Siberian jays, which are members of the crow family, have the incredible ability to recognize a distant relative even if they have never met them before.

Some animals have been known to recognize unfamiliar siblings, but this study is the first to demonstrate recognition of more distant unknown relatives, the University of Zurich reported.  Siberian jays are aggressive towards unrelated non-breeding birds of their species, and tend to chase them away from food sources. This evolved ability to recognize distant kin could serve to prevent this behavior between family members, keeping the gene pool strong.

"This finding reveals that Siberian jays are able to recognize fine-scale differences in their kinship to other individuals, even to individuals that are unfamiliar to the breeders before they settle in their group," said the first author Michael Griesser. While other bird species identify relatives based on their appearance or calls, it remains still unclear how Siberian jays assess the degree of kinship of unfamiliar individuals.

Siberian jays do not breed cooperatively but are extremely cooperative in other respects such as with food resources. Parents share food with their offspring for years after they are fully grown. The researchers noted that in an interesting twist, Siberian jay parents were equally generous with their own nestlings and nestlings from other parents that were swapped out experimentally. The jays have been observed gathering around large food sources such as dead mammals, and remaining tolerant to their unfamiliar family members.  

"It's a selective advantage to share food only with close relatives and not very distant or unrelated individuals," Griesser said.

Recognizing distant family members is also an extremely important tool for preventing inbreeding, so the ability may be more common in the animal kingdom than we thought and simply overlooked.

The findings were published in a recent edition of the journal Molecular Ecology.