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.

The female urogenital system of Trichosurus vulpecula (Marsupialia).

1964 ◽  
Vol 12 (1) ◽  
pp. 18 ◽  
Author(s):  
RI Kean ◽  
RG Marryatt ◽  
ALK Carroll
Keyword(s):  
Sexual Maturity ◽  
Post Partum ◽  
Late Pregnancy ◽  
Urogenital Sinus ◽  
Urogenital System ◽  
Wild Animals ◽  
Trichosurus Vulpecula ◽  
Protective Capacity ◽  
Vaginal Canal ◽  
In Pregnancy

This paper is based on measurements from 1000 female specimens. In a stable population, summer anoestrus was followed by oestrus in April-May. Post-partum oestrus did not occur. Juvenile females frequently came into oestrus at 12 months of age but they did not necessarily rear young. The septum which initially divides the vaginal sac is usually perforated shortly before sexual maturity is attained, but entire septa may be found in females of any age. The sac in trapped, wild animals is greatly enlarged during oestrus but it is small and apparently functionless during parturition. Formation of the median vaginal canal is commenced early in pregnancy. The median canal is usually unlined, but in some specimens (5 of 68) the canal carried a well-developed epithelium which was columnar anteriorly and stratified squamous posteriorly. The two types of lining originate as infundibula extending from the vaginal sac and the urogenital sinus respectively. The epithelium appears to organize canal formation, but it is not required in a protective capacity, and no evidence suggests that it facilitates parturition. Omission of the epithelium seems to be an evolutionary advance and, in the usual absence of median canal lining, canal organization is probably relegated to terminal epithelia of the median sac and the urogenital sinus. The lateral canals open widely during oestrus, providing for transmission of semen. During pregnancy they become constricted or sealed posteriorly, and are usually closed during dioestrus and anoestrus, separating the reproductive system from the urinary one. In principle, the lateral canals and the median canal are similar in their initiation (both types originating from evaginations of anterior and posterior epithelia) but their development differs through heterochrony, formation of the median canal being retarded. However, the canals differ also in their reactions during late pregnancy when the lateral canals close as the median one opens.

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.

THE »EARLY-ANDROGEN« SYNDROME; ITS DEVELOPMENT AND THE RESPONSE TO HEMI-SPAYING

1964 ◽  
Vol 45 (1) ◽  
pp. 1-12 ◽  
Author(s):  
H. E. Swanson ◽  
J. J. van der Werff ten Bosch
Keyword(s):  
Sexual Maturity ◽  
Compensatory Growth ◽  
Testosterone Propionate ◽  
Single Injection ◽  
Weight Increase ◽  
Corpora Lutea ◽  
Transition Stage ◽  
Adult Females

ABSTRACT The »early-androgen« syndrome in the rat – i. e. anovulatory ovaries in adult females after a single injection of testosterone propionate (TP) within a week of birth – may not become apparent until some time after the attainment of sexual maturity. Large doses (50 or 100 μg) of TP were effective earlier than lower doses (5 or 10 μg). Rats which received 5 μg TP were ovulating at 10 weeks of age, mated but were infertile at 13 weeks of age, and were anovulatory at 21 weeks. In rats between 10 and 13 weeks old there was a marked fall in the number of corpora lutea in the ovaries of animals which had been given 5 μg TP. Hemi-spaying was followed by compensatory growth of the remaining ovary which consisted of corpora lutea in ovulating, and of follicles in anovulatory rats; little or no compensatory weight increase occurred in animals which seemed to be in the transition stage from the ovulatory to the anovulatory condition.

Akodon molinae (Rodentia Cricetidae), a new laboratory animal: breeding, management and reproductive performance

1980 ◽  
Vol 14 (2) ◽  
pp. 129-131 ◽  
Author(s):  
Maria Susana Merani ◽  
Marta Susana Lizarralde
Keyword(s):  
Sex Ratio ◽  
Reproductive Performance ◽  
Sexual Maturity ◽  
Laboratory Animal ◽  
Post Partum ◽  
Animal Breeding ◽  
Haemorrhagic Fever ◽  
Sex Ratio At Birth ◽  
Breeding Management ◽  
Laboratory Colony

Akodon molinae, a vole mouse widely distributed in central Argentina, shows remarkable chromosome polymorphisms. It is one of the natural reservoirs of the actiologic agent of haemorrhagic fever, and a laboratory colony could be of great help in investigating this disease. Pregnancy lasted 23 (range 21-25) days. Litters of 4-5 young were born to monogamous breeding pairs about every 30 days, with weaning at 26 days post partum. The sex ratio at birth was 505 males to 500 females: at weaning it was 460 to 440. Sexual maturity was attained at about 16 weeks of age in males and 12-20 weeks in females. Akodon molinae is easy to handle, but fighting and killing or neglect of young are problems.

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.

scholarly journals FEEDING AND REPRODUCTIVE ACTIVITY OF THE COPEPODS Drepanopus forcipatus AND Calanus australis DURING LATE SUMMER ON THE SOUTHERN PATAGONIAN SHELF (ARGENTINA, 47°-55°S)

2014 ◽  
Vol 62 (4) ◽  
pp. 295-314 ◽  
Author(s):  
Julieta Carolina Antacli ◽  
Marina E. Sabatini ◽  
Ricardo I. Silva ◽  
Daniel R. Hernández ◽  
Andrés J. Jaureguizar ◽  
...  
Keyword(s):  
Diet Composition ◽  
Feeding Activity ◽  
Food Pellet ◽  
Late Summer ◽  
Reproductive Activity ◽  
Seasonal Temperature ◽  
Patagonian Shelf ◽  
Adult Females ◽  
Female Reproductive Status ◽  
Potential Food

Drepanopus forcipatus and Calanus australis are key planktonic copepods on the southern Patagonian shelf. Their feeding and reproductive patterns and population status were investigated during late summer, when environmental conditions may be critical. The presence of food in the gut and food-pellet length were recorded in adult females and the most abundant copepodite stages. Diet composition was also studied in adult females. Female reproductive status was evaluated by gonad staging. Despite generally low feeding conditions and decreasing seasonal temperature, both copepods fed to some degree. The most numerous copepodites and adult females of both species showed similarly low feeding activity. About half of the adult females of the two species and C5s of C. australis contained food in their guts, but the proportion of fed C4-females of D. forcipatus was much lower. All copepods were generally feeding at low or intermediate levels. Gonad stage distribution and population structure showed low but still ongoing reproduction in both species. Gut content findings suggest a preference for smaller nanoplanktonic particles, especially dinoflagellates by D. forcipatus, and for autotrophic prey, particularly large diatoms by C. australis. The feeding and reproduction patterns of the two copepods were likely influenced by the distributions of potential food resources and temperature.

scholarly journals Effect of deslorelin implants on follicular development, parturition and post-partum oestrus in the tammar wallaby (Macropus eugenii)

Reproduction ◽  
2004 ◽  
Vol 127 (2) ◽  
pp. 265-273 ◽  
Author(s):  
C A Herbert ◽  
T E Trigg ◽  
D W Cooper
Keyword(s):  
Slow Release ◽  
Post Partum ◽  
Follicular Development ◽  
Tammar Wallaby ◽  
Urogenital Sinus ◽  
Treated Animal ◽  
Subsequent Birth ◽  
Preovulatory Follicles ◽  
Effect Of Treatment ◽  
One Year

The effect of treatment with slow release implants containing the GnRH agonist, deslorelin, was investigated in female tammar wallabies. Pouch young were removed from 16 wallabies presumed to be carrying quiescent blastocysts. Eight received a 5 mg deslorelin implant and eight received a placebo implant. Animals were caught daily from day 25 to day 30 and their pouches inspected for newborn young and their urogenital sinus checked for a copulatory plug. Treatment with deslorelin did not affect reactivation of a dormant blastocyst and subsequent birth in 4/8 animals, but post-partum mating was inhibited in these animals. Five control and five treated animals were killed within 0–48 h post partum and their reproductive tracts analysed. At autopsy, all five control animals had large preovulatory follicles but only one deslorelin-treated animal showed signs of follicular development. These differences were also reflected in the weights of the lateral vaginae, with treated animals showing no evidence of oestrogenic stimulation. The remaining three control and three treated animals were monitored for approximately 2 years. The long-term contraceptive effects of a single 5 mg deslorelin implant lasted for just under one year. These results indicate that slow release deslorelin implants inhibit follicular development in the female tammar wallaby for extended periods of time and may have potential application in reproductive management of captive marsupials in the kangaroo family.

Reproductive function in average and high yielding dairy cows

2001 ◽  
Vol 26 (2) ◽  
pp. 495-498 ◽  
Author(s):  
Victoria J. Taylor ◽  
Andrew J. Hattan ◽  
Emma C.L. Bleach ◽  
David E. Beever ◽  
D. Claire Wathes
Keyword(s):  
Dairy Cows ◽  
Milk Yield ◽  
Post Partum ◽  
Reproductive Function ◽  
Reproductive Activity ◽  
Corpora Lutea ◽  
Genetic Merit ◽  
Standard Management ◽  
Service Conception ◽  
The Difference

AbstractThe resumption of reproductive activity in the early post partum period and the subsequent fertility of dairy cows are of considerable practical and economic importance to the producer. Regular milk progesterone analysis was used in this study to monitor the re-establishment of reproductive cyclicity in animals of average (AGM, n=20) and high genetic merit (HGM, n=28) kept under standard management conditions. The profiles obtained were then characterised into normal and four different types of abnormal activity. Resumption of cycles occurred significantly later in the higher yielding cows than in those of average genetic merit (23 ±2.3 days in HGM cows and 15 ± 1.6 days in AGM cows; P=0.0089). There was a significant increase in the amount of abnormal cycles encountered in the high genetic merit animals compared with average yielding animals (61% and 30% respectively; χ2 test, P=0.045); in particular, the delayed occurrence of ovulation post partum (11% vs 0%) and an increased incidence of persistent corpora lutea (32% vs 20%). For high genetic merit animals, the incidence of abnormal cycles was associated with increased peak milkyields (abnormal cycles: peak milk yield 54.7 ± 1.11 kg/day; normal cycles: peak milk yield 46.4 ± 1.35 kg/day, P=0.002). This relationship was not apparent in average genetic merit animals. First service conception rates were 50% (9/18) for AGM cows and 38% (10/26) for HGM cows (χ2 test, n.s.). The calving to conception interval was 98 ± 9.7 days for AGM animals (n=l7) and 105 ± 9.1 days for HGMs (n=24) (t-test, n.s.). In conclusion, this study confirms that high genetic merit dairy cows have compromised reproductive function in terms of a delayed resumption of cyclicity and an increased incidence of abnormal progesterone cycles, which was associated with higher peak milk yields. There was also a reduced first service conception rate in high yielders although the difference was not significant with this group size.

scholarly journals Actividad reproductiva y dieta de Hemidactylus frenatus (Sauria: Gekkonidae) en el norte de Colombia

2017 ◽  
Vol 57 (36) ◽  
pp. 459
Author(s):  
Jorge A. Díaz-Pérez ◽  
Alcides C. Sampedro-Marín ◽  
Martha P. Ramírez-Pinilla
Keyword(s):  
Diet Composition ◽  
Sampling Period ◽  
Reproductive Activity ◽  
Climatic Conditions ◽  
Relative Importance ◽  
Adult Males ◽  
Adult Females ◽  
Ecological Aspects ◽  
Environmental Availability ◽  
Hemidactylus Frenatus

Despite its success as an invasive species, little is known about the ecological aspects of the gekkonid lizard Hemidactylus frenatus in Colombia. In the present study the size at maturity, sexual dimorphism, reproductive activity, and diet composition of a population of this species in an urban locality of Northern Colombia were determined. We conducted eleven samplings from September 2011 to August 2012 in buildings of the municipality of Sincelejo. A total of 264 specimens H. frenatus were captured, 112 were adult females, 133 adult males and 19 juveniles. Males reach sexual maturity at a smaller size (snout-vent length) than females (males: 35.7 mm; females: 42.7 mm), also they are larger and have proportionally larger heads and mouths than females. Males were reproductive throughout the year; although testicular volume varied significantly between samples, this variation was not associated with body size and precipitation in the study area. Reproductive adult females were found during all the sampling period. Females have an invariable clutch size of two eggs and we found no differences in the diameter and weight of eggs in each oviduct. The diet of H. frenatus is varied, with Diptera, Hemiptera and Formicidae being the prey types with the greatest relative importance values. Individuals of both sexes consume a similar volume and number of prey. Thus, the studied population of H. frenatus has continuous reproductive activity and a generalist-opportunistic feeding behavior. The climatic conditions of the study area, environmental availability of prey and intrinsic features of this species appear to be responsible for their abundance and colonizing success in this and other localities.

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