Behaviour of free-range laying hens in distinct outdoor environments

The outdoor range in free-range, egg-production systems contains features that aim to promote the performance of natural behaviours. It is unclear what features of the range laying hens prefer and how these influence hen behaviour. We hypothesised that hens would demonstrate a preference for features of the environment in which their ancestor evolved, such as relatively dense vegetation, within the outdoor range and that the behavioural time budget of hens will differ between distinct environments. Characteristics of the outdoor range in one free-range commercial egg farm were mapped and four distinct environments ('locations') were identified based on ground substrate and cover (Wattle Tree, Gum Tree, Bare Earth and Sapling). The number of hens accessing each location and behavioural time budget of these hens was recorded over a three-week period during the southern hemisphere summer (January-February). Hens showed a clear preference for the Wattle Tree and Gum Tree locations; however, a significant interaction between location and time of day suggested that the hens' preference for different locations changed throughout the day. The most common behaviours displayed by hens were foraging, preening, locomotion, resting and vigilance, and most behaviours were influenced by the interaction between location and time of day. Overall, a wider variety of behaviours were performed in the highly preferred environments, but not all behaviours were performed equally within each environment throughout the day. Understanding what features hens prefer in the outdoor range and how this influences the performance of natural behaviours is important in promoting the welfare of hens in free-range production.