Wednesday, February 3, 2016

New twist in the case of the little blue penguin


By Jamie Morton  

Jamie Morton is the NZ Herald's science reporter. 
Researchers have revealed an Otago population of the world's smallest - and possibly cutest - penguin species actually hailed from across the Tasman. Photo / Supplied
Researchers have revealed an Otago population of the world's smallest - and possibly cutest - penguin species actually hailed from across the Tasman. Photo / Supplied
The curious case of a huddle of Aussie invaders that long managed to blend in with our native little blue penguins has just taken another mysterious twist.

Researchers recently revealed an Otago population of the world's smallest -- and possibly cutest -- penguin species actually hailed from across the Tasman and have now confirmed the immigrants arrived as recently as the past few hundred years.

It's the latest instance in which DNA analysis has dramatically changed what we know about many of our supposedly native species.

Following startling findings in December that, for the first time, described two distinct species of little blue penguin in New Zealand, a paper published today in the Proceedings of the Royal Society B: Biological Sciences finds the newcomers probably arrived here between 1500 and 1900.

This up-ended previous theories that the Australians had been here for thousands of years.

As part of her PhD research at Otago University, Dr Stefanie Grosser analysed ancient DNA from the remains of more than 100 little penguins, including bones dating back to pre-human times and specimens from archaeological deposits and museums. "Amazingly, all of the bones older than 400 years belong to the native New Zealand species," she said.

Dr Grosser said the arrival apparently followed the decline of the native penguin, which early human settlers and introduced predators hunted.

The Australian species were set apart by a few subtle differences in their colour, body and cranium size.

Other researchers had previously shown that calls differed between Australian and New Zealand little penguins and females preferred the calls of males of their own species. "You could say the Aussies like hearing 'feesh', while 'fush' sounds better to Kiwi ears," Dr Grosser joked at the time of the December findings.

But how they got here remains a mystery -- and one we might never solve. "It's one of those unlikely events that they happened to rock up on the Otago coastline and got a foothold," said study leader Professor Jon Waters, of Otago University's Department of Zoology. "You could make up a story that maybe an Australian ship picked up 10 and brought them over, but I'd find that really hard to believe."

The Australian sub-population appears confined to Otago. DNA analysis from other colonies, such as Wellington, Kaikoura and Banks Peninsula, turned up only the New Zealand lineage. "It's possible we might find another colony of Aussies somewhere like Fiordland, we don't know."

Professor Waters believed the findings should bring about a different approach to the species' conservation. "We have to think about them as being not one thing, but two, and manage them separately -- so there might be a real paradigm shift."

The native penguin, which on average stands at just 25cm and weighs 1kg, is considered in decline in New Zealand. Dogs pose their greatest threat.

The research, supported by the Marsden Fund and the now-closed Allan Wilson Centre, also provides the latest example of penguins winding up on foreign shores far from home.

Little blue penguins have been found as far as Patagonia in South America.

Other famous penguin stories have included the Antarctic emperor penguin Happy Feet, which captured Kiwi hearts after it arrived in Kapiti in 2011, and Katrina, a Fiordland penguin that swam 3000km to Mt Gambier, South Australia, in 2013.

How DNA has redefined our native species

The yellow-eyed penguin

DNA analysis and carbon-dating led to findings published last year that revealed a change-over between the yellow-eyed penguin and another penguin species that became extinct around the same time as the moa.

An Otago University team showed the waitaha, which was slightly smaller than the yellow-eyed penguin, vanished within 200 years of Polynesian settlement of New Zealand, before 1500AD.

In one of the most rapid biological transition events documented, the yellow-eyed penguin, or hoiho -- considered one of the world's rarest penguin species with a population of between 6000 and 7000 -- moved to the mainland from the subantarctic islands and replaced the waitaha within just a few decades, in the early 1500s.

The New Zealand sea lion

That research had fascinating parallels with the fate of a pre-historic species of New Zealand sea lion, which once dominated South Island shores before they became extinct as recently as between 1300 and 1500AD, soon after Polynesian settlement.

DNA analysis reported in 2014 showed their place on the New Zealand mainland was quickly taken by today's modern population, which was previously limited to the cold waters of the subantarctic.

The kiwi

2014 was also the year that scientists corrected the shocking suggestion that our national bird arrived here when its winged ancestor flew in from Australia.

The 150-year-old mystery was finally solved by DNA sequencing that revealed the bird was more closely related to the extinct, 2.3m tall elephant bird, a native of Madagascar.

The moa

A separate study in 2014 put even more genetic distance between the extinct moa and their old bush mates, the kiwi.

DNA-based research led by New Zealand scientist Professor Allan Baker suggested the giant birds were more closely related to a flying South American bird still alive today than our national icon.

The South American tinamous, one of the world's most ancient living groups of bird, can fly and are not categorised as ratites, but are considered close relatives because of the shared structure of their palate bones.


 

Penguin chicks huddle up for heat, protection

Posted By Science Codex News on February 3, 2016

Location and environmental conditions may influence when gentoo chicks huddle in cold, wet Antarctic conditions, according to a study published February 3, 2016 in the open-access journal PLOS ONE by Caitlin Black from the University of Oxford, and colleagues.

Many penguin species form aggregations for conserving heat, providing protection, and other purposes. Scientists have observed gentoo penguins aggregating during the post-guard period, a period when the parents leave the chicks without waterproof feathers daily to go find fish, but these aggregations have never been studied over a large spatial range in the Antarctic. The authors of this study observed the gentoo penguin aggregation behavior across four study sites along a latitudinal gradient. To examine the adaptive benefit of aggregations, they observed each colony during the post-guarding period of the 2012-2013 breeding season using time-lapse cameras.

The authors found that gentoo chick aggregations help individual chicks save energy during wet, cold conditions. However, they also found significant differences in aggregation behavior between colonies. Chicks form aggregations more often and in a larger size at the northern-most colony studied on the island of South Georgia than at the southern study sites on the Antarctic Peninsula, suggesting this behavior may be colony specific. Since not all post-guarding periods occurred during the same time period at each study site, the differences in environmental conditions and post-guard period timing may have also played a role. The authors suggest their results highlight the need for studies to evaluate multiple seabird colonies within one species before generalizing behaviors based on one location.

Caitlin Black notes, "Behaviors, such as chick aggregations, influence whether a chick will survive and therefore may greatly impact the success of a colony. The results show why we must evaluate behaviors at multiple locations, as these behaviors are often colony specific and cannot be generalized from one year at one location."

Source: PLOS
 

Ancient DNA Analysis Hints at Recent Arrival of Australian Little Blue Penguins in New Zealand

Feb 03, 2016
                                         Tatiana Gerus/Wikimedia Commons
 
NEW YORK (GenomeWeb) – An ancient DNA analysis has found that the Australian little blue penguin is a recent colonizer of New Zealand, according to a University of Otago-led team of researchers.

By radiocarbon dating and sequencing stretches of ancient DNA from Eudyptula samples found in New Zealand, researchers led by Otago's Jonathan Waters found that the Australian Eudyptula novaehollandiae likely arrived in New Zealand some 500 years ago, around the time of the decline of the indigenous Eudyptula minor. As they reported yesterday in the Royal Society Proceedings B: Biological Sciences, the researchers found that the decline of a native species could thus be masked by the introduction of a related taxon.

"Our results clearly show that the Australian penguin colonized Otago very recently, between 1500 and 1900 AD, apparently following the decline of the native New Zealand little penguin, which was hunted by early human settlers and introduced predators," first author and Otago researcher Stefanie Grosser said in a statement.

The little penguin genus is endemic to both Australia and New Zealand, and recent genetic analysis of mitochondrial DNA had found that there are two, divergent little penguin lineages: one that's found only in New Zealand and one that's found both on New Zealand's Otago coast and in southern Australia. Initial genetic studies had suggested that the Australian penguin had been in New Zealand for thousands of years, though a more recent study hinted at a later introduction.

Waters, Grosser, and their colleagues collected 146 prehistoric Eudyptula bones from museum and archaeological collections and nine historic Eudyptula samples that represent the full swathe of the little penguin range in New Zealand. They extracted and sequenced a 393-basepair stretch of DNA corresponding to the mitochondrial control region HVRI from 128 of those specimens, though 16 of those could only be partially sequenced.

At the same time, radiocarbon dating of nine of the prehistoric Eudyptula bones traced one sample as far back as 34,000 years before present (BP) — the oldest yet discovered, the researchers noted — though most of the others dated back to 1499 BP and 1112 BP.

The genetic analyses revealed a striking turnover in Otago, the researchers reported: E. minor was nearly completely replaced by E. novaehollandiae. All 119 Holocene samples — older than 1600 AD — were phylogenetically assigned to the endemic New Zealand E. minor lineage, while the more modern penguin samples were mostly E. novaehollandiae. Five of the six museum skin samples from birds collects in 1969 had Australian haplotypes, the researchers added.

Their analysis further found that the prehistoric New Zealand Eudyptula exhibited substantial haplotype diversity. Some of the ancient diversity has been lost as the research found that only two of the 12 detected prehistoric New Zealand haplotypes are represented in the modern samples. This, they added, indicates a haplotype diversity reduction of 35 percent.

Using a Bayesian serial coalescent approach, the researchers examined the demographic history of the Australian little penguin in New Zealand. After modeling a number of scenarios, they found that there was the most support for a two-step model in which an initial invasion of E. novaehollandiae was followed by a population expansion in Otago. Under this model, colonization likely took place about 25 generations ago, or in about 1500 AD to 1890 AD with an effective population size of the colonizers of about 2,900 individuals.

This timing, the researchers noted, broadly coincides with a 40 percent population loss of the endemic E. minor. However, they added that they had insufficient power to determine whether the E. novaehollandiae colonization or decline of E. minor occurred first.

Human colonizers, who arrived a few centuries prior, are thought to have aided in the E. minor decline likely due to hunting and the introduction of predators like the Polynesian rat and dog.
"[O]ur aDNA analyses of little penguins directly document a compelling example of rapid faunal shift coinciding with human expansion into New Zealand," the researchers wrote in their paper. "These data highlight that the decline of a native species can be masked by the cryptic invasion of a related species."

Thursday, January 28, 2016

UQ researcher's icy dinosaur (penguins?) hunt in Antarctica

Cape Lachman, James Ross Island - a dinosaur fossil site.
A University of Queensland scientist will brave ice, snow and five weeks sharing a two-man tent in an effort to learn more about dinosaurs during an expedition to Antarctica.

UQ School of Biological Sciences palaeontologist Dr Steve Salisbury will be among 12 scientists on an expedition running from 2 February to 24 March.

The seven palaeontologists, two sedimentologists, and three palaeontology graduate students will travel to the James Ross Island area— one of the few parts of Antarctica that has exposed rock during summer.

"We're going down there to look for dinosaurs, but also other animals in Antarctica that may have existed towards the end of the Age of Dinosaurs," Dr Salisbury said.

"Australia was connected to Antarctica right through the Age of Dinosaurs and beyond, up until about 40 million years ago.

"Antarctica holds the key to a lot of biogeographic problems that we're trying unravel with regard to how dinosaurs and various other creatures ended up around the globe."

Dr Salisbury said the team hoped to find new evidence that would indicate what dinosaurs may have existed in Australia, and how those already found in Australia might relate to their counterparts in Antarctica and other parts of once great southern supercontinent, Gondwana.

With a never-ending cycle of freezing and thawing, different areas are exposed each year, leaving potential for new discoveries.

"There could be skeletons exposed that weren't seen before, that are just going to be sitting there on the ridges, I hope," Dr Salisbury said.

"At first there will be a lot of walking around, kicking rocks, picking things up, looking for places to target and just systematically checking to see if anything new has appeared."

The team has been preparing for the expedition since 2012, but significant sea ice over the past seasons has prevented their research ship from getting into the areas they need to target.

This time, the team will take two helicopters to ensure they can reach the areas they want to camp in unhindered.

"One of the biggest challenges is just getting there, and we don't really know what we're going to find, so you have to be prepared for everything," Dr Salisbury said.

"We'll have to bring a lot of specialist clothing, and we'll have to set our camp up to be completely independent from the outside world for about four to five weeks.

"There's a huge amount of logistics but I think that's half the fun of operating somewhere like Antarctica."

source

Friday, January 15, 2016

U of Delaware researcher studies penguin turf war


Molly Murray, The News Journal  
January 14, 2016
 
Adélie penguins called the West Antarctic Peninsula their summer breeding turf for decades and then, about 20 years ago, another species, the gentoos, started showing up and the Adélie  population took a steep decline.

That sparked questions in the mind of a University of Delaware researcher: Were they competing for the same limited food and habitat resources? And were the gentoos the cause the Adélies' decline?
“We set out to explore whether the Adélies and gentoos were eating out of the same lunch box, so to speak,” said Megan Cimino, a doctoral candidate in the University of Delaware's College of Earth, Ocean and Environment and the lead author of a study reported recently in Scientific Reports.

It turns out, that even where the populations of the two species overlap, their feeding strategies – both target krill –  are different enough that one species isn't out-competing the other. But figuring that out took high tech tools such as tagging both species of birds to track movement and feeding patterns and use of an underwater robot that allowed researchers to pinpoint exactly where the food was and where the birds were going to get it.

The technology produced hundreds of thousands of data points that Cimino reviewed before concluding that one species wasn't out-competing another for the same food resources. The findings leave lingering questions about why gentoos expanded their range and why the Adélie population is declining so dramatically.

The Western Antarctic Peninsula is one of the most rapidly warming places in the world and Cimino's previous work with Adélie penguins there looked at shifts in climate and weather conditions. A colony of penguins in the West Antarctic Peninsula. Palmer Research Station is in the background.  Megan Cimino, University of Delaware

Since 1950, the average annual temperature in the Antarctic Peninsula has increased 3.6 degrees. The average winter temperature has risen by 10.8-degrees. Meanwhile, the climate is changing from dry and polar to warmer and sub-polar with more rain.

Cimino said that when she was there last year it was the Antarctic summer but at times it was much colder in Delaware than it was at Palmer Station where she worked. In the earlier work, Matthew Oliver, Patricia and Charles Robertson Professor of Marine Science and Policy at the university, worked with Cimino to compare data from 1987 to 2011 on the Adélie penguin’s diet, weather and the large-scale climate indices to see connections year-to-year in penguin chick weight. “The ability of a penguin species to progress is dependent on the adults’ investment in their chicks,” Oliver said. “Penguins do a remarkable job of finding food for their chicks in the ocean’s dynamic environment, so we thought that the type and size distribution of food sources would impact chick weight.”

What they found instead was that local weather and overall atmospheric climate affects chick weight gain. Among the keys were high winds, cold and precipitation such as rain and humidity. Because penguins live in rocky areas with little or no shelter there is no protection from extreme conditions when parents were away from the nest foraging for food. They were able to link weight gain to local weather conditions.

For example, westerly wind and air temperature can cause a 7-ounce change in average chick weights, as compared to 3.5-ounce change caused by wind speed and precipitation.  A 7-ounce decrease in chick weight could be the difference between a surviving and non-surviving chick.
Teams of scientists including Oliver, Mark A. Moline, the director of the College of Earth, Ocean and Environment and William R. Fraser and Donna L. Patterson-Fraser from Polar Ocean’s Research Group, have been monitoring the decline of Adélie penguin populations. In 1975, there were an estimated 15,000 breeding pairs in the Antarctic summer. Today, a few thousand pairs remain.

With the latest research, paid for by the National Science Foundation and by the NASA Biodiversity Program, the team wanted to see if the two species were in a turf war for the same food supply.
Penguins were tagged with satellite transmitters and depth recorders to see how deep they dove in search of food. The also used an autonomous underwater vehicle, REMUS, to collect water samples and measure temperature, salinity and light levels in the water. In addition, they measured levels of phytoplankton and krill, the primary food source for both penguin species.

“Gaining an understanding of where krill are in relation to their food, and where penguins are in relation to their food was an important part of the study,” Cimino said. “Without the REMUS – which can swim at about the same speed and dive almost as deep as a penguin – we would not know what’s going on in the waters where the penguins are, we would only know that the penguins were there.”
Back in Delaware, Cimino analyzed thousands of foraging dives for both penguin species and discovered in the small area where the population overlapped, the gentoos shifted their behavior and dove to deeper foraging depths for food. “It was unexpected to see the Adélies foraging much shallower than the gentoos when we know they are capable of deeper dives,” Cimino said.
They also discovered that both species foraged and returned to nesting areas with enough food for their young suggesting there was enough food to support both populations.

With the underwater robot "it's like seeing the ocean as the penguins do," Moline said. The work allowed the team to rule out competition for food as a limiting faction.

"There's something else going on" that is causing Adélie penguin populations to decline, Cimino said. “It is cool to see that two species can exist in very close quarters – less than 20 kilometers apart –and have different foraging habitats.But if their winter habitats are changing as well, for better or worse, it will likely have a direct effect on their population and how many penguins come back to breed each season."

source

Wednesday, January 6, 2016

#Penguins and robots


University of Delaware researchers are working to better understand foraging competition between Adelie and Gentoo penguins.
UD study seeks to better understand foraging competition between Adelie, gentoo penguins

Jan. 6, 2016--For hundreds of years, Adélie penguins have been breeding in the West Antarctic Peninsula (WAP), which has recently become one of the most rapidly warming areas on Earth.
At Palmer Station, a U.S. research base located along the WAP, scientists have been monitoring Adélie penguin population declines for decades. There were 15,000 breeding pairs of Adélie penguins in 1975; but today only a few thousand pairs are left.

Now, in a study reported in the Nature publication Scientific Reports, University of Delaware oceanographers consider whether Adélie penguins and gentoo penguins — newcomers to the Palmer Station region over the last two decades — may be competing for the same food resources and whether this might exacerbate the Adélie population decline.

An ecological theory called the competitive exclusion principle, also known as Gause’s law, states that “two species that compete for the exact same resources cannot stably coexist.”

“So we set out to explore whether the Adélies and gentoos were eating out of the same lunch box, so to speak,” explained Megan Cimino, a doctoral candidate in UD’s College of Earth, Ocean, and Environment and the paper’s lead author.

Co-authors on the paper, “Climate-Driven Sympatry May Not Lead to Foraging Competition Between Cogeneric Top-Predators,” include UD’s Mark A. Moline, director of the School of Marine Science and Policy, and Matthew J. Oliver, Patricia and Charles Robertson Professor of Marine Science and Policy; and William R. Fraser and Donna L. Patterson-Fraser from Polar Ocean’s Research Group.

Underwater robot views the ocean like a penguin

To test whether the species were competing, the researcher’s tagged penguins with small satellite transmitters and depth recorders to track where the penguins went and how deep they were diving. The tags were attached to a different penguin every three days over the month-long 2011 study which took place during the chick-feeding phase of the breeding cycle when adults are feeding chicks and the parental foraging ranges of both species overlap. Each penguin completed a few foraging trips and hundreds to thousands of dives while tagged.

Additionally, the research team used an autonomous underwater vehicle (AUV) called a REMUS to sample the water where the penguins were foraging, something few researchers have done before. The REMUS provided important measurements on temperature, salinity and how much light was in the water (important for visual predators like penguins).

It also measured the amount of phytoplankton and krill, the main food source for both penguin species, present in the water, systematically allowing the researchers to measure multiple levels of the food chain in the same study, from phytoplankton to krill to penguins.

“Gaining an understanding of where krill are in relation to their food, and where penguins are in relation to their food was an important part of the study,” Cimino said. “Without the REMUS — which can swim at about the same speed and dive almost as deep as a penguin — we would not know what’s going on in the waters where the penguins are, we would only know that the penguins were there.”

An analysis of the data on thousands of foraging dives revealed that while the Adélie and gentoo penguins generally foraged in different areas, there was a small area of overlap between the two populations. Interestingly, when the species overlapped, the gentoos shifted behavior and foraged at deeper depths — nearly 35 percent — below the Adélie penguins.

Both penguin species are capable of foraging as deep as 150 meters below the ocean surface, yet over the study period, the Adélies foraged in the upper 50 meters of the water and they didn’t change their behavior at all when their foraging area overlapped with the gentoos. The gentoos, however, often foraged as deep as 150 meters when in overlapping areas. The researchers theorize this may be a strategy to limit competition.

“It was unexpected to see the Adélies foraging much shallower than the gentoos when we know they are capable of deeper dives,” Cimino said. Furthermore, the fact that both penguin species were provisioning chicks during the satellite tracking implied that the adults were returning to the nest with enough food, further suggesting that competition was not limiting food resources.

Krill, the penguin’s main food source, are an important prey in the Southern Ocean because they aggregate in large groups and have high nutritional value. The researchers used the REMUS to test whether krill were affiliated with any specific water properties. The team found that krill were mostly associated with areas where the water became darker at a shallower depth and the bulk of phytoplankton, it’s food source, was located deeper in the water.

Since there are few places to hide in the open ocean except in darkness, this led the research team to determine that the krill were selecting for areas where they could eat, but also avoid being eaten by visual predators, such as penguins.

“The novel aspect of the study was that the environmental sampling done by the robot was informed by the location of the penguins. By doing this, we could couple the behavior of these two species with the distribution of their prey and make distinctions that were not possible beforehand,” explained Moline.



More work to be done

While recent theories have suggested that increased competition for krill is a main driver of Adélie penguin population declines, the oceanographers suspect the Adélie declines along the WAP may be more likely due to direct and indirect climate impacts on their life histories.

Last year UD researchers and colleagues reported a connection between local weather conditions and the weight of Adélie penguin chicks. Previous research studies near Palmer Station demonstrated how climate and weather influence penguin breeding habits, the marine foraging environment and foraging trip duration.

If the WAP climate continues to warm, sea ice extent and coverage duration will continue to decrease, potentially altering the food web and raising questions about what effect changes in winter habitat will have on the species’ survival, Cimino said.

Adélie penguins are migratory and leave their breeding colony in winter and stay out at sea. Gentoo penguins are non-migratory and remain at the breeding colony all winter.

“It is cool to see that two species can exist in very close quarters — less than 20 kilometers apart — and have different foraging habitats. But if their winter habitats are changing as well, for better or worse, it will likely have a direct effect on their population and how many penguins come back to breed each season,” Cimino said.

This work was funded by the National Science Foundation and by the NASA Biodiversity Program.
Article by Karen B. Roberts


Photos courtesy of Chris Linder and the University of Delaware


source

Thursday, December 17, 2015

Ancient four-flippered reptile flapped like a penguin

December 17, 2015
Ancient four-flippered reptile flapped like a penguin. Credit: Liu et al. 10.1371/journal.pcbi.1004605
The puzzle of the plesiosaur has been revealed by computer simulations showing how the ancient animals used their unusual four-flippered body to swim through the ocean.

The study published this week in PLOS Computational Biology by computer scientists, led by Greg Turk from the Georgia Institute of Technology and in collaboration with paleontologist Adam Smith at Wollaton Hall, Nottingham Natural History Museum, investigates the long-standing puzzle of .

The researchers find that the most effective swimming motion for the plesiosaur is flapping the two front flippers in an underwater flight motion, similar to that of a penguin. Surprisingly, however, the simulations revealed that the rear flippers would not have substantially increased their forward speed. Instead, the back flippers of plesiosaurs were probably used for steering and stability.

video

Plesiosaurs are an extinct group of marine reptiles that were apex predators for 135 million years during the age of the dinosaurs. Their unique four-flipper body plan is unlike any modern-day swimming animal and paleontologists have debated their possible swimming style since the first complete plesiosaur skeleton was described in 1824. The study uses to help resolve this question. Thousands of different swimming motions were simulated to identify the most effective swimming strategy for the plesiosaur body plan.

Future computer simulations could be used to discover the degree of agility that plesiosaurs gain from their rear flippers. The method can also be applied to understand the swimming motion of other prehistoric animals.Ancient four-flippered reptile flapped like a penguin. Credit: Liu et al. 10.1371/journal.pcbi.1004605
"Plesiosaur swimming has remained a mystery for almost 200 years, so it was exciting to see the plesiosaur come alive on the computer screen" said Smith.

"Our results show that the front limbs provide the powerhouse for plesiosaur propulsion while the hind limbs are more passive" said Smith.


More information: Liu S, Smith AS, Gu Y, Tan J, Liu CK, Turk G (2015) Computer Simulations Imply Forelimb-Dominated Underwater Flight in Plesiosaurs. PLoS Comput Biol 11(12): e1004605. DOI: 10.1371/journal.pcbi.1004605

Journal reference: PLoS Computational Biology search and more info website
Provided by: Public Library of Science search and more info 

source 

B.C. family’s fossil find identified as 25-million-year-old flightless bird

Researchers identified the animal as a new species of a plotopterid, a long-extinct penguin or cormorant-like bird never before found in Canada.
An artist's rendition shows a Stemec suntokum, a type of plotopterid which lived 25 million years ago.
THE CANADIAN PRESS
An artist's rendition shows a Stemec suntokum, a type of plotopterid which lived 25 million years ago. 

VICTORIA—A family out for a stroll on southern Vancouver Island stumbled upon the extraordinary fossilized remains of a 25-million-year-old flightless bird that has created a flap in the world of paleontology.

The fossil was in good enough condition for researchers to identify the animal as a new species of a plotopterid, a long-extinct penguin or cormorant-like bird never before found in Canada.

A collarbone from the bird was found inside a slab of rock on a Sooke, B.C., beach.

It’s only the second set of fossilized bird bones found on southern Vancouver Island since 1895, said bird expert Gary Kaiser of the Royal B.C. Museum.

Fossils of birds are extremely rare because the fragile and hollow bones don’t hold up to crushing weight, acidic soils and elements like other fossils do.

“They get broken up, crushed easily,” Kaiser said in an interview Tuesday. “The bones simply dissolve. They disappear.”

In this case, the sandstone and lack of acid in the water seemed to preserve the fossil, he said.

A father, daughter and son were out for a walk two years ago when they found the bone in a slab of rock that had fallen from the nearby cliffs, he said.

The daughter spotted the fossil. Her brother carried the slab off the beach, before the father brought it to the museum.

Next to a skull, the collarbone is the best bone to find because it sits at the shoulder where the wings function and where the collar blade, arm bone and sternum are attached.

“It is the most informative bone in a bird skeleton. It tells you more than anything else about what the bird does for a living,” Kaiser said.

The long, skinny bone wasn’t anything like he had ever seen before.

“Right away, I knew it was an unusual bone,” he said, noting that’s when he linked it to the plotopterid fossil.

Relatives of the bird have been found in Japan and in Oregon and California, but none has been as small.

“Of those several hundred birds, all but two of them are huge. I mean they’re birds that probably weighed 200 kilograms when they were alive and stood six-foot tall,” Kaiser said.

This animal was about the size of a cormorant.

Kaiser and his colleague Junya Wantanabe of Kyoto University named the bird Stemec suntokum because it’s a new species. The name means long-necked waterbird in the language of the T’Sou-Ke First Nation who live in the area.

Kaiser said he believes that if they had the fossil’s brain case the animal would look like a penguin, but an American man who studies plotopterids is convinced they are more like cormorants.

“It’s a bit of a fight, but not unusual in biology because there’s no way of telling,” he added.

The discovery announcing the new species has been published in the online journal Palaeontologia Electronica.

Penguins filmed in epic underwater fight stealing a large squid


16 December 2015

A gentoo penguin darting through the sea off the Falkland Islands catches a large squid in its bill.
The prey is too big to swallow whole – and is suddenly snatched away by a second penguin. A third penguin joins the scuffle, while the first makes a last-ditch bid for its catch. A tug of war ensues, and the hapless squid is torn in two.

This underwater brawl was captured on a video camera taped to the back of the second penguin, revealing this unexpected foraging behaviour for the first time. “This is completely new behaviour, not just for gentoo penguins but for penguins in general,” says Jonathan Handley, a doctoral student at Nelson Mandela Metropolitan University in Port Elizabeth, South Africa.

Handley used high-definition video cameras waterproofed with custom-made Perspex casings, which functioned perfectly to depths of more than 200 metres.


Video: Squid-hunting penguins caught in rare underwater food fight

“These images are unique in that they were captured underwater in a situation that would have been unobservable without this technology,” says Norman Ratcliffe, a seabird ecologist at the British Antarctic Survey in Cambridge, UK. “It is interesting that the interaction was over a squid: a large and difficult-to-capture prey item that is clearly worth fighting for.”

We already knew that penguins stole pebbles from each other’s nests and have records of seabirds fighting over food – behaviour known as kleptoparasitism.

Population centre

The Falkland Islands are home to around 130,000 breeding pairs of gentoo penguins – the world’s largest population of this species. Handley studied them over three breeding seasons from 2011 with the assistance of Falklands Conservation, a local non-governmental organisation.

He says a large squid would be prize prey for a penguin, providing high-energy food for both a parent and chick, and reducing foraging time. “The majority of their prey is small and quickly consumed,” he says.

But he believes it is unlikely that gentoos specialise in becoming food thieves. They would probably only steal food that other penguins need to handle for a long time such as a huge squid, he says, allowing them the opportunity to steal it.

Penguins filmed in epic underwater fight stealing a large squid
Handley says the theft of nesting material such as pebbles and plants – which provide eggs with thermal insulation and protection from rain and meltwater – has been observed when in short supply in penguin colonies belonging to the Pygoscelis genus (better known as brush-tailed penguins), which includes gentoos.

So why do they do it? “Individuals able to acquire more resources, including both food and nesting material, will be able to provide better parental care for offspring, thus increasing the offspring’s chance to survive until fledging,” Handley says.

Journal reference: Polar Biology, DOI: 10.1007/s00300-015-1772-2

Penguin cam captures hunt for prey

Little penguins work together to hunt schooling prey
Date:
December 16, 2015
Source:
PLOS
Summary:
Little penguins were more likely to work together to hunt schooling prey than solitary prey, according to observations made using animal-borne cameras.

This is a photograph of penguins foraging as a group.
Credit: John Arnould, Deakin University

Little penguins were more likely to work together to hunt schooling prey than solitary prey, according to observations made using animal-borne cameras published Dec. 2, 2015 in the open-access journal PLOS ONE by Grace Sutton from the Deakin University, Australia, and colleagues.
Group foraging in cooperative animals provides predators with advantages over prey, but for less cooperative colonial-breeding predators, like the little penguin, the benefits of group foraging are less clear due to the potential for competition between penguins. The authors of this study used animal-borne cameras on 21 little penguins from two breeding colonies in south-eastern Australia to determine the prey types, hunting strategies, and success of little penguins, a small, marine predator that extensively forages with other little penguins.

The researchers found that little penguins had a higher probability of associating with each other when hunting schooling prey than when encountering solitary prey. Surprisingly, individuals were no more successful at capturing schooling prey than solitary prey. However, success preying on schooling fish was similar or greater when individual penguins hunted on their own rather than together. The authors suggest that individual penguins may trade-off the potential benefits of solitary hunting to increase the probability of detecting prey by associating with other little penguins.

Grace Sutton says: "This study showed little penguins gained no benefit in capturing prey when from hunting in groups, suggesting individuals may forage in groups to improve detection of prey or avoid predation but, once they find prey, it is every penguin for themselves."

Story Source:
The above post is reprinted from materials provided by PLOS. Note: Materials may be edited for content and length.

Journal Reference:
  1. Grace J. Sutton, Andrew J. Hoskins, John P. Y. Arnould. Benefits of Group Foraging Depend on Prey Type in a Small Marine Predator, the Little Penguin. PLOS ONE, 2015; 10 (12): e0144297 DOI: 10.1371/journal.pone.0144297


PLOS. "Penguin cam captures hunt for prey: Little penguins work together to hunt schooling prey." ScienceDaily. ScienceDaily, 16 December 2015. <www.sciencedaily.com/releases/2015/12/151216151605.htm>.

Monday, December 14, 2015

Researchers find that Australian and New Zealand little penguins are distinct species

Public Release: 
University of Otago
IMAGE
IMAGE:
A team of researchers from New Zealand's University of Otago and the University of Tasmania has discovered that Australian and New Zealand little penguins represent two distinct species, rather than one.

Credit

Dr Stefanie Grosser

Scientists had previously wondered about the relationships between populations of the penguin (popularly known as little blue penguins or fairy penguins) found on either side of the Tasman. The trans-Tasman team used genetic techniques to compare populations from both countries, and surprisingly found that they are not the same species.

"We found a very strong pattern, where New Zealand has its own distinctive genetic group that is clearly very different from the Australian penguin populations," says Dr Stefanie Grosser, who carried out the study as part of her Otago PhD project.

Similar to their human counterparts, the two species also seem to have developed their own 'accents'. Other researchers have previously shown that calls differ between Australian and New Zealand little penguins and females prefer the calls of males of their own species. "You could say the Aussies like hearing 'feesh', while 'fush' sounds better to Kiwi ears," Dr Grosser jokes.

"The recognition of unique penguin species on both sides of the Tasman highlights the importance of managing and conserving them separately," she says.

Another unexpected finding of the study was the discovery that the Australian species -- Eudyptula novaehollandiae -- is surprisingly also present in Otago, in the remote southeast corner of New Zealand's South Island. "Our genetic data suggest that the Otago and Australian populations are quite closely related," says Dr Grosser.

The team is currently working to better establish the history of the Otago population using ancient DNA. "This research highlights that there is still much to be discovered about our region's unique wildlife," says Professor Jon Waters, who was involved in the study. "The new recognition of endemic species -- unique to our region -- is crucial for managing our natural heritage."

###

The research was funded by the Marsden Fund and Allan Wilson Centre and published this week in the international journal PLOS ONE.

The article is available here: http://dx.plos.org/10.1371/journal.pone.0144966

source

Sunday, December 13, 2015

Influence of Earth's history on the dawn of modern birds

New time tree indicates that avian evolution was molded by climate change and plate tectonics
Date:
December 11, 2015
Source:
American Museum of Natural History
Summary:
The evolution of modern birds was greatly shaped by the history of our planet's geography and climate. New research finds that birds arose in what is now South America around 90 million years ago, and radiated extensively around the time of the Cretaceous-Paleogene extinction. The new research suggests that birds in South America survived this event and then moved around the world via multiple land bridges while diversifying during periods of global cooling.

Modern day great blue herons. Birds arose in what is now South America around 90 million years ago, and radiated extensively around the time of the Cretaceous-Paleogene extinction event that killed off the non-avian dinosaurs, according to new research.
Credit: © SunnyS / Fotolia
 
New research led by the American Museum of Natural History reveals that the evolution of modern birds was greatly shaped by the history of our planet's geography and climate. The DNA-based work, published today in the journal Science Advances, finds that birds arose in what is now South America around 90 million years ago, and radiated extensively around the time of the Cretaceous-Paleogene extinction event that killed off the non-avian dinosaurs. The new research suggests that birds in South America survived this event and then started moving to other parts of the world via multiple land bridges while diversifying during periods of global cooling.

"Modern birds are the most diverse group of terrestrial vertebrates in terms of species richness and global distribution, but we still don't fully understand their large-scale evolutionary history," said Joel Cracraft, a curator in the Museum's Department of Ornithology and co-author of the paper. "It's a difficult problem to solve because we have very large gaps in the fossil record. This is the first quantitative analysis estimating where birds might have arisen, based on the best phylogenetic hypothesis that we have today."

Cracraft and lead author Santiago Claramunt, a research associate in the Museum's Department of Ornithology, analyzed DNA sequences for most modern bird families with information from 130 fossil birds to generate a new evolutionary time tree.

"With very few exceptions, fossils of modern birds have been found only after the Cretaceous-Paleogene (K-Pg) extinction," said Claramunt. "This has led some researchers to suggest that modern birds didn't start to diversify until after this event, when major competitors were gone. But our new work, which agrees with previous DNA-based studies, suggests that birds began to radiate before this massive extinction."

After the K-Pg extinction, birds used two routes to cover the globe: first, to North America across a Paleogene Central American land bridge and then to the Old World; and second, to Australia and New Zealand across Antarctica, which was relatively warm at that time.
Claramunt and Cracraft also found that bird diversification rates increased during periods of global cooling.

"When the Earth cools and dries, fragmentation of tropical forests results in bird populations being isolated," Cracraft said. "Many times, these small populations will end up going extinct, but fragmentation also provides the opportunity for speciation to occur and for biotas to expand when environments get warm again. This work provides pervasive evidence that avian evolution has been influenced by plate tectonics and environmental change."

This work was supported by the Museum's F. M. Chapman Fund and the U.S. National Science Foundation, award #s 1241066 and 1146423.


Story Source:
The above post is reprinted from materials provided by American Museum of Natural History. Note: Materials may be edited for content and length.

Journal Reference:
  1. S. Claramunt, J. Cracraft. A new time tree reveals Earth historys imprint on the evolution of modern birds. Science Advances, 2015; 1 (11): e1501005 DOI: 10.1126/sciadv.1501005


American Museum of Natural History. "Influence of Earth's history on the dawn of modern birds: New time tree indicates that avian evolution was molded by climate change and plate tectonics." ScienceDaily. ScienceDaily, 11 December 2015. <www.sciencedaily.com/releases/2015/12/151211145038.htm>.