Experiments On the Relationship Between the Hen and Chick (Gallus Gallus): the Role of the Auditory Mode in Recognition and the Effects of Maternal Separation

Abstract

In a series of 6 experimental studies, the means by which a chick recognises its mother, and the reversibility of filial attachments were examined using bantam hens and their chicks. In a simultaneous discrimination test it was determined that the chick could discriminate between own and alien hens by means of the hens' cluck vocalizations, on the 4th and 8th days post hatching, (Experiment 1). The chicks could make this discrimination more efficiently when live hens were presented (Experiment 2). On separating the hen and chicks for 4 h on the 4th day, the chicks could no longer discriminate between own and an alien live hen (Experiment 3) while they would accept an alien hen, (Experiment 4). These findings suggest that maternal-filial bonds may be reversed with little difficulty. Thus Experiment 5 was designed to examine the stability of these later maternal filial bonds. Chicks spent the first 3 days post hatching, with the hen who incubated the eggs. Then they spent 3 days with an alien hen, after which 3 days isolation followed. It was found that chicks could discriminate in favour of their own hen after the first period of exposure, and in favour of the alien hen after the second period of exposure. Following 3 days isolation they showed no preference for either hen. Experiment 6 was essentially a replication of Experiment 5, but included a control for familiarity. Only one test took place after the 3 days isolation. The chicks were presented with the 1st 2nd and an unfamiliar alien hen. The chicks did not discriminate in favour of any particular hen. It is concluded that after 4 h or 3 days isolation, the chicks did not discriminate between the hens presented, yet they remained responsive to hens.

Roots of a social brain: Developmental models of emerging animacy-detection mechanisms

“…Imprinting is reversible after the exposure to a second object, if both the first and the second objects to which the young animal is exposed are either naturalistic hen-like objects (live or stuffed hens; Kent, 1987) or artificial objects (Cherfas and Scott, 1981;Salzen and Meyer, 1968). The same is true if the first object to which the chick is exposed is an artificial object followed by a hen-like object.…”

Social buffering in a bird

“…A separate group of the hens' chicks was used so that these were naïve to the air puff. Domestic hens readily accept foreign chicks and do not discriminate between chicks of a similar colour and size (Kent, 1987), so the fact that we tested the hens' responses to two different groups of their chicks was deemed unlikely to affect the hens' response. To identify the chicks belonging to the two groups within a brood, chicks were marked using two coloured stock markers (Blue and Yellow, Richey Sprayline, Richey Tagg Ltd, North Yorkshire, U.K.) on the back and/or tail feathers.…”

Cerebral and Behavioural Asymmetries in Animal Social Recognition

“…In his original theorization Lorenz (1935) claimed that imprinting was irreversible. Subsequent research demonstrated that, if the first imprinting object is removed and substituted with a new one, imprinting can be directed toward this second object (even though memory for the first object may not disappear) (Kent, 1987;Bolhuis and Trooster, 1988;Cherfas and Scott, 1981). Why should the left hemisphere be particularly involved in the initial encoding of the features of a secondary imprinting object (as hypothesised in the study of Bobbo et al, 2006b)?…”