Wichman, 2007 – Perching behaviour in chickens and its relation to spatial ability

The early rearing environment plays an important role in the development of many behaviour patterns and it has been shown that an early use of perches by chicks improves their later three-dimensional spatial ability. But even if birds are reared in the same environment, there can be large individual differences in how well birds use the perches. Therefore, the aim of this study was to explore the link between the development of perching in chicks and their spatial ability. Ninety-day-old LSL chicks were housed in rearing pens (n = 18). From day 1 they had access to perches (20 and 40 cm high). At 18 weeks of age the birds were moved to layer pens which were bigger and had more perches at different heights (n = 5). The study included observations of perching behaviour of the birds in their home pens and two spatial tests. The first perching observations of the chicks were carried out in the rearing pens from 5 days until 6 weeks of age and the second during the first 5 days in the layer pens, when the birds were presumably adapting to these new pens. The two spatial tests were firstly, a detour test when the chicks were 4 days old and, secondly, a radial eight armed maze test when the birds were 15–16 weeks old. In addition to the spatial tests a TI (tonic immobility) test and a runway test
were carried out to allow comparisons of the chicks’ spatial performance with their fearfulness and sociality. There was no evidence from this study that the two-dimensional spatial skill of a newly hatched chick influenced how it learnt to perch and so no support for there being an early link between a chicks spatial ability and perching behaviour. But spatial skill as a pullet did seem to influence perch use in a new and complex situation, suggesting that spatial skill in a two-dimensional test is related to performance in a threedimensional spatial test situation.