Cornell researchers have created a solar wildlife tag, an innovation that solves key challenges in bird-tracking devices: how to make them lightweight and long-lasting.
Batteries that power wildlife trackers make them too heavy for small bird species and limit the lifespan of such devices. By going solar and using efficient chips that coordinate processes to transmit a signal, the new tags weigh less than a gram.
“We got rid of the battery entirely,” said David Winkler, professor of ecology and evolutionary biology, who led the development of the solar tags through a bioengineering development group on campus called TABER (Technology for Animal Biology and Environmental Research). “These are the first really small, totally solar-powered wildlife tags.”
Michael Lanzone, CEO of Cellular Tracking Technologies (CTT), signed a licensing agreement with the Center for Technology Licensing at Cornell University last summer and is now commercially producing the trackers, called Life Tags. A patent is also in the works.
Using 3-D printed harnesses developed by TABER and CTT, Life Tags can be permanently attached to birds without discomfort or hindrance, allowing researchers to track small birds over the course of their lifetimes. Ornithologists may now gather invaluable data on migration routes and dispersal, the movement from a young bird’s natal site to where it first breeds. The data promise to reveal valuable information about dispersal patterns, a life event that is poorly understood even though it affects every aspect of a species’ population biology, Winkler said.
One challenge of the small solar tags is they lack the power to connect with a satellite, which limits their range to just a mile or two. “That places the burden on you to get a receiver near your bird, by putting receiver stations in places where you think the birds will collect, a roost site or a migratory concentration point,” Winkler said.
To address this issue, Winkler and Lanzone and colleagues are testing a concept of using larger birds to track smaller birds, the first trial of which they are calling “VultureNet.” Turkey vultures with a battery-run receiver tuned to the frequency of the Life Tags will share air space and migration routes with smaller birds, such as tree swallows or sanderlings, that ornithologists want to study.
When the bigger bird flies within a mile of a swallow fitted with a Life Tag, it will transmit the tags ID along with GPS location and time to a satellite or cellular tower, enabling researchers to collect data remotely. “We want to do this in habitats around the world,” Winkler said.
Winkler and Lanzone are already planning an AlbatrossNet, to distribute receivers in the open ocean. Among other projects, they are also working with a colleague in Canada to design a tag and harness for eared grebes, an aquatic diving bird, and with colleagues in Monterey Bay, California, to design a Life Tag for sea otters.