Friday, April 21, 2017

Time-lapse cameras provide a unique peek at penguins' winter behavior

April 19, 2017
Researchers set up time-lapse cameras to record penguin behavior during the dark Antarctic winter. Credit: T. Hart
Not even the most intrepid researcher wants to spend winter in Antarctica, so how can you learn what penguins are doing during those cold, dark months? Simple: Leave behind some cameras. Year-round studies across the full extent of a species' range are especially important in polar areas, where individuals within a single species may adopt a variety of different migration strategies to get by, and a new study from The Auk: Ornithological Advances uses this unique approach to get new insights into Gentoo Penguin behavior.
Gentoo Penguins are of interest to scientists because they're increasing at the southern end of their range in the Western Antarctic Peninsula, a region where other penguin species are declining. Little is known about their behavior during the nonbreeding season, so Caitlin Black and Tom Hart of the University of Oxford and Andrea Raya Rey of Argentina's Consejo Nacional de Investigaciones Cientificas y T├ęcnicas used time-lapse cameras to examine patterns in Gentoo Penguins' presence at breeding sites across their range during the off season. They found both temporal and spatial factors driving winter attendance—for example, more Gentoo Penguins were present at breeding sites when there was open water or free-floating pack ice than when the shoreline was iced in, and more Gentoo Penguins were at breeding sites earlier in nonbreeding season than later.

The researchers deployed the cameras at seven sites including Argentina, Antarctica, and several islands. Each took eight to fourteen photos per day, and volunteer "citizen scientists" were recruited to count the penguins in each image via a website (penguinwatch.org). Overall, the seven sites fell into three distinct groups in terms of winter attendance, each with its own patterns of site occupation. These findings could have important implications for understanding how localized disturbances due to climate change and fisheries activity affect penguin populations during the nonbreeding season.
Time-lapse cameras recorded images of Gentoo Penguins at their breeding sites in winter. Credit: T. Hart
"Working with cameras allows us to understand half of this species' life without having to spend the harsh winter in Antarctica. It has been exciting to discover more about why Gentoos are present year-round at breeding sites without having to handle a single bird," says Black. "I believe the applications for this technology are far-reaching for colonial seabirds and mammals, and we are only just beginning to discover the uses of time-lapse cameras as deployed virtual ecologists in field studies."

"What most seabirds do away from their nest is often anybody's guess. For Antarctic birds, this is compounded by the long periods of darkness that penguins and others must face in the winter," adds Mark Hauber, Editor-in-Chief of The Auk: Ornithological Advances and Professor of Animal Behavior at Hunter College and the Graduate Center of the City University of New York. "This new research in The Auk: Ornithological Advances on Gentoo Penguins colonies reveals critical year-to-year differences in where the birds are when they are not nesting: In some years, only the most temperate sites are visited, and in other years both southerly and northerly locations are busy with penguins."

 
More information: "Peeking into the bleak midwinter: Investigating nonbreeding strategies of Gentoo Penguins using a camera network" April 19, 2017, americanornithologypubs.org/doi/full/10.1642/AUK-16-69.1

source
 

Sunday, April 16, 2017

Antarctic penguin colony repeatedly decimated by volcanic eruptions

April 11, 2017
Gentoo penguins climbing slopes to the nesting colony on Ardley Island. Credit: Stephen Roberts
One of the largest colonies of gentoo penguins in Antarctica was decimated by volcanic eruptions several times during the last 7,000 years according to a new study. An international team of researchers, led by British Antarctic Survey (BAS), studied ancient penguin guano and found the colony came close to extinction several times due to ash fall from the nearby Deception Island volcano. Their results are published this week in Nature Communications.
Ardley Island, near the Antarctic Peninsula, is currently home to a population of around 5,000 pairs of gentoo penguins. Using new chemical analyses of penguin guano extracted in sediment cores from a lake on the island, the researchers unraveled the history of the penguin colony. Climate conditions around Ardley Island have been generally favourable for penguins over the last 7,000 years and the team had expected the local population to show minor fluctuations in response to changes in climate or sea ice. The surprising result was that the nearby Deception Island volcano had a far greater impact than originally anticipated.

Lead author Dr Steve Roberts from BAS says: "When we first examined the we were struck by the intense smell of the guano in some layers and we could also clearly see the volcanic ash layers from nearby Deception Island. By measuring the sediment chemistry, we were able to estimate the population numbers throughout the period and see how penguins were affected by the eruptions. On at least three occasions during the past 7,000 years, the penguin population was similar in magnitude to today, but was almost completely wiped out locally after each of three large . It took, on average, between 400 and 800 years for it to re-establish itself sustainably."

Volcanic ash layers in lake sediment cores extracted from Kiteschee Lake on Fildes Peninsula. The ash layers shown are associated with comparatively small eruptions from Deception Island in the last c. 2000-3000 years. The largest eruptions …more
Dr Claire Waluda, penguin ecologist from BAS says: "This study reveals the severe impact volcanic eruptions can have on penguins, and just how difficult it can be for a colony to fully recover. An eruption can bury penguin chicks in abrasive and toxic ash, and whilst the adults can swim away, the chicks may be too young to survive in the freezing waters. Suitable nesting sites can also be buried, and may remain uninhabitable for hundreds of years."

The techniques developed in this study will help scientists to reconstruct past changes in colony size and potentially predict how other penguin populations may be affected elsewhere. For example, the chinstrap penguins on Zavodovski Island, which were disturbed by eruptions from the Mt Curry volcano in 2016.

Waluda continues: "Changes in on the Antarctic Peninsula have been linked to climate variability and sea-ice changes, but the potentially devastating long-term impact of volcanic activity has not previously been considered."

More information: Past penguin colony responses to explosive volcanism on the Antarctic Peninsula, Nature Communications (2017). nature.com/articles/doi:10.1038/ncomms14914

Journal reference: Nature Communications search and more info website
Provided by: British Antarctic Survey

search and more infoSource  website

Friday, February 24, 2017

The oldest fossilized giant penguin

Penguins diversified earlier than previously assumed
Date:
February 23, 2017
Source:
Senckenberg Research Institute and Natural History Museum
Summary:
A recently discovered fossil of a giant penguin with a body length of around 150 centimeters has been described in a new article. The new find dates back to the Paleocene era and, with an age of approximately 61 million years, counts among the oldest penguin fossils in the world. The bones differ significantly from those of other discoveries of the same age and indicate that the diversity of Paleocene penguins was higher than previously assumed. The team of scientists, therefore postulates that the evolution of penguins started much earlier than previously thought, probably already during the age of dinosaurs.

The foot bones of the new giant penguin (left), compared to those of an Emperor Penguin, the largest living penguin species (right).
Credit: © Senckenberg
 
Together with colleagues from New Zealand, Senckenberg scientist Dr. Gerald Mayr described a recently discovered fossil of a giant penguin with a body length of around 150 centimeters. The new find dates back to the Paleocene era and, with an age of approx. 61 million years, counts among the oldest penguin fossils in the world. The bones differ significantly from those of other discoveries of the same age and indicate that the diversity of Paleocene penguins was higher than previously assumed. In their study, published in the Springer scientific journal The Science of Nature, the team of scientists, therefore postulates that the evolution of penguins started much earlier than previously thought, probably already during the age of dinosaurs.

The fossil sites along the Waipara River in New Zealand's Canterbury region are well known for their avian fossils, which were embedded in marine sand a mere 4 million years after the dinosaurs became extinct. "Among the finds from these sites, the skeletons of Waimanu, the oldest known penguin to date, are of particular importance," explains Dr. Gerald Mayr of the Senckenberg Research Institute in Frankfurt.

Together with colleagues from the Canterbury Museum in New Zealand, Mayr now described a newly discovered penguin fossil from the famous fossil site. "What sets this fossil apart are the obvious differences compared to the previously known penguin remains from this period of geological history," explains the ornithologist from Frankfurt, and he continues, "The leg bones we examined show that during its lifetime, the newly described penguin was significantly larger than its already described relatives. Moreover, it belongs to a species that is more closely related to penguins from later time periods."

According to the researchers, the newly described penguin lived about 61 million years ago and reached a body length of approx. 150 centimeters -- making it almost as big as Anthropornis nordenskjoeldi, the largest known fossil penguin, which lived in Antarctica around 45 to 33 million years ago, thus being much younger in geological terms. "This shows that penguins reached an enormous size quite early in their evolutionary history, around 60 million years ago," adds Mayr.

In addition, the team of scientists from New Zealand and Germany assumes that the newly discovered penguin species also differed from their more primitive relatives in the genus Waimanu in their mode of locomotion: The large penguins presumably already moved with the upright, waddling gait characteristic for today's penguins.

"The discoveries show that penguin diversity in the early Paleocene was clearly higher than we previously assumed," says Mayr, and he adds, "In turn, this diversity indicates that the first representatives of penguins already arose during the age of dinosaurs, more than 65 million years ago."

Story Source:
Materials provided by Senckenberg Research Institute and Natural History Museum. Note: Content may be edited for style and length.

Journal Reference:
  1. Gerald Mayr, Vanesa L. De Pietri, R. Paul Scofield. A new fossil from the mid-Paleocene of New Zealand reveals an unexpected diversity of world’s oldest penguins. The Science of Nature, 2017; 104 (3-4) DOI: 10.1007/s00114-017-1441-0


Senckenberg Research Institute and Natural History Museum. "The oldest fossilized giant penguin: Penguins diversified earlier than previously assumed." ScienceDaily. ScienceDaily, 23 February 2017. <www.sciencedaily.com/releases/2017/02/170223102022.htm>.

Tuesday, February 21, 2017

Penguin fossil calls Waikato Museum home

A 28 million-year-old penguin fossil has officially become part of the museum's permanent collection.
CHRISTINE CORNEGE FAIRFAX NZ
 
A 28 million-year-old penguin fossil has officially become part of the museum's permanent collection.
It's 28 million years old, weighed as much as Stephen Donald, and was the about the same height as Prince.
And it calls the Waikato Museum home.
A local penguin fossil, found by Hamilton Junior Naturalist Club in 2006 has officially become part of the museum's permanent collection.

The Kawhia giant penguin was discovered by a group of young explorers from the Hamilton Junior Naturalist Club in 2007.
CHRISTINE CORNEGE FAIRFAX NZ
 
The Kawhia giant penguin was discovered by a group of young explorers from the Hamilton Junior Naturalist Club in 2007.
The bones, preserved in Mudstone, have pride of place in a glass cabinet near the entrance. The bones were found in Kawhia.
Although the fossil has been at the museum for the past several years there was a process to get it officially part of the museum's permanent collection.

A painting of the Kawhia giant penguin by Ronald Cometti.
Simon Cometti and Amanda Wilson
A painting of the Kawhia giant penguin by Ronald Cometti.

And it appears to be a hit with most of the visitors.
Sydney man John Toohey was fascinated by the fossil during his visit.
"It's good for a fossil to see other fossils," he joked.
The penguin - which scientists believed weighed about 100kg, and was 1.5m tall- was comparatively a lot larger than modern day penguins.
An Emperor penguin weighs 30kg and was 1.15m tall - both lighter and shorter than it's ancient ancestor.
"I really like seeing how things develop and the synergies of other forms of life, the science of continuity and how things have developed over time," Toohey said.
Though the fossil did not fare as well under his partner's gaze.
"There's only so much information I can hold in my brain at a time, and fossils don't fit," Robyn Alexander said.
"I'm just going to have to say sorry to my granddaughter because I can't tell her about the penguin fossil when I get home."
But Alexander did sing the praises of another famous New Zealand penguin - Dunedin's Yellow Eyed Penguin.
She saw a cluster of the birds huddling together, the eyes were the most amazing things she had ever seen, Alexander said.
"Now that sort of penguin I have space for in my brain."

source

Friday, February 17, 2017

New guidance on hand-rearing decisions for endangered penguin chicks


Penguin chicks Southern African Foundation for the Conservation of Coastal Birds
 

Penguin chick being checked over Southern African Foundation for the Conservation of Coastal Birds

Press release issued: 17 February 2017
The first model of its kind which provides guidance on the survival likelihood of abandoned penguin chicks admitted to rehabilitation has been developed by researchers from the Universities of Bristol, Exeter, Cape Town, the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) and Bristol Zoological Society.
Globally the use of rehabilitation for conservation is growing, with many research papers monitoring the success of individuals post-release. Rearing chicks that are unlikely to survive naturally has the potential to significantly contribute to the conservation of threatened bird species, such as the African penguin.

Annually, abandoned African penguin chicks are hand-reared by SANCCOB and released back into the wild. The chicks are abandoned if the adults start to moult before the chick fledges.
Once an adult begins to moult it is no longer waterproof, so can no longer feed its chick. A scarcity of prey leads to slow growth rates and can cause chicks not to fledge in time. Abandoned chicks would not survive without intervention.

This 'chick bolstering project' is an important conservation action for these endangered birds. It aims to bolster the African penguin population while methods to establish new colonies near high prey abundance are developed.

Decisions of whether and when to remove animals from the wild rarely use quantitative criteria. Where such criteria are assessed, there have been few studies to investigate their efficacy to predict rehabilitation outcomes.

In this new study, published today in Animal Conservation, researchers investigate whether a body condition index (mass correcting for structural size), other structural measurements and sex can predict rehabilitation outcome.

Joanne Morten from the University of Bristol's School of Biological Sciences, was lead author of the research.

She said: "Using data from over 1,400 chicks rescued over six breeding seasons, we identified clear body condition thresholds that colony managers can use to prioritise the removal of chicks.
"These thresholds also allow the rehabilitators to rapidly identify individuals in need of critical attention."

African penguin colony managers are currently using the body condition index to guide removal. This study demonstrates its effectiveness, with only 2.3 percent of chicks admitted with a body condition index so low there was a less than 50 percent chance of survival.

Joanne added: "However, almost a third of chicks admitted may well have survived naturally. Hand-reared African penguin chicks are just as successful as their naturally-reared counterparts, but we don’t want to cause undue stress and use resources unnecessarily. The body condition thresholds identified in this study can be used to guide future management strategies, and can be rapidly incorporated.

"The body condition index uses mass and bill length, two measurements that are easy and quick, minimising handling stress.

"This is an extremely useful guide which, when used in conjunction with nest monitoring, can effectively identify chicks that have been abandoned. This tool could be useful, not just to the endangered African penguin, but other species where chicks can be successfully hand-reared."

Further information

Paper:
‘Body condition as a quantitative tool to guide hand-rearing decisions in an endangered seabird’ by J.M. Morten, N.J. Parsons, C. Schwitzer, M.W. Holderied and R.B. Sherley in Animal Conservation.

source

Thursday, February 16, 2017

New study reveals what penguins eat

February 15, 2017
New study reveals what penguins eat
Gentoo penguin chicks at Bird Island. Credit: British Antarctic Survey
The longest and most comprehensive study to date of what penguins eat is published this month. The study, published in the journal Marine Biology, examines the diets of gentoo penguins (Pygoscelis papua) at Bird Island, South Georgia over a 22 year period and is part of a project investigating the Southern Ocean ecosystem and its response to change.
Penguin parents forage at sea returning to feed their chicks every day. The team, based at British Antarctic Survey (BAS), found that between 1989 and 2010 gentoo penguins ate approximately equal amounts of crustaceans, (mainly Antarctic , a small shrimp-like creature) and fish.

Twenty-six different prey species were found in the diet, including squid, octopus and 17 species of fish. The composition of gentoo penguin diets was variable from year to year, with krill the dominant food in 10 years of the study and fish in 12 years. Successful breeding (the number of chicks fledged per nest per year) was strongly related to the amount of krill in the diet, with few chicks fledging in years where krill was particularly scarce.

The team then compared the diets of gentoo penguins with those of (Eudyptes chrysolphus) also resident at Bird Island. Both species are able to switch to other prey when krill availability is low. However, where gentoo penguins have a broad and variable diet, macaroni penguins are specialist predators on krill. Their differing diets and foraging ranges allow the two penguin species to successfully coexist at Bird Island, South Georgia.
New study reveals what penguins eat
The team at BAS studied gentoo colonies on Bird Island over a 22 year period. Credit: British Antarctic Survey
Lead author, Dr Claire Waluda, penguin ecologist at BAS says:
"Gentoo and macaroni penguins are important indicator species and monitoring changes in their diets can help us understand changes in the Southern Ocean ecosystem."

"This work highlights the importance of long-term data collection and supports the work of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), which is responsible for setting catch limits for commercial krill and fish in the Southern Ocean. Their aim is to protect marine ecosystems and maintain sustainable levels of fishing in this region."

The paper summarises one of the longest time series of penguin diet currently available globally. Long-term variability in the diet and reproductive performance of at Bird Island, South Georgia by Claire M. Waluda, Simeon L. Hill, Helen J. Peat and Philip N. Trathan is published this month in the journal Marine Biology.

 
 
More information: Claire M. Waluda et al. Long-term variability in the diet and reproductive performance of penguins at Bird Island, South Georgia, Marine Biology (2017). DOI: 10.1007/s00227-016-3067-8

source 

Friday, January 20, 2017

Penguins Can’t Taste The Umami Flavor Of Fish

Penguins haven’t been able to taste sweet, bitter, and umami flavors for more than 20 million years.
Because penguins are fish-eaters, the loss of the umami taste is especially perplexing, says study leader Jianzhi “George” Zhang, a professor in University of Michigan’s department of ecology and evolutionary biology.
“These findings are surprising and puzzling, and we do not have a good explanation for them.”
“Penguins eat fish, so you would guess that they need the umami receptor genes, but for some reason they don’t have them,” he says. “These findings are surprising and puzzling, and we do not have a good explanation for them. But we have a few ideas.”
Penguins
By Image ID: corp2417, NOAA Corps CollectionPhotographer: Giuseppe ZibordiCredit: Michael 
Van Woert, NOAA NESDIS, ORA [Public domain], via Wikimedia Commons
Penguins
Zhang suspects the sensory changes are tied to ancient climate-cooling events in Antarctica, where penguins originated. His leading hypothesis is that the genes were lost after cold Antarctic temperatures interfered with taste perception.

A paper on the topic appears in Current Biology. The first author, Huabin Zhao, was a postdoctoral researcher under Zhang when most of the study took place.

Vertebrates typically possess five basic tastes: sweet, sour, salty, bitter, and umami (savory, meaty). Over the past 15 years, remarkable progress in understanding the molecular basis of taste has opened the door to inferring taste abilities from genetic data through the examination of taste receptor genes.

Compared with mammals, birds are thought to be poor tasters, due in part to the observations that they have fewer taste buds on their tongues and lack teeth for chewing food. Previous genetic studies showed that the sweet taste receptor gene is absent from the genomes of all birds examined to date.

Missing taste genes

Zhang says an email from colleagues at BGI, a genomics institute in China, prompted the study. Researchers there had sequenced genomes from Adelie and emperor penguins and could not find some of the taste genes. They wanted Zhang to help determine whether the absent genes were the result of incomplete sequencing or a true evolutionary deletion.

Zhang and his colleagues took a closer look at the Adelie and emperor data. In addition, they analyzed bird tissue samples (chinstrap, rockhopper, and king penguins, plus eight other closely related non-penguin bird species). They also reviewed publicly available genomes for 14 other non-penguin bird species.

They found that all five penguin species lack functional genes for the receptors of sweet, umami, and bitter tastes. In the Adelie and emperor genomes, the umami and bitter taste receptor genes have become “pseudogenes,” genetic sequences resembling a gene but lacking the ability to encode proteins. Pseudogenes often result from the accumulation of multiple mutations over time.

The genomes of all non-penguin birds studied—including egrets, finches, flycatchers, parrots, macaws, falcons, chickens, and mallards—contain the genes for the umami and bitter tastes but, as expected, lack receptors for the sweet taste. The researchers concluded that all penguins have lost three of the five vertebrate senses.

“Taken together, our results strongly suggest that the umami and bitter tastes were lost in the common ancestor of all penguins, whereas the sweet taste was lost earlier,” the authors write.

A dramatic cold snap

Penguins originated in Antarctica after their separation from tubenose seabirds around 60 million years ago, and the major penguin groups separated from one another about 23 million years ago. The taste loss likely occurred during that 37-million-year span, which included periods of dramatic climate cooling in Antarctica, Zhang says.

His leading suspect is the protein Trpm5, which is required for the transduction of sweet, umami, and bitter taste signals to the nervous system in all vertebrates. Previous studies on mice showed that Trpm5 does not function well at cold temperatures.

“This give us a hint, perhaps, that this loss of taste genes has something to do with the inability of this protein to work at lower temperatures,” says Zhang, whose former postdoc, Zhao, is planning follow-up experiments to see how well Trpm5 functions at the temperature of seawater used by Antarctic penguins.

In mice, the protein Trpm5 is also involved in insulin secretion and the detection of pheromones. If the same is true in penguins, then Trpm5 is essentially being asked to work simultaneously at a warm body temperature and at the frigid ambient temperature, which may not be possible. When such a dilemma arises, the more important function is retained by natural selection, while the less important one is sacrificed, Zhang says.

Vertebrate tastes are mediated by taste receptors usually located in taste buds found on the upper surface of the tongue and elsewhere in the mouth. The human tongue has several thousand taste buds.

Penguin tongues

A 1998 anatomical study of four penguin species found no taste buds in their tongues, strongly suggesting a reduction in taste function. The same study found that penguin tongues possess only a single type of lingual papillae, the raised protrusions that hold most of the taste buds in humans, which have four types of papillae.

Penguin papillae are stiff, sharp, and covered by a thick, horny layer, suggesting that penguin tongues are used primarily for catching and holding slippery fish or other prey. Those anatomical findings are in accord with the new genetic results showing a lack of receptors for three of the five vertebrate tastes in penguins.

But it’s not clear what came first, the anatomical adaptations or the sensory changes, Zhang says.
“Their behavior of swallowing food whole, and their tongue structure and function, suggest that penguins need no taste perception, although it is unclear whether these traits are a cause or a consequence of their major taste loss,” he says.

First author Zhao is now a professor at China’s Wuhan University. The other author is Jianwen Li of the China National GeneBank, BGI-Shenzhen.

The US National Institutes of Health, the National Natural Science Foundation of China, and Wuhan University supported the work. The University of Michigan Museum of Zoology provided tissue samples of bird species, and BGI-Shenzhen shared penguin and egret genome sequences.

Source: University of Michigan