Emperor penguins, the kings of the ice

This is article no. 6 in a series on animal conservation. Next article: Protecting rock-wallabies in Australia (coming soon). Previous article: Gorongosa National Park.

In November 2024, a malnourished emperor penguin was spotted in Australia, over 2000 miles from its home in Antarctica. It is said to be the furthest north a wild emperor has ever been seen. While scientists do not know why or how the penguin ended up there, it sparked conversations about climate change and the survival of this fascinating species. This article will describe the characteristics of the emperor penguin, and how climate change could affect it.

Introduction to emperor penguins

Emperor penguins (Aptenodytes forsteri) are the largest living penguin species, weighing 20-40 kilograms and standing about 1 metre tall. It is estimated that there are 256,000 breeding pairs of emperor penguins across 54 colonies, which are spread out along the entire coast of Antarctica. Their diet consists of krill, fish, and squid - and they can dive over 500m deep to find food. Emperor penguins are the only warm-blooded animal to breed during the Antarctic winter, one of the world's coldest and darkest times of the year. Therefore, they are adapted to the cold days, harsh winds, and high water pressure in which they live. For example, they have over 20 kinds of feathers - some of which help with waterproofing while swimming, and others help with thermal insulation. Many penguin species huddle together as juveniles to conserve body heat, but emperors are the only species to do so as adults. Thus, emperor penguins are a unique and ecologically fascinating species.

Life cycle and fast ice

The emperor penguin's life cycle is intertwined with sea ice freezing and melting over the year (Figure 1). For most of the year, emperors live on fast ice, which are ice sheets floating on the sea but attached to the coast. The first reason they need fast ice is moulting, when emperor penguins replace all their feathers in late summer. They moult on ice because they cannot swim until their new layer of waterproof feathers has grown. Emperor penguins return to fast ice at the onset of winter to mate, lay eggs, and raise chicks. While one parent stays on the fast ice to look after the chick, the other parent goes to sea to find food for the family. The chick grows waterproof adult feathers for fast ice to break up in summer. At this point, the penguins live at sea until moulting time. This way, emperor penguin survival is linked to fast ice availability.

Threat from climate change

Because emperor penguins are so heavily dependent on fast ice, scientists are concerned about the potential impacts of global warming. Rising sea surface temperatures mean fast ice may not form long enough in the year for emperor penguins to complete their life cycle. In late 2022, sea ice was dramatically reduced in the Bellingshausen Sea in Antarctica, and 4 of the 5 nearby emperor penguin colonies had a failed breeding season. These failed seasons may become more common in the future with climate change. A 2020 study predicted that in the worst case climate scenario, 80% of penguin colonies will see population declines of over 90% by 2100. If international climate targets are met, only 19% of colonies are expected to decline that badly (Figure 2). Because the International Union for Conservation of Nature classified emperors as Near Threatened, they do not meet Antarctica's criteria for being a protected species. Scientists have requested this conservation status be upgraded to better reflect the inability of emperor penguins to adapt or disperse away from the effects of climate change. Emperor penguins face no threats from humans other than global warming, so reducing greenhouse gas emissions is crucial to protect them.

Conclusion

Emperor penguins are charismatic creatures with unique adaptations to live during the cold Antarctic winter. Their survival is strongly linked to the availability of sea ice because they moult, breed, and care for their offspring on ice sheets. Global warming is making these ice sheets disappear, so emperor penguins must be monitored and protected to ensure survival through a changing climate.

Written by Simran Patel

Related articles: The Arctic Springtail / California Condors / Brain-climate connection

REFERENCES

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