Faecal Progestagen Profiles in Wild Southern White Rhinoceros (Ceratotherium simum simum)

Abstract

Knowledge of the reproductive biology of wild animals can provide valuable information for the development of appropriate in situ and ex situ management plans. The present study aimed to establish a non-invasive protocol for monitoring faecal progestagen metabolite (FPM) patterns in wild female southern white rhinoceroses (Ceratotherium simum simum). Six adult females at Lapalala Wilderness, South Africa, were tracked and accurately identified at least once every week. Three animals gave birth during the study period. Fresh faecal samples were collected for 12 months and stored frozen at -20°C until analysis with an enzyme immunoassay utilizing an antiserum raised against 5a-pregnan-3b-ol-20-one which cross-reacts with a number of progestagens. Mean FPM concentrations were 35 to 64-fold higher during pregnancy (55-145 days before parturition) compared to postpartum (120-140 days after parturition) (P < 0.001). Also, the non-pregnant animals had mean FPM concentrations significantly higher than postpartum values (P = 0.006). Our results show that non-invasive FPM measurements provide information on the pregnancy status of wild female white rhinoceroses, and may be used for the detection of pregnancy in free-living individuals, without the necessity of immobilization and/or relocation of the animal. This information has potential value for optimizing breeding management of wild and captive populations.

The female effect—how female receptivity influences faecal testosterone metabolite levels, socio-positive behaviour and vocalization in male Southern white rhinoceroses

“…While the vast majority of endocrinological studies in WR investigated progesterone levels and its development and reproductive function in females (e.g. Radcliffe et al , 1997 ; Schwarzenberger et al , 1998 ; Patton et al , 1999 ; Brown et al , 2001 ; Hermes et al , 2006 ; Sós et al , 2006 ; van der Goot et al , 2013 ; van der Goot et al , 2015b ; Hermes et al , 2020 ; Pennington et al , 2020 ), only a few studies examined androgen concentrations in males, focusing on environmenta and social effects ( Brown et al , 2001 ; Kretzschmar et al , 2004 ; Christensen et al , 2009 ), territorial behaviour ( Rachlow et al , 1998 ) as well as breeding success ( Ververs, 2018 ; Kretzschmar et al , 2020 ). Whereas the authors describe an increase in faecal androgen metabolite levels during sexual maturation ( Kretzschmar et al , 2004 ; Ververs, 2018 ) and agree on the importance of T for the reproductive state, there are some discrepancies in their results regarding the effect of females on the androgen metabolite values.…”