Rising temperatures spell trouble for Ross Sea penguins

Adelie colony at Cape Bird South,
Ross Island. Photo (c) Landcare
Research New Zealand Limited.

ANTARCTICA - The results for this year's census of the Adelie penguin population in the Ross Sea region shows it's not likely to be a good breeding season. And there's worse news to come for the region's Adelies and their emperor brethren if temperature in the region increases as predicted.

Dr Phil Lyver of Landcare Research and his fellow scientists monitor the penguin population annually both on the ground and using a low-flying plane. This year the aerial census suffered from ongoing technical and weather issues, so only four penguin colonies were photographed.

Photos of the four sites were analysed using a computer program, and results did not bode well for a good breeding season, Dr Lyver told the Otago Daily Times from Scott Base.

"The colonies of Franklin Island, Inexpressible Island and Terra Nova appeared to be quite snow covered, which meant the penguins would have struggled to find their nesting sites and stones to build their nests this year at those sites."

Research by Dr Lyver and his colleagues indicate that the long-term future for the populations of Adelie and emperor penguins in the Ross Sea is looking even more dire if temperature in the region increases within the next 40 years as predicted.

"For this region, we're looking at a 2°C increase in the troposphere occurring around 2025-50," Dr Lyver told the Otago Daily Times.

The temperature increase would cause melting of the sea ice on which both Adelie and emperor penguins depended for foraging for krill and fish.

"We are looking at losing potentially 70% of our Adelie penguin colonies north of 70° south, and that's basically a 75% loss of the entire population of Adelie penguins in Antarctica."

The rising temperature could be even more devastating for the emperor penguin population, with some research modelling predicting that emperors may be functionally extinct by the end of the century.

So this may be a tough year for the penguins, but there are even tougher times to come.

Source
Warming sends chills down penguins' spines by Joe Dodgshun, 17 February 2011, Otago Daily Times

Ecological Monographs citation
Antarctic penguin response to habitat change as Earth’s troposphere reaches 2°C above preindustrial levels. D.G. Ainley, J. Russell, S. Jenouvrier, E. Woehler, P.O'B. Lyver, W.R. Fraser, G.L. Kooyman. Ecological Mongraphs 80(1), 2010.