It was long thought that songbirds did not use their sense of smell. That was because a 1968 study had found that the olfactory bulbs in their brains are smaller than those of other kinds of birds.

But a new study reports that zebra finch fledglings can recognize their relatives by smell.

Although the olfactory region in the finches “is small, it seems to work,” said E. Tobias Krause, a biologist at Bielefeld University in Germany and one of the study's authors.

Krause and his colleagues report their findings in the journal Biology Letters.

After the zebra finches hatched, the researchers placed the chicks in different broods, away from their parents.

At the age of 20 to 23 days, each bird was presented with odour samples from the nest it hatched in and the nest that served as its foster home.

The birds indicated their preference by entering or perching in front of the artificial nest box that produced the more appealing odor.

“They choose the nest of their genetic parent,” Krause said.

Detecting relatives

The birds may be using smell to detect relatives and avoid inbreeding, Krause said.

“Our results are restricted to zebra finches, but it is very likely that other songbirds and other birds have this capacity for kin recognition,” he said. .”

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