Iverson is a co-author of one of two papers appearing Thursday in the journal Science, both illuminating the incredible strides made recently using hi-tech tagging tools and sensors not only to track the physical locations and movements of animals across land, air and sea, but also to measure changes in their bodies and environments. The resulting data streams will not only help protect the animals themselves, but also, in some cases, humans and, ultimately, the planet.
In this new body of research, seals are being turned into deep sea researchers; stork migration routes are being pinned down by solar-powered GPS tags; competing monkey group movements can be analyzed to see who has the tactical advantage; and live cougar hunts can be studied to measure how the animal’s energy expenditure relates to the size of its prey. And it has all been enabled by major technological advances that are allowing smaller and less invasive, but also longer lasting and more capable, tracking devices to be attached to both marine and terrestrial organisms.
“New technology has brought the study of animal movement into the realm of big data, and exponential increases in data volumes are expected to continue in the coming decade,” noted Roland Kays of the North Carolina Museum of Natural Sciences and his colleagues in one of the Science papers — the one focused on terrestrial animal tracking.
One of the most fundamental breakthroughs is that unlike in times past, researchers don’t necessarily have to catch a tagged animal a second time in order to gather all the data accumulated by a tag or tracking device that it is bearing. Instead, many devices can relay information to satellites or by other means — even from the freezing depths of the ocean. The animal itself may never be encountered again.
The resulting gigantic volume of data is a challenge to handle, the researchers said. But it’s also a huge opportunity not only to better protect species, but also to understand the environments in which they live and move — and how those are changing.
Kays and his team reported that the new availability of real-time data lets wildlife managers respond almost instantly to changing animal behavior — even as it helps protect animals and humans. “Wildlife managers, for example, are using GPS tags that send SMS alerts when tagged elephants cross into predefined areas to reduce human-wildlife conflict,” they wrote. Similar monitoring of great white sharks off the western coast of Australia is being employed to help keep people out of the water and thereby lower the risk of shark attacks, said Iverson.
One key aspect turns on a stunning miniaturization of tagging technology. “GPS tags with remote data readout have dropped from 250 to 20 [grams] in about a decade,” wrote Kays and his colleagues. This, in turn, has allowed devices to be placed on smaller and smaller organisms without interfering with their lives or their survival.
In some ways, the strides being made in tracking marine organisms, through tags that use either sonar communications or are tracked by satellite, are still more stunning than those for terrestrial animals.
“We’ve been able to get … more than 200,000 temperature and salinity profiles of the Arctic Ocean by tagging narwhal and beluga whales,” said Iverson. Tagging northern fur seals has allowed studies of the dangerous and hard-to-reach Bering Sea in the winter, while in the Southern Ocean, southern elephant seals and Weddell seals have served as the “researchers.”
For the oceans, there are two key technologies, said Iverson — acoustic tags, which send acoustic signals to receivers on floating buoys or at fixed spots; and “satellite pop-up tags,” which are monitored by satellite. There is also an impressive underwater technology called mobile transceiver, made by a company called Vemco. “It can be carried by larger animals, say seals, and basically that seal is transmitting its whereabouts as it moves around the ocean, but any tagged fish or seal, any other tagged animal it encounters, it also records that,” said Iverson.
In this realm, too, miniaturization has been key — Iverson and her colleagues report that aquatic acoustic tags can now weigh less than 1.4 grams — even as devices also have longer and longer battery lives.
The big picture, wrote Kays et al, is that in effect, animals might become a global sensing system that, in turn, allows us to better protect them.
“We suggest that a new approach that views animals as naturally evolved sensors of the environment has the potential to help us monitor the planet in completely new ways,” they wrote.
“Showing how animals adapt to changing conditions in upredictable ways,” they concluded, “offers a lens to the future of animal ecology in the Anthropocene.”