Reproduction in Captive Wallaroos - the Eastern Wallaroo, Macropus-Robustus-Robustus, the Euro, Macropus-Robustus-Erubescens and the Antilopine Wallaroo, Macropus-Antilopinus

1987 ◽  
Vol 14 (3) ◽  
pp. 225 ◽  
Author(s):  
WE Poole ◽  
JC Merchant
Keyword(s):  
Sexual Maturity ◽  
Post Partum ◽  
Reproductive Activity ◽  
Oestrous Cycle ◽  
Full Length ◽  
Reproductive Patterns ◽  
In Captivity

Wallaroos were bred in captivity during almost 20 years. Individual males attained sexual maturity at between 18 and 20 months old and females at between 14 and 24 months old; both sexes were capable of breeding throughout the year. Gestation was 30-38 d and extended almost the full length of the oestrous cycle, 31-46 d. Post-partum mating usually produced a blastocyst subject to lactational quiescence. Removal or loss of a pouch young usually resulted in birth 28-32 d later but up to 41 d later in the presence of an actively suckled young-at-foot. Pouch life ranged between 231 and 270 d, with vacation of the pouch usually followed by another birth 1-14 d later. Lactation exceeded 12-14 months but suckling had waned by 15-17 months. Reproductive patterns for M. r. robustus and M. r. erubescens were similar although significant differences between the subspecies were recorded in length of oestrous cycle, the interval from loss of pouch young to birth and post-partum oestrus, the length of pouch life and the time between vacation of the pouch and birth. In addition, the reproductive activity of hybrids produced by matings between the subspecies was observed, as was that of a limited number of M. antilopinus.

Breeding Biology of the Agile Wallaby, Macropus agilis (Gould) (Marsupialia : Macropodidae), in Captivity

1976 ◽  
Vol 3 (2) ◽  
pp. 93 ◽  
Author(s):  
JC Merchant
Keyword(s):  
Sexual Maturity ◽  
Post Partum ◽  
Cell Types ◽  
Morphological Characters ◽  
Oestrous Cycle ◽  
Vaginal Smear ◽  
Vaginal Smears ◽  
Main Cell ◽  
In Captivity ◽  
The Mean

Female agile wallabies in captivity reached sexual maturity at about 12 months old and males produced mature spermatozoa by 14 months. Breeding was continuous throughout the year and birth and oestrus were recorded in every month. The mean length of the oestrous cycle was 32.4 days, and the mean gestation period 29.4 days. Females exhibited post-partum oestrus, usually mating within 1 day of birth. Sixty-four young born in captivity comprised 24 males, 30 females and 10 of unknown sex. If a pouch young were removed or lost, the quiescent blastocyst resumed its development, to birth about 26.5 days later. Failure or absence of the blastocyst was followed by an oestrus at about the time of the corresponding post-partum oestrus. Both the oestrous cycle and the interval between removal of a pouch young and oestrus were significantly longer than when a pregnancy intervened. The oestrous cycle was characterized by changes in the proportions of the main cell types in the vaginal smear, and by changes in the appearance of the urogenital opening and the pouch and teats. The approach of oestrus could not be predicted from vaginal smears but the post-oestrous condition was always recognizable even without mating. Young animals first left the pouch for short periods between the ages of 176 and 211 days, and left permanently between 207 and 237 days. Animals of known age were measured and the development of various morphological characters noted at weekly intervals from about birth until 12 months old.

Reproduction of the whiptail wallaby, Macropus parryi Bennett (Marsupialia : Macropodidae), in captivity with age estimation of the pouch-young

1998 ◽  
Vol 25 (6) ◽  
pp. 635 ◽  
Author(s):  
P. M. Johnson
Keyword(s):  
Age Estimation ◽  
Sexual Maturity ◽  
Post Partum ◽  
Age Determination ◽  
Oestrous Cycle ◽  
Gestation Period ◽  
Body Measurements ◽  
In Captivity ◽  
The Mean

Reproduction of the whiptail wallaby, Macropus parryi, was studied in captivity. The mean length of the oestrous cycle was 41.8 days while the mean length of the gestation period was 38.0 days. M. parryi bred throughout the year and post-partum oestrus was not recorded although mating did occur during the pouch life when the pouch-young was 118–168 days of age. The length of the pouch-life was 256–267 days and weaning occurred 104–215 days after emergence from the pouch. Sexual maturity for females occurred at 509–647 days of age. An age-determination table was produced and found useful for predicting age of pouch-young using body measurements.

Reproductive Ecology of The Allied Rock-wallaby, Petrogale assimilis.

1996 ◽  
Vol 19 (2) ◽  
pp. 209
Author(s):  
R. Delaney
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Sexual Maturity ◽  
Post Partum ◽  
Reproductive Ecology ◽  
Oestrous Cycle ◽  
Embryonic Diapause ◽  
Minimum Age

Petrogale assimilis has a typical life history and reproductive ecology for a macropodid of its size. Both sexes are capable of reproducing continuously; gestation is about the same length as the oestrous cycle (approximately one month); a single young is born and, a post-partum oestrus and embryonic diapause probably occurs. The sex ratio of young is unbiased. Pouch young remain permanently attached to the teat until 110 - 143 days (n=11). Permanent exit from the pouch occurs at 180 - 231 days (mean=201 days, n=25), and weaning occurs between 267 - 387 days (n=5). Sexual maturity occurs at a minimum age of 17.5 months in females and 23 months in males.

Observations on the reproduction and ecology of the Brush-tailed possum. Trichosurus Vulpecula Kerr (Marsupialia), in New Zealand.

1955 ◽  
Vol 3 (2) ◽  
pp. 162 ◽  
Author(s):  
CH Tyndale-Biscoe
Keyword(s):  
Sexual Maturity ◽  
Post Partum ◽  
Reproductive Activity ◽  
Urogenital Sinus ◽  
Trichosurus Vulpecula ◽  
Reproductive Condition ◽  
Age Classes ◽  
Adult Females ◽  
Epiphyseal Union ◽  
Cyclic Changes

In all 366 adult possums and 139 pouch young were examined. Five samples were collected and a study of a live population was conducted. Data are presented on the relationships of weight, tibia1 ossification, and sexual maturity, which indicate that two age classes can be distinguished in the fully grown animals on the basis of epiphyseal union of the tibia. Correlations between body weight, testis length, and the presence of sperm are presented for 53 males. The reproductive condition of 209 females was examined and successive observations were made on another eight. It is considered that Trichosurus is dioestrous and monovular. Pregnancy lasts between 15 and 24 days and is sometimes followed by a post-partum ovulation. Cyclic changes in the uterus and the urogenital sinus are described. The urogenital sinus exhibits marked cornification at oestrus, similar to the vagina of eutherian mammals. Anoestrus in February is followed by increasing reproductive activity in March. By the beginning of May, 90 per cent. of the adult females are pregnant or post-partum and the offspring is carried in the pouch until August or September. Some females may produce a second offspring in October. Some observations on the movements of individuals are presented.

Reproduction in the parma wallaby, Macropus parma, Waterhouse

1973 ◽  
Vol 21 (3) ◽  
pp. 331 ◽  
Author(s):  
GM Maynes
Keyword(s):  
Small Proportion ◽  
Sexual Maturity ◽  
Mating Behaviour ◽  
Post Partum ◽  
Reproductive Pattern ◽  
Embryonic Diapause ◽  
Young Females ◽  
Short Intervals ◽  
In Captivity ◽  
Small Holding

Female M. parma in captivity reach sexual maturity at 11 1/2-16 months of age. Scrota1 size indicates that sexual maturity is attained in males at about 22 months. One male had spermatozoa at 19-20 months and another had a first fertile mating at 24-25 months. Mating behaviour is described and resembles that of other small macropodids. M. parma is monovular and polyoestrous. The oestrous cycle has a mean length of 4197810.72 days (n = 58; range 36-59 days) while the gestation period is 34.54*0.13 days (n = 28; range 33-36 days). Post-partum oestrus and mating occurred from 4 to 13 days after birth in a small proportion (16.7%) of those animals examined. However, most animals had an oestrus, while carrying a pouch young, between 45 and 105 days after birth. A few animals did not come into oestrus at all while carrying a pouch young. Removal of pouch young typically resulted in return to oestrus between 6 and 15 days later, in females that had not had a post-partum oestrus or an oestrus while carrying a pouch young. Females which mated at some stage during lactation prior to removal of pouch young gave birth 31.16 days later (n = 3; range 30.5-32.0 days). Three females at the Melbourne Zoo had estimated delayed gestation periods of 31, 31, and 32 days. The earliest observation of a young with its head out of the pouch was at 146 days of pouch life. Most young had left the pouch for short intervals by 175 days with the youngest observed out at 160 days. Young permanently leave the pouch at 211.9+-1.0 days (n = 10; range 207-218 days). Permanent exchange of pouch young has been observed in two cases, both at approximately the time young were first leaving the pouch for short intervals. Some females that mated while carrying a young in the pouch gave birth 6-11 days after permanent pouch exit of the primary young. Unmated females returned to oestrus 12-24 days after permanent pouch exit of their young. Young were weaned at 2 5 3 ) months after pouch exit. Most females entered anoestrus in 1968 following transfer of the animals into small holding pens. In 1969 only 5 of 24 matings resulted in young in the pouch, while in 1970 the corresponding figure was 21 of 44 matings. In both years there was evidence of young being born but apparently being lost during the climb from the urogenital opening to the pouch, probably because of overcrowding of the mothers. Evolution of embryonic diapause is discussed in relation to the reproductive pattern established for M. pavma. It is postulated that embryonic diapause first arose at the end of pouch life and has come to occupy the entire length of pouch life in most macropodids.

Reproduction in the Plain Rock-Wallaby, Petrogale penicillata inornata Gould, in Captivity, with Age Estimation of the Pouch Young

1979 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
PM Johnson
Keyword(s):  
Age Estimation ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Gestation Period ◽  
In Captivity ◽  
Hind Foot ◽  
Males And Females ◽  
Premature Removal

'Reproduction in the plain rock-wallaby was studied in captivity. The oestrous cycle ranged from 30.2 to 32.0 days and the gestation period from 30.0 to 32.0 days. A post-partum mating usually followed birth; the resultant quiescent embryo developed and was born 28-30 days after premature removal of pouch young. The pouch life of the young ranged from 189 to 227 days, males and females maturing sexually at approximately 590 and 540 days respectively. Tail and hind foot lengths were found to be useful indicators of age of young up to the end of pouch life.

Reproduction in the Bridled Nailtail Wallaby, Onychogalea fraenata Gould (Marsupialia : Macropodidae), in Captivity

1997 ◽  
Vol 24 (4) ◽  
pp. 411 ◽  
Author(s):  
P. M. Johnson
Keyword(s):  
Post Partum ◽  
Oestrous Cycle ◽  
Gestation Period ◽  
Young Males ◽  
In Captivity ◽  
Males And Females ◽  
The Mean

The reproduction of the endangered macropod Onychogalea fraenata was studied in captivity. O. fraenata breeds throughout the year. A post-partum oestrus was not recorded, although mating during the pouch life was observed when the pouch young were 80–92 days old. The mean length of the oestrous cycle was determined to be 36·2 days, while the mean length of a gestation period was 23·6 days. Pouch life ranged between 119 and 126 days, and the young males and females matured as early as 270 days and 136 days, respectively.

Survival, age estimation and sexual maturity of pouch young of the brush-tailed bettong (Bettongia penicillata) in captivity

2015 ◽  
Vol 37 (1) ◽  
pp. 29 ◽  
Author(s):  
Craig K. Thompson ◽  
Adrian F. Wayne ◽  
Stephanie S. Godfrey ◽  
R. C. Andrew Thompson
Keyword(s):  
Age Estimation ◽  
Sexual Maturity ◽  
Post Partum ◽  
Maternal Investment ◽  
Female Offspring ◽  
Accurate Predictor ◽  
Bettongia Penicillata ◽  
In Captivity ◽  
Survival And Development ◽  
In The Wild

The brush-tailed bettong or woylie (Bettongia penicillata) is a continuous and rapid breeder. However, research investigating the monthly survival and development of young woylies from parturition to parental independence is incomplete. The reproductive biology of eight female woylies was observed for 22 consecutive months within a purpose-built enclosure. Adult female woylies bred continuously and were observed caring for a dependant young 96% of the time. Pouch life of the young was ~102 days, with sexual maturity of female offspring reached as early as 122 days post partum. Crown–rump measurement was an accurate predictor of age for young restricted to the pouch, while skeletal morphometrics were a better predictor of age for ejected pouch young, young-at-foot and subadults. A four-month period between May and August of each study year accounted for 85% of pouch young mortality and 61% of pouch young births where the neonate went on to survive to subadult age. Here we discuss the possibility that pouch young born during the cooler, wetter months of May to August may have an increased chance of survival in the wild, resulting from an increased maternal investment being directed towards the rearing of ‘fitter’ progeny.

Reproduction of Pseudomys novaehollandiae (Muridae) in the laboratory

1976 ◽  
Vol 24 (2) ◽  
pp. 159 ◽  
Author(s):  
CM Kemper
Keyword(s):  
Litter Size ◽  
Sexual Maturity ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Day Length ◽  
Dark Phase ◽  
Weight Changes ◽  
External Appearance ◽  
Average Litter Size ◽  
Lactating Females

Oestrous cycle, gestation, parturition, litter size, lactation and sexual maturity were studied in a captive colony of the Australian murid P. novaehollandiae. The pattern of reproduction is similar to that of other murids, although oestrous cycle (6.0 � 1.26 days) and gestation period (31.5 � 0.96 days) are longer than those in the laboratory rat and mouse. Changes in the external appearance of the vagina were too inconsistent to identify stages of the oestrous cycle, but were of use in determining the stage of pregnancy or lactation. Parturition took place during the light phase of the day-length regime, with post-partum oestrus during the following dark phase. Weight changes in pregnant and lactating females were considered. The average litter size was 4.0 � 1.03 with a range of one to six. Oestrus was inhibited during lactation and recurred about 24 days after parturition. Sexual maturity was earlier in females (13 weeks) than in males (20 weeks).

Reproduction, Growth and Age Determinatipon in the Yellow Footed Rock Wallaby Petrogale xanthopus Gray, in Captivity

1985 ◽  
Vol 12 (2) ◽  
pp. 127 ◽  
Author(s):  
WE Poole ◽  
JC Merchant ◽  
SM Carpenter ◽  
JH Calaby
Keyword(s):  
Sex Ratio ◽  
Growth Rates ◽  
Sexual Maturity ◽  
Growth Curves ◽  
Oestrous Cycle ◽  
Season Of Birth ◽  
In Captivity ◽  
The Mean ◽  
Similar Growth

Yellow-footed rock-wallabies were studied in captivity over 13 years. Individuals of both sexes attained sexual maturity from age 18 months and were capable of breeding throughout the year. The ranges recorded were: for length of oestrous cycle 32-37 days; gestation 31-33 days; pouch life 190-201 days. Parturition was usually followed by an oestrus and mating with a consequent lactation-controlled embryonic quiescence. The mean interval from removal of pouch young to birth was 31.5 days, and to oestrus without an intervening birth, 34 days. Weight of the neonate within the 1st day was <500 mg; the sex ratio of 62 young of known sex revealed a significant departure from parity with 41 boys and 21 girls (100:51). Growth curves were fitted for length of head, ear, arm, leg, foot, tail and weight. These measurements provided a useful means of determining age within the 1st year and to a lesser extent the 2nd year, length of head being the best criterion. Both sexes maintained similar growth rates when within the pouch, but males grew larger once they vacated it. Patterns of molar eruption and molar progression provided a useful means of determining age in older animals but, on the data available, accuracy was restricted to the year and possibly no more than the season of birth.

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