Fertility control in the eastern grey kangaroo using levonorgestrel implants

Abstract

We investigated the effect of subcutaneous levonorgestrel implants on reproduction, gestation, lactation, and body condition in both captive and free-ranging populations of female eastern grey kangaroos (Macropus giganteus). Kangaroos had their pouch young removed and were given either 2 control (inert) or 2 levonorgestrel implants. During January 1999, 3 kangaroos in the captive population received control and 3 received levonorgestrel implants. All of the control-treated females had given birth 3 months after treatment. None of the levonorgestrel-treated females gave birth during the investigation (25 months). In the free-ranging population, 8 females received control and 18 received levon..