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

Individual animals are assumed to gain possession of areas where they win f ights or chases, while those that lose agonistic interactions leave areas w here they were defeated. Thus, the more dominant animal secures the territo ry, often excluding subordinates from optimal habitat. This assumption form s the basis for concluding that the degree of aggressiveness or relative do minance of an individual may be important in determining the size or qualit y of a territory that it can secure. I examined in the field the relationsh ips between home-range size, quality of home range, and degree of aggressiv eness and their effects on survivorship in juvenile male lizards (Psammodro mus algirus). The degree of aggressiveness was determined using tethered in truders presented to resident individuals in the field. The more aggressive individuals had larger home ranges than the less aggressive ones. Furtherm ore, home-range size and vegetative cover in the home range also influenced the probability of survival: survivors had larger home ranges, with a grea ter amount of vegetative cover, than nonsurvivors.