Researchers set up time-lapse cameras to record penguin behavior during the dark Antarctic winter. Credit: T. Hart Not even the most intrepid researcher wants to spend winter in Antarctica, so how can you learn what penguins are doing during those cold, dark months? Simple: Leave behind some cameras. Year-round studies across the full extent of a species' range are especially important in polar areas, where individuals within a single species may adopt a variety of different migration strategies to get by, and a new study from The Auk: Ornithological Advances uses this unique approach to get new insights into Gentoo Penguin behavior.
Gentoo Penguins are of interest to scientists because they're increasing at the southern end of their range in the Western Antarctic Peninsula, a region where other penguin species are declining. Little is known about their behavior during the nonbreeding season, so Caitlin Black and Tom Hart of the University of Oxford and Andrea Raya Rey of Argentina's Consejo Nacional de Investigaciones Cientificas y Técnicas used time-lapse cameras to examine patterns in Gentoo Penguins' presence at breeding sites across their range during the off season. They found both temporal and spatial factors driving winter attendance—for example, more Gentoo Penguins were present at breeding sites when there was open water or free-floating pack ice than when the shoreline was iced in, and more Gentoo Penguins were at breeding sites earlier in nonbreeding season than later.
The researchers deployed the cameras at seven sites including Argentina, Antarctica, and several islands. Each camera took eight to fourteen photos per day, and volunteer "citizen scientists" were recruited to count the penguins in each image via a website (penguinwatch.org). Overall, the seven sites fell into three distinct groups in terms of winter attendance, each with its own patterns of site occupation. These findings could have important implications for understanding how localized disturbances due to climate change and fisheries activity affect penguin populations during the nonbreeding season.
Time-lapse cameras recorded images of Gentoo Penguins at their breeding sites in winter. Credit: T. Hart "Working with cameras allows us to understand half of this species' life without having to spend the harsh winter in Antarctica. It has been exciting to discover more about why Gentoos are present year-round at breeding sites without having to handle a single bird," says Black. "I believe the applications for this technology are far-reaching for colonial seabirds and mammals, and we are only just beginning to discover the uses of time-lapse cameras as deployed virtual ecologists in field studies."
"What most seabirds do away from their nest is often anybody's guess. For Antarctic birds, this is compounded by the long periods of darkness that penguins and others must face in the winter," adds Mark Hauber, Editor-in-Chief of The Auk: Ornithological Advances and Professor of Animal Behavior at Hunter College and the Graduate Center of the City University of New York. "This new research in The Auk: Ornithological Advances on Gentoo Penguins colonies reveals critical year-to-year differences in where the birds are when they are not nesting: In some years, only the most temperate sites are visited, and in other years both southerly and northerly locations are busy with penguins."
Gentoo penguins climbing slopes to the nesting colony on Ardley Island. Credit: Stephen Roberts
One of the largest colonies of gentoo
penguins in Antarctica was decimated by volcanic eruptions several times
during the last 7,000 years according to a new study. An international
team of researchers, led by British Antarctic Survey (BAS), studied
ancient penguin guano and found the colony came close to extinction
several times due to ash fall from the nearby Deception Island volcano.
Their results are published this week in Nature Communications.
Ardley
Island, near the Antarctic Peninsula, is currently home to a population
of around 5,000 pairs of gentoo penguins. Using new chemical analyses of
penguin guano extracted in sediment cores from a lake on the island,
the researchers unraveled the history of the penguin colony. Climate
conditions around Ardley Island have been generally favourable for
penguins over the last 7,000 years and the team had expected the local
population to show minor fluctuations in response to changes in climate
or sea ice. The surprising result was that the nearby Deception Island
volcano had a far greater impact than originally anticipated.
Lead author Dr Steve Roberts from BAS says: "When we first examined the 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."
Volcanic ash layers in lake sediment cores extracted from
Kiteschee Lake on Fildes Peninsula. The ash layers shown are associated
with comparatively small eruptions from Deception Island in the last c.
2000-3000 years. The largest eruptions …moreDr
Claire Waluda, penguin ecologist from BAS says: "This study reveals the
severe impact volcanic eruptions can have on penguins, and just how
difficult it can be for a colony to fully recover. An eruption can bury
penguin chicks in abrasive and toxic ash, and whilst the adults can swim
away, the chicks may be too young to survive in the freezing waters.
Suitable nesting sites can also be buried, and may remain uninhabitable
for hundreds of years."
The techniques developed in this study will help scientists to
reconstruct past changes in colony size and potentially predict how
other penguin populations may be affected elsewhere. For example, the
chinstrap penguins on Zavodovski Island, which were disturbed by
eruptions from the Mt Curry volcano in 2016.
Waluda continues: "Changes in 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."
More information:
Past penguin colony responses to explosive volcanism on the Antarctic Peninsula, Nature Communications (2017). nature.com/articles/doi:10.1038/ncomms14914
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