Abstract Wapiti (Cervus elaphus manitobensis) bulls were run with 106 adult farmed red deer hinds (Cervus elaphus) selected for size over three mating seasons. Only some bulls readily mated red hinds and some bulls became sexually exhausted after mating about 20 hinds. Seventy six hinds (72%) produced F1 calves. Mean gestation length of the F1 male calves was 239.6 days, with males bom 1.8 (SE = 0.8) days earlier than females and a significant negative relationship between male gestation length and birth weight existed. At birth, males, on average, weighed 14.1 kg and females 13.3 kg. Male calves were significantly heavier at birth (6%) and at weaning (5%) than females. Growth rates of the calves to weaning (11 weeks) averaged 558 (males) and 536 g/day (females). Birth weight was related to dam mating weight, with a 0.8 kg increase in birth weight corresponding to a 10 kg increase in dam live weight. Both birth weight and metatarsus length squared of the new bom calf were significantly related to growth t...