Reproductive Performance of White-Tailed Deer in Iowa

Abstract

Reproductive biology of the white-tailed deer ( Odocoileus virginianus ) in Iowa and the Nebraska-owned portion of DeSoto National Wildlife Refuge on the Iowa side of the Missouri River was determined from female reproductive organs of deer killed on highways and by hunters from 1959 to 1963, 1965, and 1966. Rut for fawn does extended from mid-November into early January but peaked between 3 to 18 December. Presence of corpora lutea indicated 82 percent of the fawns had ovulated. Corpora albicantia in ovaries of 1½-year-old does indicated that 65 percent of the fawns had breed successfully. The peak of breeding by 1½-year-old does was about 24 November, and for 2½-year-old does about 22 November. Fertilization frequency for does (all ages) that had been in estrus was 92 percent. A primary sex ratio for 178 embryos from 109 does of all ages was 1.23 males:1 female. Corpora lutea counts and fertilization rates indicated fawns from Iowa may produce up to 30 percent of the annual increment.