How to count penguins from space

A new study using satellite mapping technology reveals there are nearly twice as many emperor penguins in Antarctica than was previously thought.

Reporting in the journal PLoS ONE, an international team of scientists describes how they used Very High Resolution (VHR) satellite images to estimate the number of penguins at each colony around the coastline of Antarctica.

Peter Fretwell from the British Antarctic Survey shows how the system works.