The influence of adult female absence on the spacing behaviour of juvenile corn mice, Calomys musculinus: a removal experiment

We tested the hypothesis that the absence of adult females promotes a restriction in spacing behaviour in juvenile male Calomys musculinus at the beginning of the breeding period. Our study was carried out in four 0.25 ha enclosures (two control and two experimental enclosures), between December 2004 and February 2005. Mothers were removed from the experimental enclosures. Home range size depended on the sex of juveniles and the treatment. Female home range sizes were always smaller than those of males. Male home ranges were larger in control enclosures than in experimental enclosures. Treatment and overlap type (intra- and inter-sexual) were not independent. The overlap proportions of male home ranges were lower in experimental enclosures than in control enclosures, in both overlap type (male/male, male/female). The intraand inter-sexual overlap proportions of female home ranges were independent of treatment. The results are discussed in the light of spacing behaviour and competition for resources.