Challenges associated with the development and transfer of assisted breeding technology in marsupials and monotremes: lessons from the koala, wombat and short-beaked echidna

This reflective review describes how a research model, which was originally established for the successful AI of the koala (Phascolarctos cinereus), is currently being developed and extended to the wombat (Lasiorhinus latifrons and Vombatus ursinus) and short-beaked echidna (Tachyglossus aculeatus). The research model centres around the establishment of an AI program and involves: (1) semen collection, evaluation and preservation, requiring an understanding of male reproductive physiology and gamete biology; (2) timing of insemination, based on a knowledge of oestrous cycle and gestation physiology and oestrous behaviour; and (3) the appropriate placement of semen, which relies on an accurate description of female reproductive anatomy. Published and unpublished studies of assisted breeding technology (ABT) development in all three species of Australian mammals reported in this review (koala, wombat and short-beaked echidna) clearly demonstrate the importance of recognising species-specific variation in reproductive biology. Even in closely related species, such as the koala and wombat, subtle differences in reproductive physiology can hinder the transfer of ABT across species. Significant progress in marsupial and monotreme ABT will also require adequate access to captive wildlife colonies (zoos, university collections and private partners) in sufficient numbers in order to conduct quality science