Grachi can collaborate not worse than primates
It turns out that boss may collaborate with each other to produce their food, as do primates. Previously, scientists were convinced that "co-operation" between the birds probably only in the construction of nests, said New Scientist.
Amanda Seed of the Institute for Evolutionary Anthropology in the Max Planck (Leipzig, Germany) and her colleagues ILC to see how the four pairs of rooks. Experts put the tray 60 centimeters in length, filled with food, beyond the reach of two rooks, sitting in a box. Birds could see through the food slot in the box, but that stretch of the tray slot, they had to take a rope, prodetoy through holes in the rear gutters. Notably, cope with this task alone birds were not in a position - tray could move only if both pull for both ends of the rope.
The experiment showed: all four pairs experimental bird quickly realized that he needed to do to get access to food, and the united efforts. Above this kind of interaction was observed only in primates. But when scientists tried to complicate the task gets "provalili" experience. In particular, the researchers again put the tray with food beyond the reach of one gracha, and the second tank of birds in the related department of the box. Thus, the second grachu required to enter in to sorodichu department, and only then it can gain access to a rope. However, the first bird never await until coming to the aid of a partner, and pull the rope in spite of the futility of efforts. Primates in the same situation behave differently - for instance, chimpanzees do not begin until waited partner.
As Amanda Seed, boss may not be fully aware of what benefits they can bring cooperation with each other, because monogamous birds and rarely compete with each other. In a polygamous society chimpanzees, by contrast, each specimen interacts with other monkeys and quickly understand what benefit to the "Biological market" can be obtained from mutual aid.