LEARNING

Summary.1 This paper is concerned with the evaluation of recent studies in the learning abilities of birds and attempts to relate them to the general body of knowledge and theory concerning individually modifiable behaviour in animals. 2 Recent work on habituation or response‐waning is summarised and reference is made to the question of genetic tameness. It is suggested that relatively long‐term waning is the type of most interest to the ethologist and that where possible the term “habituation” should be restricted to long‐term stimulus‐specific decrement of behaviour. The relation of this to internal inhibition is commented upon. 3 Trial‐and‐error learning and its complement “instrumental” or “action” conditioning is discussed as a means whereby new adaptive habit and actions are acquired by birds. 4 Modern work on imprinting is summarised. It is shown that it is not a fully distinct type of learning but that its characteristics are in some respects an expression of the particular circumstances in which learning occurs. Neither is it peculiar to the visual modality nor to the following‐situation. Its most important characteristic is as evidence for the existence of strictly delimited sensitive periods in the learning of young birds or animals. The auto‐facilitating effect of such behaviour as the following‐response and the scope this gives for secondary conditioning is stressed. 5 Problems of social facilitation (mimesis or empathic behaviour) are discussed under the heading of “Imitation and Cognate Problems”. The evolutionary importance of learned discrimination, especially of predators, is considered. 6 It is concluded that recent studies of bird behaviour have added a considerable body of evidence in support of the view that much of the behaviour of higher organisms is to be regarded as a search for consummatory situations and stimuli as such, rather than as releasers for the elici‐tation of consummatory acts.