African grey parrots help their peers complete tasks despite no immediate benefit to themselves, researchers have found in the first study to show that birds display such apparently “selfless” behaviour.
Writing in the journal Current Biology, Brucks and colleagues report how they tested African grey parrots in a task that involved the birds passing a token, in the form of a metal ring, through a hole in their section to a neighbouring bird of the same species. This token could then be passed by the second bird to a human, via another hole, who would exchange it for a piece of nut.
The team found African grey parrots helped their neighbours by passing tokens to their neighbour when a human held out their hand, allowing the second bird to drop it through-the hole and receive a tasty treat.
The same behaviour was seen when the roles of the birds were reversed (颠倒). The more tokens a bird had previously given, the more they received in return.
However, the team stress previously the birds did not know that their favour would be rewarded, suggesting it is something of a “selfless” act.
The team say it may be due to African grey parrots gathering in huge flocks at night but splitting into smaller groups during the day to forage (觅食). Brucks said such behaviour is thought to require strong social cognitive abilities, adding that being helpful might help the birds gain a good reputation with their peers, making it more likely that they would team up for foraging and other tasks.
Dr Manon Schweinfurth, an expert in animal behaviour, said evidence of reciprocal (互惠的) behaviour in African grey parrots is quite interesting. “It has been thought that it is so cognitively demanding that only humans can show it. But we now get more and more evidence from other animals that they are able to show reciprocity,” she said.
【小题1】What is paragraph 2 mainly about?| A．The methods of observation. | B．The comparison of the species. |
| C．One feeding behaviour of parrots. | D．One example of Brucks’ experiments. |
| A．A strong survival instinct. | B．A desire for food. |
| C．The need for social cognitive abilities. | D．Curiosity towards other species. |
| A．Only African grey parrots are capable of exhibiting reciprocal behavior. |
| B．Reciprocal behavior is the only demonstration of cognitive abilities. |
| C．Other animals may possess similar social cognitive abilities to African grey parrots. |
| D．The reciprocal behavior of African grey parrots is learned through experience. |
| A．Unclear. | B．Admiring. | C．Indifferent. | D．Surprised. |
