Reproductive Success of Female Fallow Deer in Relation to Age and Condition

Abstract

While the effects of age and condition on female reproductive success have been widely reported in a number of deer species, they have received little study in fallow deer (Dama dama). Beginning in 1986,we established in many British deer parks marked fallow populations with a range of densities and resource availabilities. Annual live capture of the deer provided physical data in relation to age and sex, and subsequent observations were made of marked animals to assess individual fawning and rearing success, as well as mating and parturition dates. Despite wide variation in mean live body weights between parks, reproductive rates of adult does were very high at all sites;however, fecundity of yearling does wasa consistently lower than taht of adults, with differences greatest at parks offering restricted resources. The winter body-weight threshold, at which 50% of yearling produced fawns, was determined as 32 kg. Yearlings which did reproduce were shown to produce were shown to produce lighter offring than adults, and to fawn an average of 11 days later. Near maximum reproduction was attained in park populations kept at 6 deer/ha or less, as long as at high densities animals were offered adequate supplementary feeding and access to shelter during winter.