CORVALLIS, Ore. - Researchers at Oregon State University are planning to attach miniaturized cell phones to migrating songbirds as part of an ambitious project to determine the birds' routes and critical habitat areas.
The challenges, they say, are daunting. The payoffs, however, may be enormous.
"If we are successful, the same technology could be used to track a variety of migratory animals, not just songbirds," said W. Douglas Robinson, an avian ecologist in OSU's College of Agricultural Sciences.
Funded by a three-year, $750,000 grant from the National Science Foundation, the OSU research team plans to build a series of stripped-down, miniature cell phones that could be activated via timer as the birds near cell towers in populated areas. They plan to test the prototypes on several birds, but say such technology eventually could be used on thousands of them.
About half of the world's 9,200 bird species are songbirds and include jays, robins, chickadees, warblers and sparrows - the "birds you see around your neighborhood," said Robinson, an assistant professor in OSU's Department of Fisheries and Wildlife. The research is important, scientists say, because the number of songbirds is declining. Much of that decline is attributed to habitat loss, but other factors may be involved, including nesting failure caused by the brown-headed cowbird - a species of bird that leaves its eggs in the nests of many songbirds so that those songbirds raise cowbird young, and few or none of their own.
Finding out more about the songbirds' habitat and migration routes is critical.
"We can't address management issues until we know what these songbirds do and where they go," Robinson said.
Robinson said he came up with the idea of using cell phone technology to track the birds, but admitted he had no idea if it would work. So he called up faculty members in OSU's College of Engineering and asked them if they could create an instrument that weighed as little as two grams.
Enter Huaping Liu, an assistant professor of electrical and computer engineering, and a former systems engineer for code-division multiple-access mobile cellular systems at Lucent Technologies.
"It is a very, very challenging problem," Liu said. "The first step is to strip down all of the functions that are unnecessary. The birds don't talk. They don't need games and voice mail. What is important is that when the phone powers on, it sends a signals to the cell tower that identifies which bird it is. And then we need to work with the cell companies to identify the tower locations."
Robinson, who has worked with songbirds throughout his professional career, told his engineering colleague that the weight of the phones could not exceed 5 percent of the birds' body weight. That means they will have to be as light as two grams - or the weight of two dimes.
"Another challenge," Liu said with a smile. "We think the way around that is to implement a digital clock. We'll use migration estimates from the biologists and when they think birds may arrive in an area, a pre-coded timer will turn on and try connecting with cell towers five, perhaps 10 times. If they don't connect, they'll switch off and conserve power."
Liu said he estimates that current battery capacities will allow them to try connecting to the towers about 20 times during a three-week window.
"We should have a very high probability of connecting," he said.
Whatever the odds are, they certainly will be better than previous attempts at tracking songbirds. Researchers have tried to track individual birds across long distances by other means, such as placing small, metal bands on the legs of birds captured in one place, and then releasing them and hoping they would be recaptured by researchers elsewhere. That turned out to be rather inefficient: Of one million pied flycatchers captured and marked in Europe during the summer, only one has been recaptured on its African wintering grounds.
"That certainly slowed down efforts to track small migrating birds," Robinson said. "With mammals, you can use larger batteries and monitor movement through satellites or other technology. Even with larger birds, you can use batteries with solar chargers, but they weigh at least 18 grams."
Robinson said he has a verbal agreement with TMobile to get information on individual cell towers that will help identify the birds' location, and he hopes to connect with other cellular companies. But the researchers have a lot of work to do first.
Liu and his engineering colleagues Terri Fiez, Zhong Feng Wang and Kartikeya Mayaram must create the prototype and test it on cell towers in the Willamette Valley, hopefully by early 2007. They need to determine how close the birds must get to the cell towers before a connection is made.
Later that year, they plan to do their first long-distance test, using purple martins, Robinson said.
"It is a bird that winters in Brazil, generally flies in the open, and breeds in cities in the eastern United States, frequently using backyard birdhouses," Robinson said. "So it should be close to a lot of cell towers."
Robinson said if they are successful, there may be a number of other applications for the technology - and not just for wildlife biologists.
"The military is interested in the results, and so is the medical community," Robinson said. "With cardiac patients, for example, you could monitor heart rhythms and if a troubling pattern emerges, the 'cell phone' could send a signal directly to a physician for diagnosis.
"This is just the tip of the iceberg."