Elephants counted from space using satellites and AI
Researchers combined high-resolution images captured 600 kilometres above Earth’s surface by the satellites WorldView 3 and 4 with deep computer learning to count the number of elephants in Addo Elephant National Park in South Africa.
Typically, conservationists do this from low-flying planes in order to count and monitor African bush elephants (Loxodonta africana), a method that takes many hours. With the new technique, which combines satellite imagery with artificial intelligence, up to 1,930 square miles can be surveyed on a single blue-sky day in minutes. Next, the researchers’ deep-learning computer algorithms analyse those images and pick out individual elephants. The results of this new proof-of-concept study showed the AI was as accurate as the human eye at spotting each elephant.
“While this is a proof of concept, it’s ready to go,” said Isla Duporge, a zoologist at the University of Oxford, said. “And conservation organisations are already interested in using this to replace surveys using aircraft.” The new technique is a key part of ensuring the survival of this species, which is listed as vulnerable to extinction by the IUCN Red List, the world’s leading database surrounding extinction threats to wildlife created by the International Union for Conservation of Nature (IUCN). Due to poaching and habitat destruction, just 415,000 African elephants roam the wild. “Accurate monitoring is essential if we’re to save the species,” Olga Isupova, a computer scientist at the University of Bath, who wrote the deeplearning algorithms used in the study, explained. “We need to know where the animals are and how many there are.”
What really makes this study stand apart from other satellite-tracking projects is how successful the computer program was at picking out the elephants from their complex backgrounds, known in ecology as heterogeneous landscapes, including grasslands and partially tree-covered savannah. “This type of work has been done before with whales, but of course the ocean is all blue, so counting is a lot less challenging,” Isupova said.
HARRY BAKER