A male jay chases away an unrelated jay encroaching on a piece of food. Photo by UZH
ZURICH, Switzerland, Oct. 26 (UPI) -- Previous research shows some birds, mammals and fish species recognize never-before-seen siblings. Now, a new study proves Siberian jays identify even more removed familial links.
According to researchers at the University of Zurich, Siberian jays are able to pick out unfamiliar, distant relatives. Scientists say the ability is beneficial for cooperative species like jays.
Siberian jays are a member of the crow family, native to Northern Scandinavia and the Siberian taiga. They're a rather fearless and curious species, unafraid of humans and known to snatch food from snacking campers.
Their aggression isn't reserved for humans, though. It is often directed at other jays. Breeding pairs will frequently chase away unrelated non-breeders from food.
While observing groups of Siberian jays -- which had been genetically tested for relatedness -- Zurich scientists found that birds more aggressively chase those who were most distantly related.
"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," lead study author Michael Griesser said in a press release.
But scientists found the jays decline to use this ability when caring for offspring. When researchers experimentally switched offspring from one pair with offspring from another, the parents treated all the young the same -- sharing food with them and protecting them potential predators.
Griesser says jays evolved their recognition skills as a result of their propensity for cooperative feeding.
When a group of Siberian jays gather at a large carcass, birds tend to tolerate the sharing of food among closer relatives -- lending family members a leg up in the competition for survival.
"It's a selective advantage to share food only with close relatives and not very distant or unrelated individuals," concluded Griesser.
But while other species recognize relatives via appearance or call, researchers aren't yet sure how jays yield their unique recognition skills.