It turns out that dolphins have the best memory in mammals - these animals are able to recognize their friends who had not seen for over twenty years. This recognition occurs not their appearance, and the voice. This ability is needed to dolphins in order to maintain social ties in the pack for an extended time.
Not so long ago, scientists from St Andrews University (UK) found that dolphins have individual voice signals similar to human names. Found it this way - recording conversations of these animals, the scientists noticed that the Dolphins have always started with the phrase unique sequence of sounds, that is, as if they were presented to their relatives. Thus, it became clear that the members of the dolphin pack quite aware of themselves as individuals.
Detailed feature of the behavior of primates sea greatly facilitated the study of the behavior of these unique creatures. After all, if the dolphin has a name, it is easy to find in the analysis of recorded voices. Moreover, the habit contact their relatives by name helped biologists from the University of Chicago (USA) to establish that these animals have a very good memory - they remember other people#39;s names over the past two decades. And it gives them the ability to quickly find your old friends, even after a long separation.
To find out, the researchers did a great job - they are within five years of recorded sounds have caught bottlenose dolphins (Tursiops truncatus), who lived in zoos and biological stations. It should be noted that all the animals that have taken this kind of interview from time to time transported from one place to another - so that they could form a pair for breeding. For example, some dolphins were taken away from old friends just three months, while others were separated from their twenty and a half years. The history of all these movements, the scientists also carefully recorded.
Among the animals that took part in the experiment were different in the age of the specimen - from four-month, to those who turned 47 years old. Scientists have recorded the voices of both males and females. After these recordings were made, there was a second series of experiments - biologists lost dolphins strange voices that belonged to strangers or individual, or those whom they once knew well. In the end it turned out very interesting thing - even if an unfamiliar voice belonged to someone from animals of the same age and sex as the student, the Dolphins generally does not react to it.
But when the owner was once a familiar voice to listeners, they immediately responded - swam to sounding dynamics and even tried to engage him in conversation. In one experiment, there was a very unusual thing - a young mother not only swam to the voice of his old friend, but also brought a baby to the one talked to her former friend. Thus it became clear that the Dolphins do have a very good memory - the authors of the report is that in one experiment, two females recognize each other by voice, although since their split was about twenty and a half years. This is a record for social animals - none of the animal world (except for the people, of course), does not remember his friends for so long.
It was also discovered that dolphins can store not only the voice, but the nature of the relationship that bound them to the owner of such. For example, in one experiment, two males lost the record of votes of two of their relatives, who were dominant individuals in that pack, where students lived before. In the end, hearing the conversations of their former bosses, the animals began to behave very carefully and slightly alarmed. This is due to the fact that at the time of marriage, they often get a scolding from the owners of the two votes.
According to scientists, the ability to remember voices dolphins need to maintain social ties in the long term. Indeed, in the wild, these animals do not restricted to their own group, and each dolphin can get away for a while to live in a neighboring pack, and then back again. However, his appearance during absences may change dramatically - for example, the body may well be new scars received in battle with the sharks or by their own relatives, but its distinctive call sign, however will remain the same. So with this way of life is important to primates sea immediately find out who is currently approaching the flock - a stranger from whom you can expect everything you want, or an old friend, who decided to return from wandering.
However, while the researchers can not say how exactly is going on recollection - whether in the mind there is the image of the former dolphin friend when he hears his voice. For example, it is known that horses can combine the familiar look of an individual and his neigh - held at the time experiments showed that if the voice does not match the animals submitted to the external appearance of neighbor, the horse is very, very surprised it. Presumably the dolphins present exactly the same mechanism of memory, but without undue experimentation is safe to say that you can not ...
