Males of bottlenose dolphins during group attracting females sinhroniziruete not only their movements, and vocalization. It found a group of Australian scientists, which analyzed data on the generated groups of bottlenose dolphins in shark Bay, and combined them with data about their vocal communication. It turned out that the male bottlenose dolphins do not only adjust to the frequency produced by each other sounds, but also engage in a duet with intervals up to 100 milliseconds. It not only provides reproductive success, but also helps to reduce stress within the group, write the scientists in the Proceedings of the Royal Society B.
In the natural habitat of bottlenose dolphins, males form small alliances, thereby ensuring its reproductive success: typically, these unions comprise from 4 to 14 males, but sometimes are broken and in pairs. In the presence of a desired female, the male performs complex synchronous movements around it to attract attention. The next step is to limit the movement of females to she paid no attention to other males. This is done in a fairly aggressive (the males beat the female nose) and is reinforced by a characteristic vocalization at low frequencies (from one to two kilohertz).
In fact, this is the vocalization must also be synchronized between males — exactly the same as their movement — but the proof of this has yet been received. To get it, Bronte Moore (Bronte Moore) from the University of Western Australia, and his colleagues for two years (2016 to 2018) have collected data on the communication pairs of male bottlenose dolphins in Australia’s shark Bay: all they managed to record vocalizations 59 males, divided into pairs. The duration of all records was 22 hours and 5 minutes.
Record the vocalizations of males, the scientists combined with the data obtained in the course of 30 years of observations of bottlenose dolphins in shark Bay: so they were able to identify the participants formed unions.
After analyzing the data, researchers found that male bottlenose dolphins when you are surrounded by females in reality sinhroniziruete their vocalization, singing the typical songs on the same frequency. The average vocalization 600 BPM (10 beats per second), the males are able to reduce the interval between vocalizations each other to 100 milliseconds. For comparison, people can quickly and accurately adjust bit rates up to 200 beats per minute.
This, of course, pure vocal synchronization of vocalizations of bottlenose dolphins is still not characterized (taking into account the presence of a small interval). Scientists explain this by the fact that the males are not profitable to sing in unison, the sounds overlapping each other, as in the case of this female, it may seem that males around it is smaller than it actually is.
In addition to ensuring reproductive success, have synchronized vocalizations, as scientists believe, is another important task of such cooperation helps the males to reduce social tension arising from the fact that, having won the female from a group of enemies, they in the future will have to choose who it will fertilize.
Of course, the ability to cooperate bottlenose dolphins do not lose and in captivity: for example, in October, Japanese scientists taught three males to get the toys with the help of design, which is driven only if the strings it will pull two at the same time.