An investigation into the occurrence of spontaneous alternation behaviour in the domestic hen

Spontaneous alternation behaviour (SAB) refers to the tendency for animals to alternate their choice of arms in successive runs of a T- or Y-maze. Despite the apparent reliability of the phenomemon in the laboratory rat, there has been little examination of SAB in other species. Previous studies in domestic fowl have shown no evidence of SAB, although it was inferred that regular handling might reduce alternation behaviour. The present experiment used two groups of six adult hens, with one group receiving a handling treatment prior to the maze trials. The hens were given six runs per day for 9 days in a T-maze in which one arm was red and the other green, with colour balanced for treatment. It was shown that the number of 'looks' made down the arms of the maze was positively correlated with alternation rate, indicating that decision-making processes may be involved in alternation behaviour. Generally, low levels of alternation were shown, but two hens performed above chance levels of alternation and three hens performed below this level. There was no effect of handling treatment on alternation rate. It is suggested that species differences in the level of alternation performed may reflect the primary exploratory modality of the animal concerned.