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1
Wilson, BA. "Reproduction in the Female Dasyurid Antechinus-Minimus-Maritimus (Marsupialia, Dasyuridae)". Australian Journal of Zoology 34, n. 2 (1986): 189. http://dx.doi.org/10.1071/zo9860189.
Testo completoAbstract (sommario):
Reproduction in female Antechinus minimus maritimus was investigated in the field and laboratory. Field data were obtained from a mark-recapture study. A laboratory colony was maintained to investigate the oestrous pattern, length of gestation and development of pouch young. Breeding occurred in winter with births in July or August. Gestation (mean � SD) was 30.6 � l.5 days for animals mated in the laboratory. Epithelial cells were present in the urine for 34.8 � 8.3 days, a lengthy period compared to A. stuartii (19.3 � 4.4 days). Ovaries from females before the breeding season contained small developing follicles. During the breeding season Graafian follicles (4-8 per ovary) or corpora lutea (4-13 per ovary) were found. Reproduction in A. m. maritimus females is similar to that described previously in other Antechinus.
2
Kitchener, DJ, N. Cooper e a. Bradley. "Reproduction in Male Ningaui (Marsupialia, Dasyuridae)". Wildlife Research 13, n. 1 (1986): 13. http://dx.doi.org/10.1071/wr9860013.
Testo completoAbstract (sommario):
'Stages in the spermatogenic cycle of Ningaui ridei, N. yvonneae and N. timealeyi are defined and the phenology of these stages is presented. In males of Ningaui spp. sexual maturity is reached in the first year, such that after the end of July of each year almost all male Ningaui spp. are considered reproductively mature. Male Ningaui spp. in the active spermatogenic phase are found during the entire season of births (August-January in N. ridei and N. timealeyi but perhaps terminating earlier in N. yvonneae); testes regress to an immature spermatogenic stage after January. There is no indication that in the field adult males die immediately following mating.
3
Woolley, PA, e A. Valente. "Reproduction in Sminthopsis-Longicaudata (Marsupialia, Dasyuridae) - Laboratory Observations". Wildlife Research 13, n. 1 (1986): 7. http://dx.doi.org/10.1071/wr9860007.
Testo completoAbstract (sommario):
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.
4
Woolley, PA. "Reproduction in Dasykaluta-Rosamondae (Marsupialia, Dasyuridae) - Field and Laboratory Observations". Australian Journal of Zoology 39, n. 5 (1991): 549. http://dx.doi.org/10.1071/zo9910549.
Testo completoAbstract (sommario):
Observations on reproduction in both wild-caught and laboratory-maintained Dasykaluta rosamondae have led to the conclusion that this species is one of 10 dasyurid marsupials in which males die soon after their first mating period. D. rosamondae have a short annual breeding season. The females are monoestrous, mating in September and bearing the young in November. Laboratory-reared young are weaned at an age of about 3 1/2-4 months, in February and March, and juveniles appear in the field population at this time. Both mates and females reach sexual maturity at an age of about 10 months. In the laboratory, males breed in only one season, after which those that survive become reproductively senile. Mature males disappear from the field population about the time the young are born; those collected shortly before this show signs of reproductive senescence. Males collected in the months after the young are weaned represent a single age-class; their reproductive development parallels that of maturing known-age males. Females are capable of breeding in at least two seasons and litters of up to eight are reared. Development of the pouch young is described. Unusual interstitial tissue masses develop in the ovaries of D. rosamondae; the granulosa cells of some follicles undergo transformation to interstitial cells, and the oocytes in these follicles degenerate, shortly before the females enter oestrus.
5
Wooley, P. A. "Observations on Reproduction in Captive Parantechinus biiarni (Marsupialia: Dasyuridae)". Australian Mammalogy 18, n. 1 (1995): 83. http://dx.doi.org/10.1071/am95083.
Testo completo
6
Woolley, PA. "Reproduction in Sminthopsis-Macroura (Marsupialia, Dasyuridae) .1. The Female". Australian Journal of Zoology 38, n. 2 (1990): 187. http://dx.doi.org/10.1071/zo9900187.
Testo completoAbstract (sommario):
A laboratory colony of S. macroura, founded by three females and four males, was maintained over four breeding seasons. Reproductive success was high and four generations were produced before the colony was disbanded. Descendants of these animals are still breeding in another laboratory 11 years after the founding of the colony. A detailed prescription for the maintenance and management of a breeding colony is given. The animals bred between June and February, most females first entering oestrus in the early months of the season, in July or August. Female young born early in the season (before mid-October) matured in the season of their birth at an age of 86-159 days; those born later matured in the following season at an age of 185-262 days. In each group, those born later matured earlier. Minimum body weight at sexual maturity was 12.5 g. At least two litters can be reared in a season and individuals may breed in more than one season. S. macroura is polyoestrous with a mean cycle length of 23.25 days. The gestation period is about 11 days and up to eight young can be accommodated in the pouch. Lactating females may return to oesrrus up to 10 days before the young are weaned at 70 days old. Ovulation occurs spontaneously and the mean number of corpora lutea formed was 20.7. The corpora lutea reach maximal size late in pregnancy and they regress more rapidly in lactating than in non- lactating females. Up to three generations of corpora lutea could be recognised in the ovaries of females undergoing cycles uninterrupted by lactation. Changes In body weight, the pouch, and the gross and histological appearance of the reproductive tract were the same in pregnant and pseudopregnant females.
7
Woolley, PA. "Reproduction in Sminthopsis-Macroura (Marsupialia, Dasyuridae) .2. The Male". Australian Journal of Zoology 38, n. 2 (1990): 207. http://dx.doi.org/10.1071/zo9900207.
Testo completoAbstract (sommario):
The breeding season of S. macroura extends from June to February, and individual males (both wild- caught and laboratory-reared) are capable of breeding over extended periods during the breeding season, and for up to three seasons, in the laboratory. Gross and histological changes in the reproductive organs and endocrine changes in relation to reproductive activity have been investigated. Males do not appear to reach sexual maturity until the season following that in which they were born, although spermatorrhoea may commence in the season of birth. Testis and epididymis weight of these males, which commence spermatorrhoea late in the season, approximates that of sexually mature males early in the season but androgen levels and the weight of the accessory glands are low in all males except during the early months of the season. The age at which spermatorrhoea commences ranges from 141 to 350 days. The minimum scrota1 width at which it commences is 7.9 mm and the minimum body weight, 14.0 g. The onset of spermatorrhoea is not a function of age or season and in S. macroura should be used with caution as an indicator of impending sexual maturity. Maximum corticosteroid- binding capacity (MCBC) generally exceeded corticosteroid concentration and no androgen-related fall in MCBC was evident.
8
Woolley, PA. "Reproduction in Pseudantechinus macdonnellensis (Marsupialia : Dasyuridae): Field and Laboratory". Wildlife Research 18, n. 1 (1991): 13. http://dx.doi.org/10.1071/wr9910013.
Testo completoAbstract (sommario):
Pseudantechinus macdonnellensis has a wide distribution within the arid zone of Australia. Observations have been made on reproduction in both newly captured and laboratory-maintained animals obtained from widely separated localities. They have a short annual breeding season; animals from the more westerly part of the range breed later in the year. Males are potentially capable of breeding in at least three seasons, and females in at least four. Females are monoestrous and the gestation period, timed from mating to birth, is from 45 to 55 days. The young are suckled for about 14 weeks in the laboratory and are capable of breeding in the season following that in which they were born, when they are approaching 1 year of age.
9
McAllan, B. M., e F. Geiser. "Photoperiod and the timing of reproduction in Antechinus flavipes (Dasyuridae: Marsupialia)". Mammalian Biology 71, n. 3 (maggio 2006): 129–38. http://dx.doi.org/10.1016/j.mambio.2006.01.005.
Testo completo
10
Woolley, PA. "Reproduction in the Ningbing Antechinus (Marsupialia, Dasyuridae) - Field and Laboratory Observations". Wildlife Research 15, n. 2 (1988): 149. http://dx.doi.org/10.1071/wr9880149.
Testo completoAbstract (sommario):
The ningbing antechinus is a species of small dasyurid marsupial found in the Kimberley region of Western Australia. Observations on reproduction have been made on newly captured and laboratory maintained specimens. The breeding season is short and mating occurs in June. The young are born after a long gestation, estimated to be between 45 and 52 days, in late July and early August. They are weaned in November when about 16 weeks old and they reach sexual maturity at 10-11 months, in the first breeding season after birth. Both males and females are potentially capable of breeding in a second season.
11
Geiser, Fritz, e Pip Masters. "Torpor in relation to reproduction in the mulgara, Dasycercus cristicauda (Dasyuridae: Marsupialia)". Journal of Thermal Biology 19, n. 1 (febbraio 1994): 33–40. http://dx.doi.org/10.1016/0306-4565(94)90007-8.
Testo completo
12
Woolley, P. A. "Aspects of reproduction, and morphology of the penis, of Pseudantechinus woolleyae (Marsupialia : Dasyuridae)". Australian Journal of Zoology 65, n. 6 (2017): 357. http://dx.doi.org/10.1071/zo17086.
Testo completoAbstract (sommario):
Woolley’s Pseudantechinus, P. woolleyae, has remained virtually unstudied in the 30 years since its recognition in 1988 as a species distinct from P. macdonnellensis. It has a wide distribution in arid regions of Western Australia. What little is known of its biology comes largely from studies carried out over the years 1988–91 on one wild-caught female and her offspring, and a few specimens held in the collection of the Western Australian Museum. P. woolleyae is a seasonal breeder and young are born from late July to early October. They mature when ~7 months old. Both males and females are potentially capable of breeding in more than one year. Males have accessory erectile tissue that does not form an appendage on the penis.
13
Dickman, CR, DH King, M. Adams e PR Baverstock. "Electrophoretic Identification of a New Species of Antechinus (Marsupialia, Dasyuridae) in Southeastern Australia". Australian Journal of Zoology 36, n. 4 (1988): 455. http://dx.doi.org/10.1071/zo9880455.
Testo completoAbstract (sommario):
Two electrophoretically distinct but morphologically cryptic forms of Antechinus 'stuartii', designated 'northern' and 'southern', occur together at Kioloa on the southern coast of New South Wales. These forms are distinguished by fixed allele differences in three proteins (albumin, glycollate oxidase and mannosephosphate isomerase) and by differences in allele frequencies for transferrin, and are separated by a Nei D of 0.11. The two forms are reproductively isolated in sympatry at Kioloa by asynchrony in the timing of reproduction, and may be considered separate biological species. Northern form populations were identified by screening for albumin and transferrin in seven localities on the central coast of New South Wales north of Kioloa. Southern form populations were identified similarly in 13 localities south of Kioloa and inland along the Great Dividing Range, and at a further locality in southern Victoria. Ovulation occurs at different rates of change of photoperiod in the two species, and may ensure that reproductive isolation is maintained in all potential areas of sympatry. The northern form represents A. stuartii sensu stricto and ranges from Kioloa north into south-eastern Queensland. The southern form is an undescribed species of Antechinus that appears to be widely distributed throughout southern New South Wales and Victoria.
14
Woolley, PA. "Reproductive Pattern of Captive Boullanger Island Dibbers, Parantechinus apicalis (Marsupialia : Dasyuridae)". Wildlife Research 18, n. 2 (1991): 157. http://dx.doi.org/10.1071/wr9910157.
Testo completoAbstract (sommario):
The recent discovery in Western Australia of two island populations of the dibbler, Parantechinus apicalis, which is rare on the mainland, has provided an opportunity for further study of this species. Following the finding that all males in an island population died soon after the mating period in March, in contrast to mainland males which survive beyond their first breeding season in both the field and the laboratory, a study of the pattern of reproduction in captive island dibblers was made. Like mainland dibblers, island females were found to be monoestrous, and island males potentially capable of breeding in more than one season. Island dibblers are smaller than mainland dibblers but the estimated length of pseudopregnancy was found to be similar. The results of the study on captive island dibblers, together with observations made on the island population at the time it was discovered, suggest that the 'die-off' of males observed in each of the three years following their discovery may not be an inevitable event, as it is for the males of some other species of small dasyurid marsupials (e.g. Antechinus).
15
Watt, Annemarie. "Population Ecology and Reproductive Seasonality in Three Species of Antechinus (Marsupialia : Dasyuridae) in the Wet Tropics of Queensland". Wildlife Research 24, n. 5 (1997): 531. http://dx.doi.org/10.1071/wr96033.
Testo completoAbstract (sommario):
The population and reproductive ecologies of three sympatric species of antechinus were examined in upland rainforests in the wet tropics of Queensland. The three species, Antechinus stuartii adustus, A. flavipes rubeculus and A. godmani, exhibited unusually low trapping success compared with that of sites in temperate regions of Australia. Spatial distributions were extremely patchy both between and within study sites. Comparison with trapping data for temperate populations of A. stuartii and A. flavipes suggests that densities in the wet tropics are among the lowest in Australia. The reproductive season was similar for the three species, commencing during the mid-dry season with juveniles weaned by the early to mid-wet season. The phenomenon of male die-off was observed in the three species. However, the highly synchronous two- week breeding season observed in temperate populations of A. stuartii and A. flavipes was not observed in the tropical populations. The breeding season of the tropical species extended over a six- week period. Timing of reproduction in A. s. adustus and A. f. rubeculus was more similar to temperate than to subtropical populations of A. s. stuartii and A. f. flavipes.
16
Friend, G. R., B. W. Johnson, D. S. Mitchell e G. T. Smith. "Breeding, Population Dynamics and Habitat Relationships of Sminthopsis dolichura (Marsupialia : Dasyuridae) in Semi-arid Shrublands of Western Australia". Wildlife Research 24, n. 3 (1997): 245. http://dx.doi.org/10.1071/wr96070.
Testo completoAbstract (sommario):
Demographic data were gathered from two populations of the little long-tailed dunnart, Sminthopsis dolichura, inhabiting semi-arid nature reserves in the Western Australian wheatbelt in order to place the ecology of this species (formerly part of the Sminthopsis murina complex) in perspective. In all respects, S. dolichura is similar to S. murina from south-eastern Australia, and, indeed, to most other species of the Sminthopsis group. High mobility and transiency rates, an extended seasonal pattern of reproduction, relatively rapid development of the young and the probable existence of polyoestry characterise the life history of S. dolichura and most other species within the group that have been studied. These attributes enable a high degree of reproductive flexibility and permit these species to opportunistically invade new habitats and ephemeral post-fire seral stages. The observed sympatry with highly seasonal monoestrous dasyurids of the genus Antechinus is postulated to occur through spatial and temporal selection of different microhabitats, but also suggests that phylogenetic factors may be at least as important as the predictability of climate and food resources in explaining the evolution of different reproductive strategies.
17
Selwood, L. "Synchronization of oestrus, ovulation and birth in female Antechinus stuartii (Marsupialia: Dasyuridae)." Australian Mammalogy 8, n. 2 (1 aprile 1985): 91–96. http://dx.doi.org/10.1071/am85007.
Testo completoAbstract (sommario):
Reproduction and development were studied during six annual breeding seasons in 80 female Antechinus stuartii in laboratory colonies and in 34 females which were pregnant when trapped. Oestrus, ovulation and births were each highly synchronized within any one population from a specific locality in Victoria. Before ovulation, epithelial cells were present in the urine of the females for a mean of 20.0 clays ± 4.0 (S.D.) (N=72). Matings occurred in this period. In the colonies of animals from Kinglake, the first females came into oestrus over a 4-clay period in mid-July of 1976, 1982 and 1983. In laboratory colonies, ovulations in each year occurred over a 9 to 22-day period in the first half of August for Kinglake and Cement Creek and at later dates in August and September for animals from higher altitudes. In these colonies, half the animals or more ovulated within one week. Births were also synchronized. A similar pattern was found for field animals. Synchronization of breeding and the rate of development in A. stuartii were related to events in the life history.
18
Crowther, M. S., P. B. S. Spencer, D. Alpers e C. R. Dickman. "Taxonomic status of the mardo, Antechinus flavipes leucogaster (Marsupialia : Dasyuridae): a morphological, molecular, reproductive and bioclimatic approach". Australian Journal of Zoology 50, n. 6 (2002): 627. http://dx.doi.org/10.1071/zo02030.
Testo completoAbstract (sommario):
This paper uses a combined morphological, molecular and ecological approach to assess the taxonomic status of Antechinus flavipes leucogaster from Western Australia, and its relationship to A. flavipes flavipes from eastern Australia. Morphological analyses show that A. flavipes leucogaster is smaller and finer than its eastern Australian counterpart in both cranial and dental dimensions. Phylogenetic analyses of partial cytochrome-b sequences showed that A. flavipes flavipes and A. flavipes leucogaster form reciprocally monophyletic clades that have a relatively high level of divergence (approximately 6%). Analysis of the timing of reproduction indicates that the two subspecies show opposite responses to latitude, with A. flavipes leucogaster ovulating later at high latitudes and A. flavipes flavipes ovulating later in more northerly parts of its range. The combined data and the entirely allopatric distributions of the two subspecies confirm their distinctive status. Bioclimatic analysis suggests further that A. flavipes leucogaster occupies wetter but seasonally more variable environments than its eastern relative. It is clear from the level of morphological, molecular, reproductive and distributional differences that A. flavipes flavipes and A.�flavipes leucogaster should be regarded as separate taxa for the purposes of conservation management, and their current subspecific status should be maintained.
19
Fletcher, TP. "Aspects of Reproduction in the Male Eastern Quoll, Dasyurus viverrinus (Shaw) (Marsupialia: Dasyuridae), with Notes on Polyoestry". Australian Journal of Zoology 33, n. 2 (1985): 101. http://dx.doi.org/10.1071/zo9850101.
Testo completoAbstract (sommario):
In captivity, mating activity of quolls reached a peak in late May-early June. Weights of the male accessory glands peaked about the time of mating, after which the glands regressed; in September they weighed considerably less. Weights of testes and epididymides did not vary so much, but by September spermatorrhoea had ceased and the seminiferous tubules had become aspermic. The disseminate prostate gland was divisible histologically into three segments: the anterior and posterior 2 segments had a single cell type in the tubule epithelium; but prostate 1 had two types. The three pairs of Cowper's glands had similar, simple, columnar epithelium. The seminiferous tubules, supported by numerous interstitial cells, were of diameter 360-506 �m. The mature spermatozoon was large, 232 �m long; its flagellum, oval in cross-section, was inserted midway along the wedge-shaped head at the anterior margin of a ventral groove. The gestation period varied from 20 to 24 days; if the first litter was lost early in lactation, the females might return to oestrus. The species is, therefore, polyoestrous. The oestrous cycle of one animal was 34 days.
20
Chen, Xiaolin, Chris R. Dickman e Michael B. Thompson. "Diet of the mulgara, Dasycercus cristicauda (Marsupialia : Dasyuridae), in the Simpson Desert, central Australia". Wildlife Research 25, n. 3 (1998): 233. http://dx.doi.org/10.1071/wr97087.
Testo completoAbstract (sommario):
The diet of the mulgara, Dasycercus cristicauda, from the Simpson Desert in Queensland, was analysed using scats collected between 1990 and 1995. Insects, arachnids and rodents were the main classes of prey of D. cristicauda, but reptiles, centipedes and small marsupials were also consumed. Insects represented 92% by percentage frequency of occurrence in scats, while rodents represented 33% by percentage frequency. Invertebrate prey ≥6 mm in length and vertebrate prey occurred frequently in scats, but small prey ( 1–5 mm), when present, occurred in large numbers. D. cristicauda ate more individual prey items in spring and winter than in autumn, and more large-sized prey in spring than in autumn. In autumn, D. cristicauda consumed mostly insects (100% by frequency) and few rodents (8%), but in winter and spring, switched to rodents (38% and 47% respectively) and insects (88% and 93% respectively). Seasonal shifts in diet may reflect changes in the availability of different groups of prey, or changes in prey selectivity by D. cristicauda in response to costs imposed by seasonal reproduction. The dietary flexibility of D. cristicauda may allow individuals to occupy stable ranges, and has perhaps also promoted the persistence of the species in arid areas that have been subjected to changes in land use since European settlement.
21
Friend, GR. "Ecological Studies of a Population of Antechinus bellus (Marsupialia : Dasyuridae) in Troprical Northern Australia". Wildlife Research 12, n. 2 (1985): 151. http://dx.doi.org/10.1071/wr9850151.
Testo completoAbstract (sommario):
A population of the fawn antechinus, Antechinus bellus, was monitored in tropical open-forest of the Northern Territory between June 1980 and January 1983. Sixty males and 66 females were captured and marked over 9525 trap-nights. The species exhibits the typical Antechinus life-history strategy, characterized by a highly synchronized mating period after which all males die. This field evidence supports earlier speculation based on laboratory studies and limited museum collections. Mating occurs over 2 weeks in late August and parturitions about a month later. Young remain attached to the nipples for 4-5 weeks and are suckled in the nest until weaned in early January. Reproduction patterns, population dynamics and changes in relative abundance resemble those in A. stuartii from south-eastern Australia. The life-history strategy of A. bellus contrasts with that of the regionally sympatric Parantechinus bilarni, in which fecundity is lower and males may survive to breed a second time. The strategy exemplified by A. bellus does not seem optimal for the wet-dry tropics, given the erratic nature of rainfall in the early wet season, which may influence the relative abundance of the insect food resource available for lactating females and newly weaned juveniles. However the existence of patches of structurally diverse open-forest may moderate environmental fluctuations and enhance resource availability, and thus be of critical importance for the survival of local populations.
22
Bradley, A. J. "Reproduction and life history in the red-tailed phascogale,Phascogale calura(Marsupialia: Dasyuridae): the adaptive-stress senescence hypothesis". Journal of Zoology 241, n. 4 (aprile 1997): 739–55. http://dx.doi.org/10.1111/j.1469-7998.1997.tb05745.x.
Testo completo
23
Masters, Pip, e Chris R. Dickman. "Population dynamics of Dasycercus blythi (Marsupialia: Dasyuridae) in central Australia: how does the mulgara persist?" Wildlife Research 39, n. 5 (2012): 419. http://dx.doi.org/10.1071/wr11156.
Testo completoAbstract (sommario):
Context Central Australia has been a graveyard for native mammals, with many small and medium-sized species becoming extinct or persisting in reduced geographical ranges in this region since the advent of European settlement. Species in the critical weight range (35–5500 g) have been affected most dramatically. Aims We compared the dynamics of two geographically distant populations of a medium-sized surviving desert mammal, the brush-tailed mulgara (Dasycercus blythi, ~100 g), and tested the hypothesis that this species’ persistence can be explained by its demographic plasticity. Methods Paired sampling grids, each 31.5 ha, were set up in the Tanami Desert on the northern edge of the species’ geographical range and near Uluru Kata Tjuta National Park (UKTNP) on the southern boundary. Animals were live-trapped every 3 months between 1992 and 1995, and estimates made of population size, residency, reproduction, bodyweight and tail width; the latter was used as an index of condition. Key results The UKTNP site supported a larger population of D. blythi than did the Tanami Desert site. In both areas, the population fluctuated annually, declining during the breeding season (June to October) and increasing again following the influx of juveniles in spring. Females had one litter per year, with a median and maximum litter size of six; births in the Tanami occurred in July, at least a month earlier than they did at UKTNP. Bodyweights and tail widths peaked before breeding and then declined until spring, with animals retaining better body condition in the Tanami than at UKTNP. In both regions, individuals were resident for 1–2 years; daughters remained near their mother’s home range but males moved to other areas. Conclusions The results provided little support for our initial expectation that populations of D. blythi would behave differently in disparate parts of the species’ geographical range, and suggested instead that this mulgara exhibits a predictable life history, with limited demographic flexibility. Implications The persistence of D. blythi in central Australia is most likely a result of its striking flexibility in use of food resources, its ability to enter torpor and to tolerate large declines in bodyweight and condition, and its propensity to dig deep burrows. We suggest that these attributes buffer mulgaras from the impacts of introduced predators that have contributed to extinctions of other medium-sized marsupials, and from climatic and resource uncertainties that shape the dynamics of many smaller desert mammals.
24
Czarny, N. A., K. E. Mate e J. C. Rodger. "Acrosome stability in the spermatozoa of dasyurid marsupials". Reproduction, Fertility and Development 20, n. 2 (2008): 295. http://dx.doi.org/10.1071/rd07178.
Testo completoAbstract (sommario):
The spermatozoa of most marsupials lack nuclear stabilising disulfide-bonded protamines found in eutherian mammals. However, disulfide stabilisation has been observed in the acrosome of macropodid (Macropus eugenii) and phalangerid (Trichosurus vulpecula) marsupials. As a result this organelle, which is normally fragile in eutherian mammals, is robust and able to withstand physical and chemical challenge in these marsupials. The present study examined acrosomal characteristics of the spermatozoa of three dasyurid marsupials; the fat-tailed dunnart (Sminthopsis crassicaudata), eastern quoll (Dasyurus viverrinus) and northern quoll (Dasyurus hallucatus). In all species examined Bryan’s staining demonstrated that significant acrosomal loss occurred following physical challenge with osmotic stress, cryopreservation without cryoprotectant and exposure to detergent (Triton-X). Bromobimane staining indicated that the acrosomes of dasyurids lacked stabilising disulfide bonds. As reported for the wallaby and possum, calcium ionophore (A23187) did not induce the acrosome reaction-like exocytosis in dasyurid spermatozoa but treatment with diacylglycerol (DiC8) caused significant acrosome loss at concentrations similar to those effective for other marsupials. The present study found that the spermatozoa of dasyurids are more sensitive to physical challenge than the previously-studied marsupials and we suggest that this is due to the absence of acrosomal stabilising disulfide bonds.
25
Foster, W. K., A. J. Bradley, W. Caton e D. A. Taggart. "Comparison of growth and development of the red-tailed phascogale (Phascogale calura) in three captive colonies". Australian Journal of Zoology 54, n. 5 (2006): 343. http://dx.doi.org/10.1071/zo06033.
Testo completoAbstract (sommario):
The red-tailed phascogale (Phascogale calura) is an endangered dasyurid species that has recently been brought into captivity in an effort to increase numbers before release back into the wild. As part of investigations into the reproductive biology of the species, information on the growth and development of young was collected throughout lactation from litters raised in three separate colonies. Growth curves for aging young throughout lactation and a timetable of developmental changes were constructed. While two colonies, with fourth- and fifth-generation captive animals, showed no significant difference in growth, animals from a third colony that had been wild caught before breeding displayed a slower rate of growth from 34 days of age. The pattern of development resembled that of other dasyurids, with young left in the nest from 44 days of age, fully furred by 78 days and weaned between 90 and 110 days. Captive phascogales invest heavily in their young, with litters weighing 380 ± 67% of maternal bodyweight at weaning.
26
Lazenby-Cohen, KA. "Communal Nesting in Antechinus-Stuartii (Marsupialia, Dasyuridae)". Australian Journal of Zoology 39, n. 3 (1991): 273. http://dx.doi.org/10.1071/zo9910273.
Testo completoAbstract (sommario):
Unrelated Antechinus stuartii spend a high proportion of their time in mixed-sex communal nests. Communal nesting starts early in the year, after females have weaned their young. It appears to be driven by the need for social interactions and familiarity between all the individuals in an area. The mixed communal nests persist into the mating season, when males and females often visit more than one communal nest each day. During the mating season, males spend no more than 8 hours in a communal nest, and travel extensively between communal nests, perhaps in an effort to improve their reproductive success. Lactating females nest solitarily. To meet the needs of their litter, they increase the number of foraging trips they undertake, but do not reduce the total amount of time spent within the nest at this energetically expensive time of year.
27
Geiser, F. "The role of torpor in the life of Australian arid zone mammals." Australian Mammalogy 26, n. 2 (2004): 125. http://dx.doi.org/10.1071/am04125.
Testo completoAbstract (sommario):
Approximately half of the Australian continent is arid and is characterised by low primary productivity, limited supply of food and pronounced daily fluctuations of ambient temperature (Ta). Despite these adverse conditions the diversity of small mammals in the Australian arid zone is high, although their abundance is generally low. The most successful groups of small arid zone mammals are the dasyurid marsupials, native rodents, and insectivorous bats. A probable reason for the success of the insectivorous dasyurids and bats, which must cope with strong fluctuations in food and water availability, is their extensive use of torpor. Mammalian torpor is characterised by substantial reductions of body temperature (Tb) metabolic rate (MR) and water loss. Small arid zone dasyurids use exclusively daily torpor, some even during the reproductive season, when most mammals maintain strict homeothermy. Dasyurids reduce Tb from ~ 35�C during normothermia to ~ 15�C during torpor, the MR during torpor (TMR) is ~ 30% of basal metabolic rate (BMR). Mass loss, and thus water loss, is related to the duration of torpor bouts. Dasyurids usually enter torpor at night or in the early morning and arouse around midday or in the afternoon. Recent evidence shows that desert dasyurids may bask in the sun during rewarming from torpor. This can minimise energetic cost of arousal to a fraction of that required for endogenous warming. Arid zone bats are also likely to use torpor extensively, but few species, specific to the arid zone, have been studied. Nevertheless, widely distributed bats that occur in the arid zone, such as Nyctophilus geoffroyi, enter brief torpor for part of the day in summer and prolonged torpor (hibernation) for up to two weeks in winter and can reduce Tb to a minimum of 2 - 3�C and TMR to ~ 3% of BMR; mass loss and water loss are minimal during torpor. Patterns of torpor similar to those in bats also have been observed in the insectivorous echidnas and two species of insectivorous / nectarivorous pygmy-possums, which have distribution ranges that include semi-arid and arid areas. In contrast to these species, no detailed information is available on torpor in native Australian rodents, because little work with respect to torpor has been conducted in Australia. However, many arid zone rodents on other continents employ torpor and it is likely that Australian rodents do as well. In addition to reducing energy expenditure and water loss, use of torpor also appears to prolong life span. This is important for bridging adverse conditions and for subsequent re-colonization of areas after droughts and fires in inland Australia. Thus it appears that the success of small insectivorous/nectarivorous mammals and perhaps rodents in the Australian arid zone is partially due to their use of torpor.
28
Woolley, PA. "Observations On The Reproductive Biology Of Myoictis Albopunctatus And Dasyurus Spartacus, Dasyurid Wallacei, Neophascogale Lorentzi, Dasyurus Marsupials Endemic To New Guinea." Australian Mammalogy 23, n. 1 (2001): 63. http://dx.doi.org/10.1071/am01063.
Testo completoAbstract (sommario):
FIELD and laboratory observations on the reproductive biology of seven species of dasyurid marsupials endemic to New Guinea (viz. ?Antechinus? habbema, ?Antechinus? melanurus, ?Antechinus? naso, Murexia longicaudata, Murexia rothschildi, Myoictis melas and Phascolosorex dorsalis) have been recorded by Woolley (in press). Here, less detailed observations on another four, previously unstudied, species (Myoictis wallacei, Neophascogale lorentzi, Dasyurus albopunctatus and Dasyurus spartacus) are presented to provide information on some aspects of reproduction in each species. Only a small number of individuals of each species were trapped, or collected by other means, and maintained in captivity (Table 1). The methods used for trapping and maintenance can be found in Woolley (1993), and for the observations made on the animals, Woolley (in press). Captive breeding could not be attempted because only one sex of each species was maintained. The limited reproductive data obtained from individuals at the time of capture, and from captive animals, is summarised for males in Table 2 and Fig. 1, and for females in Table 3.
29
Millis, A. L., D. A. Taggart, A. J. Bradley, J. Phelan e P. D. Temple-Smith. "Reproductive biology of the brush-tailed phascogale,Phascogale tapoatafa(Marsupialia: Dasyuridae)". Journal of Zoology 248, n. 3 (luglio 1999): 325–35. http://dx.doi.org/10.1111/j.1469-7998.1999.tb01032.x.
Testo completo
30
McAllan, B. M., T. O'Shea e J. R. Roberts. "Seasonal changes in the reproductive anatomy of maleAntechinus stuartii (Marsupialia: Dasyuridae)". Journal of Morphology 231, n. 3 (marzo 1997): 261–75. http://dx.doi.org/10.1002/(sici)1097-4687(199703)231:3<261::aid-jmor5>3.0.co;2-e.
Testo completo
31
Woolley, P. A., e C. Elliott. "Breeding in wild populations of a small dasyurid marsupial, Planigale ingrami, in north-western Queensland using a novel method for collection of specimens". Australian Mammalogy 36, n. 1 (2014): 81. http://dx.doi.org/10.1071/am13027.
Testo completoAbstract (sommario):
The reproductive biology of the long-tailed planigale (Planigale ingrami) is less well known than that of its congeners P. gilesi and P. tenuirostris. Aspects of the anatomy of reproductive structures and the pattern of reproduction of P. ingrami were established by examination of specimens extracted from the stomachs of feral cats shot in north-western Queensland. This species has an extended breeding season that commences in August and probably ends in December, and both males and females may live to breed in more than one season, providing support for the similarity of the reproductive strategies of these three species of Planigale. Females of P. ingrami have twelve nipples in the pouch, the form of which may differ from that of other planigales. Pouch morphology may prove useful in the identification of species of Planigale providing observations are made on the appearance of the pouch throughout the breeding cycle.
32
Cockburn, A. "The Duration of Lactation in Antechinus-Stuartii (Marsupialia, Dasyuridae)". Australian Journal of Zoology 40, n. 2 (1992): 195. http://dx.doi.org/10.1071/zo9920195.
Testo completoAbstract (sommario):
Free-living Antechinus stuartii at the Monga State Forest showed almost no variation in date of birth, yet weaning took place over a period of three weeks. Males were weaned slightly earlier and at greater weights than females. When daughters were considered, weaning was delayed in years when breeding density was high, and females with ten teats weaned their young later and at slightly lower weights than females with eight teats. The difference between the two teat phenotypes was not simply associated with increased reproductive investment, as successful eight-teated mothers weaned their young earlier than less successful mothers, and there was no relation between weaning success and date of weaning for ten-teated mothers. Age of mother did not influence weaning weight or date, and mothers tended to wean at the same time in each year of their life. These patterns are discussed in relation to recent debate on the detection of life-history trade-offs in free-living populations.
33
Woolley, P. A., e C. H. Tyndale-Biscoe. "Side-tracked: unique evidence for passage of foetuses through the lateral vaginal canals in a dasyurid marsupial, Sminthopsis douglasi". Australian Mammalogy 39, n. 1 (2017): 115. http://dx.doi.org/10.1071/am16025.
Testo completo
34
Gilfillan, Sandra L. "An ecological study of a population of Pseudantechinus macdonnellensis (Marsupialia : Dasyuridae) in central Australia. II. Population dynamics and movements". Wildlife Research 28, n. 5 (2001): 481. http://dx.doi.org/10.1071/wr99063.
Testo completoAbstract (sommario):
Population dynamics and movements were investigated in a population of Pseudantechinus macdonnellensis, a dasyurid marsupial occupying rocky habitats in the Australian arid zone. Intra-annual cycling in abundance, activity and numbers of resident and transient individuals was not regular from year to year, although the number of residents was high compared with the number of transients. Juvenile recruitment varied between years and was as low as 18%. Densities were low (0.05–0.2 ha–1 for females and 0.05–0.3 ha–1 for males), and individuals exhibited large stable long-term ranges – mean Minimum Convex Polygon (MCP) area for males was 427 m2 and for females 171 m2. The constraints of the monoestrous, synchronised reproductive strategy of P. macdonnellensis, together with the ameliorating effect of its rocky habitat, which may decrease food limitation and increase survival, seem to have produced a different pattern of population dynamics to that seen in arid-zone dasyurids that are polyoestrous plains-dwellers. The patterns of movement in P. macdonnellensis also differ from plains-dwelling species, in which individuals display high life-time mobility. The existence of large but non-drifting ranges in P. macdonnellensis may be seen as a consequence of a low but relatively predictable food supply, which precludes the necessity for individuals to shift their activity to temporary patches of high food supply, but requires them to occupy a large range to obtain enough food to meet energy requirements.
35
Jones, Menna, e Chris Dickman. "Introduction: Carnivorous marsupials". Wildlife Research 28, n. 5 (2001): I. http://dx.doi.org/10.1071/wrv28n5_in.
Testo completoAbstract (sommario):
Population dynamics and movements were investigated in a population of Pseudantechinus macdonnellensis, a dasyurid marsupial occupying rocky habitats in the Australian arid zone. Intra-annual cycling in abundance, activity and numbers of resident and transient individuals was not regular from year to year, although the number of residents was high compared with the number of transients. Juvenile recruitment varied between years and was as low as 18%. Densities were low (0.05–0.2 ha–1 for females and 0.05–0.3 ha–1 for males), and individuals exhibited large stable long-term ranges – mean Minimum Convex Polygon (MCP) area for males was 427 m2 and for females 171 m2. The constraints of the monoestrous, synchronised reproductive strategy of P. macdonnellensis, together with the ameliorating effect of its rocky habitat, which may decrease food limitation and increase survival, seem to have produced a different pattern of population dynamics to that seen in arid-zone dasyurids that are polyoestrous plains-dwellers. The patterns of movement in P. macdonnellensis also differ from plains-dwelling species, in which individuals display high life-time mobility. The existence of large but non-drifting ranges in P. macdonnellensis may be seen as a consequence of a low but relatively predictable food supply, which precludes the necessity for individuals to shift their activity to temporary patches of high food supply, but requires them to occupy a large range to obtain enough food to meet energy requirements.
36
Renfree, MB, e AM Lewis. "Cleavage in vivo and in vitro in the Marsupial Macropus eugenii". Reproduction, Fertility and Development 8, n. 4 (1996): 725. http://dx.doi.org/10.1071/rd9960725.
Testo completoAbstract (sommario):
In the tammar wallaby, transport down the oviduct takes less than 24 h after fertilization and a mucoid coat is deposited within a few hours of fertilization, with excess spermatozoa trapped in the mucoid layer. The mucin coat thickens as the zygote passes down the oviduct. A proteinaceous shell is laid down outside the mucin coat in the utero-tubal region of the tract. The fertilized zygote enters the uterus in the pronuclear stage with cleavage proceeding in the uterus. In vivo, the first cleavage takes place two days post coitum (p.c.) (approximately 24 h after ovulation) but the next three cleavage stages may be completed within 24 h (between 48 h and 72 h p.c.). Thus, cell-doubling time appears to be around 8 h for 2-8-cell stages. Cleavage in vitro can occur with, or without, the shell membrane. Cleavage in early embryos of the tammar in vitro is slower than that occurring in vivo, and in vitro there may be a '4-cell block' in early development, as in dasyurids. The pattern of cleavage differs markedly from that of dasyurid marsupials in that there is no extrusion of yolk material from the cells and no separation of the blastomeres during the first cleavage stages to the 8-cell stage. The blastomeres are characterized by numerous vesicular structures and lipid droplets, but no yolk bodies. Polarity is not marked in early cleavage, but by the 8-cell stage polarity has developed with surface microvilli and numerous granular vesicles and mitochondria in the cortical regions at one pole of the cells, but sparse microvilli on the inner surfaces and at the other pole. There are complex intervillous interdigitations of microvilli between cells. However, clear identification of cells as pluriblast or trophoblast cells is not possible up to the 8-cell stage examined. These results demonstrate that this macropodid marsupial has a distinctive pattern of early development which differs from that of Didelphis and of the dasyurid marsupials so far described.
37
Bennett, JH, WG Breed, DL Hayman e RM Hope. "Reproductive and Genetic-Studies With a Laboratory Colony of the Dasyurid Marsupial Sminthopsis-Crassicaudata". Australian Journal of Zoology 37, n. 3 (1989): 207. http://dx.doi.org/10.1071/zo9890207.
Testo completoAbstract (sommario):
The fat-tailed dunnart, Sminthopsis crassicaudata, is a small insectivorous dasyurid (adult weight about 16 g) widely distributed in Australia. A laboratory colony of this marsupial, which has been built up over many years, is providing material for studies of dasyurid reproductive biology and genetics. In the area of reproductive biology, we have found a marked disparity in the age of maturation between the two sexes, and we are currently studying certain aspects of spermatogenesis, sperm transport, fertilisation and early embryonic development. Genetical studies have revealed large differences between the sexes in autosomal linkage values and meiotic chromosome behaviour. In females, we have observed very limited intrachromosomal recombination and this is reflected in the distal localisation of chiasmata on the autosomes. Extreme localisation of chiasmata has not hitherto been found in a mammal, and it will be interesting to see how widely it occurs in other marsupial species. The genetical and cytological findings lead to a number of predictions that are being tested in further experimental work with the colony. Although we have been able to raise litter production to a high level, the very variable and unpredictable nature of male reproductive performance currently limits the wider use of the S. crassicaudata colony. It is clear, however, that this dasyurid has the potential to become a very useful laboratory marsupial and that it will be especially valuable for comparative biomedical studies.
38
Collett, Rachael A., Andrew M. Baker e Diana O. Fisher. "Prey productivity and predictability drive different axes of life-history variation in carnivorous marsupials". Proceedings of the Royal Society B: Biological Sciences 285, n. 1890 (31 ottobre 2018): 20181291. http://dx.doi.org/10.1098/rspb.2018.1291.
Testo completoAbstract (sommario):
Variation in life-history strategies has usually been characterized as a single fast–slow continuum of life-history variation, in which mean lifespan increases with age at maturity as reproductive output at each breeding event declines. Analyses of plants and animals suggest that strategies of reproductive timing can vary on an independent axis, with iteroparous species at one extreme and semelparous species at the other. Insectivorous marsupials in the Family Dasyuridae have an unusually wide range of life-history strategies on both purported axes. We test and confirm that reproductive output and degree of iteroparity are independent in females across species. Variation in reproductive output per episode is associated with mean annual rainfall, which predicts food availability. Position on the iteroparity-semelparity axis is not associated with annual rainfall, but species in regions of unpredictable rainfall have longer maximum lifespans, more potential reproductive events per year, and longer breeding seasons. We suggest that these two axes of life-history variation arise because reproductive output is limited by overall food availability, and selection for high offspring survival favours concentrated breeding in seasonal environments. Longer lifespans are favoured when reproductive opportunities are dispersed over longer periods in environments with less predictable food schedules.
39
Czarny, N. A., e J. C. Rodger. "143. THE FIRST EVIDENCE OF HIGH SUSCEPTIBILITY TO COLD SHOCK BY THE SPERMATOZOA OF A MARSUPIAL, THE FAT TAILED DUNNART (SMINTHOPSIS CRASSICAUDATA)". Reproduction, Fertility and Development 21, n. 9 (2009): 61. http://dx.doi.org/10.1071/srb09abs143.
Testo completoAbstract (sommario):
Carnivorous marsupials are native Australian predators including the highly threatened northern quoll (Dasyurus hallucatus) and Tasmanian devil (Sarcophilus harrisii). These species are currently actively managed in captive populations but assisted reproductive techniques such as gamete banking may also contribute to their conservation. Previous studies on a model dasyurid, the fat tailed dunnart (Sminthopsis crassicaudata), have found that spermatozoa do not survive freezing and thawing using a variety of freezing protocols and cryoprotectants. We have re-examined cold shock to investigate problems with sperm cryopreservation in S. crassicaudata. Epididymal spermatozoa were rapidly cooled to 0.5ºC in a pre-cooled tube held in an iced water slurry and upon re-warming the spermatozoa were non-motile (n=6). The addition of up to 20% egg yolk, which is considered protective to the spermatozoa of cold shock sensitive eutherians, did not improve the outcome (n=6). Similarly when S. crassicaudata spermatozoa were rapidly cooled to 4ºC, just 2% remained motile upon re-warming (n=10). However when spermatozoa were combined with at least 10% egg yolk and rapidly cooled to 4ºC only small reductions in motility were observed upon rewarming (n≥8). In order to achieve motile spermatozoa at 0ºC, controlled rate cooling at 0.5ºC/minute was examined. In the absence of egg yolk there was a decline in the percentage of motile spermatozoa below 4ºC (n=6). However if spermatozoa were combined with at least 10% egg yolk there was no significant loss of motility at temperatures as low as 0ºC (n=6). This study has revealed that at least one species of marsupial is highly susceptible to cold shock. These paradigm shifting findings give direction to future experiments aiming to develop a robust technique for sperm preservation in endangered dasyurids.
40
Woolley, P. A., N. Guedelha e J. A. M. Graves. "Anatomy and chromosomes of two intersexual dasyurid marsupials". Reproduction, Fertility and Development 15, n. 5 (2003): 293. http://dx.doi.org/10.1071/rd03045.
Testo completoAbstract (sommario):
The intersexual phenotypes of marsupials with XXY and XO chromosome constitutions imply that not all sexual dimorphisms are under the control of testicular hormones and, ultimately, the SRY gene on the Y chromosome. It has been hypothesised that there is a gene on the X chromosome that determines whether either a scrotum will form (one copy of the gene) or a pouch with teats (two copies of the gene). Here, we describe the anatomy and chromosomes of two intersexual dasyurid marsupials. One, a Dasyuroides byrnei, had a pouch, but the reproductive tract was essentially male. The other, a Sminthopsis douglasi, had a hemipouch and a hemiscrotum and the reproductive tract was essentially female. The S. douglasi was a mosaic for cells with an apparently normal 2n = 14, XX female karyotype and cells with 2n = 14 plus (usually) two dot-like supernumerary elements 2n = 14, XX + 2B. The D. byrnei cells examined also had a 2n = 14, XX + 2B karyotype. In fibroblasts from the male and female sides of the S. douglasi, it was possible to assign the 2n = 14, XX karyotype to the male side and the 2n = 14, XX + 2B to the female side.
41
McAllan, B. M. "Dasyurid marsupials as models for the physiology of ageing in humans". Australian Journal of Zoology 54, n. 3 (2006): 159. http://dx.doi.org/10.1071/zo05073.
Testo completoAbstract (sommario):
Marsupials of the order Dasyuromorphia have features that make them useful as models for ageing processes in humans. First, they are long-lived for their size, with most small species living for at least 1 year, often several years, contrasting with the mouse, a conventional model for ageing studies, where most populations turn over within 4–6 months. Longevity in some dasyurids allows biological comparisons with other long-lived mammals. Second, the predictable reproduction and life histories of the genera Antechinus and Sminthopsis allow analysis of the role of sex hormones in physiological changes as ageing progresses. For Antechinus, this includes the interaction between testosterone and cortisol in initiating pathologies in males but not females. Many ageing processes are expressed differently between male and female humans, and have a stress component. The neuropathological changes that occur in Antechinus can be used as a model for the dementias of ageing, including Alzheimer’s disease. The age-related neuropathologies in Antechinus indicate that hormonal influences may be important. Finally, in Sminthopsis, the interaction between sex hormones, reproduction and the fattening season offer insights into the interaction between longevity and reduced energy intake, including obesity. Thus these mammals offer useful models for many of the possible influences for healthy ageing in humans.
42
Russell, Tracey, Amanda Lane, Judy Clarke, Carolyn Hogg, Katrina Morris, Tamara Keeley, Thomas Madsen e Beata Ujvari. "Multiple paternity and precocial breeding in wild Tasmanian devils, Sarcophilus harrisii (Marsupialia: Dasyuridae)". Biological Journal of the Linnean Society 128, n. 1 (27 maggio 2019): 201–10. http://dx.doi.org/10.1093/biolinnean/blz072.
Testo completoAbstract (sommario):
Abstract Polyandry, a common reproductive strategy in various animal species, has potential female benefits, which include enhanced offspring fitness. Benefits can be direct, such as reduced risk of male infanticide of offspring, or indirect, such as increased genetic diversity of offspring and the acquisition of ‘good genes’. Multiple paternity of litters has been recorded in numerous marsupial species but has not been reported in Tasmanian devils, Sarcophilus harrisii (Boitard). We investigated whether multiple paternity occurred in litters within a wild population of Tasmanian devils. Using major histocompatibility complex-linked and neutral microsatellite markers, the paternity of nine litters was analysed. We found multiple paternity in four out of nine litters and that yearling (> 1, < 2 years old) male devils were siring offspring. This is the first record of multiple paternity and of male precocial breeding in wild Tasmanian devils. To date, there are no data relating to the subsequent survival of devils from single- vs. multiple-sired litters; therefore, we do not know whether multiple paternity increases offspring survival in the wild. These results have implications for the Tasmanian devil captive insurance programme, because group housing can lead to multiple-sired litters, making the maintenance of genetic diversity over time difficult to manage.
43
Leung, Luke K. P. "Ecology of Australian tropical rainforest mammals. I. The Cape York antechinus, Antechinus leo (Dasyuridae : Marsupialia)". Wildlife Research 26, n. 3 (1999): 287. http://dx.doi.org/10.1071/wr96042.
Testo completoAbstract (sommario):
This is the first detailed ecological study of the Cape York antechinus, Antechinus leo, a small marsupial endemic to rainforest on the Cape York Peninsula, North Queensland, Australia. A total of 181 animals was captured 725 times at Iron Range during a capture–mark–recapture study from 1989 to 1991. A. leo is crepuscular–nocturnal, insectivorous, semi-arboreal and nests in hollows. Its life-history strategy is typical of the genus, including the synchrony of reproductive events and the post-mating death of all males. The estimated annual mating season is from mid-September to mid-October. Young were born around 1 November ( 12 days), and were carried in the pouch until early to mid December. Juveniles became trappable around mid February. Daughters stayed in their mother’s home range, while sons dispersed soon after they left the nest. Lactation, weaning and dispersal of young were timed to coincide with the wet season when the abundance of invertebrates increased, suggesting that populations are limited by food supply.
44
Hughes, R. Leon. "Structure of the female reproductive tract of an adult parous Tasmanian tiger, Thylacinus cynocephalus". Australian Journal of Zoology 48, n. 5 (2000): 487. http://dx.doi.org/10.1071/zo00022.
Testo completoAbstract (sommario):
The present observations on the now-extinct Thylacinus are based on the reproductive system of an adult thylacine discovered among the specimens of the Hill collection at the Hubrecht Laboratory in the Netherlands. As in other marsupials, the reproductive tract was characterised by the presence of a uterus duplex and a vaginal complex where the ureters passed dorsally over each lateral vaginal canal to enter the bladder. The lateral vaginal canals each entered a urogenital sinus that terminated in a shallow cloaca. The gross dimensions of the reproductive tract of the thylacine were greater than those of any extant dasyurid marsupial. The distance from the rostral pole of the ovaries to the most caudal extremity of the urogenital sinus measured 25 cm. The distinctive aspects of the reproductive tract included a disproportionate enlargement of the corpus uteri that is without parallel in any other marsupial species. The bodies of the right and left uteri measured 10.4 cm 1.2 cm 0.9 cm and 9.1 cm 0.8 cm 0.7 cm respectively. The rostro-caudal length of the right and left cervices measured 2.7 cm and 1.7 cm respectively. The cervical canals entered the vaginal complex by way of a thick median vaginal septum. The elongated caudal component of the vaginal culs-de-sac lacked a median vaginal septum. As in other dasyurid marsupials, the lateral vaginae and associated vaginal complex were of diminutive proportions in relation to the typical marsupial pattern. The histology of the tract was remarkably good for tissue preserved since 1902 and indicated that the tissues were free of pathological changes. A characteristic marsupial pattern of ovarian folliculogenesis was evident where all but a thin peripheral zone of the cytoplasm of the primary oocyte became vacuolated during the pre-antral stage of ovarian follicle development.
45
Woolley, P. A. "The Julia Creek dunnart, Sminthopsis douglasi (Marsupialia : Dasyuridae): breeding of a threatened species in captivity and in wild populations". Australian Journal of Zoology 63, n. 6 (2015): 411. http://dx.doi.org/10.1071/zo15056.
Testo completoAbstract (sommario):
A detailed description of the methods used to house, maintain and assess the reproductive condition of captive Julia Creek dunnarts, Sminthopsis douglasi, that led to successful breeding of the species in captivity is provided. Basic features of the reproductive biology of this species of Sminthopsis have been established from observations made on captive animals. The females are polyoestrous, with a cycle length of ~28 days. Young are born 13–16 days after mating and are dependent on the mother for ~70 days. The age at which captive animals commence breeding ranged from 13 to 38 weeks (females) and 23 to 40 weeks (males). Both sexes are capable of breeding when two years old. Breeding in wild populations is seasonal and occurs over a six-month period from August to March, which encompasses the hottest and wettest time of the year. Both females and males are known to be capable of breeding in more than one season and females have the potential to rear two litters in a season. Recruitment of young to the population may be affected by heavy rainfall during the breeding season that can lead to closure of the cracks and holes in which the dunnarts shelter.
46
Taggart, D. A., e P. D. Temple-Smith. "Transport and storage of spermatozoa in the female reproductive tract of the brown marsupial mouse, Antechinus stuartii (Dasyuridae)". Reproduction 93, n. 1 (1 settembre 1991): 97–110. http://dx.doi.org/10.1530/jrf.0.0930097.
Testo completo
47
Breed, W. G., C. M. Leigh e J. H. Bennett. "Sperm morphology and storage in the female reproductive tract of the fat-tailed dunnart,Sminthopsis crassicaudata (Marsupialia: Dasyuridae)". Gamete Research 23, n. 1 (maggio 1989): 61–75. http://dx.doi.org/10.1002/mrd.1120230107.
Testo completo
48
KRAJEWSKI, CAREY, PATRICIA A. WOOLLEY e MICHAEL WESTERMAN. "The evolution of reproductive strategies in dasyurid marsupials: implications of molecular phylogeny". Biological Journal of the Linnean Society 71, n. 3 (novembre 2000): 417–35. http://dx.doi.org/10.1111/j.1095-8312.2000.tb01267.x.
Testo completo
49
Stead-Richardson, E. J., S. D. Bradshaw, F. J. Bradshaw e G. Gaikhorst. "Monitoring the oestrous cycle of the chuditch (Dasyurus geoffroii) (Marsupialia : Dasyuridae): non-invasive analysis of faecal oestradiol-17b". Australian Journal of Zoology 49, n. 2 (2001): 183. http://dx.doi.org/10.1071/zo00024.
Testo completoAbstract (sommario):
Faecal oestradiol-17β levels were monitored for three months during the breeding period in six female chuditch (Dasyurus geoffroii) held in a captive colony. Four of the females mated and gave birth to young. One female mated once but did not conceive and the other female did not mate. Peaks in oestradiol concentration, up to 9 ng g–1 of dried faecal mass, were observed during the period when urogenital swabs were dominated by cornified epithelial cells. Multiple peaks of oestradiol were also observed in the female that did not mate, suggesting that the chuditch may be a reflex ovulator. Monitoring of faecal oestradiol levels did not enable oestrus to be determined with precision, but showed potential for elucidating details of the reproductive biology of this and other marsupial species.
50
Gilfillan, Sandra L. "An ecological study of a population of Pseudantechinus macdonnellensis (Marsupialia : Dasyuridae) in central Australia. I. Invertebrate food supply, diet and reproductive strategy". Wildlife Research 28, n. 5 (2001): 469. http://dx.doi.org/10.1071/wr99062.
Testo completoAbstract (sommario):
The invertebrate food supply, diet and reproductive strategy of a population of the dasyurid marsupial, Pseudantechinus macdonnellensis, living in an arid rocky habitat was investigated at a site in the West MacDonnell National Park, Northern Territory, over two and a half years. Invertebrate food supply displayed high month to month predictability and no marked seasonal cycle correlated with temperature. Analysis of faeces indicated that P. macdonnellensis is a generalist insectivore. There was some discrepancy between the pattern revealed by invertebrate sampling and the prey types taken but it was concluded that the invertebrates sampled broadly reflected those available to P. macdonnellensis. Individual females reproduced only once per year; the estimated time of mating was in July–August, and births occurred in September–October. The maximum litter size was six and nearly all females in each season produced a full complement of young. Some males survived and showed spermatorrhea in two breeding seasons and some females survived and produced young in up to three. The seasonal pattern of invertebrate food supply at the study site appeared to be more dependable than that found in studies carried out in arid plains habitats. The difference may result from a microtopographical amelioration in the rocky habitat of the effects of extreme weather conditions that in open, arid habitats are believed to produce increased short-term unpredictability and pronounced, temperature-driven seasonality in food supply. The ameliorating effect may also increase longevity in P. macdonnellensis by reducing density-independent mortality. The monoestrous highly seasonal reproductive strategy in P. macdonnellensis differs from that displayed by most species that inhabit arid plains habitats (the latter are polyoestrous with an extended breeding season). The shortterm predictability in food supply together with a high longevity in P. macdonnellensis may account for its reproductive strategy. The results of this study provide support for the notion that habitat-specific selective pressures in arid environments may favour divergent ecological strategies in functionally similar species.