Approaches to measuring the effects of human disturbance on birds

Human recreational activities are often considered as potential threats to biodiversity, by restricting animals' access to resources that otherwise would be exploited. Because access to wildlife areas is one major means of increasing their public value, and hence the pressure to conserve them, it is clearly critical to be able to identify accurately when human presence is a threat to conservation and when it is not. A wide range of methods have been used to assess the impacts of human disturbance on wildlife and these methods are summarized here. The type of method used depends principally on whether the disturbance issue relates to a particular site, a particular group of individuals or whole populations. Within these categories, both comparative and experimental approaches have been used to assess behavioural, distributional, demographic and population responses to human presence. Examples of each approach are given here, together with an assessment of the information each method provides.