Journal articles on the topic 'Marsupials Conservation'
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1
Sherwin, WB, and ND Murray. "Population and Conservation Genetics of Marsupials." Australian Journal of Zoology 37, no. 3 (1989): 161. http://dx.doi.org/10.1071/zo9890161.
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This article summarises current knowledge of marsupial population genetics, and discusses its relevance to the conservation of marsupial species. It has been suggested that there is much lower genetic variation within marsupial populations than in eutherian mammals. This trend is not evident in the electrophoretic data summarised here. However, genetic differentiation between populations, subspecies, and species of marsupials appears to be slightly lower than comparable values for eutherians. Genetic estimates of migration between populations are scarce at present, but show values that are comparable with eutherians. Some studies of marsupial population genetics have used non-electrophoretic characteristics, or have addressed the possibility of selection on the characters analysed. Although few, these studies indicate the suitability of marsupials for such investigations. Recent debate over the theories and applications of conservation genetics has made it clear that more research is required on individual species. Given the record of extinction of marsupials in the last 200 years, it is important to test the applicability of these theories to individual marsupial species. Several examples are discussed emphasising the need for ecological studies that estimate the effective number of reproducing individuals per generation. This figure, called the effective size, is the corner- stone of conservation genetics theory, being an important determinant of both the rate of loss of variation between individuals, and the rate of inbreeding. The effective size of the mainland population of the eastern barred bandicoot, Perameles gunnii, appears to be only about one-tenth of its census number. This result is comparable with estimates made in other vertebrates, and demonstrates that many marsupial species which appear to have an adequate census size on ecological grounds may face genetic problems resulting from small effective size.
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J. Foley, William. "Marsupial Nutrition." Pacific Conservation Biology 5, no. 3 (1999): 240. http://dx.doi.org/10.1071/pc99240a.
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In the early 1980s advances in marsupial biology could no longer be encapsulated in a single volume such as Hugh Tyndale-Biscoe's "Life of Marsupials" and Cambridge University Press commissioned a series of monographs covering a range of different topics in marsupial biology. As it was, only three of that series were realized and among them was the ptedecessor to this book "Digestive Physiology and Nutrition of Marsupials" published in 1982. "Marsupial Nutrition" is a considerably expanded and comprehensive review of studies of nutrition and digestive physiology of Australasian and South American marsupials. In Australia, many ecologists view the limited nutrient status of our soils and vegetation as a fundamental limit to animal populations. This book explains firstly how Australian marsupials have responded to those limitations and secondly asks whether these responses are common amongst marsupials living in New Guinea and South America.
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Rodger, JC. "Prospects for the Artificial Manipulation of Marsupial Reproduction and Its Application in Research and Conservation." Australian Journal of Zoology 37, no. 3 (1989): 249. http://dx.doi.org/10.1071/zo9890249.
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Techniques to manipulate reproduction and productivity are well established features of the husbandry of domestic animals and the treatment of human infertility. Similar approaches are feasible in marsupials, but little work has been done to apply our considerable basic knowledge of marsupial reproduction to produce practical artificial breeding. If the reproduction and productivity of marsupials could be more effectively controlled it would greatly aid research and profoundly change both current practice in the management of zoo animals, and the strategies employed for the breeding and conservation of rare or endangered species. The present paper sets out the likely agenda, reports progress to date and discusses short and long-term prospects for the artificial breeding of marsupials. Topics discussed include: induced ovulation and superovulation, oocyte and embryo collection, semen collection and the frozen storage of sperm, artificial insemination, in vitro fertilization and embryo transfer, frozen storage of embryos, and the use of surrogate mothers in supporting both pregnancy to term, and the development of young in the pouch.
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Taggart, D. A., D. Schultz, and P. D. Temple-Smith. "Development and Application of Assisted Reproductive Technologies in Marsupials: Their Value for Conservation of Rock-wallabies." Australian Mammalogy 19, no. 2 (1996): 183. http://dx.doi.org/10.1071/am97183.
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Assisted reproductive technology is used routinely in management to treat infertility and in domestic species in basic husbandry. In eutherian mammals application of this technology is also well established in wildlife conservation programs. The development and application of this technology in marsupials, however, is a relatively new field. The reproductive techniques currently available for marsupial studies, their benefits and implications for conservation are discussed in order to remove any previous misconceptions and provide an insight into how these techniques might be applied. The potential of this technology for maintaining genetic variability and enhancing reproductive output of threatened marsupial species is highlighted, with particular reference to the conservation of rock wallabies.
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Sinclair, A. R. E. "Fertility control of mammal pests and the conservation of endangered marsupials." Reproduction, Fertility and Development 9, no. 1 (1997): 1. http://dx.doi.org/10.1071/r96057.
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Populations are bounded by negative feedbacks operating through fertility or mortality, termedpopulation regulation. If fertility is artificially reduced, the average size of the population is also reduced, but only under certain conditions. If (i) juvenile survival or (ii) adult survival improve due to lower fertility, or (iii) territoriality limits populations, the effects of lower birth rate will not change population size unless such reduction exceeds the effects of these processes. Published data on population trends and birth rates have allowed a comparison among species of instantaneous rates of change. The intrinsic rate of increase, rm, and population variability are both related to body size, because birth rates and survivorship are also related to body size. These rates are trade-offs as adaptations. Populations of species in exotic habitats may fluctuate more than when they are in their indigenous habitats. Fertility control could reduce such fluctations. Marsupials have lower birth rates than eutherians, and so rely more on survivorship, perhaps as an adaptation to unpredictable environments. Compromising survival by either habitat change or increased predation will affect marsupials more than eutherians. This explains why many marsupial populations are declining towards extinction.
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Renfree, MB. "Monotreme and marsupial reproduction." Reproduction, Fertility and Development 7, no. 5 (1995): 1003. http://dx.doi.org/10.1071/rd9951003.
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Marsupials were regarded as curiosities by their early European discoverers, animals to be wondered at. Monotremes were even more surprising; the platypus was such an amalgam of characters that it was thought to be a hoax. They were recognized very early as mammals that could make a major contribution to our understanding of reproductive processes, and work on marsupials at the turn of the century was much in evidence. It is, however, only in the past two decades, and especially in the past few years that marsupial research has regained this position. There is no doubt that future research will strengthen this contribution, but we are faced with serious conservation questions that must be solved if we are to maintain these wonderful animals as a resource for future generations.
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Hwang, Jae Yeon, Jamie Maziarz, Günter P. Wagner, and Jean-Ju Chung. "Molecular Evolution of CatSper in Mammals and Function of Sperm Hyperactivation in Gray Short-Tailed Opossum." Cells 10, no. 5 (April 29, 2021): 1047. http://dx.doi.org/10.3390/cells10051047.
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Males have evolved species-specifical sperm morphology and swimming patterns to adapt to different fertilization environments. In eutherians, only a small fraction of the sperm overcome the diverse obstacles in the female reproductive tract and successfully migrate to the fertilizing site. Sperm arriving at the fertilizing site show hyperactivated motility, a unique motility pattern displaying asymmetric beating of sperm flagella with increased amplitude. This motility change is triggered by Ca2+ influx through the sperm-specific ion channel, CatSper. However, the current understanding of the CatSper function and its molecular regulation is limited in eutherians. Here, we report molecular evolution and conservation of the CatSper channel in the genome throughout eutherians and marsupials. Sequence analyses reveal that CatSper proteins are slowly evolved in marsupials. Using an American marsupial, gray short-tailed opossum (Monodelphis domestica), we demonstrate the expression of CatSper in testes and its function in hyperactivation and unpairing of sperm. We demonstrate that a conserved IQ-like motif in CatSperζ is required for CatSperζ interaction with the pH-tuned Ca2+ sensor, EFCAB9, for regulating CatSper activity. Recombinant opossum EFCAB9 can interact with mouse CatSperζ despite high sequence divergence of CatSperζ among CatSper subunits in therians. Our finding suggests that molecular characteristics and functions of CatSper are evolutionarily conserved in gray short-tailed opossum, unraveling the significance of sperm hyperactivation and fertilization in marsupials for the first time.
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Kasai, Fumio, Patricia C. M. O'Brien, Jorge C. Pereira, and Malcolm A. Ferguson-Smith. "Marsupial chromosome DNA content and genome size assessed from flow karyotypes: invariable low autosomal GC content." Royal Society Open Science 5, no. 8 (August 2018): 171539. http://dx.doi.org/10.1098/rsos.171539.
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Extensive chromosome homologies revealed by cross-species chromosome painting between marsupials have suggested a high level of genome conservation during evolution. Surprisingly, it has been reported that marsupial genome sizes vary by more than 1.2 Gb between species. We have shown previously that individual chromosome sizes and GC content can be measured in flow karyotypes, and have applied this method to compare four marsupial species. Chromosome sizes and GC content were calculated for the grey short-tailed opossum (2 n = 18), tammar wallaby (2 n = 16), Tasmanian devil (2 n = 14) and fat-tailed dunnart (2 n = 14), resulting in genome sizes of 3.41, 3.31, 3.17 and 3.25 Gb, respectively. The findings under the same conditions allow a comparison between the four species, indicating that the genomes of these four species are 1–8% larger than human. We show that marsupial genomes are characterized by a low GC content invariable between autosomes and distinct from the higher GC content of the marsupial × chromosome.
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Deakin, Janine E. "Marsupial Genome Sequences: Providing Insight into Evolution and Disease." Scientifica 2012 (2012): 1–22. http://dx.doi.org/10.6064/2012/543176.
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Marsupials (metatherians), with their position in vertebrate phylogeny and their unique biological features, have been studied for many years by a dedicated group of researchers, but it has only been since the sequencing of the first marsupial genome that their value has been more widely recognised. We now have genome sequences for three distantly related marsupial species (the grey short-tailed opossum, the tammar wallaby, and Tasmanian devil), with the promise of many more genomes to be sequenced in the near future, making this a particularly exciting time in marsupial genomics. The emergence of a transmissible cancer, which is obliterating the Tasmanian devil population, has increased the importance of obtaining and analysing marsupial genome sequence for understanding such diseases as well as for conservation efforts. In addition, these genome sequences have facilitated studies aimed at answering questions regarding gene and genome evolution and provided insight into the evolution of epigenetic mechanisms. Here I highlight the major advances in our understanding of evolution and disease, facilitated by marsupial genome projects, and speculate on the future contributions to be made by such sequences.
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Witt, R. R., L. A. Hinds, and J. C. Rodger. "93 Oestrous Synchronisation Studies in a Marsupial." Reproduction, Fertility and Development 30, no. 1 (2018): 186. http://dx.doi.org/10.1071/rdv30n1ab93.
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There is no strategy to precisely synchronise and predict oestrus and ovulation in marsupials. This is the major limitation in applying assisted reproduction to marsupial conservation. Routine methods of female synchronization that target the ovary (effective in eutherians) are ineffective in marsupials because they do not disrupt the corpus luteum. Gondaotropin-releasing hormone (GnRH) agonists have been used to suppress female cycling in several marsupials and work by targeting GnRH action in the pituitary. After the GnRH agonist reaches its active endpoint, female cycling returns. This study investigated whether Lucrin Depot (Abbott Laboratories, Lake Bluff, IL, USA), a tailored 1-month microsphere GnRH agonist preparation, has the potential to first suppress female cycling, and then facilitate a synchronous return to female cycling in a model marsupial, the tammar wallaby (Macropus eugenii). Preliminary studies indicated that Lucrin could be used to regulate ovarian activity, but a dose >0.20 mg kg−1 was required. In this study, nonpregnant tammars (n = 18, 6 per group) had their pouch young removed (RPY) on Day 0; RPY suspends lactation and reactivates cycling, allowing for controlled assessment of oestrus and mating in treated and untreated females. On Day 0, an intramuscular (IM) injection of water (Control) or 1 mg kg−1 of Lucrin Depot (group A) was given after RPY. Group B also received 1 mg kg−1 of Lucrin Depot but this was not injected until Day 10 after RPY (a strategy to assess whether timing of Lucrin yields different results). Females were placed in breeding pens of 1 male to 3 females. Reproductive suppression and synchrony of return to female cycling was assessed by pouch and urogenital opening checks to detect newborn young and copulatory plugs. All data (time of mating/conception) were analysed using ANOVA (significance, P < 0.05). There was a significant difference between the first mating response in the Control compared with Groups A and B (P = 0.0003), but the time from Lucrin injection to mating, Day 0 or Day 10, was not significant (P = 0.1431). All control females mated before Day 32 RPY, whereas all Lucrin-treated females mated from Day 33 to 66. All Lucrin-treated females conceived as evidenced by pouch young. Further analysis revealed 2 Lucrin-injection to mating response intervals, those females delayed by ~10 days that conceived between 33 and 50 days (n = 7: 41 ± 2.1 days; mean ± SEM), and those females delayed by ~30 days that conceived between 61 and 66 days (n = 5: 62 ± 1.0 days; mean ± SEM) following injection. Thus, an IM injection of 1 mg kg−1 of Lucrin Depot is sufficient to delay oestrus in breeding tammar wallabies whether given at the time of RPY or 10 days later. This study confirmed that Lucrin Depot can be used to regulate ovarian activity in macropod marsupials, and has potential to form the basis of a GnRH agonist-based synchronisation strategy for use in assisted breeding for marsupial conservation. This research was supported by Holsworth Wildlife Research Endowment.
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Ferreira, Mariana Silva, Rui Cerqueira, and Marcus Vinícius Vieira. "What are the main drivers of survival and recruitment in tropical forest marsupials? A 16-year study." Journal of Mammalogy 101, no. 2 (February 22, 2020): 515–25. http://dx.doi.org/10.1093/jmammal/gyaa013.
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Abstract Tropical forest marsupials exhibit large interannual variation in population sizes, with direct negative density dependence capturing the essential features of their dynamics. However, the demographic mechanisms underlying population growth rate and driving both survival and reproduction are still unclear. We used a 16-year capture-mark-recapture data set for five tropical forest marsupials to test for seasonal and interannual density dependence in survival and recruitment. Hypotheses regarding the effects of exogenous (rainfall and minimum temperature) factors on survival, recruitment, and reproductive parameters (fecundity, litter size, and proportion of reproductive females) were also tested. Population size negatively affected survival in three of five species. High population sizes in a given year reduced survival rates in the following year, with strong detrimental effects on males. Recruitment and proportion of reproductive females were highly dependent on weather variables, and were not affected by previous population sizes (except for Metachirus nudicaudatus). Fecundity (number of female offspring/female) was related negatively to population size only in the black-eared opossum (Didelphis aurita), while litter size was a relatively conservative parameter, largely independent of external conditions. Our analyses indicate that density-dependent survival is the mechanism that regulates population size of tropical forest marsupials, either through a reduction in survival or an increase in emigration rates. This general regulatory mechanism may be common to other marsupials in the Atlantic Forest and other tropical forests. Marsupiais de florestas tropicais exibem grande variação interanual nos tamanhos populacionais, com dependência negativa e direta da densidade capturando a essência de sua dinâmica populacional. No entanto, os mecanismos demográficos subjacentes à taxa de crescimento populacional e determinantes da sobrevivência e reprodução ainda são incertos. Nós usamos 16 anos de dados de captura-marcação-recaptura de cinco espécies de marsupiais de florestas tropicais para avaliar a dependência de densidade sazonal e interanual na sobrevivência e recrutamento. Hipóteses sobre efeitos de fatores exógenos (pluviosidade e temperatura mínima) na sobrevivência, recrutamento e parâmetros reprodutivos (fecundidade, tamanho da ninhada e proporção de fêmeas reprodutivas) também foram testadas. O tamanho da população afetou negativamente a sobrevivência em três das cinco espécies. O tamanho populacional elevado em um ano reduziu as taxas de sobrevivência no ano seguinte, com efeitos mais negativos nos machos. Recrutamento e proporção de fêmeas reprodutivas foram dependentes das variáveis climáticas e não foram afetados pelos tamanhos populacionais anteriores (com exceção de Metachirus nudicaudatus). A fecundidade (número de filhotes fêmea/fêmea) foi relacionada negativamente ao tamanho da população do gambá-de-orelha-preta (Didelphis aurita), enquanto o tamanho da ninhada foi um parâmetro relativamente conservador e independente das condições externas. Nossas análises indicam que a sobrevivência dependente da densidade regula as populações de marsupiais em florestas tropicais, seja através da redução na sobrevivência ou no aumento da emigração. Esse mecanismo regulatório pode ser comum a outros marsupiais na Mata Atlântica e outras florestas tropicais.
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Sinclair, Andrew H., Jacyln M. Wrigley, and Jennifer A. Marshall Graves. "Autosomal assignment of OTC in marsupials and monotremes: implications for the evolution of sex chromosomes." Genetical Research 50, no. 2 (October 1987): 131–36. http://dx.doi.org/10.1017/s0016672300023533.
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SummaryThe OTC gene coding for ornithine transcarbamylase is sex linked and subject to X inactivation in humans and mice. We have used a rat cDNA probe to localize OTC by in situ hybridization in marsupials and monotremes. The gene maps to an autosomal site in two distantly related marsupial species and in one monotreme (the platypus); the first demonstration that a gene X-linked in one mammalian species may be autosomal in another. Since the conservation of the mammalian X is thought to be a consequence of its isolation by the inactivation mechanism, we propose that an autosomal or pseudoautosomal segment containing OTC has been recruited into the inactivated region of the X rather recently in eutherian evolution while it remained autosomal, or was translocated to an autosome, in metatherian and prototherian mammals.
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Cornelis, Guillaume, Cécile Vernochet, Quentin Carradec, Sylvie Souquere, Baptiste Mulot, François Catzeflis, Maria A. Nilsson, et al. "Retroviral envelope gene captures andsyncytinexaptation for placentation in marsupials." Proceedings of the National Academy of Sciences 112, no. 5 (January 20, 2015): E487—E496. http://dx.doi.org/10.1073/pnas.1417000112.
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Syncytinsare genes of retroviral origin captured by eutherian mammals, with a role in placentation. Here we show that some marsupials—which are the closest living relatives to eutherian mammals, although they diverged from the latter ∼190 Mya—also possess asyncytingene. The gene identified in the South American marsupial opossum and dubbedsyncytin-Opo1has all of the characteristic features of a bona fidesyncytingene: It is fusogenic in an ex vivo cell–cell fusion assay; it is specifically expressed in the short-lived placenta at the level of the syncytial feto–maternal interface; and it is conserved in a functional state in a series ofMonodelphisspecies. We further identify a nonfusogenic retroviral envelope gene that has been conserved for >80 My of evolution among all marsupials (including the opossum and the Australian tammar wallaby), with evidence for purifying selection and conservation of a canonical immunosuppressive domain, but with only limited expression in the placenta. This unusual captured gene, together with a third class of envelope genes from recently endogenized retroviruses—displaying strong expression in the uterine glands where retroviral particles can be detected—plausibly correspond to the different evolutionary statuses of a captured retroviral envelope gene, with onlysyncytin-Opo1being the present-day bona fidesyncytinactive in the opossum and related species. This study would accordingly recapitulate the natural history ofsyncytinexaptation and evolution in a single species, and definitely extends the presence of such genes to all major placental mammalian clades.
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Warburton, N. M., and K. J. Travouillon. "The biology and palaeontology of the Peramelemorphia: a review of current knowledge and future research directions." Australian Journal of Zoology 64, no. 3 (2016): 151. http://dx.doi.org/10.1071/zo16003.
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Bandicoots and bilbies (Marsupialia : Peramelemorphia) represent the dominant omnivorous clade of Australasian marsupials and, as ground-dwelling, small- to medium-sized mammals, have not fared well in the 200 years since European settlement. Unlike large or charismatic marsupial species, the cryptic nature of bandicoots and bilbies tends to keep them out of the public eye, at a time when public interest plays a significant role in conservation efforts. The inconspicuous ‘rat-like’ appearance of many bandicoots and a generalist ecological strategy belie a complex biology of adaptive traits and evolutionary diversity. For a few species these biological traits have enabled them to make use of urban environments. In the main, however, peramelemorphians are facing ongoing pressure from introduced predators and human impacts. Basic biological information for many species, particularly those from New Guinea, is still lacking. In this review, we examine advances in the knowledge of the biology of this group over the past 25 years including anatomical, physiological and ecological studies. We also provide a comprehensive review of the fossil records of bandicoots in order to provide an up-to-date platform for future studies. From this work, it is clear that there is still much to be done regarding the taxonomy and biology of these animals before a more detailed understanding of the evolutionary history of this group can be elucidated.
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Williams, W. F., Hugh Tyndale-Biscoe, and Marilyn Renfree. "Reproductive Physiology of Marsupials." Journal of Wildlife Management 53, no. 2 (April 1989): 511. http://dx.doi.org/10.2307/3801160.
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HUME, I. D. "Nutrition of marsupials in captivity." International Zoo Yearbook 39, no. 1 (January 2005): 117–32. http://dx.doi.org/10.1111/j.1748-1090.2005.tb00011.x.
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Teixeira, Camila Palhares, André Hirsch, Henrique Perini, and Robert John Young. "Marsupials from space: fluctuating asymmetry, geographical information systems and animal conservation." Proceedings of the Royal Society B: Biological Sciences 273, no. 1589 (January 16, 2006): 1007–12. http://dx.doi.org/10.1098/rspb.2005.3386.
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Selwood, Lynne, and Shuliang Cui. "Establishing long-term colonies of marsupials to provide models for studying developmental mechanisms and their application to fertility control." Australian Journal of Zoology 54, no. 3 (2006): 197. http://dx.doi.org/10.1071/zo05052.
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To study marsupial developmental mechanisms and their application to fertility control, it is necessary to develop reliable procedures for breeding, colony maintenance, reproductive monitoring for obtaining known-age embryos and, if possible, an induced ovulation protocol. These procedures also provide means to enhance conservation of endangered species. Such procedures are examined in the stripe-faced dunnart, an excellent model for developmental analysis, and the common brush-tail possum, an agricultural and ecological pest species in New Zealand that has become a model for fertility control in marsupials. A long-term colony of the stripe-faced dunnart has been in existence for 21 years, and the procedures for its maintenance and continued survival are outlined, and include minimal reproductive contributions from wild-caught animals, and development of an appropriate timetable of development and induced-ovulation protocols. Common brushtail possum colonies are relatively frequent but have regular input from wild-caught animals. Procedures that minimise competition for prized resources and allow successful group housing of possums are outlined. For both species the available development timetables, in vitro techniques and induced ovulation protocols are essential tools for the study of developmental mechanisms and fertility control, respectively, and also have considerable implications for conservation of these and other species.
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Abreu-Júnior, Edson F., Marco A. De Freitas, Marina J. Lapenta, Nathocley M. Venâncio, Daniella P. F. De França, and Alexandre R. Percequillo. "Marsupials and rodents (Didelphimorphia and Rodentia) of upper Rio Acre, with new data on Oxymycterus inca Thomas, 1900 from Brazil." Check List 12, no. 5 (September 10, 2016): 1956. http://dx.doi.org/10.15560/12.5.1956.
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Our goal was to inventory marsupial and rodent species from two conservation units (Reserva Extrativista Chico Mendes and Estação Ecológica do Rio Acre) of the upper Rio Acre, in Brazilian Amazonia, as well as to provide new data on the morphology and geographic distribution for several species. We recorded 25 species, including seven marsupials and 18 rodents. Among these, there are poorly sampled species in Brazil, such as Marmosa regina and Dactylomys boliviensis. We document range extensions (about 450 km towards southeastern Acre state) of Neacomys musseri, Dasyprocta fuliginosa, and Proechimys cuvieri. We also present the first confirmed record of an undescribed species of Monodelphis in Acre state and the second collecting record of Oxymycterus inca in Brazil. We describe the morphology and morphometrics of upper Rio Acre specimens of O. inca. Finally, we compare our results with other inventories in the Amazon region and discuss the high efficiency of pitfall traps for capturing nonvolant small mammals.
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Lefèvre, Christophe M., Julie A. Sharp, and Kevin R. Nicholas. "Characterisation of monotreme caseins reveals lineage-specific expansion of an ancestral casein locus in mammals." Reproduction, Fertility and Development 21, no. 8 (2009): 1015. http://dx.doi.org/10.1071/rd09083.
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Using a milk-cell cDNA sequencing approach we characterised milk-protein sequences from two monotreme species, platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus) and found a full set of caseins and casein variants. The genomic organisation of the platypus casein locus is compared with other mammalian genomes, including the marsupial opossum and several eutherians. Physical linkage of casein genes has been seen in the casein loci of all mammalian genomes examined and we confirm that this is also observed in platypus. However, we show that a recent duplication of β-casein occurred in the monotreme lineage, as opposed to more ancient duplications of α-casein in the eutherian lineage, while marsupials possess only single copies of α- and β-caseins. Despite this variability, the close proximity of the main α- and β-casein genes in an inverted tail–tail orientation and the relative orientation of the more distant kappa-casein genes are similar in all mammalian genome sequences so far available. Overall, the conservation of the genomic organisation of the caseins indicates the early, pre-monotreme development of the fundamental role of caseins during lactation. In contrast, the lineage-specific gene duplications that have occurred within the casein locus of monotremes and eutherians but not marsupials, which may have lost part of the ancestral casein locus, emphasises the independent selection on milk provision strategies to the young, most likely linked to different developmental strategies. The monotremes therefore provide insight into the ancestral drivers for lactation and how these have adapted in different lineages.
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George, GG. "Monotreme and Marsupial Breeding Programs in Australian Zoos." Australian Journal of Zoology 37, no. 3 (1989): 181. http://dx.doi.org/10.1071/zo9890181.
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Cooperative breeding programs for selected species in Australian zoos have developed rather rapidly in response to growing concerns for the status of wildlife world-wide. The need to enlarge captive populations and to manage them for genetic and demographic stability led in 1983 to the establishment of a regional Species Management Scheme among the major publicly funded zoos of Australia and New Zealand. Several Australian marsupials are being successfully managed under this scheme, and management plans for others are being developed. Managed species are designated on the basis of their restricted availability to zoos, and the desirability of having a self-sustaining captive population for conservation purposes. Captive breeding histories of most Australian and some New Guinea monotremes and marsupials are reviewed, and details of zoo breeding programs discussed for managed species.
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Renfree, Marilyn B. "WOMEN IN REPRODUCTIVE SCIENCE: Reproduction down under." Reproduction 158, no. 6 (December 2019): F127—F137. http://dx.doi.org/10.1530/rep-19-0230.
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Australia is home to a unique assembly of mammals – the marsupials and monotremes. Despite this uniqueness, they have been largely ignored by the biomedical scientific community, and yet study of marsupials has contributed to modern research on reproduction, development, evolution, conservation, molecular and comparative genomics. My lifetime passion for these long-neglected Australian fauna has led to unexpected discoveries and insights that challenged assumptions and opened up new areas of international research. I used a range of disciplinary expertise to pursue the study of these unique mammals. My main experimental species has been the tammar wallaby that I have used as a model species to investigate and understand not only biomedical problems but also to provide knowledge that is critical for the continued conservation and management of Australia’s dwindling native mammals. This model provided more than a few surprises for me and my wonderful team of students, post-docs and collaborators about how hormones, genes and signalling molecules control reproductive biology and development in a wider context as well as how the interactions of the environment with mother and conceptus, with mother and fetus and mother and young ultimately control most aspects of successful reproduction in mammals.
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Hickford, D., A. Pask, G. Shaw, and M. B. Renfree. "264. Primordial germ cell specification in a marsupial, the tammar wallaby." Reproduction, Fertility and Development 20, no. 9 (2008): 64. http://dx.doi.org/10.1071/srb08abs264.
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Primordial germ cells (PGCs) are the precursors of the gametes. In the mouse, PGCs are specified within the proximal epiblast in response to signals from the extraembryonic membranes during early gastrulation. Epiblast cells competent to form PGCs express Ifitm3. A subset of these cells then express Blimp1, a marker of PGC precursors. Once lineage-restricted, PGCs express Stella. Germ cells entering the gonads express VASA protein, which is a component of the germ plasm in animals in which germ cells are specified by the inheritance of maternal determinatives. Almost all of the research on mammalian PGC specification has used the mouse as a model and it is tacitly assumed that findings in the mouse will apply to mammals in general. We are using the tammar wallaby as a marsupial model for PGC specification. Eutherians and marsupials diverged 125–148 million years ago, so comparisons between the two will provide insights into the evolution of the control of mammalian PGC specification. There are IFITM clusters in both the human (chromosome 11) and mouse (chromosome 7). In the mouse, IFITM1, 2 and 3 are expressed in PGCs, whereas IFITM4 and 5 are not (1). Only one IFITM member, IFITM5, is annotated in the opossum Ensemble database. We have cloned one tammar IFITM member and identified at least one other putative member in the tammar trace archive database. We have also cloned tammar BLIMP1 and VASA, both of which show high sequence conservation with other mammals. RT–PCR profiles for both genes during tammar gastrulation are similar to those for the mouse. In contrast, no marsupial STELLA orthologueue has been identified in either the opossum or tammar genomes. These findings suggest that some but not all of the signals and mechanisms involved in eutherian PGC specification are also applicable to marsupials. (1) Lange UC, Saitou M, Western P, Barton SC and Surani MA (2003) BMC Dev. Biol. Epub 2003 Mar 19
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R. Dickman, Christopher, Daniel Lunney, and Alison Matthews. "Ecological attributes and conservation of dasyurid marsupials in New South Wales, Australia." Pacific Conservation Biology 7, no. 2 (2001): 124. http://dx.doi.org/10.1071/pc010124.
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This paper outlines the status of dasyurid marsupials in New South Wales, Australia, and then compares the ecological attributes of threatened and non-threatened species. Of the 21 species recorded in the state since European settlement, eight are protected but not threatened, 10 are listed or proposed for listing as vulnerable or endangered, and three are presumed extinct. Status was not related to diet, habit or habitat. However, species weighing <35 g are less likely to be threatened than heavier species, while species occupying a single region are more likely to be threatened than species occurring in two or more regions. All vulnerable and endangered species occur at least partly in reserves and other areas of protected land, but are likely to be affected by one or more threatening processes. These processes differ regionally, with larger species (=175 g) being affected by a greater range of threats than very small species (<15 g). We propose a programme of survey, research, management and education to promote and sustain recoveries.
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Arbogast, Brian S. "Secret Lives of Carnivorous Marsupials." Journal of Mammalogy 100, no. 2 (April 6, 2019): 611–13. http://dx.doi.org/10.1093/jmammal/gyz051.
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Au, Phil Chi Khang, Angela Nation, Marissa Parrott, and Lynne Selwood. "Induced ovulation mimics the time-table of natural development in the stripe-faced dunnart, Sminthopsis macroura and results in the birth of fertile young." REPRODUCTION 139, no. 2 (February 2010): 419–25. http://dx.doi.org/10.1530/rep-09-0203.
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Induced ovulation maximizes captive breeding success, increasing productivity and facilitating the contribution of otherwise infertile animals to the genetic pool. In marsupials, induced ovulation to produce fertile young is unknown. Here we present an induction protocol efficient in inducing non-cycling and non-reproductive females to cycle, mate, ovulate, and conceive. Ovulation was induced in Sminthopsis macroura using an initial injection of 0.06 IU equine serum gonadotropin (eSG)/g (time 0), followed on day 4 by 0.04 IU eSG/g. Using this induction regime, the timing of follicular and embryonic development mimics natural cycles and results in the birth of viable, fertile young. Response to induction is not significantly affected by animal age, making this protocol an effective conservation tool. We have established a time-table of development following induction, providing a source of precisely timed research material. This is the first induced ovulation protocol in any marsupial to result in demonstrated fertile offspring and to allow the reliable collection of known-age samples during both the follicular phase and the gestation period.
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Cáceres, Nilton C., Marcos R. Bornschein, Wellington H. Lopes, and Alexandre R. Percequillo. "Mammals of the Bodoquena Mountains, southwestern Brazil: an ecological and conservation analysis." Revista Brasileira de Zoologia 24, no. 2 (June 2007): 426–35. http://dx.doi.org/10.1590/s0101-81752007000200021.
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We carried out a mammalian survey in the neighborhoods of the Serra da Bodoquena National Park, Mato Grosso do Sul state, a region poorly known in southwestern Brazil. During the months of April, May and July 2002 we used wire live trap, direct observation, indirect evidence (e.g. tracks), carcasses, and interviews with local residents to record mammalian species. Fifty six mammal species were recorded, including threatened species (14%). These records were discussed regarding species abundance, distribution, range extension, habitat, and conservation. The geographic distribution and ecology of the poorly known marsupials Thylamys macrurus and Micoureus constantiae in Brazil are emphasized.
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Machado, Felipe Santana, Álvaro Fernando de Almeida, Dalmo Arantes de Barros, José Aldo Alves Pereira, Rossi Allan Silva, and Alexandre Augusto Spadoni Pereira. "Diversity of medium-sized and large mammals from Atlantic Forest remnants in southern Minas Gerais state, Brazil." Check List 12, no. 5 (September 16, 2016): 1962. http://dx.doi.org/10.15560/12.5.1962.
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Studies on mammal diversity provide the essential groundwork for the development of conservation methods and practices. The region of the Poços de Caldas Plateau is lacks such studies, which may be a problem for future conservation actions. Here, we analyze the richness of medium-sized and large mammals from Atlantic Forest remnants on the Poços de Caldas Plateau, Minas Gerais state. Diurnal censuses of direct observations and mammal signs were conducted, and we documented 20 species of mammals belonging to eight orders. Three species of primates, one carnivore, one cingulate, one lagomorpha, three rodents, one artiodactyla, and two marsupials were found. The largest forest remnant that presented the greatest richness is currently a conservation unit. Forest remnants are important for the consolidation of management strategies and have fundamental role for the conservation of mammal diversity in the south of Minas Gerais state.
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Potter, Sally, and Janine E. Deakin. "Cytogenetics: an important inclusion in the conservation genetics toolbox." Pacific Conservation Biology 24, no. 3 (2018): 280. http://dx.doi.org/10.1071/pc18016.
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Conservation uses information from genetics to assist in management decisions. However, conservation genetics typically assesses genetic diversity at the DNA level but this alone does not address all the risks associated with managing wild and captive populations. DNA is packaged into chromosomes. Differences in the number and morphology of chromosomes between species or even between populations of the same species can have important implications for management programs for threatened species. Cytogenetics, analysis of the higher molecular chromosome structure, can provide invaluable insight for the management of threatened species, where DNA alone could not address all genetic risks and threats to populations. Here we outline the important and valuable role of cytogenetics in conservation, highlighting two case studies based on threatened Australian marsupials: rock-wallabies and the Tasmanian devil. In conclusion, we summarise how cytogenetics should be better linked to conservation genetics and integrated into our management of threatened species, to ensure they have the best platform from which to persist and adapt into the future.
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Bianchi, N. O., and M. S. Bianchi. "Male Specific Sry Patterns in Marsupials." Journal of Mammalogy 74, no. 3 (August 20, 1993): 531–34. http://dx.doi.org/10.2307/1382272.
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Martin, Gabriel M., and Baltazar González-Chávez. "Observations on the behavior of Caenolestes fuliginosus (Tomes, 1863) (Marsupialia, Paucituberculata, Caenolestidae) in captivity." Journal of Mammalogy 97, no. 2 (January 5, 2016): 568–75. http://dx.doi.org/10.1093/jmammal/gyv203.
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Abstract We describe the behavior in captivity of the dusky shrew-opossum Caenolestes fuliginosus from 17 specimens captured at Finca La Martinica (Colombia), which were kept alive in plastic terraria for different periods of time (between 1 and 12 consecutive days). We found that C. fuliginosus can climb and jump well and uses its nonprehensile tail as a support when climbing. Feeding observations showed a preference towards an animalivorous diet, which included moths/butterflies (Insecta, Lepidoptera), stick-insects (Insecta, Phasmatoidea), flatworms (Platyhelminthes, Turbellaria), earthworms (Annelida, Oligochaeta), frogs (Amphibia, e.g., Pristimantis sp.), and dead rodents (Rodentia, Sigmodontinae, e.g., Microryzomys sp., Thomasomys sp.). Individuals were active throughout the day and night, with no indication of daily torpor. Our observations showed C. fuliginosus is not aggressive towards congeners and often aggregates during rest, especially when several individuals are placed together. Unlike other New World marsupials, C. fuliginosus showed nonagonistic group feeding behavior when consuming carcasses. Stereotyped behavior patterns (e.g., grooming) were not frequently observed. Our work provides comparative information for further studies on caenolestids and other New World marsupials. En este trabajo describimos el comportamiento en cautiverio del ratón Runcho, Caenolestes fuliginosus, a partir de la observación directa de 17 individuos capturados en Finca La Martinica (Colombia), que fueron mantenidos en terrarios plásticos por diferentes períodos de tiempo (entre 1 y 12 días consecutivos). Observamos que C. fuliginosus puede trepar y saltar bien, usando su cola no prensil como soporte al trepar. Los individuos mostraron preferencias alimenticias hacia una dieta animalívora que incluyó: polillas/mariposas (Insecta, Lepidoptera), insectos palo (Insecta, Phasmatoidea), gusanos planos de vida libre (Platyhelminthes, Turbellaria), lombrices (Annelida, Oligochaeta), ranas/sapos (Amphibia, e.g., Pristimantis sp.) y roedores muertos (Rodentia, Sigmodontinae, e.g., Microryzomys sp., Thomasomys sp.). Observamos actividad durante todo el día y la noche, sin preferencias, y no observamos torpor en ningún individuo. Los individuos no mostraron comportamiento agresivo hacia sus congéneres y, con frecuencia, se juntaron para descansar unos sobre otros. A diferencia de otros marsupiales del nuevo mundo, C. fuliginosus no mostró comportamiento agonístico cuando se alimenta de cadáveres. Patrones estereotipados de comportamiento (e.g., limpieza) no fueron frecuentemente observados. Nuestro trabajo aporta información comparativa para futuros estudios sobre el comportamiento de otros cenoléstidos y marsupiales del nuevo mundo.
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Michael, Damian R., Sam Niedra, and Dylan McWhinney. "The conservation of arboreal marsupials in the Albury‐Wodonga region of south‐eastern Australia." Ecological Management & Restoration 22, no. 1 (January 2021): 45–52. http://dx.doi.org/10.1111/emr.12445.
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M. McKenzie, L., and D. W. Cooper. "Conservation genetics of the Parma Wallaby Macropus parma: a case study for Australian marsupials." Pacific Conservation Biology 2, no. 2 (1995): 150. http://dx.doi.org/10.1071/pc960150.
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The Parma Wallaby Macropus parma, native only to Australia, exemplifies a number of issues currently under discussion regarding the conservation of Australian marsupials. Thought to be extinct in the earlier part of this century, an expatriate population was identified on Kawau Island, New Zealand in 1967. These animals were used to supply zoos and captive breeding colonies throughout the world. Subsequently, parma populations were rediscovered in the Great Dividing Range of New South Wales, Australia. The Australian populations are small and inhabit severely restricted localities where they are highly vulnerable to predation and further habitat loss. Strategies for the preservation of parmas in Australia include the reintroduction of parmas either directly from Kawau Island or from established captive colonies. However, the founder number of Parma Wallabies on Kawau Island is unknown, hence it is possible the New Zealand derived parmas have a restricted genetic base compromising their suitability for reintroduction programmes. Additionally, there is a possibility that introgression has occurred between parmas and Black-striped Wallabies Macropus dorsalis on the island. Here we report that the level of genetic variation in New Zealand derived Parma Wallabies is not markedly reduced, and that no detectable introgression has taken place between Parma and Black-striped Wallabies. Indeed, re-examination of records casts doubt upon the suggestion that Black-stripes were introduced to Kawau Island.
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Nagy, KA, GD Sanson, and NK Jacobsen. "Comparative Field Energetics of Two Macropod Marsupials and a Ruminant." Wildlife Research 17, no. 6 (1990): 591. http://dx.doi.org/10.1071/wr9900591.
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Field metabolic rates (FMRs) and water influx rates were measured via the doubly labelled water method in wild Tasmanian pademelons and grey kangaroos living in the Jock Marshall Reserve at Clayton, Victoria, and in wild black-tailed deer free-ranging within a nature reserve at Davis, California. Deer expended more than 3 times more energy per day than similar sized grey kangaroos. Feeding rates required to achieve energy balance were estimated from FMRs along with an estimate of metabolizable energy content of the food. The estimated feeding rates for pademelons and kangaroos were combined with similar values for 5 other species of macropods to calculate an allometric (scaling) relationship for food requirements of macropod marsupials. Feeding rate had the following relationship to body mass: g food (DM) consumed per day = 0.20 g body mass0.79 (r2 = 0.94). The findings reported herein should be useful for predicting the approximate food requirements of free-ranging macropods and deer for purposes of ecological modelling, conservation efforts and management programmes.
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O’Hara, Patricia J., Peter J. Murray, and Athol V. Klieve. "A review of the nutrition of Australian peramelid marsupials." Australian Mammalogy 34, no. 2 (2012): 133. http://dx.doi.org/10.1071/am11008.
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European settlement has had a dramatic impact on the distribution and abundance of peramelid (bandicoot and bilby) marsupials. Predation and competition from introduced species and altered habitat have been implicated in their decline or extinction. Bandicoots and bilbies inhabit a broad range of habitats in Australia. Research on the distribution, morphology, gastrointestinal histology, lactation, metabolism and nutritional physiology of extant peramelid species has increased in the last few decades. This paper provides a review that encompasses recent nutritional-based research. Peramelid research is mostly limited to only three species – Isoodon macrourus, Perameles nasuta and Macrotis lagotis – which prevents effective comparisons between species. Peramelids are broadly classified as omnivores and possess relatively uncomplicated gastrointestinal tracts. The caecum is the region of greatest diversity among species. The relatively large caecum of Chaeropus ecaudatus supports the theory that this species may have been the only herbivorous peramelid. The caecum of M. lagotis is less pronounced than other species and is continuous with the proximal colon. M. lagotis also has a longer total colon length, which aids water conservation to ensure survival in an arid environment. Temperate-zone species such as I. macrourus, I. obesulus and P. nasuta are more similar to each other with respect to gastrointestinal morphology than either C. ecaudatus or M. lagotis. Additional research on the morphometrics of the gastrointestinal tracts of P. gunnii, P. bougainville, P. eremiana, M. leucura and I. auratus would enable further comparisons to determine whether differences are a result of geographic distribution, habitat preference or variation between genera and/or individual species. Currently, histological information of the gastrointestinal tract is limited to the small intestine of P. nasuta and I. macrourus. The histology of the small intestine of the weaned juvenile I. macrourus more closely resembles that of P. nasuta pouch young than P. nasuta adults. The younger bandicoots possessed villi whereas in the adult P. nasuta and I. macrourus villi were arranged in a zig-zag formation. The reason for the zig-zag formation of the villi and the function it may serve remains unclear. Detailed nutritional research on captive M. lagotis, I. macrourus and P. nasuta indicate that the two temperate-zone species – I. macrourus and P. nasuta – are more similar to each other than to the arid-dwelling M. lagotis. Detailed nutritional studies are required on all species, both free-living and captive. Experimental diets do not always accurately reflect a natural diet, which means that results from captive studies may not reflect the situation for free-living animals. The hindgut of peramelids is the main region for retention of digesta, and presumably where microbial digestion occurs. However, no studies have been undertaken to examine the microflora of the gastrointestinal tract of bandicoots or the bilby. As captive husbandry is an important tool in conservation management, it should also improve their successful maintenance in captivity by the provision of diets that better meet their nutritional requirements.
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S. Law, Bradley, Mark Chidel, and Graham Turner. "The use by wildlife of paddock trees in farmland." Pacific Conservation Biology 6, no. 2 (2000): 130. http://dx.doi.org/10.1071/pc000130.
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Morning and dusk watches at live and dead trees were used to systematically investigate which species of vertebrates use paddock trees within farmland proposed for the establishment of Eucalyptus plantations in northern New South Wales. Tree-watches at 108 trees were stratified on farmland as isolated, in small patches, remnant vegetation and riparian strips plus in adjacent forest. Arboreal marsupials and bats emerged from hollows in 11% and 8% of trees, respectively. Only one colonial bat roost was observed, although the marsupials Trichosurus vulpecula and Petaurus breviceps were widespread in the landscape. Two threatened species of marsupials (Petaurus norfolcensis and Phascogale tapoatafa) were observed using paddock trees on flats or slopes outside of riparian strips. Among owls, only the Southern Boobook Ninox novaeseelandiae and Barn Owl Tyto alba were observed using tree hollows on farmland. For all hollow-dependent nocturnal fauna (marsupials, bats and owls), very large tree diameter best predicted occupation of a tree-hollow (especially if <800 m from the nearest forest). In addition to providing hollows, paddock trees were used for foraging. Morning surveys revealed 35 diurnal bird species on isolated trees, although most were generalists (e.g., Eastern Rosella Platycercus eximius, Noisy Miner Manorina melanocephala) that were also regular visitors to non-isolated trees in remnant vegetation. More forest-dependent and forest-associated bird species were recorded in forests and riparian strips than other tree categories, reinforcing the high conservation value of riparian strips in farmland. After dark, ultrasonic detectors recorded 21 species of bat (seven threatened species) flying in close proximity to paddock trees. Relatively high levels of activity were recorded at one study location for species rarely recorded in forests (e.g., Scoteanax rueppellii). Remnant Eucalyptus tereticornis and E. amplifolia were a significant source of blossom for nectarivores and they were also associated with high bat activity, possibly because they grow on fertile soil. Recommendations on tree retention guidelines are discussed.
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Stobo-Wilson, Alyson M., Teigan Cremona, Brett P. Murphy, and Susan M. Carthew. "Geographic variation in body size of five Australian marsupials supports Bergmann’s thermoregulation hypothesis." Journal of Mammalogy 101, no. 4 (May 16, 2020): 1010–20. http://dx.doi.org/10.1093/jmammal/gyaa046.
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Abstract Despite a large body of research, little agreement has been reached on the ultimate driver(s) of geographic variation in body size (mass and/or length). Here we use skull length measurements (as a surrogate for body mass) from five Australian marsupial species to test the primary hypotheses of geographic variation in body size (relating to ambient temperature, productivity, and seasonality). We used a revised articulation of Bergmann’s rule, wherein evidence for thermoregulation (heat dissipation or heat conservation) is considered supportive of Bergmann’s rule. We modeled the skull lengths of four Petaurid glider species and the common brushtail possum (Trichosurus vulpecula) as a function of indices of ambient temperature, productivity, and seasonality. The skull length of Petaurus ariel, P. notatus, and the squirrel glider (P. norfolcensis), increased with increasing winter minimum temperature, while that of T. vulpecula decreased with increasing summer maximum temperature. The skull length of P. ariel decreased with indices of productivity, falsifying the productivity hypothesis. Only P. ariel met the hypothesis of seasonality, as skull length increased with increasing seasonality. Thermoregulation was the most consistently supported driver of geographic variation in body size, as we found evidence of either heat conservation or heat dissipation in four of the five species examined. We found the geographic range of the individual species and the climate space in which the species occurred was integral to understanding the species’ responses to climate variables. Future studies should use specimens that are representative of a species’ entire geographic range, encompass a variety of climatic regions, and use consistent methodologies and terminology when testing drivers of geographic variation in body size.
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Czarny, N. A., M. S. Harris, and J. C. Rodger. "Dissociation and preservation of preantral follicles and immature oocytes from female dasyurid marsupials." Reproduction, Fertility and Development 21, no. 5 (2009): 640. http://dx.doi.org/10.1071/rd08303.
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The mammalian ovary contains numerous immature preantral follicles that are not dependent on endocrine support, unlike the more mature hormone-dependant antral follicles. Preantral follicles can be enzymatically dissociated to yield immature oocytes that survive sub-zero preservation better as they lack a temperature-sensitive meiotic spindle. These techniques are highly applicable to gamete banking, which is an urgent requirement for Australian carnivorous marsupials as several species have rapidly declining populations and risk extinction. The present study developed protocols for the transport, dissociation, preservation and culture of granulosa cell-oocyte complexes (GOC) from the ovaries of dasyurid marsupials. High viability of GOC following enzymatic dissociation is reported and it was demonstrated that GOC are of significantly better quality following refrigerated storage for 24 h compared with storage at room temperature. Oocytes from primary follicles were not damaged by cold shock or the toxicity of vitrification media and following vitrification in liquid nitrogen 69.42 ± 2.44% of oocytes were viable. However, the surrounding granulosa cells demonstrated significant damage post-thaw. These granulosa cells proliferated during a 48-h culture period resulting in significant improvements in GOC quality. The present study is a valuable step towards cryostorage of dasyurid gametes and represents fundamentally important methods by which we can contribute to the conservation of Australia’s native predators.
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Halley, Andrew C. "Minimal variation in eutherian brain growth rates during fetal neurogenesis." Proceedings of the Royal Society B: Biological Sciences 284, no. 1854 (May 10, 2017): 20170219. http://dx.doi.org/10.1098/rspb.2017.0219.
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A central question in the evolution of brain development is whether species differ in rates of brain growth during fetal neurogenesis. Studies of neonatal data have found allometric evidence for brain growth rate differences according to physiological variables such as relative metabolism and placental invasiveness, but these findings have not been tested against fetal data directly. Here, we measure rates of exponential brain growth acceleration in 10 eutherian mammals, two marsupials, and two birds. Eutherian brain acceleration exhibits minimal variation relative to body and visceral organ growth, varies independently of correlated growth patterns in other organs, and is unrelated to proposed physiological constraints such as metabolic rate or placental invasiveness. Brain growth rates in two birds overlap with eutherian variation, while marsupial brain growth is exceptionally slow. Peak brain growth velocity is linked in time with forebrain myelination and eye opening, reliably separates altricial species born before it from precocial species born afterwards, and is an excellent predictor of adult brain size ( r 2 = 0.98). Species with faster body growth exhibit larger relative brain size in early ontogeny, while brain growth is unrelated to allometric measures. These findings indicate a surprising conservation of brain growth rates during fetal neurogenesis in eutherian mammals, clarify sources of variation in neonatal brain size, and suggest that slow body growth rates cause species to be more encephalized at birth.
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Old, Julie M., and Hayley J. Stannard. "Corrigendum to: Conservation of quolls (Dasyurus spp.) in captivity – a review." Australian Mammalogy 43, no. 3 (2021): 378. http://dx.doi.org/10.1071/am20033_co.
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Quolls are carnivorous marsupials in the family Dasyuridae with characteristic white spots. They are distributed throughout Australia and New Guinea, but uncommonly seen due to their mostly nocturnal solitary nature, and large home ranges. All Australian quolls are listed as ‘near threatened' or ‘endangered' at state, national and international levels, largely due to human-induced threats. Threats include introduced predators, habitat loss through clearing and modifications including changed fire regimes, disease, human persecution, vehicle collisions and accidental or targeted poisoning by humans and cane toads (Rhinella marina). Conservation efforts that have focussed on reducing introduced predators, and minimising the impact of cane toads, have aided some translocations, hence species recovery in some local areas of Australia has occurred. Where species conservation has required captive breeding for translocation, successful captive management has been crucial. We summarise research conducted in captivity on aspects of birth and development, health and disease, and blood and nutrition parameters of quolls, and suggest future directions for research. Further research on captive and wild quoll populations will benefit future translocations, reintroductions and conservation through increased knowledge, improved maintenance and husbandry of captive colonies, and monitoring of wild populations.
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Rivero, Marina, and Rodrigo A. Medellín. "MAMÍFEROS DE CHIAPAS." Revista Mexicana de Mastozoología (Nueva Epoca) 5, no. 2 (December 15, 2015): 23. http://dx.doi.org/10.22201/ie.20074484e.2015.5.2.212.
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RESUMENEl estado de Chiapas se localiza en el Sureste de México y debido a la configuración del paisaje, se ha generado una compleja diversidad ecológica en el estado. Se realizó una revisión de toda la literatura referente a la mastofauna registrada en el territorio de Chiapas. Se encontró que el estado cuenta con 207 especies, incluidas en 122 géneros, 31 familias y 9 órdenes, lo que representa el 37% de la mastofauna del país. Los murciélagos (107 spp) y los roedores (64 spp) son los órdenes mejor representados, seguido de los carnívoros (21 spp) y marsupiales (8 spp). El 30% de las 207 especies registradas para el estado se encuentran el alguna categoría de protección dentro de la NOM-059. Chiapas es el segundo estado más diverso de México, sin embargo, existen grandes retos para la conservación de las especies y su hábitat debido al crecimiento de las fronteras agropecuarias y el crecimiento poblacional.Palabras clave: Chiapas, mamíferos, diversidad, conservación.ABSTRACTThe state of Chiapas is located in southeastern Mexico and due to the configuration of the landscape, has generated a complex ecological diversity in the state. We made a review of all the literature related with the mastofauna registered in the territory of Chiapas. We found that the state has 207 species, including 122 genera, 31 families and 9 orders, representing 37% of the mammal fauna of the country. Bats ( 107 spp ) and rodents ( 64 spp ) are the best represented orders, followed by carnivores (21 spp ) and marsupials (8 spp ). Of the 207 species recorded in the state, 30% are in some category of protection within the NOM-059. Chiapas is the second most diverse state in Mexico, however, there are major challenges for the conservation of species and their habitat due to the growth of agricultural borders and population growth.Key words: Chiapas, mammals, diversity, conservation.
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Lindenmayer, D. B., R. B. Cunningham, and M. A. McCarthy. "The conservation of arboreal marsupials in the montane ash forests of the central highlands of Victoria, south-eastern Australia. VIII. Landscape analysis of the occurrence of arboreal marsupials." Biological Conservation 89, no. 1 (July 1999): 83–92. http://dx.doi.org/10.1016/s0006-3207(98)00116-5.
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Bendixsen, Devin P., Tanner B. Pollock, Gianluca Peri, and Eric J. Hayden. "Experimental Resurrection of Ancestral Mammalian CPEB3 Ribozymes Reveals Deep Functional Conservation." Molecular Biology and Evolution 38, no. 7 (March 15, 2021): 2843–53. http://dx.doi.org/10.1093/molbev/msab074.
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Abstract Self-cleaving ribozymes are genetic elements found in all domains of life, but their evolution remains poorly understood. A ribozyme located in the second intron of the cytoplasmic polyadenylation binding protein 3 gene (CPEB3) shows high sequence conservation in mammals, but little is known about the functional conservation of self-cleaving ribozyme activity across the mammalian tree of life or during the course of mammalian evolution. Here, we use a phylogenetic approach to design a mutational library and a deep sequencing assay to evaluate the in vitro self-cleavage activity of numerous extant and resurrected CPEB3 ribozymes that span over 100 My of mammalian evolution. We found that the predicted sequence at the divergence of placentals and marsupials is highly active, and this activity has been conserved in most lineages. A reduction in ribozyme activity appears to have occurred multiple different times throughout the mammalian tree of life. The in vitro activity data allow an evaluation of the predicted mutational pathways leading to extant ribozyme as well as the mutational landscape surrounding these ribozymes. The results demonstrate that in addition to sequence conservation, the self-cleavage activity of the CPEB3 ribozyme has persisted over millions of years of mammalian evolution.
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Stobo-Wilson, Alyson M., Brett P. Murphy, Teigan Cremona, and Susan M. Carthew. "Contrasting patterns of decline in two arboreal marsupials from Northern Australia." Biodiversity and Conservation 28, no. 11 (June 18, 2019): 2951–65. http://dx.doi.org/10.1007/s10531-019-01807-7.
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Stannard, Hayley J., Kathryn Dennington, and Julie M. Old. "The external ear morphology and presence of tragi in Australian marsupials." Ecology and Evolution 10, no. 18 (August 28, 2020): 9853–66. http://dx.doi.org/10.1002/ece3.6634.
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Isaac, JL. "Possums: The Brushtails, Ringtails and Greater Glider. Anne Kerle. A Review by Joanne L Isaac." Australian Mammalogy 24, no. 2 (2002): 249. http://dx.doi.org/10.1071/am02249.
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DESPITE their almost ubiquitous presence across Australia, contemporary research on the biology, ecology and conservation status of the so-called 'common' possums is scant and inadequate. The majority of possum studies have been a result of the huge research effort in New Zealand to control and eradicate the common brushtail possum, a notorious introduced pest, and have concentrated primarily upon reproductive physiology. The conspicuous lack of ecological data on the larger possums across their native Australian range is particularly disturbing since evidence suggests that a number of these species are disappearing from large tracts of Australia. However, Possums: the brushtails, ringtails and greater glider, part of the Australian Natural History Series, provides a long overdue summary of up-to-date research on these familiar and intriguing marsupials.
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Withers, Philip Carew, Christine Elizabeth Cooper, Gerhard Körtner, and Fritz Geiser. "Small Alpine Marsupials Regulate Evaporative Water Loss, Suggesting a Thermoregulatory Role Rather than a Water Conservation Role." Physiological and Biochemical Zoology 95, no. 3 (May 1, 2022): 212–28. http://dx.doi.org/10.1086/719735.
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Isaac, J. L., J. L. De Gabriel, and B. A. Goodman. "Microclimate of daytime den sites in a tropical possum: implications for the conservation of tropical arboreal marsupials." Animal Conservation 11, no. 4 (August 2008): 281–87. http://dx.doi.org/10.1111/j.1469-1795.2008.00177.x.
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Mate, K. E., F. C. Molinia, and J. C. Rodger. "Manipulation of the fertility of marsupials for conservation of endangered species and control of over-abundant populations." Animal Reproduction Science 53, no. 1-4 (October 1998): 65–76. http://dx.doi.org/10.1016/s0378-4320(98)00127-4.
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King, J. M., and S. D. Bradshaw. "Comparative water metabolism of Barrow Island macropodid marsupials: Hormonal versus behavioural-dependent mechanisms of body water conservation." General and Comparative Endocrinology 155, no. 2 (January 2008): 378–85. http://dx.doi.org/10.1016/j.ygcen.2007.07.004.
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