干旱区生态环境知识资源中心

We investigated the effects of human disturbance and attitudes on the density of the tree agama Acanthocercus atricollis atricollis in a densely populated rural settlement in South Africa. In this environment agamas live on trees that are harvested for firewood or maintained for fruit production. We conducted visual encounter surveys of A. a. atricollis and interviewed local households to establish whether human attitudes and actions could affect tree agama populations. Although local residents viewed tree agamas negatively (50% of interviewees claimed to have killed an agama) and acted to exclude them from their environment, tree agama density in villages was higher than that of adjacent communal rangelands and than a previously reported density estimate in a nearby protected area. We suggest three major factors that could explain why tree agamas are favoured in this peri-urban landscape in the face of human persecution: firstly, predators such as snakes and raptors are likely to occur at a much lower density in peri-urban areas; secondly, their primary prey (insects) may be more abundant or accessible in this landscape; thirdly, they may experience less competition for resources.