The world’s largest penguin colony decimated. Researchers do not know the reasons

As recently as the 1980s. last century penguin colonyoin kroLion Islands (Aptenodytes patagonicus) on the Ile aux Cochons – one of the islands in the Indian Ocean – counted more than two million penguinsow, including some poł million pairs. It was the world’s largest penguin colonyoin krolewski and the second most numerous penguin colonyoin the ogole (The most numerous colony of penguinoIn the masks in the South Sandwich archipelago).

The colony at Ile aux Cochons has been known to scientists since the 1960s. last century. Researchers from the Center for Biological Studies in Chize (CNRS) were last there in 1982. But much has changed since then. High-resolution satellite images and photographs taken from a helicopter in 2015 and 2017 showed that the colony’s population had dropped to just 60,000. par.

Scientists do not know what caused such a dramatic decline in the colony population. Hypotheses proliferate, but one thing emerges from all of them – Such a drastic decline was not caused by a single tsunami-type event. A study on the subject appeared in the pages of the „Antarctic Science”.

Data show that the decline began in the late 1990s. of the last century, coinciding with severe climate events associated with El Niño. This event temporarily affected the foraging capabilities of another colony located 100 kilometers awayoin from Ile aux Cochons, causing its disappearance. Researchers believe a similar process befell the colony on Ile aux Cochons.

The larger the colony population, the stronger the competition between individuals in the group. This slows the growth of the entire colony. The repercussions of the lack of food are thus amplified and could trigger an unprecedented rapid and drastic population decline, especially after climatic events such as those in the late 1990s. The decline began in the 1970s.

Another hypothesis mowi about some kind of disease, whichora affected the colony. Bird cholera currently ravaging bird populationsoat sea on other islands in the Indian Ocean. The disease has affected albatross populationsoin Amsterdam Island or the penguinow of Marion Island.

But none of these concepts seem to be working for scientistsoIn a satisfactory explanation for such a drastic decline in colony size from Ile aux Cochons. Wkrotce field studies are to begin, led by scientistoat the CNRS with the support of the French Polar Institute and in close cooperation with theoWorking with the staff of the nature reserve located there. Research should verify preliminary conclusions drawn from the imageoin satellite.

„The cause of the massive collapse of the colony remains a mystery and must be solved. Although the population decline began at least 20 years ago, it appears to be still ongoing, and the causes may still be active” – wrote the researchers in a publication.

Penguins krole penguins are the second largest penguins in the world. Larger than them are only emperor penguins. An adult individual reaches a height of 90 centimetersow and weigh up to 15 kilogramsow.

Sourceobackground: Nature, Science Daily, fot. Henry Weimerskirch. Pictured is a colony of penguinoat Ile aux Cochons in 1982.