Introduction

The interaction between a predator and its prey represents a dramatic example of animal behaviour in which the capabilities of nervous systems are stretched to the limit. A hunting animal faces the fundamental problems of detecting and localising the prey, and it must solve them on the basis of purely passive information given out inadvertently by the prey. This is a formidable task and it has led to the evolution of some remarkably sophisticated neuronal systems in species that are adapted for hunting.

If one is asked to name a hunting species, the natural choice is a suitably complex animal such as a large cat or a hawk. These animals do, indeed, possess central nervous systems with the necessary sophistication to handle the complex task of tracking prey, but this sophistication makes most birds and mammals unsuitable as subjects for neuroethological research. However, the difficulty can be overcome by looking at species with a highly specialised method of hunting, based on a sensory system that is dedicated to the specialised method of prey detection and localisation. It then becomes easier to correlate the properties of particular neurons in that system with the particular behavioural task (see section 1.2).

Such dedicated systems are found in two groups of animals that employ hearing as a means of tracking prey, namely owls and bats, which use specialised auditory systems to hunt at night when visually guided predators are at a disadvantage.