Beobachtungen zur Superfetation beim Feldhasen

Studies on the European hare. 53. Reproduction of the European hare in Patagonia, Argentina

“…Litter size in Bariloche (2.12) was not very different to the following litter sizes reported for other countries: 2.76 in Poland (Raczyński 1964), 2.21 in New Zealand (Flux 1967), 2.69 in Scotland (Hewson and Taylor 1975), 2.56 in France (Pepin 1989), and 2.73 in Slovakia (Ciberej 1993). Problems of reproductive physiology (superfoetation, polyovular follicles, migration of blastocysts, and ectopic pregnancy) reported by different authors (Raczyński 1964, Bloch et al 1967, Flux 1967, Lloyd 1968 were not observed in this study.…”

Interbirth interval and duration of pregnancy in hares

“…Hediger (1948) noticed that when hares copulate during late stages of pregnancy the interval between the next two deliveries is shortened. This was later confirmed by Bloch et al (1967), who showed coexistence of a fetus, nearly ready to be delivered, and two fertilized ova (each divided into four cells) in the uterus of a pregnant hare. Although superfetation is apparently rare in hares in the wild (Raczynski, 1964;Flux, 1967;Broekhuizen & Maaskamp, 1981), it appears to be common in captivity (Hediger, 1948;Bloch et al, 1954) and was observed by Martinet et al (1970) in 66% of the pregnancies in their breeding colony.…”

Observations on breeding in the Brown hare (Lepus europaeus) during the first pregnancy of the season

“…Unequivocal demonstration of superfoetation in the hare by autopsy has rarely been achieved (Bloch, Hediger, Lloyd, Muller & Strauss, 1967). One example was observed in a yearling doe of 2850 g cleaned weight.…”