The number of hens kept in aviaries is increasing steadily. A question unanswered so far is: Do aviaries fulfil the hens behavioural priorities? In a literature review (chapter 1: social and resting behaviour, chapter 2: feeding, reproductive and dustbathing behaviour, both written in German) the behaviour of modern laying hybrids in aviaries is described. To evaluate animal welfare, typical behaviour in this housing system is compared to the behaviour of laying hens living under close to nature conditions and of their wild ancestors. The experimental part of the study focuses on two...