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1
Cifelli, Richard L., and Christian De Muizon. "Marsupial mammal from the Upper Cretaceous North Horn Formation, Central Utah." Journal of Paleontology 72, no. 3 (1998): 532–37. http://dx.doi.org/10.1017/s0022336000024306.
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Little is known of the non-dinosaurian fauna from the Cretaceous (Maastrichtian) part of the North Horn Formation, despite its biogeographic importance. Herein we describe a new marsupial mammal from the unit, founded on an exceptionally complete specimen of a juvenile individual, and present new information on the incisor region of early marsupials, based on comparison with complete specimens from the early Paleocene of Bolivia. Alphadon eatoni, new species, is the smallest Lancian species of the genus, and departs from a presumed marsupial morphotype in having the second lower incisor enlarged. The species is, however, primitive in lacking a “staggered” pattern to the incisor series and in having a labial mandibular foramen, and in these respects it differs from Paleocene and later marsupials. Poor representation of other taxa precludes meaningful comparison to most other North American Cretaceous marsupials, although Eodelphis, thought to be distantly related, also has an enlarged i2. Although Alphadon is characterized by many primitive features, the relative development of the incisors is not what would be predicted in a morphological antecedent to later Marsupialia.
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Price, Gilbert J., Kyle J. Ferguson, Gregory E. Webb, et al. "Seasonal migration of marsupial megafauna in Pleistocene Sahul (Australia–New Guinea)." Proceedings of the Royal Society B: Biological Sciences 284, no. 1863 (2017): 20170785. http://dx.doi.org/10.1098/rspb.2017.0785.
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Seasonal two-way migration is an ecological phenomenon observed in a wide range of large-bodied placental mammals, but is conspicuously absent in all modern marsupials. Most extant marsupials are typically smaller in body size in comparison to their migratory placental cousins, possibly limiting their potential to undertake long-distance seasonal migrations. But what about earlier, now-extinct giant marsupial megafauna? Here we present new geochemical analyses which show that the largest of the extinct marsupial herbivores, the enormous wombat-like Diprotodon optatum , undertook seasonal, two-way latitudinal migration in eastern Sahul (Pleistocene Australia–New Guinea). Our data infer that this giant marsupial had the potential to perform round-trip journeys of as much as 200 km annually, which is reminiscent of modern East African mammal migrations. These findings provide, to our knowledge, the first evidence for repetitive seasonal migration in any metatherian (including marsupials), living or extinct, and point to an ecological phenomenon absent from the continent since the Late Pleistocene.
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Cooper, W. James, and Scott J. Steppan. "Developmental constraint on the evolution of marsupial forelimb morphology." Australian Journal of Zoology 58, no. 1 (2010): 1. http://dx.doi.org/10.1071/zo09102.
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Compared with the placental mammals, marsupials are born at an almost embryonic stage, but nearly all of these neonates immediately climb or crawl to one of their mother’s teats using precociously developed forelimbs. Marsupial adults also exhibit limited forelimb shape diversity relative to the members of their sister group. That the functional requirements of this natal climb have imposed a developmental constraint on marsupial forelimb evolution represents a compelling and widely accepted hypothesis, yet its resulting predictions for the comparative patterns of mammal limb shape diversity have never been tested. In order to perform such tests we conducted extensive taxonomic sampling of mammal limb morphology (including fossil specimens), and then examined these data using morphometric methods, non-parametric analyses of anatomical disparity, and phylogenetic comparative analyses of evolutionary rates. Our results strongly support the constraint hypothesis, and indicate that the highly significant differences between marsupial and placental forelimb shape diversity has been strongly influenced by different rates of morphological evolution among the distal forelimb elements in these two important mammal lineages.
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Coelho, Marcella Gonçalves, Vanessa do Nascimento Ramos, Jean Ezequiel Limongi, et al. "Serologic evidence of the exposure of small mammals to spotted-fever Rickettsia and Rickettsia bellii in Minas Gerais, Brazil." Journal of Infection in Developing Countries 10, no. 03 (2016): 275–82. http://dx.doi.org/10.3855/jidc.7084.
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Introduction: Sources of pathogenic Rickettsia in wildlife are largely unknown in Brazil. In this work, potential tick vectors and seroreactivity of small mammals against four spotted-fever group Rickettsia (R. rickettsii, R. parkeri, R. amblyommii and R. rhipicephali) and Rickettsia bellii from peri-urban areas of Uberlândia, a major town in Brazil, are described for the first time. Methodology: Small mammals were captured and blood samples collected. Ticks were collected from the surface of the host and the environment and posteriorly identified. Reactivity of small mammal sera to Rickettsia was tested by indirect immunofluorescence assay (IFA) using crude antigens from five Brazilian Rickettsia isolates. Results: Information was obtained from 416 small mammals (48 Marsupialia and 368 Rodentia). Forty-eight animals were parasitized and two tick species, Ixodes loricatus and Amblyomma dubitatum, were found on several host species, with a few tick-host relationships described for the first time. From the 416 tested sera, 70 reacted to at least one Rickettsia antigen (prevalence of 16.8%) and from these, 19 (27.1%) reacted to two or more antigens. Seroprevalence was higher for marsupials (39.6%) than for rodents (13.8%). Marsupial and Rhipidomys spp. sera reacted mainly (highest seroprevalence and titers) to R. bellii, and that of Necromys lasiurus mainly to R. rickettsii. Conclusions: Although the serologic assays poorly discriminate between closely related spotted-fever group Rickettsia, the observed small mammal seroreactivity suggests the circulation of Rickettsia in the peri-urban area of Uberlândia, albeit at low levels.
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Renfree, Marilyn B., Eleanor I. Ager, Geoff Shaw, and Andrew J. Pask. "Genomic imprinting in marsupial placentation." REPRODUCTION 136, no. 5 (2008): 523–31. http://dx.doi.org/10.1530/rep-08-0264.
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Genomic imprinting is a widespread epigenetic phenomenon in eutherian mammals, which regulates many aspects of growth and development. Parental conflict over the degree of maternal nutrient transfer is the favoured hypothesis for the evolution of imprinting. Marsupials, like eutherian mammals, are viviparous but deliver an altricial young after a short gestation supported by a fully functional placenta, so can shed light on the evolution and time of acquisition of genomic imprinting. All orthologues of eutherian imprinted genes examined have a conserved expression in the marsupial placenta regardless of their imprint status. Differentially methylated regions (DMRs) are the most common mechanism controlling genomic imprinting in eutherian mammals, but none were found in the marsupial imprinted orthologues of IGF2 receptor (IGF2R), INS or mesoderm-specific transcript (MEST). Instead, histone modification appears to be the mechanism used to silence these genes. At least three genes in marsupials have DMRs: H19, IGF2 and PEG10. PEG10 is particularly interesting as it is derived from a retrotransposon, providing the first direct evidence that retrotransposon insertion can drive the evolution of an imprinted region and of a DMR in mammals. The insertion occurred after the prototherian–therian mammal divergence, suggesting that there may have been strong selection for the retention of imprinted regions that arose during the evolution of placentation. There is currently no evidence for genomic imprinting in the egg-laying monotreme mammals. However, since these mammals do have a short-lived placenta, imprinting appears to be correlated with viviparity but not placentation.
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Lindenmayer, D. B., C. MacGregor, A. Welsh, et al. "Contrasting mammal responses to vegetation type and fire." Wildlife Research 35, no. 5 (2008): 395. http://dx.doi.org/10.1071/wr07156.
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The response of terrestrial mammals and arboreal marsupials to past burning history as well as a year prior to, and then for 4 years after, a major wildfire in 2003 at Booderee National Park, Jervis Bay Territory was quantified. The present study encompassed extensive repeated surveys at a set of 109 replicated sites stratified by vegetation type and fire history. It was found that most species exhibited significant differences in presence and abundance between major vegetation types. Detections of long-nosed bandicoot (Perameles nasuta) increased significantly in all vegetation types surveyed, in both burnt and unburnt areas. Temporal patterns in captures of three species of small mammals (bush rat (Rattus fuscipes), swamp rat (Rattus lutreolus) and brown antechinus (Antechinus stuartii)) showed a trend for lower numbers of captures on burnt sites compared with unburnt sites. Three species of arboreal marsupials, common ringtail possum (Pseudocheirus peregrinus), greater glider (Petauroides volans) and common brushtail possum (Trichosurus vulpecula), were moderately common and all showed marked differences in abundance between vegetation types. Whereas P. peregrinus and P. volans exhibited a temporal decline between 2003 and 2006, T. vulpecula exhibited a general increase from 2003 levels. However, arboreal marsupial responses did not appear to be directly fire related.
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Teta, Pablo, Javier A. Pereira, Emiliano Muschetto, and Natalia Fracassi. "Mammalia, Didelphimorphia, Chiroptera, and Rodentia, Parque Nacional Chaco and Capitán Solari, Chaco province, Argentina." Check List 5, no. 1 (2009): 144. http://dx.doi.org/10.15560/5.1.144.
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We studied the small mammal assemblage (bats, marsupials and rodents) of Parque Nacional Chaco and Capitán Solari (Chaco Province, Argentina) based on captures and analysis of owl pellets. Twenty-one species were recorded during a brief survey, including two marsupials, seven bats, and twelve rodents. In addition, we documented the first occurrence of the bat Lasiurus ega in the Chaco Province, and extended to the southwest the distribution of the didelphid marsupial Cryptonanus chacoensis and the oryzomyine rodent Oecomys sp. We also provided a second occurrence site in the ents Calomys laucha and Holochilus brasiliensis. Identified taxa belonged to species that are typical of the Humid Chaco ecoregion of Argentina.
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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.
9
VAZ, V. C., P. S. D'ANDREA, and A. M. JANSEN. "Effects of habitat fragmentation on wild mammal infection by Trypanosoma cruzi." Parasitology 134, no. 12 (2007): 1785–93. http://dx.doi.org/10.1017/s003118200700323x.
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SUMMARYExpansion of human activities frequently results in habitat fragmentation, a phenomenon that has been widely recognized in the last decades as one of the major threats to world's biodiversity. The transformation of a continuous forest into a fragmented area results in a hyper-dynamic landscape with unpredictable consequences to overall ecosystem health. The effect of the fragmentation process on Trypanosoma cruzi infection among small wild mammals was studied in an Atlantic Rain Forest landscape. Comparing continous forest to fragmented habitat, marsupials were less abundant than rodents in the continuous landscape. An overall decrease in small wild mammal richness was observed in the smaller fragments. An anti-T. cruzi seroprevalence of 18% (82/440) was deteced by immunofluorescence assay. Moreover, this seroprevalence was higher in the fragmented habitat than in the continuous forest. According to the collected data, 3 main factors seem to modulate infection by T. cruzi in small wild mammals: (i) habitat fragmentation; (ii) biodiversity loss; (iii) increase of marsupial abundance in mammal communities. Furthermore, an extremely mild controlled infection by T. cruzi was detected since no patent parasitaemia could be detected in fresh blood samples, and no parasites were isolated by haemoculture.
10
Hooker, J. J. "An additional record of a placental mammal (Order Astrapotheria) from the Eocene of West Antarctica." Antarctic Science 4, no. 1 (1992): 107–8. http://dx.doi.org/10.1017/s0954102092000154.
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Recently, fossil land mammals have been recorded in the James Ross Island area, east of the Antarctic Peninsula, from the marine middle-late Eocene strata of Seymour Island. These include two endemic species of polydolopid marsupial: Antarctodolops dailyi Woodburne & Zinsmeister 1984, and Eurydolops seymourensis Case, Woodburne & Chaney 1988, and three partly determinate placentals identified as a tardigrade edentate, a sparnotheriodontid litoptern and a trigonostylopid astrapothere (Bond et al. 1989). The marsupials are represented by fragmentary jaw and complete dental material, the litoptern and astrapothere only by tooth fragments. All are recorded from Unit TELM 5 of the La Meseta Formation (Sadler 1988), the two ungulates at a lower level than the rest. The subject of the present note is a second tooth fragment from Seymour Island identified as an astrapothere. It is worth recording because such mammal remains are rare and it is from TELM 4, the unit below that yielding the other land mammals.
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Isaac, Joanne L., and Christopher N. Johnson. "Terminal reproductive effort in a marsupial." Biology Letters 1, no. 3 (2005): 271–75. http://dx.doi.org/10.1098/rsbl.2005.0326.
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Life-history theory predicts that as organisms approach the end of their life, they should increase their reproductive effort (RE). However, studies on mammals often find that measures of RE do not vary with maternal age. This might be because offspring have some control over energy transfer which may constrain adaptive variation in RE by mothers, particularly in eutherian mammals where placental function is primarily controlled by offspring. However, in marsupials, energy transfer is primarily by lactation and under maternal control, leaving marsupial mothers free to vary RE. Here, we provide the first analysis, to our knowledge, of age-specific RE in a marsupial, the common brushtail possum. RE, measured as the proportion of maternal mass lost during lactation, was strongly correlated with offspring mass as a yearling. Older females had higher RE, gave birth earlier in the season and were more likely to produce two offspring in a year. Females with high RE in one year were lighter at the beginning of the next breeding season. These results provide the clearest support yet for terminal RE in a mammal.
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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 (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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D’Andrea, PS, R. Gentile, LS Maroja, FA Fernandes, R. Coura, and R. Cerqueira. "Small mammal populations of an agroecosystem in the Atlantic Forest domain, southeastern Brazil." Brazilian Journal of Biology 67, no. 1 (2007): 179–86. http://dx.doi.org/10.1590/s1519-69842007000100025.
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This study reports 2 years of the population dynamics and reproduction of a small mammal community using the removal method. The study was conducted in a rural area of the Atlantic Forest, in Sumidouro, Rio de Janeiro State, Brazil. The population sizes, age structure and reproduction were studied for the four most common species in the study area. The overall diversity was 1.67 and ranged between 0.8 to 1.67. The species richness was 13 considering the whole study. The most abundant species were the rodents Nectomys squamipes (n = 133), Akodon cursor (n = 74), Oligoryzomys nigripes (n = 25) and the marsupials Didelphis aurita (n = 58) and Philander frenatus (n = 50). Seven other rodents were captured once: Necromys lasiurus, Akodon montensis, Sooretamys angouya, Oecomys catherine, Oxymycterus judex, Euryzygomatomys spinosus and Trinomys iheringi. There were higher peaks for diversity and species richness during the winter (dry) months, probably due to higher food availability. The marsupials had a seasonal reproduction with highest population sizes at the end of the rainy seasons. Nectomys squamipes reproduced mostly during rainy periods. Akodon cursor reproduced predominantly in the winter with the highest population peaks occurring during this season. The analysis of the population dynamics of the rodent species indicated that no species behaved as an agricultural pest, probably due to the heterogeneous landscape of high rotativity of vegetable cultivation. Rodent populations were more susceptible to the removal procedure than marsupial ones.
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Colle, Ana Cláudia, Ravena Fernanda Braga Mendonça, Maerle Oliveira Maia, et al. "Rickettsial survey and ticks infesting small mammals from the Amazon forest in midwestern Brazil." Systematic and Applied Acarology 25, no. 1 (2020): 78–91. http://dx.doi.org/10.11158/saa.25.1.6.
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In the present study, samples of tick, tissue and blood from free-living wild small mammals (rodents and marsupials) captured in two municipalities from the Amazon biome of the Mato Grosso state, were molecularly tested for rickettsial infection. A total of 148 mammal specimens (46 rodents and 102 marsupials) were trapped, and 2,700 Amblyomma ticks (2,000 larvae and 700 nymphs) were collected. Ticks were recognized into four Amblyomma species: Amblyomma cajennense sensu stricto, Amblyomma coelebs, Amblyomma humerale, and Amblyomma scalpturatum, with new data for tick-host associations from small mammals in the Amazon biome. All tissue and blood samples of small mammals tested by PCR for rickettsial detection were negative. However, concerning tick-Rickettsia associations, Rickettsia amblyommatis was detected in all four tick species identified in the present study, being the first record for A. scalpturatum ticks. Furthermore, an uncharacterized species of Rickettsia belonging to the spotted fever group was detected in A. humerale as well.
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Alho, CJR, G. Camargo, and E. Fischer. "Terrestrial and aquatic mammals of the Pantanal." Brazilian Journal of Biology 71, no. 1 suppl 1 (2011): 297–310. http://dx.doi.org/10.1590/s1519-69842011000200009.
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Different works have registered the number of mammal species within the natural habitats of the Pantanal based on currently known records, with species richness ranging from 89 to 152 of annotated occurrences. Our present list sums 174 species. However, at least three factors have to be emphasised to deal with recorded numbers: 1) to establish the ecotone limit between the floodplain (which is the Pantanal) and its neighbouring domain like the Cerrado, besides the existence of maps recently produced; 2) the lack of intensive surveys, especially on small mammals, rodents and marsupials; and 3) the constant taxonomic revision on bats, rodents and marsupials. Some species are very abundant - for example the capybara Hydrochoerus hydrochaeris and the crab-eating fox Cerdocyon thous, and some are rare, and others are still intrinsically rare - for example, the bush dog Speothos venaticus. Abundance of species is assumed to reflect ecological resources of the habitat. Local diversity and number of individuals of wild rodents and marsupials also rely on the offering of ecological resources and behavioural specialisation to microhabitat components. A large number of species interact with the type of the vegetation of the habitat, by means of habitat selection through active patterns of ecological behaviour, resulting on dependency on arboreal and forested habitats of the Pantanal. In addition, mammals respond to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal. The highest number of species is observed during the dry season, when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Major threats to mammal species are the loss and alteration of habitats due to human intervention, mainly deforestation, unsustainable agricultural and cattle-ranching practices, which convert the natural vegetation into pastures. The Pantanal still harbours about a dozen of species officially listened as in danger.
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Griffith, Oliver W., Arun R. Chavan, Stella Protopapas, Jamie Maziarz, Roberto Romero, and Gunter P. Wagner. "Embryo implantation evolved from an ancestral inflammatory attachment reaction." Proceedings of the National Academy of Sciences 114, no. 32 (2017): E6566—E6575. http://dx.doi.org/10.1073/pnas.1701129114.
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The molecular changes that support implantation in eutherian mammals are necessary to establish pregnancy. In marsupials, pregnancy is relatively short, and although a placenta does form, it is present for only a few days before parturition. However, morphological changes in the uterus of marsupials at term mimic those that occur during implantation in humans and mice. We investigated the molecular similarity between term pregnancy in the marsupials and implantation in eutherian mammals using the gray short-tailed opossum (Monodelphis domestica) as a model. Transcriptomic analysis shows that term pregnancy in the opossum is characterized by an inflammatory response consistent with implantation in humans and mice. This immune response is temporally correlated with the loss of the eggshell, and we used immunohistochemistry to report that this reaction occurs at the materno–fetal interface. We demonstrate that key markers of implantation, including Heparin binding EGF-like growth factor and Mucin 1, exhibit expression and localization profiles consistent with the pattern observed during implantation in eutherian mammals. Finally, we show that there are transcriptome-wide similarities between the opossum attachment reaction and implantation in rabbits and humans. Our data suggest that the implantation reaction that occurs in eutherians is derived from an attachment reaction in the ancestral therian mammal which, in the opossum, leads directly to parturition. Finally, we argue that the ability to shift from an inflammatory attachment reaction to a noninflammatory period of pregnancy was a key innovation in eutherian mammals that allowed an extended period of intimate placentation.
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Luo, Zhe-Xi, Chong-Xi Yuan, Qing-Jin Meng, and Qiang Ji. "A Jurassic eutherian mammal and divergence of marsupials and placentals." Nature 476, no. 7361 (2011): 442–45. http://dx.doi.org/10.1038/nature10291.
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Palma, Alexandre R. T., and Rodrigo Gurgel-Gonçalves. "Morphometric identification of small mammal footprints from ink tracking tunnels in the Brazilian Cerrado." Revista Brasileira de Zoologia 24, no. 2 (2007): 333–43. http://dx.doi.org/10.1590/s0101-81752007000200011.
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An alternative method for identifying and inventorying rodents and marsupials inhabiting forests and grasslands of Brazilian Cerrado is presented and discussed. Ink tracking tunnels were designed according to the size of target species and used to build a reference collection of small mammal footprints composed of 1408 footprints belonging to 251 individuals from 30 species (21 rodents and nine marsupials). Sherman traps and ink tracking tunnels were used to conduct inventories in gallery forests. Footprints obtained in ink tracking tunnels were digitalized and compared with those in reference collection using Discriminant Analysis (DFA). DFA allowed good footprint differentiation, even among congeneric species. In DFA analysis, the first two axis were related to size and arboreality. The efficiency of ink tracking tunnels was higher (track-success = 31%) than conventional trapping (trap-success = 14%) in inventories. Ink tracking tunnels gave a good description of the small mammal community of gallery forest by detecting rodents and marsupials of different habits, including trap-shy species. This paper also discusses advantages and limitations of ink tracking tunnels use in inventories and ecological studies, and concludes that this technique can be efficient in long-term studies and in rapid inventories as a complementary technique for trapping.
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Corrêa, Matheus R. J., Yuri M. Bellagamba, Adriele P. de Magalhães, et al. "Microhabitat structure and food availability modelling a small mammal assemblage in restored riparian forest remnants." Mammalia 82, no. 4 (2018): 315–27. http://dx.doi.org/10.1515/mammalia-2017-0026.
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Abstract Small mammal populations respond to environmental changes in secondary riparian forest remnants in different ways, depending on the influences of biotic and abiotic variables. The present study evaluated how habitat/microhabitat structure and food availability influence small mammal assemblages in restored riparian forest remnants. Pitfall traps disposed in three linear transects were used to collect small mammals during 9 months of field work. General linear models were built to test the hypothesis that microhabitat structure (litter biomass and type – leaves and branches) and food availability (richness of zoochoric tree species and arthropods) influence species richness and abundance of small mammals. Three hundred and eighty-two individuals belonging to 14 species were captured. Biomass and type of litter (leaves or branches) provided greater structural to microhabitats, allowing the coexistence of morphologically similar species. Besides, food availability influenced foraging strategies of marsupials, forcing them to use the forest floor when zoochoric plants were rare. Thus, litter structure and food availability, allowing spatial segregation of the small mammal species using the forest fragments. We concluded that the maintenance of small mammals and their ecosystem services in restored riparian forests are dependent on habitat structure and food availability, thus, litter and zoochoric plants should be conserved in riparian forest fragments, especially those reforested.
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Pereira, LG, and L. Geise. "Karyotype composition of some rodents and marsupials from Chapada Diamantina (Bahia, Brasil)." Brazilian Journal of Biology 67, no. 3 (2007): 509–18. http://dx.doi.org/10.1590/s1519-69842007000300016.
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The Chapada Diamantina (CD) is located in Bahia State, between 11-14° S and 41-43° W, being part of the Serra do Espinhaço. The occurrence of different habitats and transition areas permits an interesting mammal fauna composition, with species from different biomes living in sympatry. Species of Didelphimorphia and Rodentia are important members of mammal communities in almost all different habitats, and morphological and cytogenetic characters are important for a correct identification of most of these species. In this work 258 specimens of small mammals from the orders Didelphimorphia (six genera and six species) and Rodentia (two families, five Sigmodontinae tribes, nine genera and 11 species) were collected during the whole field work (44 nights with traps). Chromosome preparations were obtained from 145 specimens from the species: Marmosops incanus, Gracilinanus microtarsus, Monodelphis domestica, Akodon aff. cursor, Necromys lasiurus, Cerradomys sp., Oligoryzomys fornesi, O. nigripes, O. rupestris, Calomys expulsus, Rhipidomys macrurus, Wiedomys pyrrhorhinus and Thrichomys inermis. Didelphis albiventris, Micoureus demerarae, Thylamys karymii and Nectomys sp. were identified by morphological characters. Most analyzed specimens do not show karyotype variation. However, numerical chromosomic variation was found in two individuals of Akodon aff. cursor (2n = 15) and in one individual of Cerradomys sp. (2n = 51). Structural variation in karyotype was observed in seven individuals of Cerradomys sp., showing one additional pair of metacentric chromosomes.
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Scheibler, DR, and AU Christoff. "Habitat associations of small mammals in southern Brazil and use of regurgitated pellets of birds of prey for inventorying a local fauna." Brazilian Journal of Biology 67, no. 4 (2007): 619–25. http://dx.doi.org/10.1590/s1519-69842007000400005.
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We inventoried terrestrial small mammals in an agricultural area in southern Brazil by using trapping and prey consumed by Barn Owls (Tyto alba) and White-tailed Kites (Elanus leucurus). Small mammals were trapped in three habitat types: corn fields, uncultivated fields ("capoeiras"), and native forest fragments. A total of 1,975 small mammal specimens were trapped, another 2,062 identified from the diet of Barn Owls, and 2,066 from the diet of White-tailed Kites. Both trapping and prey in the predators' diet yielded 18 small mammal species: three marsupials (Didelphis albiventris, Gracilinanus agilis, and Monodelphis dimidiata) and 15 rodents (Akodon paranaensis, Bruceppatersonius iheringi, Calomys sp., Cavia aperea, Euryzygomatomys spinosus, Holochilus brasiliensis, Mus musculus, Necromys lasiurus, Nectomys squamipes, Oligoryzomys nigripes, Oryzomys angouya, Oxymycterus sp.1, Oxymycterus sp.2, Rattus norvegicus, and Rattus rattus (Linnaeus, 1758)). The greatest richness was found in the uncultivated habitat. We concluded that the three methods studied for inventorying small mammals (prey in the diet of Barn Owls, White-tailed Kites, and trapping) were complementary, since together, rather than separately, they produced a better picture of local richness.
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Johnson, Christopher N., Joanne L. Isaac, and Diana O. Fisher. "Rarity of a top predator triggers continent-wide collapse of mammal prey: dingoes and marsupials in Australia." Proceedings of the Royal Society B: Biological Sciences 274, no. 1608 (2006): 341–46. http://dx.doi.org/10.1098/rspb.2006.3711.
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Top predators in terrestrial ecosystems may limit populations of smaller predators that could otherwise become over abundant and cause declines and extinctions of some prey. It is therefore possible that top predators indirectly protect many species of prey from excessive predation. This effect has been demonstrated in some small-scale studies, but it is not known how general or important it is in maintaining prey biodiversity. During the last 150 years, Australia has suffered the world's highest rate of mammal decline and extinction, and most evidence points to introduced mid-sized predators (the red fox and the feral cat) as the cause. Here, we test the idea that the decline of Australia's largest native predator, the dingo, played a role in these extinctions. Dingoes were persecuted from the beginning of European settlement in Australia and have been eliminated or made rare over large parts of the continent. We show a strong positive relationship between the survival of marsupials and the geographical overlap with high-density dingo populations. Our results suggest that the rarity of dingoes was a critical factor which allowed smaller predators to overwhelm marsupial prey, triggering extinction over much of the continent. This is evidence of a crucial role of top predators in maintaining prey biodiversity at large scales in terrestrial ecosystems and suggests that many remaining Australian mammals would benefit from the positive management of dingoes.
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Mares, Michael A., Kristina A. Ernest, and Donald D. Gettinger. "Small mammal community structure and composition in the Cerrado Province of central Brazil." Journal of Tropical Ecology 2, no. 4 (1986): 289–300. http://dx.doi.org/10.1017/s0266467400000948.
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ABSTRACTCommunity structure, macrohabitat selection, and patterns of species co-occurrence were examined during a 14-month study of small mammals in the Cerrado Province of central Brazil. Data were collected from mark-recapture grids in brejo and gallery forest, and from live-trapping and specimen collection in all habitat types within cerrado (campo limpo, campo sujo, cerrado [s.s.], cerradão, brejo, valley-side wet campo, and gallery forest). Gallery forest supported the highest species richness, most complex vertical distribution of species, highest level of trophic diversity, and highest macroniche diversity. Degree of habitat selection varied widely. All habitat types supported both rodents and marsupials, although marsupials tended to be much less common in the grasslands (campos) than in woodlands (cerrado) and forests (cerradão, gallery forest). Some species, such as Didelphis albiventris, occurred in all habitat types, while others were much more restricted. Oryzomys bicolor, for example, ocur-red only in gallery forest. No habitat type had a completely distinct fauna: overlap in species composition always occurred with at least one other habitat type. Because of the great variability of habitats, and the fact that subsets of the mammal fauna were frequently habitat specific, the overall species richness of any portion of mixed cerrado vegetation is remarkably high.
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Korth, William W., Clint A. Boyd, Robert J. Emry, and Jeff J. Person. "Marsupials (Mammalia, Metatheria) from the Brule Formation (Whitneyan, Oligocene) North Dakota." Journal of Paleontology 95, no. 1 (2020): 193–204. http://dx.doi.org/10.1017/jpa.2020.41.
Full textAbstract:
AbstractFive marsupial species are recognized from the Brule Formation at two localities in southwestern North Dakota: Fitterer Ranch and Obritsch Ranch (middle Oligocene; Whitneyan North American Land Mammal Age [NALMA]). The herpetotheriids Herpetotherium fugax Cope, 1873a, Copedelphys superstes new species, and the peradectid Nanodelphys hunti (Cope, 1873b) are represented at both localities. A fourth species is H. sp., cf. H. merriami (Stock and Furlong, 1922), represented by a single specimen from Fitterer Ranch, being limited elsewhere to the later Arikareean NALMA. A fifth species is represented by two isolated lower cheek teeth, interpreted as m1s, from Fitterer Ranch that are unique in lacking a trigonid (only two cusps present) while having a well-developed talonid. These specimens are referred to an indeterminate herpetotheriine species. The new species of Copedelphys is distinct from other species of the genus in that the anterior two lower molars are enlarged relative to the posterior molars. Overall, this new species is more similar in proportions to the latest Eocene (Chadronian) C. titanelix (Matthew, 1903) than the Oligocene (Orellan and Whitneyan) C. stevensoni (Cope, 1873b). This study adds a third and fourth Whitneyan marsupial fauna from the Great Plains region of North America, increases the known diversity of Whitneyan marsupials, and provides further evidence that marsupial diversity during the late Paleogene in North America was relatively stable until the late early Arikareean NALMA.UUID: http://zoobank.org/b8534802-b9ed-4120-baca-fc72917f7d6a
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Santos-Filho, M., F. Frieiro-Costa, ÁRA Ignácio, and MNF Silva. "Use of habitats by non-volant small mammals in Cerrado in Central Brazil." Brazilian Journal of Biology 72, no. 4 (2012): 893–902. http://dx.doi.org/10.1590/s1519-69842012000500016.
Full textAbstract:
Non-volant small mammals are organisms capable of yielding precise information on richness, abundance and species composition variations related to the use of habitats. The aim of this research was to compare these variations in Cerrado sensu stricto, Palm Forest, Gallery Forest and Rocky Field. From May 1999 to February 2000, we surveyed non-volant small mammals (hence small mammals) in Serra das Araras Ecological Station. We captured 218 individuals and recaptured 62 individuals, belonging to 21 taxa, 13 rodents and eight marsupials, in a total of 13200 trap-nights. Capture success was 1.7%. We observed higher richness of small mammals in forested areas (Gallery Forest and Palm Forest) than in open areas (Rocky Field and Cerrado sensu stricto). The Palm Forest had the highest richness of marsupials, possibly due to the quality of a specific niche. The Rocky Field had the smallest richness, but with very high abundance of few species, mainly Thrichomys pachyurus and Monodelphis domestica. Forest habitats had similar species composition. The open habitats, Cerrado sensu stricto and Rocky Field, had a distinct species composition between them, and also when compared to forested areas. Different species are exclusive or showed preference for specific habitats. The protection of horizontally heterogeneous biomes, such as Cerrado, has a fundamental importance to the maintenance of the regional diversity of the small mammal community of Central Brazil.
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Mendes-Oliveira, Ana Cristina, Paulo Guilherme Pinheiro dos Santos, Oswaldo de Carvalho-Júnior, et al. "Edge effects and the impact of wildfires on populations of small non-volant mammals in the forest-savanna transition zone in Southern Amazonia." Biota Neotropica 12, no. 3 (2012): 57–63. http://dx.doi.org/10.1590/s1676-06032012000300004.
Full textAbstract:
The impact of fire and edge effects on the community of small non-volant mammals was investigated in transitional Amazon forest within a matrix of soybean plantations. The animals were live trapped on 24 line transects, of which 16 were distributed in unburned areas and 8 in a burned area. A total of 11 species was recorded, including six rodents and five marsupials. The abundance and richness of small mammals appeared to decrease in burned areas, although this impact appeared to mask edge effects. In the absence of fire impacts, a positive relationship was found between mammal abundance and the distance from the forest edge. The impact of the edge effect on the diversity of small mammals appears to be influenced by the type of anthropogenic matrix and the ecological characteristics of the different species.
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Mancini, Matheus C. S., Paulo Ricardo O. Roth, Pamela G. G. Brennand, Juan M. Ruiz-Esparza Aguilar, and Patrício A. Rocha. "Tyto furcata (Tytonidae: Strigiformes) pellets: tools to access the richness of small mammals of a poorly known Caatinga area in northeast Brazil." Mammalia 83, no. 4 (2019): 390–98. http://dx.doi.org/10.1515/mammalia-2018-0017.
Full textAbstract:
Abstract Owls are efficient predators and are widely distributed around the globe. Remains of undigested prey is regurgitated by these birds in the form of pellets, and these are a valuable source of information about prey communities and the diet of owls. In this study, the composition of mammals present in the diet of owls that inhabit different caves was evaluated through the analysis of their pellets. We found 373 pellets from seven caves, and small mammals composed at least 80% of the diet of these birds in all caves. The mammal composition found in the pellets showed a richness of 26 distinct taxa including 12 rodents, three marsupials and 11 bats. In this work, we highlight the richness of small mammals in a poorly known Caatinga area. We also highlight the importance of morphology and taxonomy in supporting this kind of research, which relies upon vertebrate parts as its source of information for identification. Finally, we reiterate the efficiency of the study of owl pellets as a rapid approach for assessing local mammal richness and as a complementary method in studies of diversity and conservation.
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Renfree, Marilyn B., Shunsuke Suzuki, and Tomoko Kaneko-Ishino. "The origin and evolution of genomic imprinting and viviparity in mammals." Philosophical Transactions of the Royal Society B: Biological Sciences 368, no. 1609 (2013): 20120151. http://dx.doi.org/10.1098/rstb.2012.0151.
Full textAbstract:
Genomic imprinting is widespread in eutherian mammals. Marsupial mammals also have genomic imprinting, but in fewer loci. It has long been thought that genomic imprinting is somehow related to placentation and/or viviparity in mammals, although neither is restricted to mammals. Most imprinted genes are expressed in the placenta. There is no evidence for genomic imprinting in the egg-laying monotreme mammals, despite their short-lived placenta that transfers nutrients from mother to embryo. Post natal genomic imprinting also occurs, especially in the brain. However, little attention has been paid to the primary source of nutrition in the neonate in all mammals, the mammary gland. Differentially methylated regions (DMRs) play an important role as imprinting control centres in each imprinted region which usually comprises both paternally and maternally expressed genes ( PEG s and MEG s). The DMR is established in the male or female germline (the gDMR). Comprehensive comparative genome studies demonstrated that two imprinted regions, PEG10 and IGF2-H19 , are conserved in both marsupials and eutherians and that PEG10 and H19 DMRs emerged in the therian ancestor at least 160 Ma, indicating the ancestral origin of genomic imprinting during therian mammal evolution. Importantly, these regions are known to be deeply involved in placental and embryonic growth. It appears that most maternal gDMRs are always associated with imprinting in eutherian mammals, but emerged at differing times during mammalian evolution. Thus, genomic imprinting could evolve from a defence mechanism against transposable elements that depended on DNA methylation established in germ cells.
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Jarman, Peter J., Lee R. Allen, Dennis J. Boschma, and Stuart W. Green. "Scat contents of the spotted-tailed quoll Dasyurus maculatus in the New England gorges, north-eastern New South Wales." Australian Journal of Zoology 55, no. 1 (2007): 63. http://dx.doi.org/10.1071/zo06014.
Full textAbstract:
In 1313 scats of the spotted-tailed quoll Dasyurus maculatus, collected over 5 years from the gorge country of north-eastern New South Wales, the most frequent and abundant items were derived from mammals and a restricted set of insect orders. These quolls also ate river-associated items: waterbirds, eels, crayfish, aquatic molluscs and even frogs. Macropods contributed most of the mammal items, with possums, gliders and rodents also being common. Some food, particularly from macropods and lagomorphs, had been scavenged (as shown by fly larvae). The most frequent invertebrates were three orders of generally large insects Coleoptera, Hemiptera and Orthoptera, which were most frequent in summer and almost absent in winter scats. Monthly mean numbers of rodent and small dasyurid items per scat were inversely related to these large insects in scats. The numbers of reptile items were inversely related to the numbers of mammal (especially arboreal and small terrestrial mammal) items per scat, thus types of items interacted in their occurrences in monthly scat samples. Frequencies of most vertebrate items showed no seasonal, but much year-to-year, variation. This quoll population ate four main types of items, each requiring different skills to obtain: they hunted arboreal marsupials (possibly up trees), terrestrial small mammals and reptiles (on the ground), and seasonally available large insects (on trees or the ground), and scavenged carcases, mostly of large mammals but also birds and fishes (wherever they could find them).
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van der Ree, R., and R. H. Loyn. "The influence of time since fire and distance from fire boundary on the distribution and abundance of arboreal marsupials in Eucalyptus regnans-dominated forest in the Central Highlands of Victoria." Wildlife Research 29, no. 2 (2002): 151. http://dx.doi.org/10.1071/wr98055.
Full textAbstract:
The impact of time since fire after two consecutive wildfires 44 years apart (1939 and 1983) within the same area, and the distance from the fire boundary (<100 m or 500-2000 m), were investigated in relation to the distribution and abundance of arboreal marsupials in 1994. Arboreal marsupials were censused by stagwatching and spotlighting in two relatively young age classes of mountain ash (Eucalyptus regnans) dominated forest in the Central Highlands of Victoria. Five species of arboreal marsupial were detected, but only three were detected in sufficient numbers to determine habitat preferences. Petauroides volans (greater glider) was statistically more abundant in 1939 regrowth forests, while Trichosurus caninus (mountain brushtail possum) showed no significant preference for either age class of forest. All but one record of Gymnobelideus leadbeateri (Leadbeater's possum) came from young forest, though the effect of age-class was not statistically significant. Distance from fire boundary explained little or no variation in mammal distribution or abundance. While the actual number of hollow-bearing trees was similar in both age classes of forest, the long-term lifespan of hollow-bearing trees in more recently burnt forest is predicted to be lower than in unburnt or not recently burnt forest. Post-fire salvage logging following the 1983 wildfires appears to have reduced the number of hollow-bearing trees at sites burnt in 1983.
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dos Reis, Mario, Jun Inoue, Masami Hasegawa, Robert J. Asher, Philip C. J. Donoghue, and Ziheng Yang. "Phylogenomic datasets provide both precision and accuracy in estimating the timescale of placental mammal phylogeny." Proceedings of the Royal Society B: Biological Sciences 279, no. 1742 (2012): 3491–500. http://dx.doi.org/10.1098/rspb.2012.0683.
Full textAbstract:
The fossil record suggests a rapid radiation of placental mammals following the Cretaceous–Paleogene (K–Pg) mass extinction 65 million years ago (Ma); nevertheless, molecular time estimates, while highly variable, are generally much older. Early molecular studies suffer from inadequate dating methods, reliance on the molecular clock, and simplistic and over-confident interpretations of the fossil record. More recent studies have used Bayesian dating methods that circumvent those issues, but the use of limited data has led to large estimation uncertainties, precluding a decisive conclusion on the timing of mammalian diversifications. Here we use a powerful Bayesian method to analyse 36 nuclear genomes and 274 mitochondrial genomes (20.6 million base pairs), combined with robust but flexible fossil calibrations. Our posterior time estimates suggest that marsupials diverged from eutherians 168–178 Ma, and crown Marsupialia diverged 64–84 Ma. Placentalia diverged 88–90 Ma, and present-day placental orders (except Primates and Xenarthra) originated in a ∼20 Myr window (45–65 Ma) after the K–Pg extinction. Therefore we reject a pre K–Pg model of placental ordinal diversification. We suggest other infamous instances of mismatch between molecular and palaeontological divergence time estimates will be resolved with this same approach.
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Saffer, V. M. "Are diel patterns of nectar production and anthesis associated with other floral traits in plants visited by potential bird and mammal pollinators?" Australian Journal of Botany 52, no. 1 (2004): 87. http://dx.doi.org/10.1071/bt02056.
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Plants pollinated predominantly by vertebrates are thought to have suites of floral traits (e.g.�colour, conspicuousness, odour) that favour either birds or mammals, with brightly coloured, conspicuous flowers associated with birds and drab, concealed flowers with non-flying mammals. This study examined two other floral traits, diel patterns of nectar production and pollen presentation (anthesis). It would be expected that these would be nocturnal in putatively mammal-pollinated plants and diurnal in bird-pollinated plants. In four Banksia and two Dryandra species, all known to be visited by honeyeater birds and small marsupials at one site in south-western Australia, there was no clear correspondence between visual cues and diel patterns of resource presentation. This lack of correlation between floral traits does not support the idea of specialised pollination syndromes, but rather is consistent with generalised pollination systems.
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Fournier, R. A., and J. M. Weber. "Locomotory energetics and metabolic fuel reserves of the Virginia opossum." Journal of Experimental Biology 197, no. 1 (1994): 1–16. http://dx.doi.org/10.1242/jeb.197.1.1.
Full textAbstract:
Marsupials have lower resting metabolic rates than placental mammals, but it is not clear whether particular species can extend this energetic advantage to locomotion. Some active marsupials have a low cost of locomotion, but other more sedentary species, such as the Virginia opossum, appear to run very inefficiently. Steady-state rates of O2 consumption (VO2) and CO2 production (VCO2) were measured at rest and during horizontal treadmill exercise in wild-caught, trained opossums. Average daily VO2 in in undisturbed animals was 7.73 +/- 0.40 ml O2 kg-1 min-1 (5.67 +/- 0.20 ml O2 kg-1 min-1 during light and 9.84 +/- 0.81 ml O2 kg-1 min-1 during dark hours, mean +/- S.E.M., N = 6). Net cost of locomotion ranged between 6.16 and 8.99 J kg-1 s-1 as speed increased and was always higher than for an average mammal of equivalent mass. Net cost of transport decreased as speed increased and was 15-80% higher than for an average mammal. During aerobic locomotion, most of the energy was provided by carbohydrate oxidation, which accounted for 60-95% of VO2 as speed increased. Glycogen and triglyceride reserves were quantified in the major storage depots to estimate potential survival time and travelling distance. Enough metabolic fuel was stored to survive for at least 1 week without eating, and 95% of this energy was in adipose tissue triglycerides. However, maximal travelling distance was less than 2 km because opossum locomotion is mainly supported by carbohydrate reserves, which represented only 4% of the available energy. We conclude that aerobic, ground locomotion of Virginia opossums is associated with two major energetic handicaps because their particularly high cost of transport and the nature of the main oxidative fuel they consume are both incompatible with prolonged locomotion.
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Leiner, Natália Oliveira, and Wesley Rodrigues Silva. "Non-volant small mammals at an Atlantic forest area situated nearby a limestone quarry (Limeira quarry), state of São Paulo, Brazil." Biota Neotropica 12, no. 4 (2012): 191–97. http://dx.doi.org/10.1590/s1676-06032012000400020.
Full textAbstract:
Our aim was to survey the non-flying small mammals inhabiting an Atlantic forest area situated nearby a limestone quarry (Limeira quarry), located at Ribeirão Grande municipality (SP), southeastern Brazil. Species were captured with pitfall and Sherman traps along eight pairs of 60 m transects distributed at four different distances from the quarry (60, 220, 740 and 1300 m). Between October 2005 and January 2008, 20 small mammal species (11 rodents and nine marsupials) were captured through 4080 pitfall trap-nights and 2040 Sherman trap-nights. The high values of richness, diversity (H' = 2.65) and equability (J = 0.88), and the presence of endemic and threatened species indicates a preserved study site and small mammal assemblage. Marmosops incanus, Monodelphis americana and Oligoryzomys nigripes were the commonest species at the study site. Trapping sites located closer to the quarry (60 and 220 m away from the quarry) presented lower richness and were dominated by disturbance-tolerant species, such as O. nigripes, that usually benefit from habitat alterations. On the other hand, sites located away from the quarry and closer to Serra do Mar Protected Area (740 and 1300 m away from the quarry) presented higher richness and diversity, and a higher abundance of disturbance-intolerant species. These results suggest a negative distance-dependent impact of quarrying on small mammal communities. In this way, our results point out to the importance of long-term monitoring of quarrying impacts on small non-flying mammal communities and populations, and the need of conservation strategies in order to ensure species persistence in these areas.
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Meiga, Ana Y. Y., and Alexander V. Christianini. "Potential impact of mammal defaunation on the early regeneration of a large-seeded palm in the Brazilian Atlantic Forest." Neotropical Biology and Conservation 15, no. 2 (2020): 177–93. http://dx.doi.org/10.3897/neotropical.15.e54017.
Full textAbstract:
Defaunation, the decline in animal species and populations, is biased towards large-bodied animals that have unique roles as dispersers of large seeds. However, it is speculated that these roles may still be performed by smaller animals, such as small mammals like rodents and marsupials, that thrive in defaunated sites. We investigated if small mammals can disperse the large-seeded palm Attalea dubia. We performed the study in a well-conserved Atlantic Forest remnant in southeast Brazil that still harbours large mammals, such as tapirs. Focal observations showed that capuchin-monkeys consumed the mesocarp of the fruits and dropped the seeds beneath the plant crown thereafter. Mammals preyed on ca. 1% and removed ca. 15% of the fallen fruit/seed and deposited them up to 15 m away. Amongst them, small mammals (< 1 kg), such as the squirrel Guerlinguetus brasiliensis and non-identified nocturnal Sigmodontinae, as well as the marsupial Philander frenatus performed the bulk of interactions. Dispersal enhances recruitment, but the short distances of seed removal did not match the current spatial distribution of palm seedlings and juveniles. Recaching rates of hoarded seeds were small (2%) and unlikely to increase distances of seed dispersal achieved. Short distances of dispersal would increase plant clumpiness and negative density-dependent effects with time. Although small mammals can provide legitimate dispersal, they cannot fully replace larger frugivorous mammals and maintain long-distance seed dispersal that feeds plant metapopulation dynamics and seed gene flow.
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Fernández, Fernando J., Fabricio Idoeta, César García-Esponda, et al. "Small mammals (Didelphimorphia, Rodentia and Chiroptera) from Pampean Region, Argentina." Check List 8, no. 1 (2012): 130. http://dx.doi.org/10.15560/8.1.130.
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We studied small mammal assemblages recovered from owl pellets collected at 11 locations throughout the Argentina’s Pampean Region. We identified 21 species, including two marsupials, one bat, and 18 rodents. From the analysis of this dataset, we could distinguish three main groups of small mammals that currently inhabit the Pampean Region: 1) a group of taxa related to Pampean agroecosystems (Calomys spp., Akodon azarae, and Oligoryzomys flavescens); 2) a group of Brazilian species (Cavia aperea, Oxymycterus rufus, Necromys lasiurus, Necromys obscurus, Holochilus brasiliensis, and Monodelphis dimidiata); and 3) a group including species from Patagonia, Espinal and Monte phytogeographic provinces (Microcavia australis, Oligoryzomys longicaudatus, Eligmodontia typus, Graomys griseoflavus, and Akodon molinae). In addition, we documented the first record of a species of the large-bodied group of Calomys in Buenos Aires province, expanding its distribution ca. 420 km southward.
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Marks, Clive A. "Bait-delivered cabergoline for the reproductive control of the red fox (Vulpes vulpes): estimating mammalian non-target risk in south-eastern Australia." Reproduction, Fertility and Development 13, no. 8 (2001): 499. http://dx.doi.org/10.1071/rd01076.
Full textAbstract:
Cabergoline (CAB) is a potent dopamine agonist and an inhibitor of prolactin (PRL). In red foxes (Vulpes vulpes), a single oral dose of 100 g kg–1 CAB can cause abortions and postnatal cub mortality from at least Day 21 of the 52-day pregnancy. The abortifacient activity of CAB is owing to the suppression of PRL, which is essential for luteotrophic support in some eutherian species. Postnatal cub mortality probably results from a reduction in the development of the mammary ductile system, which is also partially dependant on PRL during pregnancy. This paper investigates the potential risks faced by non-target mammalian species that may consume CAB baits intended for fox control. Baiting with CAB is proposed from 1 August until 1 October each year, to correspond with the time that most vixens are pregnant in south-eastern Australia. Thirty-four endemic mammals in south-eastern Australia (9 eutherians and 25 marsupials) are considered to be potentially bait-consuming (PBC) species. The percentage overlap of pregnancy and birth periods for each PBC species was compared with the duration of the proposed CAB baiting period. Only Antechinus (3 species) and Sminthopsis leucopushave greater than 40% overlap, whereas overlap in endemic rodents ranges from 0% to 22%. Overall, most PBC rodent populations appear to face little risk from CAB baiting, as their period of pregnancy does not overlap significantly with the proposed CAB baiting period. The Antechinus species, Phascogale tapoatafa and Dasyurus maculatus are the only PBC mammals that are seasonally mono-oestrous and are thus probably more susceptible to disruption of breeding compared with polyoestrous species that may breed many times a year. At a baiting density of 8 baits km–2, theoretical bait availability for small dasyurids, rodents and peramelids is low. This suggests a low potential for affecting these populations if CAB was indiscriminate in affecting reproductive success in all mammal groups. Presently, studies in a limited range of marsupials suggest that, unlike eutherians, the marsupial corpus luteum is independent of pituitary control and thus suppression of PRL is not likely to cause abortions in marsupials. As yet, CAB has not been shown to be orally active in any PBC species other than rodents and carnivores. Oral doses of CAB given post partum have not been found to affect lactation in Sminthopsis crassicaudata,Trichosurus vulpecula, Macropus eugenii andSetonix brachyurus. Further studies are required in order to assess the potential for high doses of oral CAB to affect pre-partum mammary development and early lactation post partum, especially in peramelids and larger dasyurids. Highly target-specific baiting techniques, may eliminate most PBC species from being exposed to CAB and these are briefly discussed.
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Montes de Oca, Daniela Paula, Martín Neyen Lammel, and Regino Cavia. "Small-mammal assemblages in piggeries in a developing country: relationships with management practices and habitat complexity." Wildlife Research 47, no. 6 (2020): 485. http://dx.doi.org/10.1071/wr19199.
Full textAbstract:
Abstract ContextPig production is increasing in developing countries and is increasing the coexistence of different production systems regarding management practices. Small mammals can cause major economic and sanitary problems on pig farms. The interactions among small mammals, production practices and habitat complexity have been sparsely studied. AimsThe aim was to compare small-mammal assemblages on extensive and intensive pig-production systems, and to analyse the relationship with environmental characteristics and management practices. MethodsSeasonal live-trapping of small mammals within 18 farms (under intensive or extensive management) was performed in central Argentina, simultaneously with a survey of environmental and management practices. Multiple regression analyses were performed to assess the relation between infestation levels and environmental characteristics. Key results In total, 472 small mammals were captured, including the exotic murids Rattus norvegicus, R. rattus and Mus musculus, three native sigmodontines, namely, Akodon azarae, Oligoryzomys flavescens and Oxymycterus rufus, and two native marsupials, namely, Didelphis albiventris and Lutreolina crassicaudata. The location of waste deposits, the density of cats, the frequency of rodent control and the way pig food was stored influenced wild small-mammal abundance; exotic rodent species were lower when the density of cats increased. Rattus norvegicus was more abundant where rodent control was not frequent or null, contrary to M. musculus. Both species were more abundant in food and pig sheds, whereas native species were associated with vegetated areas outside of sheds. Also, A. azarae was associated with the density of pigs. Didelphis albiventris was more abundant on extensive farms, whereas L. crassicaudata was captured on intensive farms. Conclusions Small-mammal abundance did not respond to the type of production system per se, but exotic species abundance was influenced by management decisions. The most important human behaviours related to exotic rodent infestation were the possession of cats, the frequency of rodent control and the way waste and pig feed were managed. Implications Our findings highlighted the need for integrated studies on factors influencing the dynamics of rodent populations in commercial piggery systems, for the development of effective pest management. Management recommendations need to assess environmental complexity and human behaviour as important moderators of the population dynamics of small mammal species in and around piggeries.
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Geise, Lena, Roberta Paresque, Harley Sebastião, Leila T. Shirai, Diego Astúa, and Gabriel Marroig. "Non-volant mammals, Parque Nacional do Catimbau, Vale do Catimbau, Buíque, state of Pernambuco, Brazil, with karyologic data." Check List 6, no. 1 (2010): 180. http://dx.doi.org/10.15560/6.1.180.
Full textAbstract:
We report the results of a terrestrial small mammal survey at one National Park in the northeastern Brazil, in the state of Pernambuco. The Catimbau National Park is located within the Caatinga domain with the characteristic thorn scrub vegetation. Our sampling encompasses several different vegetation/habitat types within the park area. All specimens collected were prepared as vouchers to be deposited in the Museu de Zoologia da Universidade de São Paulo. Karyotypes were obtained for all representative purported species collected. We report here the results of this first survey – two species of marsupials and seven of rodents - and added new occurrence localities for several small mammal species of this region, provide karyotypic information and register an undescribed species of arboreal rat of the genus Rhipidomys. This survey illustrates the need for extensive and planned sampling of the Caatinga domain.
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Samuels, Mark E., Sophie Regnault, and John R. Hutchinson. "Evolution of the patellar sesamoid bone in mammals." PeerJ 5 (March 21, 2017): e3103. http://dx.doi.org/10.7717/peerj.3103.
Full textAbstract:
The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of an ossified patella is highly variable. Among extant (crown clade) groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here, we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that bony patellae most likely evolved between four and six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals and up to three times in therian mammals. Furthermore, an ossified patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition) and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa). Where a bony patella is present it plays an important role in hindlimb function, especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats—from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds—remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across mammalian evolution. This meta-analysis takes an initial step toward such a synthesis by collating available data and elucidating areas of promising future inquiry.
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Menzies, B. R., G. Shaw, T. P. Fletcher, A. J. Pask, and M. B. Renfree. "208. Absence of GH-R exon 3 in marsupials and monotremes argues for a eutherian specific origin and fetal specific purpose of this domain." Reproduction, Fertility and Development 20, no. 9 (2008): 8. http://dx.doi.org/10.1071/srb08abs208.
Full textAbstract:
Growth hormone receptor (GH-R) plays a critical role in the control of growth and metabolism in all vertebrates. GH-R consists of 9 coding exons (2–10) in all eutherian mammals, while the chicken only has 8 coding exons, and does not have an orthologous region to eutherian exon 3. To further understand the evolutionary origins of exon 3 of the GH-R we have cloned the full-length GH-R sequence in a marsupial, the tammar wallaby to determine whether exon 3 was present or absent in marsupial liver cDNA. There was no evidence for the presence of an exon 3 containing mRNA in sequence of tammar pouch young and adult livers. We next examined the genomes of the platypus (a monotreme mammal) and the grey short-tailed opossum (another marsupial). Like the tammar, the GH-R gene of neither species contained an exon 3. GH receptor can obviously function in the absence of this exon, raising speculation about the function of this domain, if any, in eutherians. A comparison of exon 3 protein sequences within 16 species of eutherian mammals showed that there was ~75% homology in the domain despite only 3 residues being identical (Leu12, Gln13 and Pro17). Interestingly, we detected greater evolutionary divergence in exon 3 sequences from species that have variants of GH or prolactin (PRL) in their placentas. These data show that exon 3 was inserted into the GH-R after the divergence of marsupial and eutherian lineages at least 130 million years ago.
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Faria, Michel Barros, Rayque De Oliveira Lanes, and Cibele Rodrigues Bonvicino. "Non-volant small mammals (Rodentia and Didelphimorphia) diversity in an isolated area of the Serra da Mantiqueira, Minas Gerais state, Brazil." Boletim do Museu Paraense Emílio Goeldi - Ciências Naturais 15, no. 3 (2020): 643–62. http://dx.doi.org/10.46357/bcnaturais.v15i3.203.
Full textAbstract:
The southeastern Atlantic Forest of the Zona da Mata Mineira is located in the extreme north of Minas Gerais state, Brazil. The Serra da Mantiqueira, is a mountainous region with a high diversity of small non-volant mammal species, several of which are rare species or endemic lineages. The presence of cryptic species in small mammals makes the karyotype an excellent tool for identification and detection of new lineages. We analyzed the karyotype of 14 species: 11 rodents – Abrawayaomys ruschii, Akodon cursor, Blarinomys breviceps, Delomys sublineatus, Juliomys ossitenuis, Oligoryzomys nigripes, Oligoryzomys flavescens, Oxymycterus dasytrichus, Rhipidomys tribei, Sooretamys angouya, and Thaptomys nigrita; and three marsupials – Monodelphis scalops, Philander quica, and Marmosops incanus. We described for the first time the fundamental autosomal number and the morphology of sex chromosomes of Abrawayaomys ruschii, a rare sigmodontine species, and described a new karyotype for Blarinomys. The revision of published karyotypes of the species herein studied enabled the expansion of the geographic distribution of Oligoryzomys nigripes and Delomys sublineatus.
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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 (2007): 426–35. http://dx.doi.org/10.1590/s0101-81752007000200021.
Full textAbstract:
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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Mills, D. J., B. Harris, A. W. Claridge, and S. C. Barry. "Efficacy of hair-sampling techniques for the detection of medium-sized terrestrial mammals. I. A comparison between hair-funnels, hair-tubes and indirect signs." Wildlife Research 29, no. 4 (2002): 379. http://dx.doi.org/10.1071/wr01031.
Full textAbstract:
We compared the efficacy of two different designs of hair-tube for detecting medium-sized, terrestrial marsupials in a range of forest types in south-east New South Wales. The two designs compared were a large-diameter PVC pipe (large hair-tube) and a tapered hair-funnel. In addition, the relative abundance of forage-diggings of the same marsupials was estimated simultaneously in order to provide an independent assessment of their distribution within the same study area. Only two hair-tubes out of 620 contained hair that could be attributed to the target fauna, both from the long-nosed bandicoot (Perameles nasuta). This was despite the widespread occurrence of forage-diggings at all of the 31 transects that were surveyed. Only two species of mammal, the agile antechinus (Antechinus agilis) and the bush rat (Rattus fuscipes), were detected in sufficient quantity to enable statistical analysis comparing the efficacy of the two hair-tube types. For R. fuscipes the large hair-tube was significantly more effective than the hair-funnel. Conversely, the hair-funnel was significantly more effective in detecting A. agilis than the large hair-tube. Our results suggest that both designs of hair-tube, in their current form, are ineffective for surveying for medium-sized terrestrial marsupials. We see three important issues regarding hair-tube design and implementation that require more attention before this technique can be considered an effective surveying tool: hair-tube morphology, the material used to capture hair, and bait type.
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N. Deacon, J., and R. Mac Nally. "Local extinction and nestedness of small-mammal faunas in fragmented forest of central Victoria, Australia." Pacific Conservation Biology 4, no. 2 (1998): 122. http://dx.doi.org/10.1071/pc980122.
Full textAbstract:
A survey of small mammals was undertaken in eight forest fragments of three sizes (2.5, 10 and 40 ha) and in five "pseudofragments" within a large area of State Forest. The latter were used to provide "reference" results against which the fragments could be compared. There was a paucity of dasyurid marsupials in fragments and pseudofragments, but arboreal "herbivores" (possums and a glider) were 7.5 times more abundant in fragments than in pseudofragments. The Short-beaked Echidna Tachyglossus aculeatus was recorded in both fragments and pseudofragments. All sites were impoverished, with a maximum of four native species of small mammals recorded at any one site, and six native species recorded overall. There was significant faunal "nesting" as a function of fragment size, with the small-mammal fauna of smaller fragments being subsets of larger fragments. The extant fauna in fragments appears to be a result of a sequence of local extinctions such that some species are more vulnerable to habitat loss, fragmentation and degradation and become locally extinct earlier than other, hardier species. The impoverishment within pseudofragments seems to be a function of broad-scale habitat modifications and especially timber harvesting, which maintains the forest as a dense array of small, pole-sized trees with few large, old trees. Several of the arboreal mammals are dependent on hollows found in larger trees, so the absence of the latter probably constrains the occurrence and density of the hollow users.
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Baynes, A., and RF Baird. "The original mammal fauna and some information on the original bird fauna of Uluru National Park, Northern Territory." Rangeland Journal 14, no. 2 (1992): 92. http://dx.doi.org/10.1071/rj9920092.
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Investigation of mammal bones, accumulated mainly by owls, from four cave deposits, combined with observations and museum records, has revealed an original (i.e. immediately pre-European) fauna for Uluru National Park (UNP) of 34 species of native ground mammals and 12 species of bats. This fauna comprises one monotreme, 22 marsupials from eight families, 12 microchiropterans from four families, 10 murid rodents and the dingo. For six of the species the UNP records represent an extension of range over published distribution maps, though originally all the ground mammals were probably widespread in the arid zone. A recent survey found that the present fauna of UNP includes 15 native ground mammals and a minimum of seven bats, indicating a loss in about the last century of up to 19 species of ground mammals and at least one bat. The local status of three of these is uncertain, 10 appear to be locally extinct, two are extinct throughout the Australian mainland and five are probably totally extinct. As elsewhere in the arid zone, the mammals that survive are the largest and smallest species and the echidna. The cave deposit sites yielded two orders of magnitude fewer bird remains, some of which could not be identified below family or genus. The material includes at least 16 species representing 13 families. All identified species were recorded in the present fauna of UNP by the recent survey. This relatively small sample suggests that in non-pastoral areas of the arid zone, bird faunas, unlike mammals, have so far survived European colonisation of Australia without loss of diversity.
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Geise, L., L. G. Pereira, D. E. P. Bossi, and H. G. Bergallo. "Pattern of elevational distribution and richness of non volant mammals in Itatiaia National Park and its surroundings, in Southeastern Brazil." Brazilian Journal of Biology 64, no. 3b (2004): 599–612. http://dx.doi.org/10.1590/s1519-69842004000400007.
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Itatiaia National Park (PNI) and its surroundings present a unique fauna due to different forest formations with well-defined climatic and vegetation bands. The Itatiaia massif has four vegetation types that follow an altitudinal gradient: lower montane forest, montane forest, upper montane forest, and Campos de Altitude. Hence, this region is ideal for studying geographical variation in biological diversity. The main objectives of this study were to report on nonvolant mammal species known to occur in Itatiaia National Park and its surroundings and to determine if their distributional pattern is related to elevation. A review of the literature and a complete survey of specimens deposited in museums, as well as small-mammal trapping were carried out in order to obtain a complete record of the species from the region. Precise locality data were obtained for all specimens recorded, allowing the inclusion of each collected or observed individual in an altitude and vegetational class. We made a direct ordination gradient of marsupial, primate, and rodent species abundance with the altitude. Sixty-nine mammal species were collected or reported for the Itatiaia massif, belonging to seven orders and 20 families. Of these, 33 species (47.8%) are included in the official list of threatened or believed-to-be threatened species in Rio de Janeiro State. The orders Rodentia, Carnivora, and Didelphimorphia had the highest species richness, with 25, 14, and 13 species respectively. When species were grouped according to the vegetation, 16 species occured in the lower montane, 56 in the montane forest, five in the upper montane, and 21 in the high-altitude fields (Campos de Altitude). The communities of marsupials, primates, and rodents have an ordination pattern related to the altitude. Species richness was higher between 500 m and 1,500 m above sea level in montane forest, which is in agreement with recent studies showing that species richness can reach its maximum at mid-elevations.
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MELO, GERUZA L., BARBARA MIOTTO, BRISA PERES, and NILTON C. CACERES. "Microhabitat of small mammals at ground and understorey levels in a deciduous, southern Atlantic Forest." Anais da Academia Brasileira de Ciências 85, no. 2 (2013): 727–36. http://dx.doi.org/10.1590/s0001-37652013000200017.
Full textAbstract:
Each animal species selects specific microhabitats for protection, foraging, or micro-climate. To understand the distribution patterns of small mammals on the ground and in the understorey, we investigated the use of microhabitats by small mammals in a deciduous forest of southern Brazil. Ten trap stations with seven capture points were used to sample the following microhabitats: liana, fallen log, ground litter, terrestrial ferns, simple-trunk tree, forked tree, and Piper sp. shrubs. Seven field phases were conducted, each for eight consecutive days, from September 2006 through January 2008. Four species of rodents (Akodon montensis, Sooretamys angouya, Oligoryzomys nigripes and Mus musculus) and two species of marsupials (Didelphis albiventris and Gracilinanus microtarsus) were captured. Captured species presented significant differences on their microhabitat use (ANOVA, p = 0.003), particularly between ground and understorey sites. Akodon montensis selected positively terrestrial ferns and trunks, S. angouya selected lianas, D. albiventris selected fallen trunks and Piper sp., and G. microtarsus choose tree trunks and lianas. We demonstrated that the local small-mammal assemblage does select microhabitats, with different types of associations between species and habitats. Besides, there is a strong evidence of habitat selection in order to diminish predation.
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Arena, Derrick A., Michael Archer, Henk Godthelp, Suzanne J. Hand, and Scott Hocknull. "Hammer-toothed ‘marsupial skinks' from the Australian Cenozoic." Proceedings of the Royal Society B: Biological Sciences 278, no. 1724 (2011): 3529–33. http://dx.doi.org/10.1098/rspb.2011.0486.
Full textAbstract:
Extinct species of Malleodectes gen. nov. from Middle to Late Miocene deposits of the Riversleigh World Heritage Area, northwestern Queensland, Australia are enigmatic, highly specialized, probably snail-eating marsupials. Dentally, they closely resemble a bizarre group of living heterodont, wet forest scincid lizards from Australia ( Cyclodomorphus ) that may well have outcompeted them as snail-eaters when the closed forests of central Australia began to decline. Although there are scincids known from the same Miocene deposits at Riversleigh, these are relatively plesiomorphic, generalized feeders. This appears to be the most striking example known of dental convergence and possible competition between a mammal and a lizard, which in the long run worked out better for the lizards.
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Augee, ML. "Predators with Pouches. The Biology of Carnivorous Marsupials. M. Jones, C. Dickman AND M. Archer (Eds) A Review by M.L. Augee." Australian Mammalogy 25, no. 2 (2003): 217. http://dx.doi.org/10.1071/am03217_br.
Full textAbstract:
THIS book arose from a symposium on ?Carnivorous Marsupials? held by the Australian Mammal Society in 1999. However it is not a symposium volume in the usual sense of being a compilation of papers presented at the symposium. Research papers on specific topics from the symposium have been hived off to the Australian Journal of Zoology 48(5) and to Wildlife Research 28(5). Predators with Pouches is comprised of review papers, some from the symposium but most apparently solicited. Like traditional symposium volumes, the papers included are of very different levels of coverage and quality of presentation. Most however present solid data and thoughtful reviews.