Birds may have a more highly developed sense of smell than researchers previously thought, contend scholars who have found that penguins may use smell to determine if they are related to a potential mate. The research by the University of Chicago and the Chicago Zoological Society, which manages Brookfield Zoo, shows how related birds are able to recognize each other. The study, published Sept. 21 in the journal PLoS ONE, could help conservationists design programs to help preserve endangered species.

"Smell is likely the primary mechanism for kin recognition to avoid inbreeding（近亲交配） within the colony," said Heather Coffin, lead author of the paper.

Coffin conducted the research while a graduate student at UChicago and was joined in writing the paper by Jill Mateo, associate professor in Comparative Human Development at UChicago, and Jason Watters, director of animal behavior research for the Chicago Zoological Society.

"This is the first study to provide evidence for odor-based kin discrimination in birds," said Mateo, who is a specialist on kin recognition.

Experts said the work offers important insights into how birds use smell to guide behavior.

"The work by the research group is truly groundbreaking in that it shows for the first time ever in birds how the olfactory（嗅觉的） sense of captive penguins is both informative and functional in a behaviorally critical context: namely the recognition of friends from foes in general, and relatives from non-relatives in particular," said Mark E. Hauber, professor of psychology at Hunter College, a specialist on bird social recognition.

Penguins are ideal subjects because they typically live in colonies made up of thousands of birds. They live in monogamous（一夫一妻的） pairs -- an arrangement that facilitates rearing of their young, since parents frequently take turns leaving the nest to gather food. Despite the size of the community, mates are able to find each other after traveling for days foraging for food in the ocean.

Research on other sea birds has shown that smell helps guide birds to their home territory and helps them forage for（搜寻） food. Other research has shown that birds could use sound and sight to recognize each other, but no other studies have shown that smell might be used in connection with kin（亲戚） recognition, Mateo said.