Scientists are seeing changes off Alaska that have never been documented before, as warming upsets a vast ecosystem and one of the world’s vital fisheries. Visser ME (2008) Keeping up with a warming world: assessing the rate of adaptation to climate change. PRSB 275, 649–659. The waters around and beneath the sea ice are important to the penguins as an area for feeding and the ice itself is essential as a place for the animals to rest, to shelter during their annual molt and to escape from predators. But the loss of sea ice, due to global heating, threatens the habitat of these penguins, while ocean acidification is diminishing the supply of krill, a key food source. The Emperors are in big trouble,” said Steve Emslie, an expert in Adelie penguins at University of North Carolina Wilmington who was not involved in this research. Due to their longer lifespan, penguins may take three to eight years to reach sexual maturity. Some smaller species may begin breeding at three or four, while the larger species do not reach sexual maturity until later.

Jenouvrier S, Barbraud C, Weimerskirch H (2005) Long term contrasted responses to climate of two Antarctic Seabird species. Ecology 86; 2889–2903.In some cases it’s possible the sea broke up into smaller floes or under the feet of the penguins,” he said.

Ensconced on the ice, emperor penguins have largely avoided human efforts to hunt them, overfish their prey or encroach on their territory. Forcada J, Trathan PN (2009) Penguin responses to climate change in the Southern Ocean Glob Change Biol. 15: 1618–1630 During a previously recorded breeding failure at a large colony in the Weddell Sea, Fretwell said adults had likely moved to another colony less than 100km away.

8. Fish suppers

The study, published in the journal Communications Earth & Environment, observed the sea ice breaking apart from late October to early December at colonies at Verdi Inlet, Smyley Island, Bryant Coast and Pfrogner Point. Stammerjohn SE, Martinson DG, Smith RC, Yuan X, Rind D (2008) Trends in Antarctic annual sea ice retreat and advance and their relation to El Nin∼o–Southern Oscillation and Southern Annular Mode variability. J Geophys Res 113, C03S90: The only other penguin that lives in Antarctica is the Adélie penguin. These birds are ice-dependent and rely on the ice for foraging. There are currently over seven million individuals, and they are listed as Least Concern. Subantarctic Islands Only a relatively small number of emperor colonies have been studied across Antarctica [1], [12], [22], [24], with the longest study based at Pointe Géologie, which has been continually monitored since the 1950s [1], [4], [5], [24]. The behaviour of breeding on ice-shelves, as reported here, has only been reported once at a small colony in East Antarctica [15]. That this behaviour is not the exception but is apparently more common among emperor penguins is a surprising result. The reasons why this behaviour has not been recorded before are unclear, possible explanations include: