2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
New Caledonian crows learn to use tools to pull larvae out from under the bark
Scientists have proposed a model of the influence of external factors on the development of the cognitive abilities of animals, in which childhood and parental care play a central role. The authors of the work, published in the journal Philosophical Transactions of the Royal Society B: Biological Sciences, illustrate their hypothesis with two examples: New Caledonian crows remain under the care of their parents for a year to learn how to make tools; Kukshas, who have to grow up in someone else's family, lose the opportunity to learn how to search for prey and protect themselves from predators.
Human cognitive abilities are unique, and the basis for their development is a long childhood - a period of plasticity, in which people master skills and develop cognitive potential. However, long maturation is also characteristic of other animals: bats, whales, elephants and some birds. Whether a long childhood provides a cognitive advantage for these species as well as for humans remains unclear.
Scientists from the UK, Germany and China, led by Michael Griesser of Sun Yatsen University, suggested that cognitive ability is dependent on the length of childhood, and parental care plays a key role in the development of cognitive skills. The researchers built a model of the influence of external factors on the cognitive abilities of animals, in which the contribution of parents to the education and upbringing of young plays a central role.
Model of the influence of parents on the development of cognitive skills in animals
According to the proposed model, the saturation of the environment in which the individuals develop and the adaptability to it allows one to reduce mortality, increase the lifespan and, accordingly, the period of development of the young. As a result, young animals have the opportunity to spend more time with their family, which provides protection and nourishment. During this period, cubs imitate their parents and develop their skills. Greenhouse environments are conducive to the development of a broader range of skills and cognitive abilities, and adult animals can enter new ecological niches. An important role, according to the authors of the work, is also played by caring for someone else's offspring ("extended family"). If many individuals take care of the young at once, then their protection and the ability to learn increases.
The benefits of a long childhood and parental care have a significant counterbalance - the energy consumption of these processes. To acquire an expanded set of skills, develop a large brain and remain under the protection of a family for a long time, you need to pay a "tax" in the form of resources and energy. Each type finds its own balance between the costs and benefits of the acquired skills.
The researchers illustrated their model with two examples of corvids. Corvids possess cognitive abilities that are rare among birds, they know how to use tools and plan their actions. The relative brain size of these birds is on average larger than that of other passerines; as chicks, they stay in the nest longer, and after plumage they do not immediately part with their parents.
The first example that scientists cite in their work is kukshi (Perisoreus infaustus). Some of the chicks of these corvids stay with their parents for a long time, but the more successful offspring drive out their brothers and sisters and force them to join another group of birds soon after fledging. Kukshi distinguish their chicks, and strangers do not enjoy the protection and patronage of their elders. As a result, for example, they do not learn to drive away predators or get food, and they turn out to be less adapted. In the experiment, it was shown that if you give stranger chicks the opportunity to copy the behavior of their elders, they successfully master the necessary skills.
The researchers chose the New Caledonian ravens (Corvus moneduloides) as a second illustration of their hypothesis. These birds know how to make tools - hook-shaped sticks, with which crows pull the larvae out from under the bark. Chicks remain under the care of their parents for a long time, repeat their movements and learn to use tools. Birds learn such a complex skill throughout the year, and at this time they cannot get food on their own. Long-term dependence on parents is extremely resource-intensive, but as a result, crows acquire a wide range of cognitive skills, are able to solve complex problems and establish cause-and-effect relationships.
The researchers suggest that the protracted period of childhood inherent in humans predetermines the outstanding cognitive abilities not only of primates, but also of other animals with developed intelligence, and the upbringing and care of parents are critical factors for the formation of complex cognitive skills.
From the editor
Initially, in the note, the author indicated Perisoreus infaustus, the name of kukhs, as the Latin name for the New Caledonian ravens. Thanks to the direction of attentive readers, we noticed and fixed this error.
The cognitive performance of animals is often associated with relative brain size. Before the Cretaceous-Paleogene extinction, bird brains were no larger than that of tetrapods, while the catastrophe freed up ecological niches, and the relative size of the birds' brains began to increase rapidly. Perhaps it was the largest extinction that predetermined the development of the intelligence of birds.
