Overabundance of sika deer and immunocontraception.

The impact of deer overabundance is a worldwide problem. Along with habitat expansion and population increase, damage by sika deer to the forest ecosystem and agriculture has become a serious issue in Japan. Deer also transmit a number of diseases and parasites to humans and livestock. The overabundance of deer is a result of their strong fecundity, and therefore the present situation should, in theory, be tackled by experts in reproductive biology.