New Radar Tech Reveals Hidden Penguin Colonies

Satellite radar imaging is now being utilized for the first time to track endangered emperor penguin colonies in Antarctica, even during the dark winter months.

Traditionally, satellite imagery requires sunlight, hindering observations during the critical breeding season. However, synthetic aperture radar (SAR) from the European Space Agency's Sentinel-1 satellite sends microwave pulses that return radar imagery regardless of light or cloud cover. Researchers identified penguin colonies as moving clusters of bright pixels on stable sea ice.

This breakthrough enables year-round tracking by combining SAR data from winter with optical images from warmer seasons. Analysis of eight years of data (2017-2024) has revealed colony movements, including a notable shift from sea ice to glacier ice by the Atka Bay colony in seven out of eight years. This information is vital for understanding the species' response to environmental changes and declining Antarctic sea ice.

Emperor penguins were recently classified as endangered due to projected sea ice declines, making enhanced monitoring essential. The ability to observe colonies throughout their breeding cycle using freely available satellite data offers opportunities to better understand their adaptation to a changing climate.