Scientists used to think birds build nests that look like the one they were born in — generation after generation. But new research from the University of Alberta and the University of St. Andrew’s in Scotland proves that assumption wrong, instead identifying a bird’s early adolescence as the key point in time that affects nest creation.
“Adult birds will use social information when they come to build their nest, so we wanted to know how young birds learn,” says Lauren Guillette, an assistant professor in the department of psychology at the University of Alberta and lead researcher on the project.
The researchers thought there might be a specific point in development when the nest building skill is learned. To identify when in development that might be, they allowed zebra finches to hatch into nests and grow up semi-normally, says Guillette. Then as adults, the birds built their nests without any outside training or direction.
“These birds, based on what we’ve known so far, should have built nests similar to the nest they were born into. They didn’t,” says Guillette.
They found that the presence of an adult bird during early adolescence — from 60-90 days old — is important for how a young bird learns. Birds who had adult males present during this time “overwhelmingly” chose to build nests of the colour they were in at the time.
“If [the bird] is playing with that material but there’s no adult around, it has no effect,” says Guillette. “There’s something magical and special about having an adult around, that seems to affect what colour [a bird] builds when it’s an adult.”