brought about by human activities.

In general, the regions with the most cumulative impacts from human activities are in the northern hemisphere. That makes sense, since proportionally, more humans live in the northern hemisphere. But that doesn’t mean that the southern hemisphere in unaffected by human activity. The Southern Oceans, however, are less studied. If researchers can figure out the factors that cause penguin populations to suffer, then they might be able to determine what factors are threatening the Southern Oceans more generally. For Trathan’s team, penguins might as well be canaries.

768px Location Southern Ocean.svg  Penguins Act As Coalmine Canaries for the Southern Ocean
The Southern Ocean, highlighted in blue.

They found that penguin populations are in some ways resilient and, if given sufficient habitat and food, can recover from historic threats like hunting (for oil and feathers) and egg harvesting. Given the threats we aren’t equipped to mitigate in the near- or medium-terms like climate change, infectious disease transmission, and toxic algal blooms, Trathan argues that it is more important that we address those stressors over which we do have control.

The threats from habitat degradation, invasive species, oil pollution, plastic pollution, fisheries bycatch, and competition with fisheries over their prey sources, represent major concerns and “require concerted action to mitigate future population declines for many species.” In other words, the ability for penguins to survive global pressures like climate change and ocean acidification will depend on our ability to protect their prey, to protect their breeding grounds, and to eliminate the pollution from the waters in which they swim. “A risk averse or precautionary approach to the conservation of penguins would thus take immediate action to off-set these impacts,” writes Trathan.

The best solution identified by Trathan’s group is the establishment of marine protected areas (MPAs) both in sovereign waters and on the high seas. Because penguins have different spatial needs as they age, most existing MPAs are inadequate to protect penguins throughout their lifespan. Despite the challenge of coordinating local, national, and international conservation efforts, protecting penguins would also have a positive effect on the other species who share their ecosystems, including fish and marine mammals.

MPAs alone won’t get the job done, however, which is why Trathan and colleagues say that other, flexible, creative approaches will be required to supplement them. Coastal breeding habitats should be protected, especially since penguins have such extreme site fidelity. Introduced or invasive species need to be strictly controlled. Shipping lanes ought to be routed away from critical penguin resting, transit, and foraging areas. “Concerted action to conserve penguin populations today,” they write, “will be essential to facilitate populations that are robust and resilient to climate change impacts in the future.” 

– Jason G. Goldman | 13 August 2014


Source: Trathan P.N., García-Borboroglu P., Boersma D., Bost C.A., Crawford R.J.M., Crossin G.T., Cuthbert R.J., Dann P., Davis L.S. & DE LA Puente S. et al. (2014). Pollution, Habitat Loss, Fishing, and Climate Change as Critical Threats to Penguins., Conservation biology : the journal of the Society for Conservation Biology, PMID: http://www.ncbi.nlm.nih.gov/pubmed/25102756
 
Header image: Rockhopper penguin, Patagonia, Argentina via shutterstock.com; Southern ocean graphic via Connormah/Wikimedia commons

source 

Thursday, August 7, 2014

Giant fossil penguin features on coin

Wednesday, 6 August 2014
Ewan Fordyce with coin image
Professor Ewan Fordyce proudly holds the 2014 collectable coin with his discovery – a Kairuku penguin – depicted on it. Photo: Sharron Bennett.

In what is thought to be a first for an Otago researcher, Geology’s Professor Ewan Fordyce has had one of his research findings emblazoned on a collectable coin issued recently by New Zealand Post.
A Kairuku penguin is depicted on the 2014 New Zealand Annual Coin. The extinct species of giant penguin was named by Professor Fordyce and a team working from the Department of Geology in 2012.

Professor Fordyce says he was “very delighted” when contacted by New Zealand Post earlier this year with the proposal and request to use the image of a Kairuku on the coin.
"It's nice to see Otago research recognised in this way."
“It's nice to see Otago research recognised in this way. Actually, the fossils can be a bit personal, if they are unusual like the Kairuku penguins (in this case, well preserved and big), and if we can remember the original discovery.”

The first discovery of Kairuku remains involved 27-million-year-old fossilised bones spotted “by chance” by Professor Fordyce in 1977. An account of the fossil’s discovery and significance can be found here.

He plans to keep his own copy of the coin at hand, bringing it out now and then to share with those who might really appreciate it from a scientific perspective – the occasional visiting paleospheniscologist (fossil penguin researcher).

Just 1500 of the commemorative coins were minted in the series produced annually by New Zealand Post to highlight endangered native species.

About Kairuku penguins:

The giant penguins are taller than any species of penguin known to have lived in New Zealand. They are thought to have lived about 27 million years ago and probably became extinct somewhere between 24 and 25 million years ago.

These penguins were much taller and heavier than their modern counterparts. When standing, they were 1.3 metres tall and stretched out to an impressive 1.5 metres when swimming. Their weight is estimated to have been at least 60 kilograms. The Kairuku has unusual proportions, with a long beak, long flippers, a slender body and short, thick legs and feet compared with modern penguins. This body type and beak suggest that they were divers that speared or snapped at their food.

source

Risks to penguin populations analyzed

Date:
August 6, 2014
Source:
British Antarctic Survey
Summary:
A major study of all penguin populations suggests the birds are at continuing risk from habitat degradation. Scientists recommend the adoption of measures to mitigate against a range of effects including; food scarcity (where fisheries compete for the same resources), being caught in fishing nets, oil pollution and climate change.
King penguins.
Credit: Pete Bucktrout, BAS

A major study of all penguin species suggests the birds are at continuing risk from habitat degradation. Writing in the journal, Conservation Biology, scientists recommend the adoption of measures to mitigate against a range of effects including; food scarcity (where fisheries compete for the same resources), being caught in fishing nets, oil pollution and climate change. This could include the establishment of marine protected areas, although the authors acknowledge this might not always be practical. A number of other ecologically based management methods could also be implemented.

Populations of many penguin species have declined substantially over the past two decades. In 2013, eleven species were listed as 'threatened' by the International Union for Conservation of Nature (IUCN), two as 'near threatened' and five as 'of least concern'. In order to understand how they might respond to further human impacts on the world's oceans the scientists examined all eighteen species, looking at different factors where human activity might interfere with their populations. Forty-nine scientists contributed to the overall process.

They considered all the main issues affecting penguin populations including; terrestrial habitat degradation, marine pollution, fisheries bycatch and resource competition, environmental variability, climate change and toxic algal poisoning and disease. The group concludes that habitat loss, pollution, and fishing remain the primary concerns. They report that the future resilience of penguin populations to climate change impacts will almost certainly depend upon addressing current threats to existing habitat degradation on land and at sea.

The group of scientists recommends that the protection of penguin habitats is crucial for their future survival. This could be in the form of appropriately scaled marine reserves, including some in the High Seas, in areas beyond national jurisdiction.

Dr Phil Trathan, Head of Conservation Biology at the British Antarctic Survey and the lead author of the study, said: "Penguins and humans often compete for the same food, and some of our other actions also impinge upon penguins. Our research highlights some of the issues of conservation and how we might protect biodiversity and the functioning of marine ecosystems. "Whilst it is possible to design and implement large-scale marine conservation reserves it is not always practical or politically feasible. However, there are other ecosystem-based management methods that can help maintain biodiversity and a healthy ecosystem. For example, the use of spatial zoning to reduce the overlap of fisheries, oil rigs and shipping lanes with areas of the ocean used by penguins; the use of appropriate fishing methods to reduce the accidental bycatch of penguins and other species; and, the use of ecologically based fisheries harvesting rules to limit the allowable catches taken by fishermen, particularly where they target species that are also food for penguins."
 
The scientists believe their work will be of benefit to other studies of animal species, not just in the southern hemisphere, but the northern one too, where human impacts on the environment is even greater.

All 18 species of penguin were studied; Emperor and Adelie (Antarctica), King, Chinstrap, Gentoo, Macaroni, Royal, Southern Rockhopper, Northern Rockhopper (Sub-Antarctic), Little, Fiordland, Snares, Erect-crested, Yellow-eyed (Oceania), and African, Magellanic, Humboldt and Galapágos (Africa and South America).

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

Journal Reference:
  1. Phil Trathan, Pablo García-Borboroglu, Dee Boersma, Charles-André Bost, Robert Crawford, Glenn Crossin, Richard Cuthbert, Peter Dann, Lloyd Spencer Davis, Santiago De La Puente, Ursula Ellenberg, Heather Lynch, Thomas Mattern, Klemens Pϋtz, Philip Seddon, Wayne Trivelpiece and Barbara Wienecke. Pollution, Habitat Loss, Fishing and Climate Change as Critical Threats to Penguins. Conservation Biology, 2014 (in press)


British Antarctic Survey. "Risks to penguin populations analyzed." ScienceDaily. ScienceDaily, 6 August 2014. <www.sciencedaily.com/releases/2014/08/140806102808.htm>.

Saturday, August 2, 2014

Extinct mega penguin was tallest and heaviest ever

  • 16:16 01 August 2014 by Jeff Hecht
Forget emperor penguins, say hello to the colossus penguin. Newly unearthed fossils have revealed that Antarctica was once home to the biggest species of penguin ever discovered. It was 2 metres long and weighed a hefty 115 kilograms.

Palaeeudyptes klekowskii lived 37 to 40 million years ago. This was "a wonderful time for penguins, when 10 to 14 species lived together along the Antarctic coast", says Carolina Acosta Hospitaleche of the La Plata Museum in Argentina.

She has been excavating fossil deposits on Seymour Island, off the Antarctic peninsula. This was a warmer region 40 million years ago, with a climate like that of present-day Tierra del Fuego, the islands at the southern tip of South America.

The site has yielded thousands of penguin bones. Earlier this year, Acosta Hospitaleche reported the most complete P. klekowskii skeleton yet, although it contained only about a dozen bones, mostly from the wings and feet (Geobios, DOI: 10.1016/j.geobios.2014.03.003).

Now she has uncovered two bigger bones. One is part of a wing, and the other is a tarsometatarsus, formed by the fusion of ankle and foot bones. The tarsometatarsus measures a record 9.1 centimetres. Based on the relative sizes of bones in penguin skeletons, Acosta Hospitaleche estimates P. klekowskii was 2.01 meters long from beak tip to toes.


Its height will have been somewhat less than its length owing to the way penguins stand. But it was nevertheless larger than any known penguin.

Emperor penguins can weigh 46 kilograms and reach lengths of 1.36 metres, 0.2 metres above their standing height. Another extinct penguin used to hold the height record, at around 1.5 metres tall.
P. klekowskii's tarsometatarsus "is the longest foot bone I've ever seen. This is definitely a big penguin," says Dan Ksepka at the Bruce Museum in Greenwich, Connecticut. However, he cautions that the estimate of its length is uncertain because giant penguins had skeletons "very differently proportioned than living penguins."

Larger penguins can dive deeper and stay underwater longer than smaller ones. A giant like P. klekowski could have stayed down for 40 minutes, giving it more time to hunt fish, says Acosta Hospitaleche.


Wednesday, July 30, 2014

Emperor penguins on the decline?

Modeling the future of a charismatic bird

July 30, 2014 | Emperor penguins, the large, charismatic birds known from their frequent film and TV appearances, are in danger. A collaborative research project is drawing attention to the impending plight of the emperors. By 2100, according to a new study, their numbers will have fallen by around 19% and will continue to decline, qualifying the species for endangered status.

Emperor penguin communities entirely ring the continent of Antarctica. Of the 45 known colonies, only one has been extensively studied for decades, and most of the others have never been visited by humans, nor are they likely to be. Emperors live on sea ice off the coast of the continent, and the amount of ice plays a major role in determining the health of a colony. Too much ice and the penguins have a long, debilitating walk to the sea and food; too little ice and the colony is more exposed and vulnerable to predation.
Penguins and climate change: Emperor penguins at Snow Hill Island, Antarctica, 2009
A colony of emperor penguins at Australia's Snow Hill Island, October 2009. (Photo by Jenny Varley, Wikimedia Commons.)
Stéphanie Jenouvrier (Woods Hole Oceanographic Institution) is an expert on penguin life, and she wanted to project the size of emperor populations into the future as Earth’s climate warms. The problem, she says, was her “limited background on climate science.” Meanwhile, at NCAR, senior scientist Marika Holland is a climate scientist with a longstanding specialty in modeling sea ice changes, although she has never been to Antarctica and has never seen an emperor penguin.

Aware of Holland’s previous work, Jenouvrier contacted her and Julienne Stroeve at the University of Colorado’s Cooperative Institute for Research in Environmental Sciences. The three of them collaborated on preliminary studies published in 2009. Jenouvrier received a fellowship from CIRES and worked in Boulder for almost a year, collaborating closely with Holland, Stroeve, Mark Serreze at the CIRES National Snow and Ice Data Center, and other scientists on a follow-up study, published in 2012, and on their most extensive update, recently published in Nature Climate Change.

The biologists used long-term data from the one well-studied emperor colony, off the coast of Terre Adélie, to estimate the relationship between sea ice and rates of breeding success and survival of chicks. They used the record of penguin population and sea ice concentrations at Terre Adélie to estimate vital rates (births/deaths) and population dynamics at each colony.

Learning each other’s languages: biology and climate

The next challenge was to project sea ice changes over the rest of the 21st century and relate that to the health of each penguin community. Sea ice off Antarctica does not behave uniformly: although the total area of sea ice around the continent has increased somewhat in recent years, the trends vary by region during the course of a year and over longer periods. Sea ice must therefore be studied in the relatively small segments that host individual colonies, in order to assess the viability of penguin populations. At first, says Holland, the biologists and climate modelers spoke two different languages, which was “a bit of a barrier.” The frequent interchanges during Jenouvrier’s year in Boulder helped bridge that gap, she adds.

The sea ice scientists began with a group of 20 or so climate models and settled on a widely used midrange scenario of emissions produced for the Intergovernmental Panel on Climate Change called SRES A1B. Once the penguin population models and sea ice change models were set, climate projections were fed into the penguin population models. Due to inherent uncertainties in the models, Jenouvrier ran tens of thousands of computer simulations to achieve the results that the team published.

They found that sea ice will generally decline and its variability will increase by the end of this century. As a result, the simulations indicate that emperor populations will increase by around 10% through midcentury, but then decline to 19% below current levels by 2100. One group of 7 colonies facing the Ross Sea will still be non-threatened by that time, although with a reduced population. On the other side of the continent, facing the Indian Ocean and Weddell Sea, 10 colonies will face quasi-extinction. Most of the rest will qualify as endangered.

The collaborative nature of a study like this, Holland says, allows the expertise of NCAR scientists to inform such other fields as biology and economics to better understand the global system. The researchers conclude that the emperor penguin is “fully deserving of Endangered status due to climate change, and can act as an iconic example of a new global conservation paradigm for species threatened by future climate change.”
WriterHarvey Leifert

ContactDavid Hosansky, NCAR & UCAR Communications
Collaborating institutionsNational Center for Atmospheric Research
University of Amsterdam
University College London
University of Colorado/Cooperative Institute for Research in Environmental Sciences
University of La Rochelle
Woods Hole Oceanographic Institution
FundersAlexander von Humboldt Foundation
European Research Council
Grayce B. Kerr Fund
National Oceanic and Atmospheric Administration
National Science Foundation
Penzance Endowed Fund in Support of Assistant Scientists
Woods Hole Oceanographic Institution


Dive deeper

Stéphanie Jenouvrier, Marika Holland, Julienne Stroeve, Mark Serreze, Christophe Barbraud, Henri Weimerskirch and Hal Caswell, Projected continent-wide declines of the emperor penguin under climate change, Nature Climate Change (2014), doi:10.1038/nclimate2280

In Graphic Terms

Map of emperor penguin colonies
Annual mean change of sea ice concentrations (SIC) between the twentieth and twenty-first centuries and conservation status of emperor penguin colonies by 2100. SIC projections were obtained from a subset of atmosphere-ocean general circulation models. Dot numbers refer to each colony evaluated, with dot color showing conservation status (red = quasi-extinct, orange = endangered, yellow = vulnerable, green = not threatened).  (Figure 1 from Jenouvrier et al., Projected continent-wide declines of the emperor penguin under climate change, doi:10.1038/nclimate2280; image courtesy Nature Climate Change.)

Scientists Decode African Penguin Calls


An African penguin (Spheniscus demersus) calls out near Table Mountain National Park, Cape Town, South Africa. (Photo: © 167/Ralph Lee Hopkins/Ocean/Corbis)

Researchers are trying to figure out how "jackass" penguins—nicknamed for their braying vocalizations—communicate

smithsonian.com
There’s nothing quite like the sultry squawk of a jackass penguin. Coastal residents of Namibia and South Africa, African penguins (Spheniscus demersus) got the nickname “jackass” from their donkey-like calls.

But it turns out their vocalizations are a lot more complicated than haws and brays. A study published today in the journal PLoS ONE examines the vocal repertoire of African penguins. Researchers analyzed hours of audio and video and found that the quirky birds emit four different calls and that baby penguins emit two previously undescribed vocalizations. Perhaps most important, the researchers think they were able to discern what the penguins were trying to communicate with each call.

Understanding penguin call function has implications for conservation and learning about penguin biology. “Vocalizations have the opportunity to provide a huge amount of information about these birds,” says Livio Favaro, a biologist at the University of Turin and the lead author on the study. Encoded in penguin vocal calls are clues to their sex, age and social status.

Before this study, penguins were known to vocalize in four ways: contact calls (“Hey! I’m here. Where are you guys?”), agonistic or threat calls (“Watch it, buddy!”), and display songs directed towards mates, chicks and parents (“Heyyy”). Display songs fall into two categories, ecstatic and mutual, and are uttered alone or in pairs, respectively.

Most penguin vocal research has focused on species that don’t build nests, such as the Emperor and king penguin species in Antarctica, which rely on their vocal system to stick together. By contrast, aside from some basic descriptions and minimal audio, the vocalizations of African penguins—a species that does build nests—remain largely unknown. Previous work also limited the focus to the breeding season, rather than observing the birds over a longer time period.

Favaro and colleagues wanted to know if these nesting penguins voice different calls than their non-nesting cousins. They also sought to discern the accoustic intricacies of different types of calls. But studying penguin vocalizations in the wild can be difficult. Ambient noise, sounds from other animals and human interference can mess with the audio.

So for their study, Favaro and his colleagues selected a captive colony of 48 African penguins living at a zoo in Torino, Italy. For 104 separate days in 2010 and 2011 (both in and out of the breeding season), the researchers took audio and video of the penguins.

Using visualizations of the call notes called spectrograms, the researchers analyzed the acoustics of each call as well as the behavior of the penguin making the call. Based on patterns of behavior and acoustic similarities, four types of adult calls and two new calls unique to penguin chicks emerged from the noise. Statistical analysis of spectrograms confirmed that each call type represented a different vocalization.

You can see video footage of all six calls here:


Contact calls were single-syllable, averaging around half a second in length. When voicing them, penguins typically stood up with their beaks half open and extended their necks vertically as much as possible. When fighting, they extend their necks toward the other penguin and emitted agonistic calls, also one-syllable and sometimes followed by a peck.

Mutual display songs began with noise pulses, and when making them the penguins stretched out horizontally with wide-open beaks while emitting a lower pitched harmony. Finally, the penguins emitted an ecstatic display song, the longest and loudest of all vocalizations. The birds began with a series of short syllables as they thrust their chests upwards with wings spread and ended with one long note, occasionally two.

Both adults and juveniles displayed agonistic calls and contact calls, but penguin chicks emitted some additional calls of their own: begging moans and begging peeps. Begging moans were short, but typically emitted in sequence until fed. The chicks also bobbed their heads. Begging peeps were higher pitched and short, but could go on for several minutes until feeding.

Chicks began emitting begging peeps at three months of age. Moans, which sound more like adult calls, were more common in older chicks. So Favaro thinks that peeps and moans may represent the evolution of the same noise with age.

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African penguin (Spheniscus demersus) with chicks, at the Boulders Colony, Cape Town, South Africa. Researchers found that penguin chicks emitted two unique sounds: begging moans and peeps. (Photo: © Herbert Kratky/imagebroker/Corbis)
Understanding penguin lingo could be used to develop audio systems that could provide a cheap and easy way of tracking and estimating populations. From a practical perspective, deciphering penguin audio could prove useful in penguin conservation. The International Union for the Conservation of Nature (IUCN) elevated African penguins to endangered status in 2010, and the birds currently face threats from habitat destruction to pollution and even egg collection.

Such threats put pressure on researchers to learn as much as they can about penguin vocalizations—and how they fit into the broader picture of the evolution of animal communication—before it’s too late.

Favaro and his colleagues next plan to delve into how penguins produce these complex calls through their syrinx, the bird equivalent of the larynx in humans, and how vocalizations identify an individual. In non-nesting species, birds use a two-voice system that creates a beat pattern unique to each individual, while other nesting species, such as the Adelie penguin, use pitch, frequency, and harmony to make unique calls from one penguin to another.

It’s even possible, the researchers suggest, that African penguin speech production follows a theory based on human vocalization that links individuality to variation in the vocal tract. If that proves to be the case, we may be more similar to penguins than we ever imagined.

source