Sunday, July 20, 2014

Setting the Record Straight on Penguins

by Claire Christian

The way climate change research is reported in the media can be confusing, even if it’s part of your job to keep up with the latest findings. As many, many commentators, scientists, and fake news anchors have noted, this unfortunately means that people think that climate change, if it exists, is some sort of scam cooked up by environmentalists who want to stop doing fun things like removing mountaintops and dumping them into streams so we can get more coal to burn. The truth is that climate change is a complex phenomenon. If you don’t understand this, you are likely to run into trouble when you read news stories about scientific research, sometimes even when those stories are really not about proving or disproving climate change. Take this post, for example. The writer completely misrepresents the results of a recent global Adélie survey by Lynch and LaRueand fans the flames of climate denialism.

The post suggests that this research and other studies indicate that penguins are doing super great under climate change, so why can’t we all stop worrying? In fact, these studies don’t say that at all. We know this because we actually talked to the researchers involved. To clarify a few technical points, the survey by Lynch and LaRue demonstrates that the known breeding population of Adélie penguins is 53% larger than was previously estimated in 1993. As the paper points out, this increase in known breeding population is roughly divided between growth at known populations and the discovery of several new populations, the latter of which include some populations that were so remote that they may have simply been missed in previous surveys. Nevertheless, the survey results do suggest that the populations of breeding Adélie penguins in East Antarctica and in the Ross Sea have grown over the last several decades, and these increases in abundance have more than offset the losses previously reported on the Antarctic Peninsula (and confirmed by this recent study).

These kinds of results are not particularly surprising to people who follow Antarctic scientific research closely. Antarctica is a big place, and climate change affects different regions of the continent differently. The Antarctic Peninsula is warming more rapidly than other Antarctic areas, and more rapidly than the rest of the world, save, perhaps, for the Arctic. So although the total number of Adélie penguins has not declined, climate change is still having a measurable impact on Antarctica. This may be good for penguins in some areas like East Antarctica and the Ross Sea, but it doesn’t mean that warmer temperatures are necessarily a Good Thing for Adélies, the continent as a whole, or the planet.

In fact, the authors note that one climate-related explanation for increasing populations may be glacial retreat (not happy news if you live in a coastal city), which opens up new habitat for Adélie penguin breeding. Study author Heather Lynch also notes, “That climate change may cause both increases and decreases in Adélie penguin populations is a tribute to its utility as a biomonitor, and highlights the Adélie’s important role as an early warning system for ecological change. Adélie penguin increases have previously been linked to a growing toothfish fishery, which itself presents concerns over the influence of Southern Ocean fisheries on the Antarctic food web.” Therefore, what’s important about this study is that it establishes a “baseline for understanding future changes in abundance and distribution”, not that it proves that all is well with penguins now and forever.

Another penguin researcher (not connected with the global Adélie survey study) who was also quoted in the National Review’s blog post, Ron Naveen, told me that “To suggest that Adélies are booming or that all penguins globally are booming is bad reporting. The only way to really know that, of course, would be to compare the latest numbers with a previous survey using the same technology — and that's not possible. Rather, the big story is that we humans know more than we did because we now have more sophisticated tools in our kit. And, as a result, we have much improved baselines for detecting and assessing change.”

Species-threatening decreases in abundance, such as those projected to occur for emperor penguins within the next century (see Jenouvrier et al.'s recent paper in Nature Climate Change), remain a grave concern. Other rapid changes in abundance and distribution, including the increasing abundance reported by Lynch and LaRue, provide a reminder that both climate change and resource extraction can upset the natural ecological balance of the Southern Ocean. While the warning signs in this case represent good news for the Adélie penguin as a species, they nevertheless reflect major changes in Southern Ocean ecosystems that will have enormous consequences. Thus the Adélie penguin can be both be helped and hurt by climate change. It’s not the kind of simple message the media likes, but it’s a scientific reality.

Claire Christian
Director, Secretariat
Antarctic and Southern Ocean Coalition

source

King Penguin Chicks Use Collective Decision Making to Find Home Spot

king penguin chicks

King penguin chicks form groups to navigate to their home spot and they need to make collective decisions as they move along their way. As with humans or any animal, when behaving in a group, decisions have to be made. Some will be leaders, some followers. Sometimes there will be cooperation and sometimes conflict. A recent study, published in the journal Animal Behavior, provided some empirical data on how well king penguin chicks work in pairs to navigate. The study was carried out by scientists from the University of Oxford in the United Kingdom, the University of Amsterdam in The Netherlands and CFE-CNRS Montpellier in France.

King penguins live in Antarctica and an entire colony of adult king penguins may consist of a half a million breeding pairs. The colony moves in groups of different sizes on land and in the water. After eggs are hatched and chicks are born, the parents at first split up and one parent makes a very long trip (up to 400 km, which is about 250 miles) traveling to the sea in winter for food. An interesting thing to note is that when the parents return from their long trip, they can identify their own chick’s voice among the crowd, even though the crowd may consist of about 500,000 penguins. When the chicks are a bit older, then both parents leave to get food and the younger chicks are left in the care of other juveniles.

The chicks form crèches, which are chick groups, to keep warm and avoid predators, and each crèche has a specific location. Being able to navigate to the location of the crèche is crucial for a chick’s survival. When parents eventually return with food, they need to return to the locality of the home crèche to feed their young. If the chicks are not in the right place, they will not get food.

The chicks must move together to get to their home spot. The researchers in the study aimed to determine how king penguin chicks make collective decisions about which direction to move in to find the crèche. They considered the trade-off between group cohesion and individual preferences. The aim of the study was to collect empirical data on conflict resolution during navigation.

In the study, they chose to look at pairs of chicks. The scientists manipulated the levels of conflict by pairing individuals from either the same crèche (no conflict) or different crèches (conflict over desired destination). They then observed the “homing” behavior of both types of pairs. 15 pairs of same- crèche chicks and 16 pairs of different crèche chicks were studied. Each chick had a GPS system attached to their body.

The results showed whether the chicks were better at navigating to their crèche in pairs or when moving alone. The results also determined whether conflict over the desired destination changed the navigation and how the chicks resolve conflicts. Chicks from the same crèche were more precise in getting to their home crèche. Each of the king penguin chicks in a pair took turns being the leader and following. Chicks that were from different crèches were more likely to split up the pair than those pairs that were from the same crèche. The results showed that king penguin chicks use collective decision making when traveling long distances to get to their home spot.

Sources:
Elsevier
The Scientist
BBC Nature
final source

Wednesday, July 16, 2014

Animal foraging tactics unchanged for 50 million years


Date:
July 15, 2014
Source:
University of Southampton
Summary:
Animals have used the same technique to search for food that's in short supply for at least 50 million years, a new study suggests. Researchers analyzed fossilized sea urchin trails from northern Spain and found the tracks reflect a search pattern still used by a huge range of creatures today.



Fossilized sea urchin tracks at Zumaia.
Credit: Richard Twitchett / Trustees NHM




Animals have used the same technique to search for food that's in short supply for at least 50 million years, a University of Southampton-led study suggests.
 


Researchers analysed fossilised sea urchin trails from northern Spain and found the tracks reflect a search pattern still used by a huge range of creatures today. But this is the first example of extinct animals using such a strategy. The findings could explain why so many modern animals use the technique, and suggest the pattern may have an even more ancient origin.
Creatures including sharks, honeybees, albatrosses and penguins all search for food according to a mathematical pattern of movement called a Lévy walk -- a random search strategy made up of many small steps combined with a few longer steps. Although a Lévy walk is random, it's the most efficient way to find food when it's scarce.

David Sims, Professor of Marine Ecology at the University of Southampton and lead author of the study, says: "How best to search for food in complex landscapes is a common problem facing all mobile creatures. "Finding food in a timely fashion can be a matter of life or death for animals -- choose the wrong direction to move in often enough and it could be curtains. But moving in a random search pattern called a Lévy walk is mathematically the best way to find isolated food."

Even though a wide range of modern creatures search for food according to this pattern, scientists had no idea how the pattern came about, until now. Professor Sims and colleagues from the University of Southampton, NERC's National Oceanography Centre, Rothamsted Research, VU University Amsterdam and the Natural History Museum analysed the fossilised Eocene-era tracks that were made by sea urchins that lived on the deep sea floor around 50 million years ago. The long trails are preserved in rocky cliffs in a region called Zumaia in northern Spain.

"Finding the signature of an optimal behaviour in the fossil record is exceedingly rare and will help to understand how ancient animals survived very harsh conditions associated with the effects of dramatic climate changes," says Professor Sims, who is currently seconded to the Marine Biological Association in Plymouth. "Perhaps it's a case of when the going got tough, the tough really did get going." "The patterns are striking, because they indicate optimal Lévy walk searches likely have a very ancient origin and may arise from simple behaviours observed in much older fossil trails from the Silurian period, around 440 million years ago," he adds.
 
Professor Richard Twitchett of the Natural History Museum and co-author of the study adds: "It's amazing to think that 50 million-year-old fossil burrows and trails have provided us with the first evidence of foraging strategies in animals that live on and in the deep-sea floor -- studies which would be nearly impossible and very expensive to do in modern oceans. "Trace fossils are remarkable and beautiful records of the movements of ancient animals, which have been frozen in time and tell us so much about the evolution of life on Earth and the environments of the past."

The researchers think the collapse of primary producers, such as phytoplankton, and widespread food scarcity caused by mass extinctions, which show up in the fossil record, could have triggered the evolution of Lévy-like searches.

The Eocene lasted from 56 to 33.9 million years ago, and began as a time of global warming, with temperatures soaring across the planet.

Lévy walks aren't just confined to animals; our ancient hunter-gatherer ancestors used exactly the same approach, as do modern hunter-gatherers in northern Tanzania.

The study is published in The Proceedings of the National Academy of Sciences.

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

Journal Reference:
  1. D. W. Sims, A. M. Reynolds, N. E. Humphries, E. J. Southall, V. J. Wearmouth, B. Metcalfe, R. J. Twitchett. Hierarchical random walks in trace fossils and the origin of optimal search behavior. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1405966111

University of Southampton. "Animal foraging tactics unchanged for 50 million years." ScienceDaily. ScienceDaily, 15 July 2014. <www.sciencedaily.com/releases/2014/07/140715215730.htm>.

Friday, July 11, 2014

Researchers use genome analysis to understand how King Penguins came to breed on Crozet Islands

Jun 11, 2014 by Bob Yirka report
Researchers use genome analysis to understand how King Penguins came to breed on Crozet Islands
Past demographic trend of the king penguin colony of ‘La Baie du Marin’ on Possession Island, Crozet archipelago: median value (red) and 95% confidence interval ( pale red). Credit: Proceedings of the Royal Society B, DOI: 10.1098/rspb.2014.0528
(Phys.org) —A team made up of researchers from several European countries has used DNA analysis to better understand how it was that King Penguins came to breed on the Crozet Islands. In their paper published in Proceedings of the Royal Society B, the team describes how they managed to gather DNA samples from King Penguins without disturbing them and how analyzing what they found helped to reveal how the penguins came to colonize the Crozet Islands.

King Penguins are the second largest penguins and live and breed on islands north of Antarctica—most predominantly the Crozet Islands in the southern Indian Ocean. In this new effort the researchers sought to learn more about the history of the penguins on the islands, which they hoped would help in discovering what might happen to them as global warming causes changes to their environment.

The research team ventured to one of their island breeding grounds and snuck chicks out from under their watchful parents, replacing them temporarily with fake eggs. In addition to taking physical measurements, blood samples were taken from each of the chicks before they were returned to their parents, apparently none the worse for the wear. The team then analyzed over 65,000 snippets of DNA obtained from eight of the chicks. Their genomes revealed that the penguins had existed as a small group until about 15,000 years ago—after that, their population soared. This time period, the researchers note, coincides with the end of the last ice age.

As the ice abated, conditions for the penguins became ideal. When taking care of their young, adults swim 250 miles offshore to what is known as the polar front—a place where cold polar water collides with warm tropical waters. There the penguins fill up on lanternfishes, returning every three to five days to feed their chicks. In the winter, the adults swim even farther, traveling over 600 miles to find food.

Unfortunately, for the penguins, as the planet heats up, some climate models suggest it's likely the site of the polar front will move farther south, perhaps taking food out of reach of adults who need to return to breeding grounds to feed their offspring. Thus, the fate of King Penguins, could very well be in doubt.


More information: Paper: rspb.royalsocietypublishing.or… .1098/rspb.2014.0528
Journal reference: Proceedings of the Royal Society B search and more info

source 

Rise and fall of prehistoric penguin populations charted

Jun 12, 2014
Rise and fall of prehistoric penguin populations charted
A pair of Gentoo penguins. Credit: Gemma Glucas
A study of how penguin populations have changed over the last 30,000 years has shown that between the last ice age and up to around 1,000 years ago penguin populations benefitted from climate warming and retreating ice. This suggests that recent declines in penguins may be because ice is now retreating too far or too fast.

An international team, led by scientists from the Universities of Southampton and Oxford, has used a genetic technique to estimate when current genetic diversity arose in and to recreate past population sizes. Looking at the 30,000 years before human activity impacted the climate, as Antarctica gradually warmed, they found that three species of penguin; Chinstrap, Adélie and southern populations of Gentoo penguins increased in numbers. In contrast, Gentoo penguins on the Falkland Islands were relatively stable, as they were not affected by large changes in ice extent.
A report of the research is published in the journal Scientific Reports.

Lead author of the paper, Gemma Clucas, from Ocean and Earth Sciences at the University of Southampton comments: "Whereas we typically think of penguins as relying on ice, this research shows that during the last there was probably too much ice around Antarctica to support the large populations we see today. The penguins we studied need ice-free ground to breed on and they need to be able to access the ocean to feed. The extensive ice-sheets and sea ice around Antarctica would have made it inhospitable for them.
Rise and fall of prehistoric penguin populations charted
A Chinstrap penguin. Credit: Dr Tom Hart
"What is particularly interesting is that after the ice age, all of these were climate change 'winners', that is to say the warming climate allowed them to expand and increase in number. However, this is not the pattern we're seeing today. Adélie and Chinstrap penguins appear to be declining due to climate change around the Antarctic Peninsula, so they've become 'losers'. Only the Gentoo penguin has continued to be a 'winner' and is expanding its range southward."

Dr Tom Hart of the University of Oxford's Department of Zoology, an author of the paper, continues: "We are not saying that today's warming climate is good for penguins, in fact the current decline of some penguin species suggests that the warming climate has gone too far for most penguins.
"What we have found is that over the last 30,000 years different penguin species have responded very differently to a gradually warming world, not something we might expect given the damage current rapid warming seems to be doing to penguins' prospects."
Rise and fall of prehistoric penguin populations charted
A group of Adélie penguins. Credit: Dr Tom Hart
To estimate changes in penguin genetic diversity, the researchers collected feathers and blood samples from 537 penguins in colonies around the Antarctic Peninsula. The scientists then sequenced a region of mitochondrial DNA that evolves relatively quickly. Using the rate of mutation of this region of DNA as a calibration point, the researchers were able to chart how the size of these populations has varied over time. The team working on the project included scientists from the British Antarctic Survey and also US scientists from Oceanites Inc, Woods Hole Oceanographic Institution, and the University of North Carolina, Wilmington.

"During the last ice age Antarctica was encircled by 100 per cent more winter sea ice than today," says Dr Tom Hart. "As ice retreated, these penguins had access to more breeding sites and more open ocean to feed."

More information: A reversal of fortunes: climate change 'winners' and 'losers' in Antarctic Peninsula penguins, Scientific Reports, 2014.

source

Adélie penguin population actually on the rise

Date:
July 9, 2014
Source:
Stony Brook University
Summary:
The first global census of the Adélie penguin, long considered a key indicator species to monitor and understand the effects of climate change and fishing in the Southern Ocean, has revealed its population (3.79 million breeding pairs) to be 53 percent larger than previously estimated. By using high-resolution satellite imagery, researchers have applied a new method that permits regular monitoring of Adélie penguins across their entire breeding range, and by extension the health of the Southern Ocean ecosystem.



Adélie penguin incubating chicks.
Credit: Philip McDowall 





 

The first global census of the Adélie penguin, long considered a key indicator species to monitor and understand the effects of climate change and fishing in the Southern Ocean, has revealed its population (3.79 million breeding pairs) to be 53 percent larger than previously estimated. By using high-resolution satellite imagery, Stony Brook University ecologist Heather Lynch, PhD, and conservation biologist Michelle LaRue, PhD, of the University of Minnesota, have applied a new method that permits regular monitoring of Adélie penguins across their entire breeding range, and by extension the health of the Southern Ocean ecosystem. Their findings are published in The Auk, Orinthological Advances.
Ecologists have been tracking Adélie penguin population declines on the Antarctic Peninsula for decades but have found conflicting trends elsewhere in their breeding range. Lynch and LaRue's new paper, titled "First global census of the Adélie Penguin," finally puts all of these scattered pieces of information into a global perspective, finding that Adélie populations at the global scale appear to be growing. Key to identifying the colonies -- including the discovery of 17 populations not known to exist -- was use of satellite imagery to pinpoint the spectral characteristics of the excrement (called guano) of Adélies, a way to clearly identify the species' breeding grounds. The research has implications to better inform policy makers and scientists regarding Marine Protected Areas and climate change.

"We believe this is a landmark study with data that provides not only information on the population dynamics of Adélie penguins but injects critically needed information into the ongoing negotiations regarding the implementation of Marine Protected Areas in the Southern Ocean," said Dr. Lynch, Assistant Professor of Ecology & Evolution at Stony Brook University and a leading researcher using the increasingly popular technique of high-resolution satellite imagery to map the presence and abundance of Antarctic seabirds.

Over the past several years, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) has discussed the establishment of a series of Marine Protected Areas surrounding Antarctica and the sub-Antarctic islands. Dr. Lynch explained that Adélie penguins are not only themselves a species of conservation concern, but their distribution and abundance globally also reflect the distribution of their marine prey -- primarily krill and fish.

"Our finding of a 53 percent increase in Adélie penguin breeding abundance compared to 20 years ago suggests that estimates of krill consumption by this species may be seriously underestimated. Leaving enough prey for natural krill predators is an important element in ensuring fisheries proceed sustainably, and for the first time we have a global map of Adélie abundance that can be used by CCAMLR," added Dr. Lynch. "Not only do we have a comprehensive baseline that can be updated and improved in the future, but we've identified a method for monitoring this important species at a global scale."

Other key findings from the global census include:
  • High-resolution satellite imagery can be effectively used to get near real-time information about penguin populations and their distribution.
  • The 53 percent increase in known abundance is roughly equally divided between genuine growth of known colonies and the discovery of, or first population estimates at, previously unknown or unsurveyed colonies.
  • Stable or growing populations of Adélie penguins in Eastern Antarctica and the Ross Sea more than offset the rapid declines witnessed on the Antarctic Peninsula, where climate change has significantly changed the timing and decreased the extent of sea ice.
  • The researchers discovered 17 previously unknown Adélie colonies. The survey did not find 13 previously known colonies, 8 of which were declared extirpated.
While we celebrate the news that Adélie penguin populations are thriving, learning of these population booms reinforces the need to protect the Antarctic food web," said Andrea Kavanagh, director of The Pew Charitable Trusts' global penguin conservation campaign. The project's aim is to restore and protect penguin breeding and feeding grounds in coastal waters throughout the Southern Hemisphere, and to create large no-take marine reserves in the Southern Ocean. "We call on CCAMLR to implement a strong ecosystem management plan for the Antarctic krill, so that all penguin species have access to abundant protein and can continue to thrive."

Drs. Lynch and LaRue used high-resolution satellite imagery, recent ground counts and other techniques to identify Adélie Penguin colonies over the 5,500 kilometer Antarctic coastline in the lowest regions of the Antarctic Ocean, or Southern Ocean -- a distance 40 percent longer than from New York to Los Angeles.

There has been an exploding interest among scientists internationally in using satellites to survey Antarctic species such as penguins, seals and whales. The relative simplicity of the landscape makes satellite-based surveys an exciting way to look at Antarctic biology at scales not previously thought possible, paving the way for Antarctica to become an unlikely hotbed of discovery for understanding the population dynamics of seabirds and marine mammals.

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


Stony Brook University. "Happy Feet III: Adélie penguin population actually on the rise." ScienceDaily. ScienceDaily, 9 July 2014. <www.sciencedaily.com/releases/2014/07/140709095303.htm>.

Birdlike fossil challenges notion that birds evolved from ground-dwelling dinosaurs

Date:
July 9, 2014
Source:
Springer
Summary:
The re-examination of a sparrow-sized fossil from China challenges the commonly held belief that birds evolved from ground-dwelling theropod dinosaurs that gained the ability to fly. The birdlike fossil is actually not a dinosaur, as previously thought, but much rather the remains of a tiny tree-climbing animal that could glide.





This is a skeletal reconstruction of Scansoriopteryx with outlines to indicate the extent of the feathers.
Credit: Stephen A. Czerkas


The re-examination of a sparrow-sized fossil from China challenges the commonly held belief that birds evolved from ground-dwelling theropod dinosaurs that gained the ability to fly. The birdlike fossil is actually not a dinosaur, as previously thought, but much rather the remains of a tiny tree-climbing animal that could glide, say American researchers Stephen Czerkas of the Dinosaur Museum in Blanding, Utah, and Alan Feduccia of the University of North Carolina. The study appears in Springer's Journal of Ornithology.



The fossil of the Scansoriopteryx (which means "climbing wing") was found in Inner Mongolia, and is part of an ongoing cooperative study with the Chinese Academy of Geological Sciences. It was previously classified as a coelurosaurian theropod dinosaur, from which many experts believe flying dinosaurs and later birds evolved. The research duo used advanced 3D microscopy, high resolution photography and low angle lighting to reveal structures not clearly visible before. These techniques made it possible to interpret the natural contours of the bones. Many ambiguous aspects of the fossil's pelvis, forelimbs, hind limbs, and tail were confirmed, while it was discovered that it had elongated tendons along its tail vertebrae similar to Velociraptor.
Czerkas and Feduccia say that Scansoriopteryx unequivocally lacks the fundamental structural skeletal features to classify it as a dinosaur. They also believe that dinosaurs are not the primitive ancestors of birds. The Scansoriopteryx should rather be seen as an early bird whose ancestors are to be found among tree-climbing archosaurs that lived in a time well before dinosaurs.

Through their investigations, the researchers found a combination of plesiomorphic or ancestral non-dinosaurian traits along with highly derived features. It has numerous unambiguous birdlike features such as elongated forelimbs, wing and hind limb feathers, wing membranes in front of its elbow, half-moon shaped wrist-like bones, bird-like perching feet, a tail with short anterior vertebrae, and claws that make tree climbing possible. The researchers specifically note the primitive elongated feathers on the forelimbs and hind limbs. This suggests that Scansoriopteryx is a basal or ancestral form of early birds that had mastered the basic aerodynamic maneuvers of parachuting or gliding from trees.

Their findings validate predictions first made in the early 1900's that the ancestors of birds were small, tree-dwelling archosaurs which enhanced their incipient ability to fly with feathers that enabled them to at least glide. This "trees down" view is in contrast with the "ground up" view embraced by many palaeontologists in recent decades that birds derived from terrestrial theropod dinosaurs. "The identification of Scansoriopteryx as a non-dinosaurian bird enables a reevaluation in the understanding of the relationship between dinosaurs and birds. Scientists finally have the key to unlock the doors that separate dinosaurs from birds," explained Czerkas.

Feduccia added, "Instead of regarding birds as deriving from dinosaurs, Scansoriopteryx reinstates the validity of regarding them as a separate class uniquely avian and non-dinosaurian."

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

Journal Reference:
  1. Stephen A. Czerkas, Alan Feduccia. Jurassic archosaur is a non-dinosaurian bird. Journal of Ornithology, 2014; DOI: 10.1007/s10336-014-1098-9


Springer. "Birdlike fossil challenges notion that birds evolved from ground-dwelling dinosaurs." ScienceDaily. ScienceDaily, 9 July 2014. <www.sciencedaily.com/releases/2014/07/140709140203.htm>.

Sunday, July 6, 2014

Why Some Penguins Thrive in Climate Change


PHOTO: A Gentoo Penguin is seen in Antartica.
Penguins are on the front line of climate change, as rising global temperatures melt the ice the iconic and lovable creatures call home. Scientists who count the birds are finding that penguins are beginning to feel major impacts from the drastic changes to their habitat. 

But, perhaps surprisingly, the breeding populations of three brush-tailed species of penguins inhabiting the Western Antarctic Peninsula, where the temperatures are warmest, are not all falling as the ice is quickly melting. "We know two of the three penguin species in the peninsula, chinstrap and Adélie, are declining significantly in a region where, in the last 60 years, it's warmed by 3 degrees C. (5 degrees F.) annually and by 5 degrees C. (9 degrees F.) in winter," said Ron Naveen, the founder of Oceanites, a U.S. based non-profit and scientific research organization. He oversees the Antarctic Site Inventory which monitors penguin populations. 

A third species, however, has not been losing numbers and in fact has even been expanding its range.
Counting penguins in the wild is a complicated art. Naveen's team makes repeated visits every year to the Antarctic Peninsula from November to February when egg-laying and chick creching are at their peak. 

Since 1994, he has conducted 1,421 visits to the peninsula and collected data from 209 sites.
Naveen and fellow penguin counter Heather Lynch of Stony Brook University say the warming climate and the consequent loss of sea ice are contributing to the decline in Adelie and chinstrap, because the two species are dependent on the ice. Warming temperature is only one part of the whole story, however, according to the Naveen. "There are a number of possibilities," he said. 

Adelies and chinstrap nest primarily near the ice and rely on krill as their main food source. These shrimp-like vertebrates live underneath the ice, feeding on the algae that grows there. As the ice retreats, the krill disappear. 

PHOTO: A Gentoo Penguin is seen in Antartica.
Darci Amundson Photography
PHOTO: A Gentoo Penguin is seen in Antarctica.
 
Other factors such as commercial overfishing and the expanding population of humpback whales, which also feed on krill, may also contribute to the loss of their main food source. By contrast, Gentoo penguins, the third of these species, are expanding both in numbers and in geographical range, according to Naveen and Lynch's research. There are an estimated 387,000 Gentoo breeding pairs and their populations are moving southward along the peninsula. "Gentoos are an open water species and can move southward as the declining ice concentration makes new habitat available to them," Lynch said. 

Gentoos, the most flexible of the three species, will eat anything, not just krill, and can adjust their life cycle more easily in response to variable conditions. If the snow melts early, for example, they can breed earlier or relay their eggs. 

PHOTO: A Chinstrap Penguin is seen in Antartica.
Darci Amundson Photography
PHOTO: A Chinstrap Penguin is seen in Antarctica.
 
Naveen uses simple tools to conduct his field work -- a handheld counting device known as a tally counter, a pencil, and a notebook -- and combines the data with Lynch's work with remote sensing to ascertain as complete a count as possible. 

Lynch analyzes hi-res satellite images to help her map out and analyze contours of breeding colonies, look at biological and physical data sets to determine breeding pairs, and assess breeding populations in remote places too difficult to get to, such as some locations in the South Sandwich Islands. 

The team's combination of field work and remote sensing allowed them to get the first site-wide inventory of Penguins at Deception Island. For example, Naveen found 79,849 breeding pairs of chinstrap penguins, including 50,408 breeding pairs at Baily Head. That 2012 census, combined with data from Lynch's satellite imagery, also indicates the chinstrap population has declined 50 percent as compared to previous population estimates conducted in 1987.

PHOTO: A Chinstrap Penguin is seen in Antartica.
Darci Amundson Photography
PHOTO: A Chinstrap Penguin is seen in Antarctica.
 
Monitoring penguin populations in the western Antarctic Peninsula, how they shrink and grow in response to changing conditions, not only provides critical clues to how to manage the environment down there, but perhaps for us as well, Naveen said. "Are they sending us a message we should be thinking about?" he said. "Are we canaries in the coal mine?"

Monday, June 30, 2014

Emperor Penguins are now endangered, warn biologists

A new study has estimated that by 2100, at least two-thirds of Emperor penguin colonies will have dramatically declined by more than half if temperatures rise at the rate predicted by the Intergovernmental Panel on Climate Change (IPCC)

Emperor Penguins on frozen sea ice in Antarctica.
Emperor Penguins on frozen sea ice in Antarctica. Photo: Paul Souders / Barcroft Media
 
Emperor penguins should be classed as an endangered species because the majority of colonies will have lost half their populations by the end of the century, biologists have warned.
The flightless birds which inhabit Antarctica are threatened by changes to sea ice which are being driving by climate change.
Emperor penguins are heavily dependent on sea ice as it provides krill, one of their primary food sources.
A new study has estimated that by 2100, at least two-thirds of emperor penguin colonies will have dramatically declined by more than half if temperatures rise at the rate predicted by the Interngovernmental Panel on Climate Change (IPCC)
The study was conducted by lead author Stephanie Jenouvrier, a biologist with the Woods Hole Oceanographic Institution (WHOI).
Researchers have been returning to Terre Adélie, which lies across the Southern Ocean from New Zeland, every year to chart populations, monitoring their their mating, foraging, chick-rearing patterns, and following marked individuals. "If sea ice declines at the rates projected by the IPCC climate models, and continues to influence emperor penguins as it did in the second half of the 20th century in Terre Adélie, at least two-thirds of the colonies are projected to have declined by greater than 50 percent from their current size by 2100," said Jenouvrier. "None of the colonies, even the southern-most locations in the Ross Sea, will provide a viable refuge by the end of 21st century.
"We propose 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.” 
 
Stephanie Jenouvrier with an emperor penguin chick
 
The emperor penguin is currently under consideration for inclusion under the US Endangered Species Act. In 2012 the status of the birds was changed from ‘least concern’ to ‘near threatened’ by the International Union for Conservation of Nature. (IUCN), but they are not on the ‘red list.’

Emperor penguins are heavily dependent on sea ice for their livelihoods, and, therefore, are sensitive to changes in sea ice concentration "The role of sea ice is complicated Too much ice requires longer trips for penguin parents to travel to the ocean to hunt and bring back food for their chicks,” said Jenouvrier. “But too little ice reduces the habitat for krill, a critical food source for emperor penguins. Our models take into account both the effects of too much and too little sea ice in the colony area."


Listing the species as endangered would kick-start conservation efforts and prevent the animals being further disturbed through bad fishing practices or habitat loss. "When a species is at risk due to one factor – in this case, climate change – it can be helped, sometimes greatly, by amelioration of other factors,” said Hal Caswell, a scientist emeritus at WHOI and professor at the University of Amsterdam. “That's why the Endangered Species Act is written to protect an endangered species in a number of ways – exploitation, habitat, disturbance, etc. – even if those factors are not the cause of its current predicament."

The research was published in the journal Nature Climate Change.

source

Journal article

Friday, June 27, 2014

Is Global Warming Creating Penguin Winners And Losers?

Researchers look to ancient melts to predict which species might survive in the present

Adélie penguins and chicks
Adélie penguins
The species is found only in Antarctica.
PLOS Biology via Wikimedia Commons 
Planetary temperatures warmed up naturally thousands of years ago, at the end of the last Ice Age. Some Antarctic penguin populations flourished under the changes. 11,000 years later, however, some Adélie and chinstrap colonies are turning from winners into losers: As temperatures around the western Antarctic Peninsula increase at some of the fastest rates on Earth, their population numbers are falling quickly, while gentoo penguins appear to holding their own.

What's the difference between then and now?

Looking the past to learn more about how different species might fare under today's anthropogenic climate change, researcher Gemma Clucas of the University of Southhampton, U.K., and her team collected samples of feathers and blood from 537 individual Adélie, chinstrap, and gentoo penguins, which live and breed near each other on the Antarctic Peninsula, and sequenced DNA from the samples.

By calculating the rate of genetic diversification revealed in the DNA, Clucas and her team were able to project how the different species' populations changed over time, and draw some tentative conclusions about why. Their findings are published in the June 12, 2014 edition of the open-access journal Scientific Reports.

Their findings suggest that while a certain absence of ice is important to improving the welfare of penguins, too little can tip things against them.

During the last Ice Age, the amount of ice covering land and water around the Antarctic Peninsula limited the growth of these penguin populations, because all three species need access to the sea to feed, and ice-free land for breeding. When snow and ice cover on both water and land decreased, the penguins were able to get at increased amounts of krill, minute shrimp which feed on algae growing beneath the ice. There was also more ice-free land available for nesting and raising chicks. Gentoo, chinstrap, and Adélie penguins all appear to have flourished for thousands of years under these conditions.

But with sea-ice further melting over the last half-century, krill habitat has also decreased. Most colonies of chinstraps and Adélie, which have krill-heavy diets, are losing numbers fast, while gentoo penguins, which eat a wider array of fish and squid in addition to krill, seem to be showing greater resilience to the shifting environment. Clucas and her colleagues think the more varied diet is a key:
This ‘reversal of fortunes’ for two former climate change ‘winners’ has resulted from anthropogenic impacts outside the range of natural variation that has occurred in the past. Rapid warming trends in the Antarctic Peninsula over the past 50 years has led to decreased sea ice, loss of winter habitat, and a reduction in krill stocks that is negatively affecting Adélie and chinstrap penguins, but not gentoo penguins5, 18, which apparently are not as reliant on krill17. While we know of no other examples of ‘reversal in fortunes’ as documented here, we expect many more will be identified as global warming proceeds and biodiversity declines.
The researchers don't want the findings to be taken as a sign that global warming is nothing to worry about, however. Says one report co-author in a statement, "We are not saying that today's warming climate is good for penguins. In fact, the current decline of some penguin species suggests that the warming climate has gone too far for most penguins."

source

Friday, June 20, 2014

Penguin Research Update from South Georgia Newsletter

Baby King Penguins, Where Do They Go?

Little was known about where king penguin chicks go when they fledge and first head to sea, or why some survive their first year when many don’t, so researchers have been trying to answer these questions with fieldwork based in South Georgia and the Falkland Islands.

To discover where newly fledged king penguin chicks go researchers put small satellite tags on chicks in two colonies in December 2007. The study sites in South Georgia and the Falklands contrasted, being located on different sides of the Antarctic Polar Front (APF) and having a different climate. The APF is a key oceanographic feature generally thought to be important for king penguin foraging success.

Of the fledglings tracked, eight penguins were tracked for periods greater than120 days; seven of these (four from South Georgia and three from the Falkland Islands) migrated into the Pacific. Results showed that birds from both sites foraged predominantly in the vicinity of the APF. Only one bird, from the Falkland Islands, moved into the Indian Ocean, visiting the northern limit of the winter pack-ice; three others from the Falkland Islands migrated to the eastern coast of Tierra del Fuego before travelling south. The birds usually swam no more than 10km in a day, though they could travel more than 100km in 24 hrs. The tracks of the tagged birds from the two colonies can be seen in the figure below.

Though migratory behaviour from both sites was broadly similar, the young birds from the Falkland Islands spent more time in comparatively shallow waters whilst the new fledeged birds from South Georgia spent more time in deeper waters. The satellite tracks also showed that, to start with, the young birds stayed clear of areas being used by adult birds. King penguins usually spend four or five years “exploring the Southern Ocean” before they settle down and start breeding, the researchers noted.

A paper on the study entitled ‘Post-fledging dispersal of king penguins (Aptenodytes patagonicus) from two breeding sites in the South Atlantic’ was published in PLOS ONE on May 14th by authors Kelmens Putz, Phil Trathan, Martin Collins, Sally Poncet and Benn Luthi.

The satellite tracks obtained from the South Georgia juvenile king penguins. The breeding site is marked by a yellow asterisk over South Georgia. Track colours represent a monthly time scale, with positions in pink (December 2007), blue (January 2008), yellow-green (February), orange (March), golden (April), red (May), olive (June), violet (July) and green (August 2008). The black line indicates the approximate position of the Antarctic Polar Front.
The satellite tracks obtained from the South Georgia juvenile king penguins. The breeding site is marked by a yellow asterisk over South Georgia. Track colours represent a monthly time scale, with positions in pink (December 2007), blue (January 2008), yellow-green (February), orange (March), golden (April), red (May), olive (June), violet (July) and green (August 2008). The black line indicates the approximate position of the Antarctic Polar Front.

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Ten Year Study Of Bird Island Macaroni Penguins

Scientists at Bird Island have been studying macaroni penguins for over ten years. The BAS-led team of scientists studied the birds during a period that their numbers were declining. The macaroni penguin population on South Georgia has declined by almost 70% since the early 1980s.


The electronically tagged macaroni penguins are recorded by a sensor as they pass through this gate at the entrance to their colony on Bird Island. Photo BAS.
The electronically tagged macaroni penguins are recorded by a sensor as they pass through this gate at the entrance to their colony on Bird Island. Photo BAS.


Since 2003 birds that had been fitted with small electronic tags have passed an electronic scanner at the entrance to the colony, which records the birds as they come and go. The resultant data was analysed to determine survival rates. The results have now been presented in a paper.

The penguins’ survival rates are influenced by both environmental and predation pressures. The scientists found penguins were particularly vulnerable to predation by other seabirds such as giant petrels. The macaroni chicks were found to be particularly vulnerable, with only a third surviving their first fledgling year.

Catharine Horswill, from BAS, said: “Penguins are facing rapid changes in their environment, but at South Georgia we found compelling evidence that predators are the most important factor influencing the survival of chicks as they leave the colony for the first time. This is a big leap forward as we had no idea that predation could be such a strong driving force. Knowing what drives survival rates of penguins puts us in a much better place to predict how these populations may change in the future.”

The research paper, ‘Survival in macaroni penguins and the relative importance of different drivers; individual traits, predation pressure and environmental variability.’ is published by the Journal of Animal Ecology.
Info BAS



This very short video shows the macaroni penguins crossing the recording bridge.

source

Thursday, June 19, 2014

A call to better protect Antarctica: Human activity threatening continent

Date:
June 18, 2014
Source:
Monash University
Summary:
With visitor numbers surging, Antarctica's ice-free land needs better protection from human activities, leading environmental scientists say. The new study found that all 55 areas designated for protection lie close to sites of human activity. Antarctica has over 40,000 visitors a year, and more and more research facilities are being built in the continent's tiny ice-free area. Most of the Antarctic wildlife and plants live in the ice-free areas -- and this is also where people most visit.

Antarctic view from land.

Credit: Photo credit: Aleks Terauds



With visitor numbers surging, Antarctica's ice-free land needs better protection from human activities, leading environmental scientists say.



The new study, published in the journal PLoS Biology, found that all 55 areas designated for protection lie close to sites of human activity. Seven are at high risk for biological invasions, and five of the distinct ice-free eco regions have no protected areas.
Antarctica has over 40,000 visitors a year, and more and more research facilities are being built in the continent's tiny ice-free area. Most of the Antarctic wildlife and plants live in the ice-free areas -- and this is also where people most visit.

One of the researchers from the collaborative study, Professor Steven Chown from the School of Biological Sciences at Monash University, said the ice-free area contains very simple ecosystems due to Antarctica's low species diversity. This makes its native wildlife and plants extremely vulnerable to invasion by exotic species. "Antarctica has been invaded by plants and animals, mostly grasses and insects, from other continents. The very real current and future threats from invasions are typically located close to protected areas," Professor Chown said. "Such threats to protected areas from invasive species have been demonstrated elsewhere in the world, and we find that Antarctica is, unfortunately, no exception."
 
Dr Justine Shaw of the National Environmental Research Program's Environmental Decisions Hub at the University of Queensland said the 'last wilderness on Earth' is one of the planet's least-protected regions "Most of Antarctica is covered in ice, with less than one per cent permanently ice-free. Only 1.5 per cent of this ice-free area belongs to Antarctic Specially Protected Areas under the Antarctic Treaty System, yet ice free land is where the majority of biodiversity occurs," Dr Shaw said.

The study shows that protected areas in Antarctica currently fall well short of the Aichi Biodiversity Targets -- an international biodiversity strategy that aims to reduce threats to biodiversity, and protect ecosystems, species and genetic diversity.The team compared Antarctica's protected area system with the protected areas of nations round the world, and found that Antarctica ranks in the lowest 25 per cent of assessed countries.
 
Dr Shaw said many people think that Antarctica is well protected from threats to its biodiversity because it's isolated and no one lives there, however the study clearly shows threats to Antarctic biodiversity. "We need to establish protected areas that are representative of Antarctic biodiversity to protect a diverse suite of native insects, plants and seabirds, many of which occur nowhere else in the world," Dr Shaw said. "We also need to ensure that Antarctic protected areas are not going to be impacted by increasing human activities, such as pollution, trampling or invasive species," she added.
 
Professor Hugh Possingham of the National Environmental Research Program's Environmental Decisions Hub at the University of Queensland said Antarctica is one of the last places on Earth that has no cities, agriculture or mining. "It is unique in this respect -- a true wilderness. If we don't establish adequate and representative protected areas in Antarctica this unique and fragile ecosystem could be lost," Professor Possingham said. "Although we show that the risks to biodiversity from increasing human activity are high, they are even worse when considered together with climate change. This combined effect provides even more incentive for a better system of area protection in Antarctica," he said.
 

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

Journal Reference:
  1. Justine D. Shaw, Aleks Terauds, Martin J. Riddle, Hugh P. Possingham, Steven L. Chown. Antarctica’s Protected Areas Are Inadequate, Unrepresentative, and at Risk. PLoS Biology, 2014; 12 (6): e1001888 DOI: 10.1371/journal.pbio.1001888

Monash University. "A call to better protect Antarctica: Human activity threatening continent." ScienceDaily. ScienceDaily, 18 June 2014. <www.sciencedaily.com/releases/2014/06/140618100620.htm>.