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113 Emperor Penguins at Halley Bay

24 . 11 . 2020

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Emperor penguins are probably one of the most difficult animal species to reach, as they are true Antarctic penguins that spend the winter on the ice around the southern continent to hatch their young. They breed in large colonies, the largest ones being at Coulman Island in the Ross Sea and at Halley Bay in the Weddell Sea. Over the past 60 years that researchers have been observing the Halley Bay colony, between 14,300 and 23,000 pairs have flocked to the site’s sea ice to breed. But since 2016, breeding failures have been “catastrophic” and the penguins appear to have abandoned what was once a reliable haven.

In 2015 the strongest El Niño in decades began disrupting Halley Bay’s “fast ice,” that is anchored to the shore or ocean floor. Between April and December, the penguins depend on fast ice to provide stable ground for mating, incubating eggs and caring for chicks. But in 2016, the ice broke apart before the baby penguins would have developed the feathers they needed to swim. Thousands of them appear to have drowned. The ice failed to properly reform in 2017 and 2018, leading to the death of almost all the chicks at the site each season. And now, the colony at Halley Bay has largely disappeared.

The Brunt Ice Shelf at the colonies' edge is traversed by a crack. Previously stable for about 35 years, this crack recently started accelerating northward last year as fast as 4 kilometers per year.

Today the large Chasm 1 crack is only [within a few kilometers]((https://www.abc.net.au/news/2019-10-09/formation-of-brunt-ice-shelf-iceberg-in-antarctica-captured/11370748?nw=0) of the McDonald Ice Rumples and the Halloween crack. If the cracks merge, the area of ice lost from the shelf will likely be at least 1700 square kilometers (660 square miles).

It seems that many of the adult emperor penguins have travelled elsewhere to find more reliable breeding ground. Satellite data shows that a colony of emperor penguins at the nearby Dawson-Lambton Glacier suddenly experienced a “massive increase” in numbers starting in 2016.

At the same time, scientists have been looking for new colonies for the last 10 years. Through satellite mapping technology they know have located 11 previously unknown emperor penguin colonies based on mapping the brown-red guano stains the birds leave on the ice. So it's literally the penguin poo seen by satellites that leads to the discovery of these previously unknown emperor colonies in Antarctica. There are now known to be 61 emperor penguin colonies scattered around the continent.

112 The Largest Seasonal Event

19 . 11 . 2020

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Buy us a coffee: Chris: https://ko-fi.com/chrismarquardt Henry: https://www.buymeacoffee.com/aguycalledpaul

The world’s largest seasonal event is the change from summer to winter ice in Antarctica. Every year a magical event happens largely unnoticed by the general public. When the summer comes to an end, the already low Antarctic temperatures drop even further and start a process that is truly astonishing. When the water temperature drops roughly below a negative 1.7 degrees Centigrade the ocean starts freezing over despite its salty waters. By the end of the Antarctic summer, only about 3 million square kilometres (1.1 million square miles) of sea ice remain, largely in the Weddell Sea, in the Amundsen Sea off Ellsworth Land, off the probably windiest place on Earth - the George V. Coast and around Enderby Land. But during this world’s largest seasonal event, the ice undergoes a change in area from 3 million square kilometres to up to 18 million square kilometres (6.9 million square miles) in the winter. Unlike the Arctic—an ocean basin surrounded by land—the Antarctic is a large continent surrounded by an ocean. Because of this geography, sea ice has more room to expand in the winter. But that ice also stretches into warmer latitudes, leading to more melting in summer. Considering the permanent ice cover of the continent al year-round of about 14 million square kilometres (5.4 million square miles) this means that the total ice cover doubles from summer to winter. In early spring the sea ice breaks up and retreats back to roughly 3 million square kilometres again.

Picks of the week: Marquardt International Pinhole camera and a documentary about Iceland's remote Eastfjords, feel free to check them out.

111 Three New Penguin Species Discovered

10 . 11 . 2020

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It’s not so much heroic exploration but rather [scientific research that leads to the discovery of three new species of penguin](Their DNA alone is a dead giveaway, confirming these groups are not breeding with each other. This basic difference suggests all four species are now evolving independently of one another.The four groups of penguins look superficially very similar. But when we measured their skulls, bills, flippers, and legs we found that they were significantly different in size, with those living on the Antarctic Peninsula being smallest and those on the Falkland Islands largest.These physical and genetic differences are great enough that the former gentoo penguin (Pygoscelis papua) is now recognised as four distinct species: P. papua from the Falkland Islands, P. ellsworthi from the Antarctic Peninsula, P. poncetii from South Georgia, and P. taeniata from Kerguelen Island.The four species inhabit distinct environmental conditions across a large range of latitudes. P. ellsworthi lives on the cold, icy Antarctic Peninsula at a latitude of around 65° south, in stark contrast to the milder conditions experienced by P. taeniata at 49° south. The four species also consume different diets, with the more southerly species eating more krill and fewer fish.). First described in 1781, the gentoo penguin was considered one species with two subspecies, one that lives in the Falkland Islands (Pygoscelis papua papua) and one that lives in the South Shetland Islands and Western Antarctic Peninsula (Pygoscelis papua ellsworthi).

Now it seems that one species has been split into four. Despite sharing roughly the same appearance, in habitats not so far apart, the gentoo penguin appears to have divided itself into four populations that have little to do with one another, according to new research.

For the first time, scientists have shown that these penguins are not only genetically distinct but that they are also physically different too. Gentoos tend to stick close to their home colonies, and over hundreds of thousands of years have become geographically isolated from each other to the point where they don't interbreed with each other, even though they could easily swim the distance that separates them. And that's essentially the concept of a species: an interbreeding group reproductively isolated from other such groups.

Using genome data and measurements from museum samples, researchers found clear differences in the genes and morphology of gentoo penguins. The differences are great enough that the authors think both recognised 'subspecies' should be elevated to their own species, while two new species should also be added. They look very similar to the untrained eye, but when we measured their skeletons we found statistical differences in the lengths of their bones and the sizes and shape of their beaks.

Their DNA alone is a dead giveaway, confirming these groups are not breeding with each other. This basic difference suggests all four species are now evolving independently of one another.

The four groups of penguins look superficially very similar. But when we measured their skulls, bills, flippers, and legs we found that they were significantly different in size, with those living on the Antarctic Peninsula being smallest and those on the Falkland Islands largest. These physical and genetic differences are great enough that the former gentoo penguin (Pygoscelis papua) is now recognised as four distinct species: P. papua from the Falkland Islands, P. ellsworthi from the Antarctic Peninsula, P. poncetii from South Georgia, and P. taeniata from Kerguelen Island. The four species inhabit distinct environmental conditions across a large range of latitudes. P. ellsworthi lives on the cold, icy Antarctic Peninsula at a latitude of around 65° south, in stark contrast to the milder conditions experienced by P. taeniata at 49° south. The four species also consume different diets, with the more southerly species eating more krill and fewer fish.

Tyler J, Bonfitto MT, Clucas GV, Reddy S, Younger JL. Morphometric and genetic evidence for four species of gentoo penguin. Ecol Evol. 2020;00:1–11.

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