Long-term fertility control in the kangaroo and the wallaby using levonorgestrel implants.

Abstract

Non-lethal management techniques are needed for overabundant captive and wild populations of macropodid marsupials for which lethal techniques are considered inappropriate and may be hazardous. The tammar wallaby, Macropus eugenii, was used as a model species to investigate the effect of s.c. levonorgestrel implants on reproduction during breeding and non-breeding seasons. Implants were tested on captive and wild populations of eastern grey kangaroos, Macropus giganteus. In both species, levonorgestrel successfully stopped reproduction by inhibiting oestrus. However, levonorgestrel did not affect the reactivation and subsequent development of blastocysts in diapause that had been conceived b..