Abstract:

A stochastic modeling framework for representing and simulating marine-mammal spatial distributions, collective motions, and vocalization occurrence times was previously developed [J. Acoust. Soc. Am. 101, 3197(A) (1997)]. Emergent behaviors in these models include clustered and polarized motions simulating collective motions of marine mammals. The present work explores the potential of these models for representing and simulating more complex acoustic emission and collective motion behaviors related to short-range echolocation and predation by dolphins. A simplified predation scenario is constructed by including predator, prey, and nonprey species in the collective motion model. Echolocation is simulated by a simplified, sonar equation-based representation of the backscattered acoustic energy, with different backscattering characteristics for predator, prey, and nonprey individuals. Parameters determining echolocation signal types and collective motion characteristics are then allowed to vary in a random search that favors parameter values leading to higher prey capture rates. Emergent collective behaviors, including echolocation signals and prey pursuit and capture, are then observed in computer-generated video animations. The potential of the models for representating sound generated by groups of marine mammals and for interpreting observed marine mammal collective behavior is discussed. [Work supported by ONR Base funding at NRL.]