Penguin forensics: Tracking the winter whereabouts of penguins by analyzing tail feathers

( Louisiana State University, Physorg 8 >August 2017; Photo M. Polito)

While a postdoctoral researcher at Woods Hole Oceanographic Institution, Polito and his colleagues conducted high-resolution forensic analyses of the chemical composition of the feathers using a technique called compound-specific stable isotope analysis of amino acids.

The scientists were able to identify the unique chemical signatures of penguin’s wintering areas in the ocean based on the coordinates from the tags and the data from the feather analyses. From this understanding, they were able to deduce where the other penguins that had not been tagged went over the winter based solely on the analyses of their tail feathers.

“This novel approach could be applied to different tissues from a wide variety of marine animals that migrate over long distances including seabirds, sea turtles, seals and whales,” Polito said. “Using stable isotope forensics to increase the size and scope of animal tracking studies will help us to better understand these charismatic species and ultimately aid in their conservation.”

Knowing where and how Antarctic penguins, and other seabirds and marine predators, migrate is critical for conservation efforts. Although electronic tracking devices have helped scientists track marine animals’ migration patterns, the devices can be expensive, invasive for the animal and challenging to retrieve. Scientists have discovered a new and potentially better way to track where penguins go over the winter using forensics.

“You can say, penguins ‘are where they eat,’ because a geochemical signature of their wintering area is imprinted into their feathers,” said LSU Department of Oceanography & Coastal Sciences Assistant Professor Michael Polito, the lead author of this study that will be published Aug. 9 in Biology Letters.

Chinstrap and Adélie penguins are part of the family of “brush-tailed” penguins named after their approximately 15-inch long, stiff tail feathers. These birds shed all of their feathers after each breeding season and before they migrate to their oceanic wintering grounds. However, their long tail feathers continue to grow well into the winter when penguins are at sea.

Polito and his collaborators from NOAA Southwest Fisheries Science Center, Oxford University and the Instituto Antártico Argentino attached tags to 52 adult Chinstrap and Adélie penguins at their breeding colonies and retrieved the tags the following breeding season to determine where the birds went over the winter. When they retrieved these tags, the researchers also took a tail feather grown over the winter from each tracked penguin and from 60 other penguins that had not been tagged.

Finding new homes won’t help emperor penguins cope with climate change

(ScienceDaily, Woods Hole Oceanographic Institution 7 June 2017; Photo: Stephanie Jenouvrier)

Unlike other species that migrate successfully to escape the wrath of climate change, a new study shows that dispersal may help sustain global Emperor penguin populations for a limited time, but, as sea ice conditions continue to deteriorate, the 54 colonies that exist today will face devastating declines by the end of this century.

If projections for melting Antarctic sea ice through 2100 are correct, the vanishing landscape will strip Emperor penguins of their breeding and feeding grounds and put populations at risk. But like other species that migrate to escape the wrath of climate change, can these iconic animals be spared simply by moving to new locations?

According to new research led by the Woods Hole Oceanographic Institution (WHOI), they cannot. Scientists report that dispersal may help sustain global Emperor penguin populations for a limited time, but, as sea ice conditions continue to deteriorate, the 54 colonies that exist today will face devastating declines by the end of this century. They say the Emperor penguin should be listed as an endangered species. The study was published in the June 6, 2017 edition of the journal Biological Conservation.

“We know from previous studies that sea ice is a key environmental driver of the life history of Emperor penguins, and that the fifty-percent declines we’ve seen in Pointe Géologie populations along the Antarctic coast since the 1950s coincide with warmer climate and sea ice decline,” said Stephanie Jenouvrier, WHOI biologist and lead author of the study. “But what we haven’t known is whether or not dispersal could prevent or even reverse future global populations. Based on this study, we conclude that the prospects look grim at the end of 2100, with a projected global population decline as low as 40 percent and up to 99 percent over three generations. Given this outlook, we argue that the Emperor penguin is deserving of protection under the Endangered Species Act.”

The relationship between Emperor penguins and sea ice is a fragile one: Too little sea ice reduces the availability of breeding sites and prey; too much sea ice means longer hunting trips for adults, which in turn means lower feeding rates for chicks. Only in the past few years have scientists become aware of the penguins’ ability to migrate to locations with potentially more optimal sea ice conditions.

“Before 2014, our studies of the impacts of climate change on these animals hadn’t factored in movement among populations,” said Jenouvrier. “But between then and now, a number of satellite imagery studies and genetic studies have confirmed their ability to disperse, so this was an important new variable to work into the equation.”

To determine whether migration will ultimately help Emperor penguins defend against population decline, Jenouvrier worked with mathematicians to develop a sophisticated demographic model of penguin colonies based on data collected at Pointe Géologie, one of the few places where long-term Emperor penguin studies have been conducted.

The model tracks the population connectivity between penguins as they take their chances moving to new habitats offering better sea ice conditions. “It’s like we’ve added roads between the cities the penguins live in and now get to see what happens when they travel between them,” she said.

A range of model inputs were used, including penguin dispersal distance, behavior and rate of migration. The model also factors in end-of-century sea ice forecasts from climate projection models to predict the fate of each colony.

According to Shaye Wolf, climate science director for the Center for Biological Diversity, the new modeling technique is key to informing policy around “much-needed protections” for the Emperor penguin.

“Dr. Jenouvrier’s research has been at the forefront of advancing our understanding of how climate change is impacting these animals now and into the future,” she said.

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New report documents dramatic Antarctic penguin population loss

(Birdwatching Daily; 28 April 2017; Photo David Grémillet)

The inaugural “State of Antarctic Penguins” (SOAP) report, released on World Penguin Day (April 25) by international science-based NGO Oceanites, reveals that at least two species of Antarctic penguin — Adélie and Chinstrap — have suffered dramatic declines in population due to warming on the Antarctic peninsula. The SOAP report also identifies important trends about the keystone Antarctic penguin species — Adélie, Chinstrap, Emperor, and Gentoo — noting future concerns about these populations. Up-to-date data from more than 660 sites across the entire Antarctic continent has been aggregated and summarized for the report, including 3,176 records from 101 sources of on-the-ground colony counts and satellite photo analyses. The results are both significant and alarming, according to Oceanites founder and president Ron Naveen.

“In one generation, I have personally witnessed the precipitous decline of once abundant Adélie and Chinstrap Penguin populations,” said Naveen. “These iconic birds are literally canaries in the coal mine. They provide critical insights into the dramatic changes taking place in the Antarctic. What’s happening to penguin populations can have important implications for all of us.”

Critical scientific expertise for the SOAP report was provided by the Lynch Lab for Quantitative Ecology at Stony Brook University, who partnered with NASA to develop the Mapping Application for Penguin Populations and Projected Dynamics (MAPPPD), a unique open-ended scientific support tool intended to provide “one-stop shopping” for scientists studying penguin populations in the Antarctic.

Heather Lynch, associate professor and director of the Lynch Lab, states, “We can now use advanced satellite technology and data analyses to better understand how these penguin populations are changing. By integrating expert biological field surveys, satellite imagery analyses, and citizen science, we can further enhance our ability to understand the changes taking place in an incredibly important world we are just learning about.”

The SOAP report presents findings both continent-wide and per key Antarctic fishing areas designated by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).

Key report findings:

Over the past 60-plus years in the vastly warmed Antarctic Peninsula, Gentoo populations have increased significantly; Adélie Penguin populations have, in general, declined significantly; and Chinstrap Penguin populations have declined — at some locations significantly.

By contrast, in East Antarctica and the Ross Sea, regions that have not experienced a warming trend, Adélie Penguin populations appear to be increasing.

The SOAP 2017 report notes various concerns, all related to climate, potentially affecting these penguin populations — including the potential for ice sheet collapse both in West and East Antarctica.

Key implications:

In the vastly warmed Antarctic Peninsula, there are “winners” (rising numbers of Gentoos) and “losers” (decreasing numbers of Adélies and Chinstraps), foreboding concerns on whether humans will be able to adapt to warming trends.

Limiting warming to no more than 2°C / 3.6° F has become the de facto target for global climate policy; yet the Antarctic Peninsula already has warmed by more than that over the last 60 years — by 3°C / 5°F year-round and by 5°C / 9°F in the austral winter.

Ongoing studies are underway to ascertain whether penguins can maintain “the four vitals” necessary for adaptation and survival: food, habitat, health (disease-free environment), and reproduction (future generations).

Two species are in decline in the Antarctic Peninsula and another is adapting. Food might be an explanation; all the penguins can eat both krill and fish, but Gentoos, at this point in time, appear to have adapted better to reduced krill availability by eating more fish.

45% of Arctic shorebirds are disappearing – here’s the plan to save them

(Pacific Shorebirds 21 April 2017; Photo: Glenn Bartley)

Across the globe, 45% of Arctic-nesting shorebirds are decreasing. The Pacific Americas Shorebird Conservation Strategy aims to identify the threats and develop strategies to save them.

Shorebirds—plovers, oystercatchers, sandpipers, godwits, curlews—can be found along the entirety of the Pacific coast of the Western Hemisphere during some time of the year.

Many species travel from Arctic breeding areas to spend their winter on the beaches and mudflats of North America, Central America and South America, where they share the environment with resident species.

Whether migrants or residents, shorebirds and the habitats they depend upon are exposed to an increasing myriad of anthropogenic threats. Within the Pacific Flyway, 11% of shorebird populations face long-term declines; none are known to be increasing.

Although the challenges are great, they are not without solutions. Across the Western Hemisphere, shorebird scientists, conservationists and managers have come together to tackle the conservation issues across the annual life cycle of this incredible group of birds.

Although there is no doubt that successful conservation depends upon actions initiated locally, isolated interventions will have the best chance for positively affecting populations if coordinated at a flyway scale.

The Strategy follows a logical sequence of setting shorebird conservation targets, identifying major threats and identifying highly effective actions to restore and maintain shorebird populations throughout the Pacific Americas Flyway.

The Strategy is being lead by an international group of more than 85 experts in 15 countries, including BirdLife and some of its Partners.

The intent is to assemble and synthesize information to present a comprehensive approach and to address the most pressing conservation needs in the flyway from Alaska to Patagonia, while considering the human communities that interact with shorebirds. Only with investments in the portfolio of strategies and actions will conservation of this extraordinary group of birds be achieved.

The strategy is not a step-by-step recipe for conservation success but rather a framework for ceaseless collaboration, innovation and accomplishment.

Extensive partner involvement in the development of the Pacific Americas Shorebird Conservation Strategy will need to be sustained and augmented to achieve success across the flyway and to mold the broad strategies presented here into tangible, spatially explicit actions.

A well-coordinated, collective effort will be needed to achieve overall strategy success; thus, people, and transparent communication among them, are crucial for success.

Readers are encouraged to engage with the strategy’s partners to endeavor to sustain shorebird populations along the Pacific Americas Flyway well into the future.

Can barnacle geese predict the climate?

(Netherlands Institute of Ecology; Photo: Thomas Lameris; 18 April 2017)

The breeding grounds of Arctic migratory birds such as the barnacle goose are changing rapidly due to accelerated warming in the polar regions. They won’t be able to keep up with this climate change unless they can somehow anticipate it. A research team from the Netherlands Institute of Ecology (NIOO-KNAW) employed computer models to assess the future of the geese and their young.

It’s the time of year when barnacle geese and many other migratory birds prepare to depart for their breeding grounds above the Arctic Circle. From their wintering grounds in the Netherlands, the geese fly all the way up to the Barentsz Sea in northern Russia, where they should arrive just as the snow has melted. But in the polar regions, the climate is warming much more rapidly than in more temperate areas like the Netherlands — a phenomenon known as ‘Arctic amplification’.

It’s hard enough for humans to get to grips with the accelerated warming, let alone for barnacle geese, as an earlier NIOO-led study showed. After all, how can they tell from their wintering grounds if the snow has begun to melt thousands of kilometres away? So is it possible for the barnacle geese to advance their spring migration nonetheless, to predict climate change?

First study, fewer young

Ecologist Thomas Lameris and his fellow researchers from NIOO, and also the Swiss Ornithological Institute among other institutions, have tried to find the answer. “This is the first study that tests if migratory birds are in any way able to adjust their timing to the accelerated warming in the polar regions. We used a model to show that the availability of enough edible grass to build up reserves for their journey is not a problem for the barnacle geese. It’s the unpredictability of the climatic changes in their breeding grounds that spells trouble for them.”

If the geese continue to mistime their arrival, their reproductive success will be reduced. Lameris: “They miss their optimal breeding window and the peak in local food abundance, so fewer goslings will survive.” Some compensation for this comes from the fact that as well as starting earlier, the breeding season is becoming longer. This gives the goslings more time to grow. But that’s not enough.

To establish the barnacle geese’s potential for anticipating climate change, the researchers built a model that…….

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Penguin colony repeatedly decimated by volcanic eruptions

(Dr Steve Roberts; 11 April, 2017)

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 today (Tuesday 11 April) 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 sediment cores 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 volcanic eruptions. It took, on average, between 400 and 800 years for it to re-establish itself sustainably.”

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.”

Waluda continues:

“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.

“Changes in penguin populations 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.”

Sandpiper detectives pinpoint trouble spots in continent-wide migration

(Physorg; 5 April 2017)

Understanding and managing migratory animal populations requires knowing what’s going on with them during all stages of their annual cycle—and how those stages affect each other. The annual cycle can be especially difficult to study for species that breed in the Arctic and winter in South America. A new study from The Condor: Ornithological Applications tackles this problem for Semipalmated Sandpipers, historically one of the most widespread and numerous shorebird species of the Western Hemisphere, whose populations in some areas have undergone mysterious declines in recent years.

Stephen Brown, Vice President of Shorebird Conservation for Manomet, assembled a large group of partner organizations to deploy 250 geolocators, tiny devices that use light levels to determine birds’ locations, on adult sandpipers at sites across their breeding range in the North American Arctic. Recapturing 59 of the birds after a year to download their data, they found that the eastern and western breeding populations use separate wintering areas and migration routes. Birds that breed in the eastern Arctic overwinter in areas of South America where large declines have been observed. The researchers believe these declines are tied to hunting on the wintering grounds and habitat alteration at migration stopover sites, although their precise impacts remain unclear.

“This study was a response to the discovery of a large decline in the population of Semipalmated Sandpipers in the core of their wintering area in South America, and the need to determine which birds were involved. We didn’t know if the decline affected the entire population or just part of it,” says Brown. “Bringing together the 18 partner organizations that worked collaboratively on this project allowed us to track the migration pathways used by Semipalmated Sandpipers at the enormous geographical scale of their entire North American Arctic breeding range and provided critical new information about what sites are important to protect to support their recovery.”

“The authors here present one of the few studies that examine year-round connectivity, including stopover sites, of Arctic-breeding shorebirds,” according to the University of Guelph’s Ryan Norris, an expert on migration tracking who was not involved with the study. “Multi-site, range-wide studies on connectivity, such as this, are critical if we are to understand the population consequences of environmental change in migratory birds.”

In life, ivory gull draws crowd—and in death, will contribute to science

(Elliot Nelson; 17 March 2017)

On the evening of March 9, 2017, Lauren LaFave, 16, was walking across a bridge over the Flint River on the campus of the University of Michigan-Flint. LaFave noticed an unusually white bird resting on the bridge and was able to snap a few quick pictures on her phone. After those photos were shared among a number of Facebook groups it was confirmed that the bird photographed was, in fact, one of the rarest birds in all of North America, an ivory gull.

To understand the rarity of finding an ivory gull in downtown Flint, one must understand a bit about the species. The ivory gull is a bird rarely found south of the Arctic Circle. In North America, ivory gulls breed in the high arctic regions of Canada on bare rocks exposed only during the summer months. Unlike most arctic birds that head south for the winter, the ivory gull spends its winters remaining in the arctic. It can be found foraging on pack ice in the Bering Sea as well as the ice edge region between 50°–65° north latitude around Labrador and Greenland. The bird research database Birds of North American Online notes that only 2000-3000 of these birds breed in North America. It is listed in the 2014 State of the Birds report as being a species that will most likely become threatened or endangered unless conservation actions are taken. The species decline is due in part to declining sea ice associated with climate change as well as high mercury levels that accumulate in their tissue.

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Antarctic penguin numbers double previous estimates: scientists

(Physorg; 15 March 2017)

Almost six million Adelie penguins are living in East Antarctica, more than double the number previously thought, scientists said Wednesday in findings that have implications for conservation.

Research by an Australian, French and Japanese team used aerial and ground surveys, tagging and resighting data and automated camera images over several breeding seasons, which allowed them to come up with the new figure.

They focused on a 5,000 kilometre (3,100 mile) stretch of coastline, estimating it was home to 5.9 million birds—some 3.6 million more than previously thought. On this basis, they estimate a likely global population of 14 to 16 million.

Before, population estimates only took into account breeding pairs, said Australian Antarctic Division seabird ecologist Louise Emmerson.

“Non-breeding birds are harder to count because they are out foraging at sea, rather than nesting in colonies on land,” she said.

“However, our study in East Antarctica has shown that non-breeding Adelie penguins may be as, or more, abundant than the breeders.

“These birds are an important reservoir of future breeders and estimating their numbers ensures we better understand the entire population’s foraging needs.”

Adelie penguins, slick and efficient swimmers, live on the Antarctic continent and on many small, surrounding coastal islands. They spend the winter offshore in the seas surrounding the pack ice.

Seabird ecologist Colin Southwell said the research had implications for conservation, with more birds potentially interacting with humans in Antarctica and the Southern Ocean than previously thought.

He said the rocky, ice-free areas preferred by penguins for nesting were also favoured by research stations due to ease of resupply.

“There are currently nine permanently occupied research stations in the ice-free areas of East Antarctica and we found over one million birds breed within 10 kilometres of a station,” he said.

“By identifying significant penguin breeding populations near stations we can better identify which areas may need enhanced protection into the future.”

The study also estimated the amount of krill and fish needed to support the Adelie penguin population, prey that is also sought after by seals and whales.

“An estimated 193,500 tonnes of krill and 18,800 tonnes of fish are eaten during the breeding season by Adelie penguins breeding in East Antarctica,” Emmerson said.

This information will now be used by the Commission for the Conservation of Antarctic Marine Living Resources to set sustainable krill fishery catch limits.

How Will an Arctic-Breeding Songbird Respond to Taller Shrubs and Warmer Temperatures?

(Heather McFarland, 1 Feb, 2017)

How will songbirds that nest in tundra respond as the Arctic transforms into a warmer and shrubbier environment? This is the question that drove us to study a small songbird known as the Smith’s Longspur. Endemic to North America, this songbird breeds in only a few remote mountain valleys in Canada and Alaska, making it particularly susceptible to changes at northern latitudes. Smith’s Longspur’s are also unique in that they are polygynandrous. This is a rare mating strategy where both sexes are polygamous, and birds of either sex may mate with up to three individuals each breeding season. Rather than a single male and female establishing a territory, Smith’s Longspurs usually form larger groups called neighborhoods which contain many inter-mated individuals. Since this mating strategy is poorly understood and so different from other tundra nesting songbirds, it is difficult to predict how breeding Smith’s Longspurs may respond to climate change. Therefore, prior to further change, baseline information about breeding requirements is needed. To fill this void, we monitored more than 250 Smith’s Longspur nests between 2007 and 2013 in the Brooks Range of Alaska. All of the nests were found in open tundra areas, and females never placed their nests in tall vegetation.

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