Scientists have always wondered how birds navigate their long migration paths, but it seems the answer isn't as complicated as they thought and insticts aren't the answer.
Researchers believe older whooping cranes simply teache the youngsters the route, a University of Maryland press release reported. The team also observed that the bird's got better at migrating with experience.
The endangered cranes typically make a 1,300-mile journey between Wisconsin and Florida. The research team found that migratory groups accompanied by an eight-year-old "senior" tended to stray from the route 38 percent less often than younger teams.
The experts were surprised to find no strength in numbers, the size of the group had no effect on the accuracy of their path.
"Many biologists would have expected to find a strong effect of group size, with input from more birds' brains leading to improved navigation, but we didn't see that effect," UMD Biology Professor William F. Fagan, a co-author of the paper, said.
Inexperienced birds of about a year old were observed to stray an average of 60 miles off the direct path to their Florida wintering grounds. If these novices traveled with an older group they only went less than 40 miles off route.
As the more solitary migrating "whoopers" aged, they went off the route less frequently. After about the fifth time making the trip, the bird's ability to navigate generally remained constant.
"Here we could look over the course of the individual animals' lifetimes, and show that learning takes place over many years," study leader Thomas Mueller said.
The Whooping Crane Eastern Partnership has been working to restore the dwindling whooper population. They hand raise crane chicks and teach them how to migrate using an aircraft similar to the one in the 1996 movie "Fly Away Home."
After their first human-assisted migration the young birds are on their own, although some choose to travel with other cranes. The team tracks their migration over the following few years.
"This is a globally unique data set in which we can control for genetics and test for the effect of experience," Fagan said. "and it gives us an indication of just how important this kind of socially learned behavior is."
