EN
Monthly samples totalling 202 European hares Lepus europaeus Pallas, 1778 were collected in southern Argentina from August 1993 to March 1994. The sex ratio of the whole sample was 1:1.2 in favour of females. Pregnant females were present from August to February and lactating females were present from September to March. The percentage of pregnant females was 59% for the whole breeding season. The mean ovulation rate for female hares was 2.78; the number of ova ovulated was not significantly correlated with body weight. The mean number of implantation sites per reproducing female was 2.46. The number of embryos in a litter varied from 1 to 4, the average being 2.12. The prenatal mortality was 56.5% of all ova ovulated and of these 34.7% were lost before implantation and 21.8% after implantation.