Organization of Communication System in Tursiops Truncatus Montagu

Abstract

The problem of the degree of complexity and semantic capabilities of the acoustic communicative system in bottlenose dolphins has been under discussion for over a quarter of a century, ever since John Lilly published his book "Man and Dolphin" (Lilly, 1962). Nowadays, there is an abundance of literature, with different viewpoints, but no consensus has been reached so far among researchers. The problem proved to be very complicated, both methodologically and experimentally, while the methods used turned-out to be labor-consuming and, on the whole, inefficient; all kinds of straightforward attacks failed. Meanwhile, one can try and assess potential capabilities of communicative system by analysing dolphins' mechanisms ensuring its productivity, i.e. the creation of signals and messages in amounts nessesary for communication. These mechanisms ensure the encoding of information and, in accordance with the theory, their functioning, in this way or other, affects the structure of signals and their sequences, in other words,it affects the organization of communicative system. The increase of communicative system productivity in the course of evolution was associated with the expansion of the species' semantic field which, in its turn, depended on the increasing level of higher nervous activity and more complex intraspecific social relations. Therefore, there exists a close relationship between semantic capabilities of communicative systems and their organization. One can hardly imagine the existence of a developed communica-cative system in a species which does not need such a system or can not use it properly. The functioning of the system is ensured by adequately developed functions of the brain which must be capable of solving both organizational problems of communicative system control and semantic problems. Therefore, if one knows how the communicative system of a species is organized,what mechanisms ensure its productivity and how fully it uses capabilities provided by the above mechanisms, one can make an overall assassment of its semantic capabilities. The study of communicative system organization is inhibited strongly by their heterogeneity caused by a simultaneous use of several sensory chanals for communication. Consequently, signals with different physical natures, mul-timodal signals and motor behavioral acts used as independent signals, can be used within one communicative system. One can overcome this difficulty if one bears in mind that communicative systems transfer information, hence,natural SensoT.V Abi/Wes 0/ Cetaceans