Adelie Penguins are a true Antarctic species. They breed further south as Emperor Penguins, making it one of the southernmost breeding species of bird in the world. In most of their breeding range they are doing quite well, but on the northern edge, it is a different story. Here, on the Antarctic Peninsula, the sea ice is melting, which takes away their feeding platform and changes the ecosystem they are part of.
Gentoo Penguins are less dependent on sea ice and are doing great on the Peninsula.
Petermann Island has one of the northernmost Adelie Penguin colonies and the second southernmost Gentoo Penguin colony in the world. It is also the colony with one of the longest records of population counts, with the first one done by Charcot in the early 20th century. At that point around 80% of the penguins were Adelies, the remaining 20% being Gentoos. When I came here for the first time in 2005, it had changed already to 40% Adelie and 60% Gentoo. This year only a few Adelies were left, we didn’t do a full island count of course, but I don’t expect more as 10% of the penguins to be Adelie. As said in the beginning, on a world population scale not much is wrong, but it is still sad to see them disappear on these islands around the Peninsula.