Reproductive Collapse in Saiga Antelope Harems
A common assumption is that breeding in polygnous systems is not limited by the number of males because one male can inseminate many females1,2. But here we show that reproductive collapse in the critically endangered saiga antelope (Saiga tatarica tatarica) is likely to have been caused by a catastrophic drop in the number of adult males in this harem-breeding ungulate, probably due to selective poaching for their horns. Saiga horns are also known as ling yang (羚羊) and used in Traditional Chinese Medicine.
Fecundity and calf survival are known to be affected by markedly skewed sex ratios, but in saiga antelope the sex ration has become so distorted as to lead to a drastic decline in the number of pregnancies - a finding that has implications both for the conservation of the species and for understanding the reproductive ecology of polygynous ungulates.