Home-range ecology, aggressive behaviour, and survival in juvenile lizards, Psammodromus algirus

Abstract

Individual animals are assumed to gain possession of areas where they win fights or chases, while those that lose agonistic interactions leave areas where they were defeated. Thus, the more dominant animal secures the territory, often excluding subordinates from optimal habitat. This assumption forms the basis for concluding that the degree of aggressiveness or relative dominance of an individual may be important in determining the size or quality of a territory that it can secure. I examined in the field the relationships between home-range size, quality of home range, and degree of aggressiveness and their effects on survivorship in juvenile male lizards (Psammodromus algirus). The degree of aggressiveness was determined using tethered intruders presented to resident individuals in the field. The more aggressive individuals had larger home ranges than the less aggressive ones. Furthermore, home-range size and vegetative cover in the home range also influenced the probability of survival: survivors had larger home ranges, with a greater amount of vegetative cover, than nonsurvivors.