Beak Movements Research Articles

The performance of nest building by domestic hens: is it more important than the construction of a nest?

Domestic hens were presented with three different types of littered nest: a flat litter surface (A), a preformed hollowed nest (B) and a preformed nest with an egg (C). Nests B and C had been previously constructed by the hen under test. The overall duration of pre-laying behaviour was greater in nest type C than in both nest types A and B. Of the three nest-building behaviour patterns, gathering, in which the hen moved litter nearer to her body with head and beak movements, and litter-placing, in which she picked up particles of litter and dropped them over her shoulder, increased in the preformed nests compared with the control. Rotating, in which the hen crouched on the nest, rotated and scraped outwards with her feet, did not differ between treatments. Thus, nest-building behaviour was not inhibited by the existence of a preformed nest. This finding does not support the hypothesis that animal welfare in intensive housing can be safeguarded merely by providing that environment which would have been created by the animal's own activities. Rather, it suggests that performance of behaviour can in itself be reinforcing and that provision is required for such behaviour to be carried out. This finding may also have important implications for general motivational theory.

“On-line” monitoring of jaw movements in the pigeon

A system for the monitoring of jaw movements in the pigeon is described. A Hall-effect device mounted on the pigeon's upper beak is used to sense voltage changes induced by variations in the position of a magnet mounted on the lower beak. Analogue voltage changes are digitized and monitored by a microprocessor. The system produces data comparable to that obtained using high speed cinematography but permits “on-line” measurements of gape and increases the rapidity of data acquisition and analysis. It may be used to monitor beak movements during consumatory (eating, drinking) and conditioned (key-pecking) behaviors.

The Effects of Precision Feeding on the Behavior of Adult Cockerels

The behavior of 15 precision-fed (PF) cockerels was compared with that of 15 normal (N) and 15 fasted (F) birds. In the 10 min after feeding, the PF birds had a higher incidence of beak movements (P<.01) than N and F birds. Five PF birds retracted their heads and necks, and 3 made regurgitation-like movements, but the effects were generally slight and fleeting. When a flock of 48 PF birds was observed more casually, only 2 birds showed abnormal behavior. The low incidence of conspicuous abnormal behavior, after precision feeding, in contrast to that reported by Wehner and Harrold (1982), is probably due to the shorter time required to administer the feed.

The effects of zinc deficiency on oral behaviour and taste bud morphology in chicks.

The number of beak and tongue movements was measured in chickens (Gallus domesticus) following oral stimulation with different concentrations of quinine hydrochloride (0.01 to 0.25 M), acetic acid (0.25 to 5.0 M), sodium chloride (0.5 to 5.0 M) and distilled water. The birds showed an increase in behaviour with increasing concentration up to a certain point, when the response showed no further increase. 2. Two groups of chicks, one fed on a normal diet and one fed on a diet deficient in zinc, were stimulated orally every 3 to 4 d with 0.1 ml of sodium chloride (2 M), acetic acid (2 M), quinine hydrochloride (0.1 M) and water, and the numbers of beak and tongue movements were recorded. 3. All the birds fed on the zinc-deficient diet showed significant increases in beak and tongue movements compared with the control birds. The time of onset of this increase in behaviour was variable: with quinine hydrochloride it was 3 d whereas with acetic acid, sodium chloride and water it was between 6 and 9 d. 4. The morphology of the taste buds in zinc deficiency was investigated and there was no evidence of primary or preferential involvement of the taste buds; these structures were either morphologically normal or were involved in a generalised degeneration of the epithelium. 5. The increase in oral behaviour is discussed in relation to the possible ageing of the taste cells and to the general degeneration of the oral epithelium.