An Internet of Wings

Renowned naturalist John James Audubon noticed that each winter, local birds disappeared for a few months and reappeared in the spring. But were these birds the same as those from the previous year, or a new crop? To find out, he conducted the first bird banding study in 1803 by attaching silver string to an eastern phoebe’s leg. He found that it came back to the same nesting site year after year.

Two centuries later, zoologist Martin Wikelski has taken up Audubon’s charge, albeit with far more sophisticated tools. Wikelski is director of the International Cooperation for Animal Research Using Space (ICARUS), a collaboration between scientists and the German, Russian, and European space agencies. Instead of string, ICARUS researchers are attaching GPS sensors, some the size of a euro one-cent coin and weighing a mere 5 grams, to bats, geese, and other animals. Since the project’s start in 2002, scientists from all over the world have collectively tagged more than 2,000 animals representing 600 species. Armed with data from this network of roving wildlife, scientists can see in unprecedented detail where they go, how they live, and perhaps even how they transmit disease—all from space.

The Centers for Disease Control estimate that more than six out of ten infectious diseases are zoonotic: passed between animals and humans. Previous research has shown that outbreaks of diseases such as avian influenza tend to track with migration routes, and birds that travel long distances and reconvene once a year have the highest risk of transmitting the disease.

Using ICARUS, scientists will track the travel routes and health of fruit bats, mallards, and geese, creating what Wikelski calls “a heat map of life and death.” In one recent project, ICARUS researchers implanted a handful of Swedish mallards with sensors that recorded not only location but also body temperature to monitor the spread of avian influenza. Those temperature readouts could identify infected individuals; a higher-than-average body temperature reading likely indicates infection. By comparing an individual’s data with their travel history, scientists can piece together where animals contract and transmit diseases.

The data can also indicate how virulent a particular strain is and how likely it is to spread to other species. “If you have a body temperature increase, then you know that some low-path[ogenic] avian influenza is coming through—or if you have a massive fever and the animal dies, you know you have high-path[ogenic] avian influenza,” he says.

Currently, that data can be collected only from base locations on the ground, close to where tagged animals live. But this October, the ICARUS team will install a receiver on the International Space Station, making it easier than ever to collect data from animals anywhere on the planet. Wikelski describes the receiver as similar to a cell tower: as the ISS orbits the earth, passing above tagged animals, ICARUS’s receiver will signal animals’ sensors to transmit their data.

Wikelski’s next step is to correlate this information with even richer data from blood samples, for example, which would reveal how animals carry and spread antibodies. The team’s long game is to create better models of disease transmission, which will lead to improved accuracy in predicting outbreaks and, potentially, the ability to intervene.

Drawing parallels to the “Internet of Things” made up of “smart” technology embedded in everyday objects such as cars and thermostats, Wikelski calls ICARUS the “Internet of animals” or the “Internet of wings.” Standing upon Audubon’s shoulders and those first silver strings, it allows us to see the world as never before.

Jane C. Hu is a Seattle-based science journalist. Her writing has appeared in Slate, Scientific American, Nautilus, and other publications.