U of Delaware study connects penguin chick weights to local weather conditions

UD researchers have reported a connection between local weather conditions and the weight of Adélie penguin chicks.

Penguin chicks

Oct. 24, 2014--Adélie penguins are an indigenous species of the West Antarctic Peninsula (WAP), one of the most rapidly warming areas on Earth. Since 1950, the average annual temperature in the Antarctic Peninsula has increased 2 degrees Celsius on average, and 6 degrees Celsius during winter.
As the WAP climate warms, it is changing from a dry, polar system to a warmer, sub-polar system with more rain.

University of Delaware oceanographers recently reported a connection between local weather conditions and the weight of Adélie penguin chicks in an article in Marine Ecology Progress Series, a top marine ecology journal.

Penguin chick weight at the time of fledgling, when they leave the nest, is considered an important indicator of food availability, parental care and environmental conditions at a penguin colony. A higher chick mass provides the chick a better likelihood of surviving and propagating future generations.

In the study, Megan Cimino, a UD doctoral student in the College of Earth, Ocean, and Environment and the paper’s lead author, compared data from 1987 to 2011 related to the penguin’s diet, the weather and the large-scale climate indices to see if they could correlate year-to-year penguin chick weight with a particular factor. She also evaluated samples from the penguin’s diet to determine what they were eating. “The ability of a penguin species to progress is dependent on the adults’ investment in their chicks,” said Matthew Oliver, an associate professor of marine science and policy and principal investigator on the project. “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.”

Impact of weather and climate

Instead, the study revealed that weather and overall atmospheric climate seemed to affect weights the most. In particular, local weather —  including high winds, cold temperatures and precipitation, such as rain or humidity — had the largest impact on penguin chick weight variations over time. 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.

Cimino explained that while penguins do build nests, they have no way of building nests that protect the chicks from the elements. This leaves penguin chicks unprotected and exposed while adult penguins are away from the nest. Precipitation, while not considered a key variable, can cause chick plumage to become damp or wet and is generally a major factor in egg and chick mortality and slow growth. “It’s likely that weather variations are increasing the chicks’ thermoregulatory costs; and when they are cold and wet, they have to expend more energy to keep warm,” she said.

The wind can also affect the marine environment, she continued, mixing up the water column and dispersing the krill, a penguin’s main source of food, which may cause parent penguins to remain at sea for longer periods of time and cause chicks to be fed less frequently. “This is an interesting study, because it calls into question what happens to an ecosystem when you change climate quickly: Is it just large-scale averages that change the ecosystem or do particular daily interactions also contribute to the change,” Oliver said.

Research team

Other co-authors on the paper include William Fraser and Donna Patterson-Fraser, from the Polar Oceans Research Group, and Vincent Saba, from NOAA National Marine Fisheries Service. Fraser and Patterson have been collecting data on Adélie penguins since the late 1970s, creating a strong fundamental data set that includes statistics collected over decades, even before rapid warming was observed.

By correlating the relevant environmental variables through analysis of data from sources such as space, weather stations, etc., the researchers were able to scientifically validate a potential cause for chick weight variation over time. Using big data analyses to statistically sift through the possible causes allowed the researchers to take a forensic approach to understanding the problem.

“Climate change strikes at the weak point in the cycle or life history for each different species,” Oliver said. “The Adélie penguin is incredibly adaptive to the marine environment, but climate ends up wreaking havoc on the terrestrial element of the species’ history, an important lesson for thinking about how we, even other species, are connected to the environment.” 

Cimino will return to Antarctica next month to begin working with physical oceanographers from University of Alaska and Rutgers, through funding from the National Science Foundation. Using robotics, she will investigate what parent penguins actually do in the ocean in order to gain a broader perspective on how the penguins use the marine environment. In particular, she hopes to explore other possible contributing factors to chick weight variation such as parental foraging components that were not part of this study. “It’s important for us to understand what’s going on, especially as conditions are getting warmer and wetter, because it may give us an idea of what may happen to these penguins in the future,” Cimino said.

The work reported here is supported in part through funds from the National Marine Fisheries Service, NASA and the National Science Foundation.

Article by Karen B. Roberts
Photos by Megan Cimino

Source: University of Delaware

Upper Cretaceous Antarctica

Upper Cretaceous Antarctica, 1994, William Stout

Rescued 'abandoned' penguin chicks survival similar to colony rates -more information

Date:

October 22, 2014

Source:

PLOS

Summary:

Abandoned penguin chicks that were hand-reared and returned to the wild showed a similar survival rate to their naturally-reared counterparts.

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Abandoned penguin chicks that were hand-reared and returned to the wild showed a similar survival rate to their naturally-reared counterparts, according to a study published October 22, 2014 in the open-access journal PLOS ONE by Richard Sherley from University of Cape Town and colleagues.

The Endangered African penguin population has been rapidly decreasing since 2001. In the Western Cape of South Africa, penguins breed from February to September and moult between September and January, once chicks have fledged. If adult penguins begin the moulting process, a 21 day period where they no longer have the waterproofing necessary to dive for food, with chicks in the nest, the chicks may starve. Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) recovers 'abandoned' penguin chicks that are no longer being fed and cares for them until they can be reintroduced into breeding colonies. Researchers documented the care, release, and survival of over 840 and 480, in 2006 and 2007 respectively, hand-reared chicks.

Of those admitted, 91% and 73% respectively were released into the wild. Post-release juvenile and adult survival rates were similar to recent survival rates recorded for naturally-reared birds. By December 2012 researchers observed that 12 birds had bred, six at their colony of origin. The authors suggest that hand-rearing of 'abandoned' penguin chicks may be a useful conservation tool to limit mortality and to strengthen the population at specific colonies. "Over the last decade, food availability has decreased dramatically for penguins breeding in Western South Africa and many birds now struggle to rear their chicks before they need to initiate moult. Hand-reared chicks can sustain populations in the short-term and help us understand how we might create new breeding colonies in areas of higher food availability," said Dr. Sherley.

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

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Journal Reference:

1. Richard B. Sherley, Lauren J. Waller, Venessa Strauss, Deon Geldenhuys, Les G. Underhill, Nola J. Parsons. Hand-Rearing, Release and Survival of African Penguin Chicks Abandoned Before Independence by Moulting Parents. PLoS ONE, 2014; 9 (10): e110794 DOI: 10.1371/journal.pone.0110794

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PLOS. "Rescued 'abandoned' penguin chicks survival similar to colony rates." ScienceDaily. ScienceDaily, 22 October 2014. <www.sciencedaily.com/releases/2014/10/141022143630.htm>.

Rescued 'abandoned' penguin chicks survival similar to colony rates

Posted By News On October 22, 2014

Abandoned penguin chicks that were hand-reared and returned to the wild showed a similar survival rate to their naturally-reared counterparts, according to a study published October 22, 2014 in the open-access journal PLOS ONE by Richard Sherley from University of Cape Town and colleagues.

The Endangered African penguin population has been rapidly decreasing since 2001. In the Western Cape of South Africa, penguins breed from February to September and moult between September and January, once chicks have fledged. If adult penguins begin the moulting process, a 21 day period where they no longer have the waterproofing necessary to dive for food, with chicks in the nest, the chicks may starve.

Southern African Foundation for the Conservation of Coastal Birds (SANCCOB) recovers 'abandoned' penguin chicks that are no longer being fed and cares for them until they can be reintroduced into breeding colonies. Researchers documented the care, release, and survival of over 840 and 480, in 2006 and 2007 respectively, hand-reared chicks.

Of those admitted, 91% and 73% respectively were released into the wild. Post-release juvenile and adult survival rates were similar to recent survival rates recorded for naturally-reared birds. By December 2012 researchers observed that 12 birds had bred, six at their colony of origin. The authors suggest that hand-rearing of 'abandoned' penguin chicks may be a useful conservation tool to limit mortality and to strengthen the population at specific colonies. "Over the last decade, food availability has decreased dramatically for penguins breeding in Western South Africa and many birds now struggle to rear their chicks before they need to initiate moult.

Hand-reared chicks can sustain populations in the short-term and help us understand how we might create new breeding colonies in areas of higher food availability," said Dr. Sherley.

Source: PLOS via Science Codex

Antarctic sea ice reaches new record maximum

Date:

October 8, 2014

Source:

NASA/Goddard Space Flight Center

Summary:

Sea ice surrounding Antarctica reached a new record high extent this year, covering more of the southern oceans than it has since scientists began a long-term satellite record to map the extent in the late 1970s.

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On Sept. 19, 2014, the five-day average of Antarctic sea ice extent exceeded 20 million square kilometers for the first time since 1979, according to the National Snow and Ice Data Center. The red line shows the average maximum extent from 1979-2014.

Credit: NASA's Scientific Visualization Studio/Cindy Starr

Sea ice surrounding Antarctica reached a new record high extent this year, covering more of the southern oceans than it has since scientists began a long-term satellite record to map sea ice extent in the late 1970s. The upward trend in the Antarctic, however, is only about a third of the magnitude of the rapid loss of sea ice in the Arctic Ocean.

The new Antarctic sea ice record reflects the diversity and complexity of Earth's environments, said NASA researchers. Claire Parkinson, a senior scientist at NASA's Goddard Space Flight Center, has referred to changes in sea ice coverage as a microcosm of global climate change. Just as the temperatures in some regions of the planet are colder than average, even in our warming world, Antarctic sea ice has been increasing and bucking the overall trend of ice loss.

"The planet as a whole is doing what was expected in terms of warming. Sea ice as a whole is decreasing as expected, but just like with global warming, not every location with sea ice will have a downward trend in ice extent," Parkinson said.

Since the late 1970s, the Arctic has lost an average of 20,800 square miles (53,900 square kilometers) of ice a year; the Antarctic has gained an average of 7,300 square miles (18,900 sq km). On Sept. 19 this year, for the first time ever since 1979, Antarctic sea ice extent exceeded 7.72 million square miles (20 million square kilometers), according to the National Snow and Ice Data Center. The ice extent stayed above this benchmark extent for several days. The average maximum extent between 1981 and 2010 was 7.23 million square miles (18.72 million square kilometers).

The single-day maximum extent this year was reached on Sept. 20, according to NSIDC data, when the sea ice covered 7.78 million square miles (20.14 million square kilometers). This year's five-day average maximum was reached on Sept. 22, when sea ice covered 7.76 million square miles (20.11 million square kilometers), according to NSIDC.

A warming climate changes weather patterns, said Walt Meier, a research scientist at Goddard. Sometimes those weather patterns will bring cooler air to some areas. And in the Antarctic, where sea ice circles the continent and covers such a large area, it doesn't take that much additional ice extent to set a new record.
"Part of it is just the geography and geometry. With no northern barrier around the whole perimeter of the ice, the ice can easily expand if conditions are favorable," he said.
Researchers are investigating a number of other possible explanations as well. One clue, Parkinson said, could be found around the Antarctic Peninsula -- a finger of land stretching up toward South America. There, the temperatures are warming, and in the Bellingshausen Sea just to the west of the peninsula the sea ice is shrinking. Beyond the Bellingshausen Sea and past the Amundsen Sea, lies the Ross Sea -- where much of the sea ice growth is occurring.

That suggests that a low-pressure system centered in the Amundsen Sea could be intensifying or becoming more frequent in the area, she said -- changing the wind patterns and circulating warm air over the peninsula, while sweeping cold air from the Antarctic continent over the Ross Sea. This, and other wind and lower atmospheric pattern changes, could be influenced by the ozone hole higher up in the atmosphere -- a possibility that has received scientific attention in the past several years, Parkinson said.

"The winds really play a big role," Meier said. They whip around the continent, constantly pushing the thin ice. And if they change direction or get stronger in a more northward direction, he said, they push the ice further and grow the extent. When researchers measure ice extent, they look for areas of ocean where at least 15 percent is covered by sea ice.

While scientists have observed some stronger-than-normal pressure systems -- which increase winds -- over the last month or so, that element alone is probably not the reason for this year's record extent, Meier said. To better understand this year and the overall increase in Antarctic sea ice, scientists are looking at other possibilities as well.

Melting ice on the edges of the Antarctic continent could be leading to more fresh, just-above-freezing water, which makes refreezing into sea ice easier, Parkinson said. Or changes in water circulation patterns, bringing colder waters up to the surface around the landmass, could help grow more ice.

Snowfall could be a factor as well, Meier said. Snow landing on thin ice can actually push the thin ice below the water, which then allows cold ocean water to seep up through the ice and flood the snow -- leading to a slushy mixture that freezes in the cold atmosphere and adds to the thickness of the ice. This new, thicker ice would be more resilient to melting.

"There hasn't been one explanation yet that I'd say has become a consensus, where people say, 'We've nailed it, this is why it's happening,'" Parkinson said. "Our models are improving, but they're far from perfect. One by one, scientists are figuring out that particular variables are more important than we thought years ago, and one by one those variables are getting incorporated into the models."

For Antarctica, key variables include the atmospheric and oceanic conditions, as well as the effects of an icy land surface, changing atmospheric chemistry, the ozone hole, months of darkness and more.

"Its really not surprising to people in the climate field that not every location on the face of Earth is acting as expected -- it would be amazing if everything did," Parkinson said. "The Antarctic sea ice is one of those areas where things have not gone entirely as expected. So it's natural for scientists to ask, 'OK, this isn't what we expected, now how can we explain it?'"

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Story Source:
The above story is based on materials provided by NASA/Goddard Space Flight Center. Note: Materials may be edited for content and length.

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NASA/Goddard Space Flight Center. "Antarctic sea ice reaches new record maximum." ScienceDaily. ScienceDaily, 8 October 2014. <www.sciencedaily.com/releases/2014/10/141008122102.htm>.

Penguins Use Their Personalities to Prepare for Climate Change

Birds’ individual personalities may be among the factors that could improve its chances of successfully coping with environmental stressors. Credit: John F. Cockrem, PhD

Date: October 8, 2014

Source: American Physiological Society (APS)

As the global climate continues to change, the ability of many animal species to adapt is being put to the test. Bird populations may be at particular risk. According to the Audubon Society, nearly half of all North American bird species are severely threatened by shifts in climate. The threat reaches beyond North America and could have similar effects on global bird populations.

John Cockrem of the Institute of Veterinary, Animal and Biomedial Sciences at Massey University in New Zealand suggests that a bird's individual personality may be among the factors that could improve its chances of successfully coping with environmental stressors. He studied differences in the level of the stress hormone corticosterone that native little penguins (Eudyptula minor) secreted when exposed to stressful stimulus.

"There is considerable individual variation in corticosterone responses, and a stimulus that initiates a large response in one bird may initiate a small response in another bird," Cockrem wrote. "Corticosterone responses and behavioral responses to environmental stimuli are together determined by individual characteristics called personality. Birds with low corticosterone responses and proactive personalities are likely to be more successful (have greater fitness) in constant or predictable conditions, whilst birds with reactive personalities and high corticosterone responses will be more successful in changing or unpredictable conditions."

These findings may help in predicting the adaptability of bird species as they face a new normal. Cockrem will present the talk "Corticosterone responses and the ability of birds to cope with environmental change" at the American Physiological Society (APS) intersociety meeting "Comparative Approaches to Grand Challenges in Physiology" on October 8, 2014.

 Story Source:

The above story is based on materials provided by American Physiological Society (APS). Note: Materials may be edited for content and length.

American Physiological Society (APS). "Penguins Use Their Personalities to Prepare for Climate Change." ScienceDaily. ScienceDaily, 8 October 2014. <www.sciencedaily.com/releases/2014/10/141008140933.htm>.

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How dinosaur arms turned into bird wings

Date:

September 30, 2014

Source:

PLOS

Summary:

Although we now appreciate that birds evolved from a branch of the dinosaur family tree, a crucial adaptation for flight has continued to puzzle evolutionary biologists. During the millions of years that elapsed, wrists went from straight to bent and hyperflexible, allowing birds to fold their wings neatly against their bodies when not flying. A resolution to this impasse is now provided by an exciting new study.

(A) Whole-mount alcian blue staining confirms the ulnare is the first carpal formed in avian embryos, distal to the ulna. Thereafter, a distal carpal 3 (referred to as “element x” in previous embryological descriptions) is formed distal to the ulnare, coexisting with it. Finally, the ulnare disappears, whereas dc3 persists.

Credit: J. Botelho et al.; DOI: 
10.1371/journal.pbio.1001957

Although we now appreciate that birds evolved from a branch of the dinosaur family tree, a crucial adaptation for flight has continued to puzzle evolutionary biologists. During the millions of years that elapsed, wrists went from straight to bent and hyperflexible, allowing birds to fold their wings neatly against their bodies when not flying.

How this happened has been the subject of much debate, with substantial disagreement between developmental biologists, who study how the wings of modern birds develop in the growing embryo, and palaeontologists who study the bones of dinosaurs and early birds. A resolution to this impasse is now provided by an exciting new study publishing on September 30 in PLOS Biology.

Underlying this striking evolutionary transformation change is a halving in the number of wrist bones, but developmental biologists and palaeontologists have different names for most of them, and seldom agree on the correspondence between specific dinosaur bones and those of their bird descendants. Indeed, each field has radically different data sources, methods, and research objectives, talking little to each other.

The critical advance made in the new study involved combining these two strands of research. Using an interdisciplinary approach, the lab run by Alexander Vargas at the University of Chile has re-examined fossils stored at several museum collections, while at the same time collecting new developmental data from seven different species of modern birds. Joao Botelho, a Brazilian student in Vargas' lab, developed a revolutionary new technique that allows him to study specific proteins in 3D embryonic skeletons. By combining these data from both fossils and embryos, the research team has made a major step forward in clarifying how the bird wrist evolved.

From early dinosaur ancestors with as many as nine wrist bones, birds have only kept four during the course of evolution, but which of the original bones are they? The identity of each of these bones was debated. For instance, the late Yale professor John Ostrom famously pointed out in the 1970's that the wrists of both birds and bird-like dinosaurs possess a very similar, half-moon shaped bone called the semilunate, and that this bone resulted from the merging of two bones present in dinosaurs. This formed part of Ostrom's then-controversial argument that birds descended from dinosaurs. However, the failure of developmental biologists to confirm this raised doubts that it was the same bone, and even that birds came from dinosaurs.

Now, the new data obtained by the Vargas lab has revealed the first developmental evidence that the bird semilunate was formed by the fusion of the two dinosaur bones. They go on to show that another bone -- the pisiform -- was lost in bird-like dinosaurs, but then re-acquired in the early evolution of birds, probably as an adaptation for flight, where it allows transmission of force on the downstroke while restricting flexibility on the upstroke. Combined, the fossil and developmental data provide a compelling scenario for a rare case of evolutionary reversal.

The study by the Vargas lab also settled the identity of the other two bones of the bird wrist, which were commonly misidentified in both fields. This emphasizes the downsides of not integrating all data sources, and reveals a situation perhaps akin to that of astronomy and experimental physics in the pursuit of cosmology: Together, palaeontology and development can come much closer to telling the whole story of evolution -- this integrative approach resolves previous disparities that have challenged the support for the dinosaur-bird link and reveals previously undetected processes, including loss of bones, fusion of bones, and re-evolution of a transiently lost bone.

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

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Journal Reference:

1. João Francisco Botelho, Luis Ossa-Fuentes, Sergio Soto-Acuña, Daniel Smith-Paredes, Daniel Nuñez-León, Miguel Salinas-Saavedra, Macarena Ruiz-Flores, Alexander O. Vargas. New Developmental Evidence Clarifies the Evolution of Wrist Bones in the Dinosaur–Bird Transition. PLoS Biology, 2014; 12 (9): e1001957 DOI: 10.1371/journal.pbio.1001957

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PLOS. "How dinosaur arms turned into bird wings." ScienceDaily. ScienceDaily, 30 September 2014. <www.sciencedaily.com/releases/2014/09/140930144157.htm>.