The amazing breeding cycle of the tallest of all penguin species has made studying them a hard time for scientists. Emperor penguins are the only penguin specie that lays their eggs during the harsh Antarctic winter deep inside the continent.
Therefore, scientists have been looking for new ways to study their behavior and, especially, register and measure their evolution and any possible alteration produced by climate change.
A new study using satellite mapping technology reveals there are twice as many emperor penguins in Antarctica than previously thought.
Scientists used Very High Resolution (VHR) satellite images to estimate the number of penguins at each colony around the coastline ofAntarctica. Using a technique known as pan-sharpening to increase the resolution of the satellite imagery, the science teams were able to differentiate between birds, ice, shadows and penguin poo. They then used ground counts and aerial photography to calibrate the analysis.
“We are delighted to be able to locate and identify such a large number of emperor penguins. We counted 595,000 birds, which is almost double the previous estimates of 270,000 – 350,000 birds. This is the first comprehensive census of a species taken from space”, says geographer Peter Fretwell from the British Antarctic Survey.
This new method allows scientists to conduct research safely and efficiently with little environmental impact. Satellite mapping technology is a cost-effective way to study other poorly-understood species in the Antarctic and to strengthen on-going field research.
Biologist Phil Trathan, co-author of this research, alerts about its importance: “Current research suggests that emperor penguin colonies will be seriously affected by climate change. An accurate continent-wide census that can be easily repeated on a regular basis will help us monitor more accurately the impacts of future change on this iconic species”.
Scientists are concerned that in some regions of Antarctica, earlier spring warming is leading to loss of sea ice habitat for emperor penguins, making their northerly colonies more vulnerable to further climate change.
Images where obtained from Quickbird2, Worldview2 and Ikonos satellites. The latest count of 238,000 breeding pairs far exceeds the last estimate from 1992 of 135,000-175,000 breeding pairs.