2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
Aberdeen Angus calf
Among cows, as well as among humans, there are optimists and pessimists, Canadian zoologists report in Scientific Reports. According to scientists, knowing the individual characteristics of animals is important in order to provide them with the best care.
Some animals behave differently in stressful situations, which, scientists believe, may be due to their individual characteristics. Thus, experiments show that among dogs and pigs there are optimists and pessimists: the former, as a rule, show curiosity in new conditions, while the latter, on the contrary, express distrust. The authors of the new work decided to find out if there are similar patterns of behavior in cows, and if so, how they are related to their character traits.
To find optimists and pessimists among cows, scientists conducted an experiment with the participation of 22 calves. First, each animal was placed in a special enclosure, in the wall of which there were five windows located in one line. In the left opening there was a bottle of milk, and in the right opening there was an empty bottle and a device that abruptly released air, frightening off the calves. After the subjects remembered where the reward and where the punishment were, the scientists proceeded to the main stage of the experiment.
Now the bottle of milk was placed in three intermediate holes between the two outer ones, which were already empty. Then the researchers monitored the behavior of the calves. According to their hypothesis, optimists should have approached the bottle, even if it was close to the hole, from which a sharp stream of air was previously blowing. Conversely, pessimists had to avoid the new item, even if it was close to the hole where the treat was in the past.
Delay time before the calves approach the milk bottle. The x-axis is the first session, the y-axis is the second session. More optimistic cows are on the left side of the graph, while pessimistic cows are on the right.
All animals behaved differently, but their behavior remained unchanged for three weeks from the beginning of the experiment. Zoologists have concluded that pessimism is an individual trait, and not the result of temporary moods or emotions. Due to the lack of strictly polar behavior of animals, scientists do not directly indicate the number of unambiguous optimists or pessimists, but the distribution of the calves' reaction can be seen in the graph above.
In addition, the scientists decided to find out how the behavior patterns are associated with the characteristics of the character of cows, in particular with fearfulness and sociability. They conducted four tests that assessed the calves' reaction to unfamiliar situations, such as a new pen or an object in it. While sociability and behavior were unrelated in the main experiment, fearfulness was correlated with pessimism.
According to scientists, their work will help to better understand the behavior of farm animals and provide them with appropriate care. In the future, zoologists plan to find out what conditions are more suitable for optimistic and pessimistic calves.
Individual character traits are inherent not only in mammals, but also in fish - sharks and guppies show different reactions to stress. Zebrafish, in turn, are prone to emotional fever, which is characterized by a short-term increase in body temperature in conditions of danger.
