Scientists drilling deep into the edge of modern Antarctica have pulled up proof that palm trees once grew there, the BBC reports citing the results of a study carried by Nature journal. Analyses of pollen and spores and the remains of tiny creatures have given a climatic picture of the early Eocene period, about 53 million years ago.
Scientists drilling deep into the edge of modern Antarctica have pulled up proof that palm trees once grew there, the BBC reports citing the results of a study carried by Nature journal. Analyses of pollen and spores and the remains of tiny creatures have given a climatic picture of the early Eocene period, about 53 million years ago. The study suggests Antarctic winter temperatures exceeded 10C, while summers may have reached 25C.Scientists hope that better knowledge of past "greenhouse" conditions will enhance guesses about the effects of increasing CO2 today. Source: Voice of Russia.
Bisarbeat Nearly twice as many emperor penguins inhabit Antarctica as was thought. UK, US and Australian scientists used satellite technology to trace and count the iconic birds, finding them to number almost 600,000. Their census technique relies in the first instance on locating individual colonies, which is done by looking for big brown patches of guano on the white ice. High resolution imagery is then used to work out the number of birds present. It is expected that the satellite mapping approach will provide the means to monitor the long- term health of the emperor population. Climate modelling has suggested their numbers could fall in the decades ahead if warming around Antarctica erodes the sea ice on which the animals nest and launch their forays for seafood. "If we want to understand whether emperor penguins are endangered by climate change, we have to know first how many birds there are currently and have a methodology to monitor them year on year," said Peter Fretwell from the British Antarctic Survey (BAS). "This study gives us that baseline population, which is quite surprising because it's twice as many
as we thought, but it also gives us the ability to follow their progress to see if that population is changing over time," he said. Their survey identified 44 key penguin colonies on the White Continent, including seven that had not previously been recognised. Although finding a great splurge of penguin poo on the ice is a fairly straightforward - if laborious - process, counting individual birds in a group huddle is not, even in the highest resolution satellite pictures. This means the team therefore had to calibrate their analysis of the colonies by using ground counts and aerial photography at some select sites. Fretwell and colleagues totted 595,000 penguins, which is almost double the previous estimates of 270,000-350,000 emperors. The count is thought to be the first comprehensive census of a species taken from space. Michelle LaRue from the University of Minnesota said the monitoring method provided "an enormous step forward in Antarctic ecology". "We can conduct research safely and efficiently with little environmental impact," she explained. The emperor breeds in the coldest environment of any bird species on Earth. The implications for this study are far-reaching. We now have a cost-effective way to apply our methods to other poorly understood species in the Antarctic. The extent of sea ice in the Antarctic has
been relatively stable in recent years. Nonetheless, computer modelling suggests a warming of the climate around Antarctica could result in the loss of more northern ice floes later this century. If that happens, it might present problems for some emperor colonies if the seasonal ice starts to break up before fledglings have had a chance to acquire their full adult, waterproof plumage. And given that the krill that penguins feed on are also dependent on the ice for their own existence - some colonies affected by eroded floes could face a double-whammy of high fledgling mortality and restricted food resources. But this can all now be tested by the methodology outlined. "The emperor penguin has evolved into a very narrow ecological niche; it's an animal that breeds in the coldest environment in the world," explained Peter Fretwell. "It currently has an advantage in that environment because there are no predators and no competition for its food. If Antarctica warms so that predators and competitors can move in, then their ecological niche no longer exists; and that spells bad news for the emperor penguin." Image Link Photobucket, Source: Bisarbeat
The long-term future looks bleak for Emperor penguins, but our new research shows some birds may be able to survive in certain conditions, depending on where they live, at least for the next few decades.
Over the past two years, Antarctic sea ice has declined dramatically, prompting scientists to suggest it could reach a “new state”.
A study based on satellite images shows that sea ice broke out early in Antarctica’s Bellingshausen Sea in 2022, potentially resulting in breeding failures across several Emperor penguin colonies in that region.
Our research shows Emperors form colonies in surprisingly diverse environmental conditions that vary depending on location around the continent. Within each of these regions, there is little difference between where birds make their homes and other sites, suggesting they could shift if they had to. This provides a ray of hope in an otherwise bleak outlook.
Emperor penguins may be the only birds to rarely set foot on land. They are unique among penguin species in that they breed on sea ice during the harsh Antarctic winter.
Male Emperor penguins incubate eggs and raise the chicks on sea ice during the Antarctic winter. Sara Labrousse/French Polar Institute, CC BY-SA
We know that they need “fast ice” – the coastal sea ice attached to the Antarctic continent or ice shelves. But they actually inhabit a range of fast-ice locations that differ in the timing of ice formation, how much ice forms and breaks, and even how close they get to other penguin species.
Depending on where they are along the Antarctic coast, Emperors make use of the habitat available to them. Their behaviour may be flexible enough to allow some colonies to cope better in a warming world.
Why fast ice is important
Emperor penguins rely on fast ice as a stable platform for their breeding season. Female Emperors lay their eggs and the males incubate them for about two and a half months.
Even though Antarctica’s sea ice is diminishing, this refers to a measure known as “sea ice extent”, which includes all sea ice covering the polar ocean, whether it is fast ice or drifting pack ice.
A decrease in sea ice extent is not necessary linearly linked to a drop in the area covered by fast ice (although the reverse is true).
If fast ice were to disappear, we would expect more than 90% of Emperor colonies to become functionally extinct by the end of the century. However, our study suggests that in the short to medium term, we should consider the differences in the penguins’ breeding habitats when we think about ways to protect them.
Emperors are unlikely to move far
By looking a little closer at different fast-ice habitats, we found Emperor penguins have certain preferences. The persistence of the ice (how long it lasts into the summer) was important because chicks had more time to develop their water-proof swimming feathers.
Our results suggest that two of these habitat conditions support larger colonies: stable fast ice that lasts throughout the breeding season (with only small changes in the growth and retreat seasonal cycle) and a good balance between a fast-ice platform that is wide enough to raise chicks but close enough to the ocean to get food for them.
Emperor penguins need access to the ocean to feed their chicks during the breeding season. Sara Labrousse/French Polar Institute, CC BY-SA
We need further studies to clarify these links and the relationship between population size and habitat quality. In our study, we weren’t able to consider prey availability and there may be other factors that play an important role.
Previous research has already shown that Emperor penguins have limited capacity to disperse to find more suitable climate refuges. This is supported by the genetic partitioning among the penguin populations in different Antarctic regions we studied.
It is therefore unlikely Emperors would move far to avoid more severe climate impacts, even if “better” habitats existed and could host larger colonies.
Emperors don’t easily move to other breeding sites, even if the conditions are better. Sara Labrousse/French Polar Institute, CC BY-SA
Protecting penguin habitat
Climate change is currently one of the main pressures driving Emperor penguins closer to extinction.
However, the latest global assessment by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) clearly identified fishing activities as historic and current drivers of the erosion of marine biodiversity worldwide.
This is also true for Antarctica. While fishing pressure there is limited to a fraction of the global fishing fleet, some of the largest vessels target krill, a tiny shrimp-like crustacean consumed by many Antarctic predators, including Emperor penguins.
With climate models predicting further reductions in sea ice extent, new fishing grounds could open and amplify pressure on other Antarctic wildlife.
If we want to live in a world with Emperor penguins, the most important thing to do would be to cut greenhouse gas emissions steeply. Another key action could be to prevent fishing in areas where climate change will have the most impact.
In this respect, truly protected areas are one conservation tool at our disposal. Now that our research provides more detailed information about penguin habitats, we can begin the process of more careful planning for conservation.
The world’s largest marine protected area exists in the Ross Sea, which is home to about 25% of the world’s Emperor penguins. Lessons we learn from protection there could help mitigate future declines of Emperors around Antarctica.
Sara Labrousse/French Polar Institute, 
Male Emperor penguins incubate eggs and raise the chicks on sea ice during the Antarctic winter. Sara Labrousse/French Polar Institute, 
Emperor penguins need access to the ocean to feed their chicks during the breeding season. Sara Labrousse/French Polar Institute, 
Emperors don’t easily move to other breeding sites, even if the conditions are better. Sara Labrousse/French Polar Institute, 
