Imprinting: a comparative study of a range of avian species.

Abstract

This thesis investigates the field of imprinting by comparing the behaviour of a range of precocial, nidifugous avian species, i.e. types of bird which leave their nest soon after hatching. In the first chapter literature relevant to imprinting is reviewed. A fact emerging from this review is the lack of comparability between various imprinting experiments. In this thesis the importance of experimental uniformity is stressed. It had been thought by Lorenz: (1935) that some species of wader, i.e. curlews (Numenius arquata), and godwits (Limosa limosa), could not imprint on an inappropriate stimulus. This suggestion was investigated in the present comparative study in which, for the species studied, the experimental method was kept uniform. In the second chapter the experimental method is described as is the type of species and the taxonomic group from which they come. The species used were: the domestic fowl; pheasant; partridge; wild mallard; curlew; lapwing and oyster-catcher. The stimulus used to encourage approach from these species was a rotating, white disc, with a 45 red sector. In the third chapter, four experiments are described. In the first three experiments the effects of various stimuli and training procedure in imprinting, were investigated using domestic fowl. This was done in order to examine the effectiveness of the stimuli in inducing approach. The fourth experiment compared a range of species responses to a combined visual and auditory stimulus. In chapter five, two further experiments are described which were conducted on lapwings, extending the generality of conclusions from experiment four. Chapter six contains the conclusions drawn from the experiments, and the need to consider the natural parent-chick bond is stressed.