Climate Change pushes the Penguins in real Danger in Antarctica

Washington: According to a new study,  continued warming of Antarctica due to climate change may lead to decline of 60 per cent of Adelie Penguin colonies by the end of this century.

Antarctic Climate is be behaving very peculiarly. It is cooling is some places and warming in others. According to the researchers this is causing a dramatic shifting in the population of  the Adelie Penguins. 

Historic satellite observations and future climate model projections were used to estimate past and future changes in habitat suitability during the penguins' chick-rearing period.

The climate change impacts will be highly site specific based on regional climate trends on Antarctica, said Vincent Saba who works at the geophysical fluid dynamics laboratory at Princeton.

A continued southward contraction of the range of Adelie penguins is likely over the next century.
Saba helped analyse the global climate model output and applied the climate change projections to the penguin presence-absence models.

Over time, Adelie penguins were once positively affected by warming and negatively affected by cooling. 

Researchers found that further warming is no longer beneficial at some locations on Antarctica, although some cooler regions could serve as a refuge and buffer the effects for a while.

Continued warming is expected to lead to population declines at approximately 30 per cent of colonies by 2060 and 60 per cent of colonies by 2099, researchers said.  

Antarctic Ozone Layer is Healing

Scientists at MIT and elsewhere have identified the "first fingerprints of healing" of the Antarctic ozone layer.

The team found that the September ozone hole has shrunk by more than 4 million square kilometers -- about half the area of the contiguous United States -- since 2000, when ozone depletion was at its peak. The team also showed for the first time that this recovery has slowed somewhat at times, due to the effects of volcanic eruptions from year to year. Overall, however, the ozone hole appears to be on a healing path.

The ozone hole was first discovered using ground-based data that began in the 1950s. Around the mid-1980s, scientists from the British Antarctic survey noticed that the October total ozone was dropping. From then on, scientists worldwide typically tracked ozone depletion using October measurements of Antarctic ozone.

Ozone is sensitive not just to chlorine, but also to temperature and sunlight. Chlorine eats away at ozone, but only if light is present and if the atmosphere is cold enough to create polar stratospheric clouds on which chlorine chemistry can occur -- a relationship that Solomon was first to characterize in 1986. Measurements have shown that ozone depletion starts each year in late August, as Antarctica emerges from its dark winter, and the hole is fully formed by early October.

The researchers tracked the yearly opening of the Antarctic ozone hole in the month of September, from 2000 to 2015. They analyzed ozone measurements taken from weather balloons and satellites, as well as satellite measurements of sulfur dioxide emitted by volcanoes, which can also enhance ozone depletion. And, they tracked meteorological changes, such as temperature and wind, which can shift the ozone hole back and forth.

They then compared their yearly September ozone measurements with model simulations that predict ozone levels based on the amount of chlorine that scientists have estimated to be present in the atmosphere from year to year. The researchers found that the ozone hole has declined compared to its peak size in 2000, shrinking by more than 4 million square kilometers by 2015. They further found that this decline matched the model's predictions, and that more than half the shrinkage was due solely to the reduction in atmospheric chlorine.

Antarctic Birds can Recognize Individual Humans

Brown skuas in Antarctica can discriminate individual people, even though they normally do not see many people around. Scientists studied brown skuas living in Antarctica.

We have heard of crows, mockingbirds and magpies recognizing individual people. These birds live among people, so it may be natural that they learn to differentiate people. But what about the animals that live in remote areas? Can anyone one of them can do the same?

Scientists in South Korea studied brown skuas living in Antarctica and reported that these birds too recognize people who had previously accessed against the skuas living in Antarctica and reported that these birds too recognize people who had previously accused the nests to measure their eggs and nestlings. 

The research team performed a series of experiments. The researchers checked the nests once a week to monitor the breeding status and the skuas attacked at closer distances with repeated visits of the researchers. to test if the birds specifically distinguish the researchers who visited the nests from those who did not, a pair of humans consisting of nest intruder and neutral human approached to the nests and walked towards the opposite directions. All seven skua pairs followed and tried to attack the nest intruder but never followd the neutral human.

Source: Animal Cognition