Control of feeding patterns in the barbary dove (streptopelia risoria)

Abstract

This thesis reports a study of the temporal patterns of feeding behaviour in the Barbary dove or Blonde Ring dove, Streptopelia risoria. The normal diurnal distribution of feeding in the intact, freely feeding bird is described, as is the way in which this pattern may be altered by,a. surgical manipulation which removes much of the sensory inflow from the trigeminal nerve. On the basis of the observation of the effect of this sensory trigeminal nerve section in the doves, an alternative interpretion of the role of this nerve in the control' of feeding behaviour and food intake in birds to that presented in the literature, is offered. In line with this interpretation, it is shown that a manipulation of the physical nature of an offered food material will produce a change in the temporal patterning of food intake in a way similar to that brought about by trigeminal nerve section, and that the past feeding experience of a bird has an effect on the probability that nerve section will produce a noticeable disruption in gross food intake. The fine structure of feeding behaviour is described to demonstrate the principle that the feeding control system of these birds acts so that future needs are anticipated, and it is shown that environmental cues giving information about future deprivation are used by them to feed in advance of such deprivation. In addition, the feeding behaviour of the birds in a continiousy fixed ratio operant situation is described, to show how the means of observing a behaviour can alter the pattern of that behaviour, and also how this alteration can give information about the operation of the underlying control system.