After more than 10 years of research, Associate Professor Yuki Kawabata of Nagasaki University and his colleagues have discovered a highly universal phenomenon in which prey run away from predators in multiple directions. We succeeded in theoretically explaining it for the first time in the world using a model (geometric model).
Until now, it has been confirmed that a wide range of taxonomic groups, including fish, amphibians, insects, reptiles, and mammals, have multiple preferred escape directions, but no theoretical explanation has been given.
In this study, using fish, we found the suitable direction (120 to 140 degrees to the predator) and the suitable direction (170 to 180 degrees) to fend off the predator's attack. ), and it was found to be easier to catch in an intermediate direction.In addition, by changing the parameters of the mathematical model, it is possible to explain other patterns of escape directions, which could be a basis for understanding escape directions in animals in general.
In addition, not only the best direction for escaping, but also the second best direction was used while changing the frequency of use according to the difference between the first and second best directions.For example, when approaching a predator from the side, the dodge direction (1-2 degrees) is the best choice, and the shake-off direction (1-2 degrees) is the second best choice, considering the time it takes to change direction.In addition, if the difference in ease of escape between 120 and 140 is about the same, both will be used with a probability of about 1: 170, and if the difference in ease of escape is large, the percentage of using 180 will be increased to about 2%. was using both.
The results of this research will also provide important findings in the field of neurophysiology in terms of what neural circuits determine the direction of escape.It is also expected to be applied to the problem of collision accidents between cars and wild animals, fishing gear and fishing methods, and sports science.