It looks like Penguins are showing signs of environmental stress.
from the Sydney Morning Herald:
Some of climate's best canaries are turning out to be penguins. Down the mine, an upturned songbird in a cage was the first warning of a deadly gas seep. Above ground, an age of fossil fuels later, there are different silences.
In the sub-Antarctic, king penguins fledge fewer chicks if the parents must forage in warming seas.