Faecal progesterone metabolites and behavioural observations for the non-invasive assessment of oestrous cycles in the common wombat ( Vombatus ursinus) and the southern hairy-nosed wombat ( Lasiorhinus latifrons)

Abstract

Wombats belong to Australia’s unique marsupial species. Two of the three remaining species, the common wombat ( Vombatus ursinus) and the southern hairy-nosed wombat ( Lasiorhinus latifrons) are abundant. The third species, the northern hairy-nosed wombat ( Lasiorhinus krefftii) has only about 115 individuals left in the wild. This study aimed to gain further insight into the basic reproductive biology of wombat species and evaluate the value of faecal progesterone metabolites and behavioural patterns as a means for non-invasive monitoring of the oestrous cycle in common and the southern hairy-nosed wombats. In an initial study, three different faecal steroid assays showed that 20α-OH-pregnanes were the main progesterone metabolites. These metabolites were examined in captive female common wombats ( n=5) and southern hairy-nosed wombats ( n=2). In one female common wombat and in one male common wombat oestrous related behavioural data were obtained. Individual cycling females exhibited a significant relationship between plasma progesterone and faecal pregnanes. In the common wombat, the values for faecal pregnanes showed an oestrous cycle length of 55.1±11.7 days with a follicular phase of 25.6±6.3 days and a luteal phase of 28.2±12.7 days. The data for faecal pregnanes obtained in the southern hairy-nosed wombat during the breeding season gave an oestrous cycle length of 41.1±12.8 days with a follicular phase of 27.9±12.3 days and a short luteal phase of 13.3±1.1 days. The behavioural data show that the faecal sniffing behaviour of the male, tended to increase around the time that oestrous was found. In conclusion, monitoring of 20α-OH-pregnanes in wombat faeces could be a useful methodology to monitor reproductive cycles in the wombat, and can possibly be applied to monitor the endangered northern hairy-nosed wombat.