Reproduction in Sminthopsis-Longicaudata (Marsupialia, Dasyuridae) - Laboratory Observations

1986 ◽  
Vol 13 (1) ◽  
pp. 7 ◽  
Author(s):  
PA Woolley ◽  
A Valente
Keyword(s):  
Endangered Species ◽  
Breeding Season ◽  
Early Summer ◽  
Oestrous Cycle ◽  
Gestation Period ◽  
Late Winter ◽  
Breeding Condition ◽  
Males And Females ◽  
The Mean

Observations on the pattern of reproduction in Sminthopsis longicaudata, at present considered to be an endangered species, are presented. S. longicaudata is polyoestrous and in the laboratory females are in breeding condition from late winter (August) to early summer (December). They enter oestrus up to four times during the breeding season. Two litters were born 17 and 19 days post-mating, but the gestation period may be less than 15 days. The mean length of the oestrous cycle is 34.4 days. Both males and females may be able to breed in more than one season.

Reproduction in Antechinomys laniger ('spenceri' Form) ( Marsupialia : Dasyuridae): Field and Laboratory

1984 ◽  
Vol 11 (3) ◽  
pp. 481 ◽  
Author(s):  
PA Woolley
Keyword(s):  
Breeding Season ◽  
Oestrous Cycle ◽  
Average Rainfall ◽  
Proximate Factor ◽  
Breeding Condition ◽  
Males And Females ◽  
Sexually Mature ◽  
Length Of Gestation

Antechinomys laniger is polyoestrous, and animals from Sandringham Station in south-western Queensland are in breeding condition from midwinter to midsummer. Laboratory observations suggest that photoperiod may be the proximate factor controlling the timing of the breeding season. Females enter oestrus up to six times during the season, and as the season progresses the length of the oestrous cycle decreases. The estimated length of gestation is 12 days or less. Females may rear up to six young. The young are weaned when about 3 months old and become sexually mature at 11.5 months. Both males and females are potentially capable of breeding in more than one season. Higher than average rainfall may have led to a decline in the numbers of A. laniger on Sandringham Station.

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.

Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. V. Chlorophyll Distribution

1959 ◽  
Vol 10 (3) ◽  
pp. 316
Author(s):  
PS Davis
Keyword(s):  
Surface Waters ◽  
Vertical Profile ◽  
Chlorophyll Concentration ◽  
Euphotic Zone ◽  
Early Summer ◽  
Late Winter ◽  
Light Penetration ◽  
Chlorophyll Distribution ◽  
The Mean ◽  
Made In

The chlorophyll a in samples from five stations in Lake Macquarie was determined over the period July 1955 to November 1956. The mean surface value for the four stations within the lake proper was 1.26 mg/m³. The vertical profile at one station was studied and the mean of these profile values was 1.23 mg/m³. Throughout the period of the survey chlorophyll concentrations in the lake varied from 0.1 to 4.0 mg/m³. The lowest values were found in the late winter and early summer (November) and the peaks during spring and autumn. The chlorophyll concentration in the surface waters of Lake Macquarie was shown to be significantly higher than that of the marine water entering the lake, but lower than that of a comparison station in the Hawkesbury River. One series of light penetration measurements made in December 1956 showed that all the water in the lake, and all but one section of Dora Creek, lay within the euphotic zone.

Observations on the onset of the breeding season and on the oestrous cycle of the Welsh Mountain ewe

1964 ◽  
Vol 63 (1) ◽  
pp. 59-60 ◽  
Author(s):  
J. S. M. Hutchinson ◽  
P. J. O'Connor ◽  
H. A. Robertson
Keyword(s):  
Breeding Season ◽  
Cycle Length ◽  
Oestrous Cycle ◽  
The Mean ◽  
Mean Cycle

1.Within a flock of 55 Welsh Mountain ewes maintained under lowland conditions the first ewe came into oestrus on the 14th October. The mean cycle length of 44 normal cycles was 16 days 3 hr.2. The onset of oestrus as assessed by the time of mounting of the ram does not appear to be evenly distributed throughout the day (24 hr.).

Biology and population dynamics of the black-flanked rock-wallaby (Petrogale lateralis lateralis) in the central wheatbelt of Western Australia

2011 ◽  
Vol 33 (2) ◽  
pp. 117 ◽  
Author(s):  
Nicole Willers ◽  
Peter Mawson ◽  
Keith Morris ◽  
Roberta Bencini
Keyword(s):  
Population Dynamics ◽  
Body Condition ◽  
Resource Competition ◽  
Condition Index ◽  
Early Summer ◽  
The Body ◽  
Conservation Strategies ◽  
Late Winter ◽  
Body Condition Index ◽  
Males And Females

Through a mark–recapture study, we explored aspects of the biology and population dynamics in the largest known population of the black-flanked rock-wallaby (Petrogale lateralis lateralis) at Mt Caroline Nature Reserve, in the Western Australian wheatbelt in 2007–10. The body condition index of males and females varied significantly over time but fluctuated similarly for both sexes. Males and females followed a pattern of best condition in early summer, declining through autumn and reaching their poorest condition in early spring. Body condition was closely related to rainfall in the period ~3–6 months before trapping sessions. Births occurred throughout the year with two reproductive peaks, in autumn and late winter/spring. Reproductive rates averaged over 90% annually, except in 2007 when they averaged 76%. Significantly fewer females bred during 2007, and those females were in poorer body condition. Females with a higher body condition index were more likely to reproduce (P = 0.003) but body condition did not influence the sex of offspring. The sex ratio of offspring did not differ significantly from parity and did not support either the Trivers–Willard or local resource competition hypotheses. This information should help to predict population trends and develop appropriate conservation strategies for this threatened species.

Use of Nest Trees by the Mountain Brushtail Possum (Trichosurus caninus) (Phalangeridae : Marsupialia). III. Spatial Configuration and Co-occupancy of Nest Trees

1997 ◽  
Vol 24 (6) ◽  
pp. 661 ◽  
Author(s):  
D. B. Lindenmayer ◽  
A. Welsh ◽  
C. F. Donnelly
Keyword(s):  
Breeding Season ◽  
Spatial Configuration ◽  
Brushtail Possum ◽  
Adult Males ◽  
Long Distance ◽  
The Core ◽  
Eastern Australia ◽  
Large Trees ◽  
Males And Females ◽  
The Mean

Radio-tracking was used to examine the spatial configuration and co-occupancy of large trees with hollows occupied by 16 mountain brushtail possums (Trichosurus caninus) at Cambarville in the central highlands of Victoria, south-eastern Australia. The distance that animals moved between trees on successive days was also examined. Our analyses showed that animals often remained in a given den tree on successive days. On nights when animals did shift between den sites, they typically moved to a new tree that was relatively nearby (< 200 m). Long-distance movements (e.g. > 300 m) between den trees were rare. Considerable variation was found between individuals in the size of areas encompassing trees used frequently (≥5 times) (‘core denning range’) and those encompassing all occupied trees [i.e. including those used infrequently (< 5 times)] (‘total denning range’). The mean area of the core denning range averaged about 1·1 ha for males and 0·7 ha for females. The mean value for the total denning range was approximately 2·6 ha for males and females respectively. Considerable overlap was found in the total denning ranges of pairs of adult males and pairs of adult females. For most animals, the total denning range was shared with the total denning ranges of several other animals. There was substantial variation in the extent of this overlap, ranging from complete enclosure to the sharing of a single tree. The extent of overlap was more limited for the core denning ranges, particularly among females. We observed differences in the extent of the overlap of the total denning ranges of pairs of males and pairs of females in the breeding season (January–March) and non-breeding season (the remaining months of the year). Fewer instances of overlapping total denning ranges among pairs of both males and females were found during the breeding season. The total denning ranges in the breeding season were generally smaller than those in the non- breeding season. Simultaneous co-occupancy of a given den tree by T. caninus was relatively common. Unexpectedly, there was a number of instances of groups of three or four adult animals sharing the same den site on the same night. We recorded several instances of sharing by pairs of animals of the same sex, especially adult males. However, most records of simultaneous tree use were by an adult male and an adult female T. caninus. The extent of overlap in the denning ranges of animals and the prevalence of simultaneous co-occupancy of den trees indicate that the social behaviour of T. caninus at Cambarville may be different from that observed among populations of the species elsewhere in Australia. Possible reasons for these differences are outlined.

VARIATIONS IN THE WEIGHT OF THE ADRENAL GLANDS OF THE FIELD VOLE, MICROTUS AGRESTIS

1961 ◽  
Vol 22 (4) ◽  
pp. 387-393 ◽  
Author(s):  
HELEN CHITTY
Keyword(s):  
Body Weight ◽  
Breeding Season ◽  
Social Behaviour ◽  
Adrenal Glands ◽  
Microtus Agrestis ◽  
Field Vole ◽  
Lactating Females ◽  
Males And Females ◽  
The Mean ◽  
Fluctuating Populations

SUMMARY 1. Mean weights are given for the adrenal glands of 1167 male and 806 female voles from naturally fluctuating populations at Lake Vyrnwy, Wales, during 1952–58. 2. Although the mean standardized adrenal weights of both males and females varied from year to year, no consistent relationship with population trend could be found, except that females from expanding populations tended to have the heaviest adrenals. 3. The adrenal weights increased seasonally each year from low values in the spring to maxima in midsummer and decreased again to low values in the autumn. 4. This fluctuation was exhibited not only by breeding animals but also by those that were sexually immature. It therefore seems unlikely that the seasonal enlargement is entirely a direct effect of gonadal activity, though it may be due to changes in social behaviour during the breeding season. 5. In each month the adrenals of pregnant or lactating females were heavier than those of nulliparous animals of the same body weight.

STUDIES ON THE BIOLOGY OF THE MUSKRAT IN MANITOBA: PART I. OESTROUS CYCLE AND BREEDING SEASON

1952 ◽  
Vol 30 (4) ◽  
pp. 243-253
Author(s):  
J. A. McLeod ◽  
G. F. Bondar
Keyword(s):  
Breeding Season ◽  
Cycle Length ◽  
Oestrous Cycle ◽  
Minimum Time ◽  
Vaginal Smear ◽  
In Captivity ◽  
In The Wild ◽  
The Mean ◽  
Time Required ◽  
Mean Time

A study of oestrus in female muskrats was conducted during the summers of 1950 and 1951 as part of a five year investigation of the biology of the muskrat in Manitoba. Two captive females examined daily by the vaginal smear method from June 30 to Aug. 10, 1950, inconclusively indicated an oestrous cycle length of about 30 days which agreed with the findings of Beer on Wisconsin muskrats. In 9151 10 female muskrats of various ages and of different lengths of time in captivity were examined daily beginning on March 13 and continuing until August 15. The data obtained at this time showed a considerable variation in the lengths of the oestrous cycles in different females or, even, in the same individual from time to time. The minimum time required for the completion of an oestrous cycle was found to be two days while the maximum time observed was 22 days. On the basis of 136 complete oestrous cycles studied, the modal time was found to be approximately four days and the mean time 6.1 days. The longer cycles found by ourselves in 1950 and by Beer are interpreted as representing pseudopregnancies and not oestrous cycles. Failure of muskrats to mate in captivity or in the wild during the latter part of the summer is attributed to sexual inactivity of the males and not the females.

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.

Reproduction in Antechinus maculatus Gould (Dasyuridae)

1975 ◽  
Vol 2 (1) ◽  
pp. 77 ◽  
Author(s):  
HJ Aslin
Keyword(s):  
Breeding Season ◽  
Reproductive Potential ◽  
Gestation Period ◽  
In Captivity ◽  
Males And Females

The smallest member of the genus Antechinus, A. maculatus has a breeding pattern unlike that of its congeners. Captive females are polyoestrous, and can rear several litters of young each year. Both males and females show an extended breeding season in captivity, and males do not become senile after 12 months of age. Seven litters of A. maculatus, each containing up to 11 young, have been bred; the gestation period is 19-20 days. In comparison with most other marsupials, A. maculatus has a high reproductive potential in captivity.

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