Blood maybe thicker than water when it comes to human relationships and it seems that the same is true of jackdaws(寒鸦) after scientists found they readily change friends to gain food but stick with family even at the risk of going hungry.
Alex Thornton, a professor of leaning ability development, said, "We kept track of hundreds of wild jackdaws, each of which was equipped with a small chip. In this experiment we divided jackdaws into two groups—A or B—and programmed a pair of computer-controlled devices(装置) to provide worms. Only if individuals from the same group (AA or BB) visited together, will they get the worms." If birds from different groups arrived together—A with B―the feeders would remain closed. Single birds would I get seeds(种子), but not the worms that they preferred.
Thornton said, "We wanted to find out if jackdaws could build new relations with new partners. They might have friends in the wrong group. Do jackdaws leave them and start to hang out with individuals who are in the right group? The jackdaws turned out to be very smart quickly learning to give up friends from the wrong group to get the best food. However, they acted differently when it came to their close relations even if they got nothing.
Thormton said jackdaws were an excellent subject matter as they were clever and had energetic social networks. "You've got individuals coming and going far beyond their strong relationships, and they have lots of other company. They are similar to human society." Michael Kings, of the University of Exeter, said, "These results help our understanding of the development of intelligence as they show that being able to track and remember information about social partners can bring them good."
