Donated corvids: The social life of birds in the Corvidae family determines their generosity, a new study shows. According to this, even with ravens, crows, magpies and the like, joint rearing of young and low aggression towards conspecifics who come close lead to generous behavior – similar to that of primates. According to the researchers, parallels to human evolution become visible.
Ravens and their relatives are among the most intelligent animals in the world: They can count, use tools, solve brain teasers and even plan ahead. They are surprisingly flexible and capable of learning. But their social intelligence is even more pronounced. Because the birds, which live in complex, constantly changing associations, know very well who has which social rank and with whom teamwork is worthwhile.
Only shaped by selfishness?
In particular the ravens, which are also native to us, are also known for their rather selfish behavior. But do all corvids only act for their own benefit? An international research team led by Lisa Horn from the University of Vienna has now got to the bottom of this question. To do this, they examined a number of different species of raven bird for their generosity. Previous studies had experimentally demonstrated generous behavior mainly in humans, primates, and very few bird species. In human evolution, generosity is said to have arisen as a result of raising the offspring together in a group and a low potential for aggression, according to the common assumption.
In their experiment, the researchers compared the prosocial behavior of a total of eight bird species in the Corvidae bird family – the corvids. Some of these species raise their offspring collectively, while others do not. Similarly, some of the tested species nest in a confined space with their conspecifics, while others suspiciously defend their territories against conspecifics. In the experiment, by landing on a perch, the birds were able to trigger a seesaw mechanism that brought food within reach of their group members. But she could never reach the food herself. The researchers described the animals that provided food for the other group members throughout all of the test rounds as generous.
The closer they live together, the more generous
The experiments showed: The social life of the corvids is decisive for whether the animals give something to their conspecifics or not. It was found that especially those corvid species that raised their young together gave up their own food in favor of others. An example of this are magpies. In the case of the male animals, the scientists also noticed that their generous behavior depends on the close coexistence with their conspecifics: the males of those species that nest without conflict in a confined space with other animals were particularly generous towards the group members. These results confirm that community rearing and low potential for aggression encourage the appearance of generous tendencies not only in humans and their ancestors, but also in other animal species.
“Spontaneous generosity without always expecting something in return is a cornerstone of human society,” explains Horn. “I am particularly fascinated by the fact that even in animals, which are so different from us humans, apparently very similar evolutionary mechanisms have contributed to the development of generous behavior as in our human ancestors.” According to the research team, this may even show a parallel to human evolution. To further investigate these relationships, however, further experiments with other birds, such as the equally intelligent parrots, or completely different animal species will be required in the future, according to the scientists.
Source: University of Vienna, Article: eLife, doi: 10.7554 / eLife.58139