The last 2 weeks have been very good – and very bad – for Martin Wikelski and Walter Jetz. As a key testament to the principle of their space-based wildlife tracking project, they published a paper tracing the journeys of 15 species, including the meandering of an endangered saiga antelope through Central Asia and cuckoo marathon flights from Japan to Papua New Guinea. But even that same week, their data stream dried up from an antenna on the International Space Station (ISS), probably because data was being transmitted through a Russian ground station.
The war in Ukraine seems to have founded their project, International Cooperation for Animal Research Using Space (ICARUS), just as it was about to get underway. “This will ruin all the efforts of a great many scientists,” said ecologist Nyambayar Batbayar, director of the Wildlife Science and Conservation Center in Mongolia, whose team has used ICARUS to track snipe and cuckoos. New studies of pinyon jays and robins have been put on hold because researchers do not want to burden animals with tags whose data may not be recoverable.
Wikelski, an ornithologist at the University of Konstanz and the Max Planck Institute of Animal Behavior, and Jetz, a Yale University ecologist, say they are now dusting off planned efforts to set up other space-based receivers. But researchers who were already skeptical of ICARUS ‘goals say its future is in doubt. “I’ve seen many ambitious attempts, but ambitions do not always lead to success,” says ecologist Greg Breed of the University of Alaska, Fairbanks.
To understand animal behavior and how humans affect it, researchers have increasingly put GPS tags on animals and tracked them with handheld or ground-based receivers. But tagged animals often move out of reach, and the tags were expensive so few individuals could be traced. ICARUS, founded in 2002, aims to lift tracking into space and develop cheaper tags that are affordable for researchers worldwide. By expanding the number – and sizes – of tagged animals and tracking their complete journeys, Wikelski and his colleagues hoped to see how both the environment and human influences shape their survival.
It was such a magnificent vision that Breed and others were skeptical that it would come true. NASA initially rejected Wikelski’s attempt to cooperate, so he collaborated with the German and Russian space agencies; they and the Max Planck Society have funded the project with € 30 million to date. In 2019, a German-built antenna was unfolded on the Russian module on the ISS. By the end of last year, scientists had inserted tags on animals at 91 locations around the world, 21 in Russia.
Each time the space station passes over a tagged person, it turns on its tag and uploads stored data. This data is transferred to a ground station in Russia and is automatically entered into Movebank, a public archive with information on animal movements.
The brands have provided new and at times surprising insights, Jetz, Wikelski and colleagues reported on March 8 in Trends in ecology and evolution (TREE). The technology tracked the animals’ entire journeys, not just the endpoints, and gave clues as to why some birds fall.
Take the mountain plow, a prairie with short grass the size of a blue jay, which has fallen by 80% since the 1960s. ICARUS data on 17 birds tagged last year showed that when the plows left their breeding grounds in Colorado, “they all went to different locations,” mostly in eastern Colorado, Kansas and Oklahoma, says co-author Roland Kays, an ecologist at North Carolina Museum of Natural Sciences. Then they moved on to various wintering areas further south and into Mexico (see map below). The finding adds evidence that migrants do not always go back and forth between two fixed points, but instead follow food and avoid floods, fires and other disturbances. Data like these “change the whole picture of [the] animal migration phenomenon as we know it, ”says Batbayar.
The tags revealed that some deer birds die at the stopovers, says project director Michael Wunder, a quantitative ecologist at the University of Colorado, Denver. “Once you get [this] ‘where’ can you try to find out what contributes to mortality, ”says Georgetown University ecologist Peter Marra.
Ecologists are also enthusiastic about the project’s GPS tags, developed with a company that with 4 grams and $ 300 apiece is far lighter and cheaper than most. ICARUS “makes technology available to researchers in countries where we do not have the resources to purchase other types of tags,” says behavioral ecologist Adriana Maldonado-Chaparro of Del Rosario University in Bogotá, Colombia.
In it TREE paper, Jetz and colleagues propose to expand ICARUS to 100,000 animals that could serve as Earth’s “watchdogs” in the same way that smartphone data on individual car movements and speeds has revolutionized traffic forecasting. Tracking data on seabirds has e.g. shown that they are changing their course in anticipation of typhoons.
But shortly after the war in Ukraine began last month, all data downloads from the space station stopped. No one knows exactly why, although Wikelski suspects it is because the German and Russian space agencies are no longer cooperating.
Still, he, Kays and Jetz remain optimistic. They say the ISS antenna was always intended as a temporary measure and they had already planned to expand the number of space-based receivers by flying them on microsatellites called CubeSats or by piggybacking them on other satellites. Their efforts have given preliminary promises from space agencies and satellite companies to get receivers back into space by the end of the year, and more by 2024. And by 2027, a joint NASA and German space agency mission to measure gravity variations, Gravity Recovery and Climate Experiment, can carry ICARUS receivers.
In the short term, however, Breed and others believe that ecologists can do better to put their hopes in more proven technologies. He and Sara Maxwell, a marine sustainability ecologist at the University of Washington, Bothell, suggest that the 20,000 animals around the world that now carry GPS tags, retrieved locally or rarely with private satellites, can already serve as environmental guards. Movebank is developing software to collect this data in the future, says Kays.
Wikelski believes that ICARUS has proven itself. He does not give up on getting the big picture of animal movements from space – and promises that his project will take flight again.