Body Mass at Weaning and Juvenile Recruitment in the Red Squirrel

This paper describes the factors affecting local recruitment of juvenile red squirrels, Sciurus vulgaris L., in a coniferous and a deciduous woodland. It also investigates which factors affect body mass at weaning (10-12 weeks old). In a 4-year study, of 85 weaned juveniles from 53 different nests, heavy young were more likely to be recruited in the study areas than lighter young. More young born early in a breeding season were recruited than young from later nests, but there was no difference in recruitment rate between juveniles from spring and summer litters. Differential local recruitment by body mass at weaning occurred from weaning to 6 months after birth (when the period of natal dispersal and heavy early mortality is finished)