Evidence from the oestrous cycle for male-induced ovulation in Bettongia penicillata (Marsupialia)

Abstract

Summary. Female brush-tailed bettongs (Bettongia penicillata) housed in a breeding group of one male and one to three females had an average gestation period of 21.2 days (n = 58) and parturition was followed within 24 h by oestrus and mating. If a young was not born as a result of the mating, oestrus recurred after about 21\m=.\7 days (n = 12). From removal of pouch young to birth was 17\m=.\5 days, on average (n = 85), in females that had mated post partum, but most females that were isolated from a male before parturition returned to oestrus about 6\m=.\6 days after simultaneous removal of pouch young and return to the male (n = 9). Females housed in female-only groups appeared not to come into oestrus or to do so irregularly. These females, when returned to the male, usually came into oestrus within 10 days. These data provide evidence that, in most females of B. penicillata, ovulation does not occur in the absence of a male and that previously isolated females return to oestrus within 10 days of return to the male.

Establishment of a captive colony of Bettongia tropica (Marsupialia: Potoroidae) by cross‐fostering; and observations on reproduction

“…B. tropica lies between B. penicillata and B. gaimardi in this respect. Reproduction in B. penicillata is unusual in that females do not come into oestrus unless a mature male is present (Hinds & Smith, 1992;Smith, 1992), a phenomenon that has not been reported for either B. lesueur (Tyndale-Biscoe, 1968) or B. gaimardi (Rose, 1987). The present study did not address the question of male-induced oestrus in B. tropica and, considering the apparent variation within the genus, the situation in B. tropica requires clari®cation.…”

“…The length of pouch life is a little shorter in B. penicillata (99 days, Smith, 1992) than in B. gaimardi (106 days, Rose, 1987) and B. lesueur (115 days, Tyndale-Biscoe, 1968). B. tropica lies between B. penicillata and B. gaimardi in this respect.…”

“…Studies of B. lesueur, B. gaimardi and B. penicillata, and now of B. tropica, have shown that all have postpartum mating and embryonic diapause and that the reproductive parameters are similar within the genus, with oestrous cycle 21±23 days long, gestation 21 days and removal of pouch young to birth about 18 days (Tyndale-Biscoe, 1968;Rose, 1987;Smith, 1992). The length of pouch life is a little shorter in B. penicillata (99 days, Smith, 1992) than in B. gaimardi (106 days, Rose, 1987) and B. lesueur (115 days, Tyndale-Biscoe, 1968).…”

“…The brush-tailed bettong, B. penicillata, was established in captivity by the South Australian National Parks and Wildlife Service and breeding was so successful in this and subsidiary colonies that over 200 animals were released on to selected South Australian islands as part of a reestablishment program (Delroy et al, 1986;Nelson, Storr & Robinson, 1992). The National Parks and Wildlife Service colony also provided the founders of a successful colony at the South Australian Museum (Smith, 1989(Smith, , 1992(Smith, , 1994Hinds & Smith, 1992). Many close similarities but also some differences in the reproductive patterns of these three species were shown and it was decided to investigate reproduction in B. tropica.…”

Vomeronasal Organ Removal Blocks Pheromonal Induction of Estrus in Gray Short-Tailed Opossums (Monodelphis Domestica)1

“…Scent-marking behavior and sexually dimorphic scent glands appear to be quite common in marsupials [44], particularly as a means of sexual and individual recognition [26,45]. However, evidence for male effects on female reproductive function among the array of marsupial taxa is limited to reports on one or two species in Didelphidae [7,8], Dasyuridae [46], and Macropodidae [47,48], and, except for the results of this study, the importance of the VNO in chemosensory control of marsupial reproduction is unknown.…”