Wednesday, November 24, 2010

Social Cognition of Turkey - Thanksgiving Dinner

Science and Ben Franklin on the Turkeys - here:

It is well-known that when the bald eagle was picked for the emblem of America after six years of debate, Ben Franklin expressed his dismay that the turkey was not picked instead. In a letter to his daughter, he wrote,



"For the Truth the Turkey is in Comparison a much more respectable Bird, and withal a true original Native of America . . . He is besides, though a little vain & silly, a Bird of Courage, and would not hesitate to attack a Grenadier of the British Guards who should presume to invade his Farm Yard with a red coat on."

Apocryphal or not, Ben Franklin may have been on to something with the "Bird of Courage."

Wild turkeys, like many birds, are social creatures. About six months after hatching, the males from the same brood break away and form a sibling group that generally persists for life. Like any other group of siblings, they're fiercely loyal to each other and extremely hostile to outsiders. And, like most groups of social animals, there is a very strict dominance hierarchy both within and between groups. If an outsider turkey wanders into the wrong side of the forest, the ensuing fight won't be pretty. Feathers would fly and beaks would peck. Whatever injuries might be sustained in such a turkey altercation, though, aren't usually particularly dangerous or life-threatening. But domestic turkeys are a different story. While they also display aggressive behavior towards each other, injuries due to pecking are much more severe and can result in death or can necessitate early euthanization of the bird.

"Assuming that individual recognition enables stable hierarchies to be established," write Swiss scientists Drs. Buchwalder and Huber-Eicher, "it has been suggested that large flocks continually attempt to establish dominance, leading to high levels of aggression." The problem is that domestic turkeys live in such large flocks that the neural computation and memory requirements to identify each member of the flock and to distinguish flock members from outsiders may be too great, resulting in failure. It is indeed the case that domestic turkeys live in much larger flocks than their wild ancestors (which have groups containing up to twenty individuals), but it was not known whether they are able to distinguish in-group members from out-group members. Buchwalder and Huber-Eicher reasoned that if domestic turkeys directed their aggression preferentially towards members of a different flock or social group, they might indeed be able to distinguish among individuals.

No comments: