Rooks cooperate to get treats

["Richard W. Travsky" <rtravsky@uwyo.edu>]

Interesting dinosaur er bird behavior

http://news.bbc.co.uk/2/hi/science/nature/7322113.stm

Pairs of rooks can co-operate to solve problems, scientists report.

An experiment revealed that the rooks would team up so they could reach a 
tray of food that was inaccessible to lone birds.

The researchers from the University of Cambridge were surprised to find 
that the birds performed as well as chimpanzees at the test. 
...
The researchers presented pairs of captive birds with a tray topped with 
tasty morsels of egg yolk and mealworm - however, it was placed just out 
of reach, outside of the birds' cage.

A single piece of string was threaded through two hooks on the tray, with 
each end left dangling 60cm (24in) apart, just inside the rooks' 
enclosure.

Psychologist Amanda Seed, the lead author of the paper, who is now based 
at the Max Planck Institute for Evolutionary Anthropology in Germany, 
said: "If just one bird pulled on one end of the string, it would slip out 
from the loops.

"The question was would they work out, without any training, that they 
needed one bird to pull on one end of the string and another to pull on 
the other, simultaneously, to get to the food?"
...