Peter Fretwell has never been to the remote islands off the coasts of Argentina and New Zealand where albatross make their homes, but he has seen hundreds of them.
Well, he’s seen hundreds of tiny, pixelated white dots against a greenish-brown background on a computer screen. That’s how albatross—white seabirds known for their wingspans—appear in images taken by a high-resolution camera on a satellite orbiting Earth. Fretwell, along with his colleagues at the British Antarctic Survey and the Canterbury Museum in New Zealand, used these images to scour the landscape of distant islands from the comfort of office desks and count albatross one by one to create a census from space.
“It’s a strange way of birdwatching,” Fretwell said.
Fretwell said their recent survey marked the first time that satellites have been used to count individual birds from space. The research, described in a paper in Ibis, targeted two threatened species of albatross: wandering albatross on South Georgia, an island located southeast of Argentina, and northern royal albatross, found on the Chatham Islands to the east of New Zealand’s mainland.
Researchers have gone and studied these birds the old-fashioned away, showing up on boats and wandering through the flora to observe the albatross with their own eyes, or chartering low-flying planes to take aerial photographs. The work can be labor-intensive and expensive. Fretwell described a colleague who spends the Antarctic summers sailing to the islands on a yacht, battling rough seas, and scaling cliffs to catch a glimpse of the birds. Counting albatross from space, Fretwell said, requires much less effort and doesn’t risk disturbing the animals. The Chatham Islands are especially difficult to access, and there were no recent population estimates of northern royal albatross there before the satellite survey, Fretwell said.