Reproductive cycle length and pregnancy in the southern white rhinoceros (Ceratotherium simum simum) as determined by fecal pregnane analysis and observations of mating behavior

Abstract

Pregnancy and the reproductive cycle were monitored in 13 captive southern white rhinoceros (Ceratotherium simum simum) by measuring progesterone metabolites in fecal extracts and by observing behavior patterns. Fecal hormones were measured using a monoclonal antibody produced against 4-pregnen-11-o1-3,20-dione hemisuccinate:BSA. Several subjects exhibited flat or erratic endocrine profiles, but we found evidence for 17 reproductive cycles in five females. Mating behavior coincided with nadirs in pregnane concentrations. These cycles appeared to fall into two general categories: those of approximately 1 month in duration (Type I: X -± SEM = 35.4 ± 2.2 days; n = 10) and those lasting approximately 2 months (Type II: 65.9 ± 2.4 days; n = 7). Interluteal phase lengths were similar for the two cycle types, but Type II cycles were characterized by extended luteal phases lasting more than twice as long as Type I luteal phases. Because Type I cycles predominated in our data and because evidence suggests that some Type II cycles may be aberrant, we argue that these approximately monthly cycles represent the typical reproductive cycle for this species. Three females became pregnant during the course of the study. We were able to detect pregnancy by approximately 3 months post-breeding, as indicated by sustained pregnane concentrations markedly higher than nonpregnant luteal phase concentrations. These data help to characterize important reproductive events of this species and should be useful for captive breeding efforts for this threatened species.

Assisted Reproduction in Female Rhinoceros and Elephants – Current Status and Future Perspective

“…Early embryonic loss has been reported in three rhinoceros species (black: Berkeley et al, 1997, white: Radcliffe et al. 1997; Patton et al. 1999, Sumatran: Roth et al.…”

“…The longer cycle, which has yet not resulted in a pregnancy, is discussed as being associated with reproductive ageing in older females (Schwarzenberger et al. 1998; Patton et al. 1999; Brown et al.…”

“…2004, 2006). Anecdotal reports that the transport of females to other facilities or the introduction of new males initiated regular oestrous cycle activity (Patton et al. 1999, Fchwarzenberger, personal communication) indicate that the impact of behavioural aspects to initiate or resume the oestrous cycle activity are underestimated.…”

“…1987; Hodges and Green 1989; Schwarzenberger et al. 1993, 1996, 2000; Czekala and Callison 1996; Berkeley et al, 1997; Patton et al. 1999; Brown et al.…”

Dietary impact on circulating glucose profiles in the white rhinoceros

“…The global captive white rhinoceros population is approximately 800 animals and not self‐sustaining because of low fertility and long periods of reproductive senescence, especially amongst captive born females (Hermes et al., 2006; Roth, 2006; Emslie, 2008). The reproductive pathologies contributing to poor fertility in captive white rhinos include polycystic ovaries, uterine tumours, extended luteal phases or cycle lengths, and may be partially caused by dietary imbalances, including overcondition (Patton et al., 1999; Hermes et al., 2005; Swaisgood et al., 2006; Morrow et al., 2008).…”