However, to find food for their chicks, adult penguins must venture to an ocean boundary known as the Antarctic Polar Front, where cold Antarctic waters meet and sink beneath warmer waters from mid-latitude regions.

And while king penguins, the second largest penguin species, can swim a 400-mile round trip during that time, they are traveling farther and farther from their nests on the islands near Antarctica, endangering their hungry offspring.

The study published this week in the journal Nature Climate Change found that 70 percent of Antarctica’s 1.6 million king penguin population could either disappear or be forced to find new breeding grounds by 2100 because of the changing ecosystem.

If there will not be taken any measures against climate change, the king penguins species will be in serious danger. “There will surely be losses on the way – if we are to save anything, proactive and efficient conservation efforts but above all coordinated global action against global warming should start now”.

However, the APF will move further south as the oceans get warmer.

For each island, orange shows the presence of a breeding colony; grey indicates that the island is too far away from a foraging site; white shows that the island that has never been occupied by penguins and blue shows that the island is covered in ice and, therefore, too cold for penguins to establish a breeding colony.

Penguins in the Crozet Islands will have to swim 435 miles to feed, study co-author Emiliano Trucchi, an evolutionary biologist at the University of Ferrara in Italy, told The Verge.

King penguins are not living on ice, as their relatives, the emperor penguins, do.

As of now, there are about 3.2 million King penguins in the wild right now.

“We know that penguin populations will collapse soon”, says study co-author Céline Le Bohec, an ecologist at the Hubert Curien Multi-disciplinary Institute in France, to The Verge.

“Penguins, like other seabirds and marine mammals, occupy higher trophic levels in the ecosystems: they are what we call bio-indicators of their ecosystems”, she said.

Today, there are an estimated 3.2 million breeding adult king penguins in the world that are not now vulnerable to extinction.

King penguins might die out soon if nothing is done to combat climate change, scientists say.

If no suitable breeding spots emerge in time, a large proportion of king penguins could “disappear” by the end of the century, the researchers said.

King penguins can only shift breeding grounds in a stepping-stone manner, hopping between available islands, according to the Press Association.

If little is done to tackle climate change, up to 70 percent of king penguins could be forced to find new places to breed by 2100, the lead authors told Carbon Brief. “I’m anxious about the future of the species”, says Le Bohec. Because they live only on ice-free islands that are around 32 degrees Fahrenheit (0 degrees Celsius) year round and breed on sandy or pebbly beaches, finding a new home is hard.

Relocating for king penguins is complicated.

Trucchi told NPR that king penguins hunt small fish and other ocean creatures – up to 80 percent from the Antarctic Polar Front – to bring back to their young.