Gotowa bibliografia na temat „Perameles bougainville”

The metabolic, thermoregulatory and ventilatory physiology of western barred bandicoots (Perameles bougainville bougainville), measured in the laboratory during summer and winter at ambient temperatures of 10 and 30°C, is relatively unusual for a peramelid marsupial. It has a low thermoneutral body temperature (33.7 ± 0.2°C), a very high basal metabolic rate (0.68 ± 0.03 mL O2 g–1 h–1 at ambient temperature = 30°C), low respiratory exchange ratios (often less than 0.7) and a high thermal conductance, reflecting its high oxygen consumption rate and low body temperature. Ventilatory frequency and tidal volume were variable between seasons, although minute volume and oxygen extraction efficiency were not. Minute volume of the western barred bandicoot was higher than expected, reflecting its high metabolic rate. Time of year (i.e. season) had an effect on some aspects of metabolic, thermoregulatory and ventilatory physiology (carbon dioxide production, respiratory exchange ratio, total evaporative water loss), but this effect was not as substantial nor as general as the effect of ambient temperature.

12S rRNA sequences resolve the two Australian bandicoot genera Perameles and Isoodon as monophyletic clades which diverged from one another in the middle Miocene. Perameles bougainville, the most divergent species of this genus, appears to have split from the P. gunnii + P. nasuta lineage in the late Miocene, whilst subsequent speciation events occurred in the latter half of the Pliocene. Within Isoodon, although there was a clear recognition of an I. macrourus group of taxa, little support could be found for the continued recognition of the Tasmanian I. obesulus and the Barrow Island form of I. auratus as separate subspecies. Major radiations within Isoodon appear to have occurred in the last 3 million years as Australia became more arid.

The nematode genus Labiobulura Skrjabin & Schikhobalova, presently known from bandicoots (Isoodon Desmarest and Perameles Geoffroy), and bilbies (Macrotis Reid) from Australia and rodents (Leptomys Thomas) from Papua New Guinea is revised. Diagnoses of Labiobulura, Labiobulura (Archeobulura) Quentin and Labiobulura (Labiobulura) Quentin and a key to all species of the genus are given. Five species are redescribed: L. (A.) leptomyidis Smales from L. paulus Musser, Helgen & Lunde, L. (A.) peragale Johnston & Mawson from M. leucura (Thomas), L. (L.) baylisi Mawson from I. macrourus (Gould) and P. nasuta Geoffroy, L. (L.) inglisi Mawson from I. obesulus (Shaw), P. bougainville Quoy & Gaimard and P. gunnii Gray, L. (L.) peramelis Baylis from I. macrourus and two are described as new: L. (A.) perditus from P. bougainville, L. (L.) quentini from I. obesulus and the identification of the hosts determined. The significance of the relationship between the placement of the amphids and cephalic papillae and the labial lobes is discussed and the denticles surrounding the mouth opening in the sub genus Labiobulura are described, both for the first time. There is evidence for host specificity in the Archeobulura with each parasite species limited to a single host species but less so for the Labiobulura with three of five species found in more than one host species.

Predator recognition testing was used to determine whether two species of captive bred marsupials have retained the skills to respond to native and exotic predators. Captive-bred western barred bandicoots Perameles bougainville and bilbies Macrotis lagotis were exposed to a model hawk or a stuffed cat to determine their level of recognition and response to these predators. Both species responded to the avian predator (hawk). M. lagotis showed stronger responses involving running or adopting an alert posture, while P. bougainville responded with altered walking behaviour. M. lagotis were also exposed to a stuffed cat. They showed an increase in running behaviour in response to this exotic mammalian predator. The level of response for both species was neither rapid nor vigorous, providing little confidence in their effective response to predators if released back in to the wild. Further research should include the feasibility of predator recognition training and behavioural studies after release.

Conservation efforts to prevent the extinction of the endangered western barred bandicoot Perameles bougainville (WBB) are currently hindered by a debilitating progressive papillomatosis and carcinomatosis syndrome. Now extinct on mainland Australia, wild populations of the WBB are known only to exist on Bernier and Dorre Islands in Shark Bay, Western Australia. This thesis describes and analyses the pathological (gross, histological, ultrastructural) and immunohistochemical features of a papillomatosis and carcinomatosis syndrome in the WBB. The detection and characterisation of a novel virus, the bandicoot papillomatosis carcinomatosis virus type 1 (BPCV1), found in association with cutaneous and muco-cutaneous papillomas and carcinomas, is described. BPCV1 was found to exhibit genomic and morphological features of both the Papillomaviridae and the Polyomaviridae, and may represent the first member of a new family of viruses. The findings of this study provide evidence that BPCV1 is the causative agent of the papillomatosis and carcinomatosis syndrome. Clinical, pathological and molecular evidence of the syndrome and BPCV1 were found in the Bernier Island WBB population at Red Cliff and in captive populations comprising all or a proportion of founder WBBs from this site, but not at all in the WBB population on Dorre Island or Heirisson Prong. The papillomatosis and carcinomatosis syndrome in the western barred bandicoot is a pertinent example of a disease process hampering efforts to prevent the extinction of an endangered species.

Conservation efforts to prevent the extinction of the endangered western barred bandicoot Perameles bougainville (WBB) are currently hindered by a debilitating progressive papillomatosis and carcinomatosis syndrome. Now extinct on mainland Australia, wild populations of the WBB are known only to exist on Bernier and Dorre Islands in Shark Bay, Western Australia. This thesis describes and analyses the pathological (gross, histological, ultrastructural) and immunohistochemical features of a papillomatosis and carcinomatosis syndrome in the WBB. The detection and characterisation of a novel virus, the bandicoot papillomatosis carcinomatosis virus type 1 (BPCV1), found in association with cutaneous and muco-cutaneous papillomas and carcinomas, is described. BPCV1 was found to exhibit genomic and morphological features of both the Papillomaviridae and the Polyomaviridae, and may represent the first member of a new family of viruses. The findings of this study provide evidence that BPCV1 is the causative agent of the papillomatosis and carcinomatosis syndrome. Clinical, pathological and molecular evidence of the syndrome and BPCV1 were found in the Bernier Island WBB population at Red Cliff and in captive populations comprising all or a proportion of founder WBBs from this site, but not at all in the WBB population on Dorre Island or Heirisson Prong. The papillomatosis and carcinomatosis syndrome in the western barred bandicoot is a pertinent example of a disease process hampering efforts to prevent the extinction of an endangered species.

Thesis (Ph. D.)--University of Sydney, 2005.
Title from title screen (viewed 19 May 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Science. Degree awarded 2005; thesis submitted 2004. Includes bibliographical references. Also available in print form.

Almost half of the world�s mammal extinctions in the last two hundred years have occurred in Australia (Short and Smith 1994). The western barred bandicoot Perameles bougainville is one of a suite of species that is currently threatened with extinction, surviving only on two islands in Shark Bay, Western Australia. Reintroduction has been used as a tool in conservation biology to assist in the recovery of threatened species, such as the western barred bandicoot. The aims of this project were to 1) successfully reintroduce and establish a free-ranging mainland population of the western barred bandicoot at Heirisson Prong, Shark Bay, 2) contribute information on the biology of the species, its interactions with introduced species, and its likelihood of persistence as a reintroduced population in the longer-term, and 3) to provide recommendations to assist future reintroductions of the species. The first reintroduction of the western barred bandicoot from surviving remnant island populations to the mainland, some 60 years after its apparent mainland extinction, was from Dorre Island to Heirisson Prong in 1995. Animals were translocated initially to a predator-free refuge on Heirisson Prong, and then subsequently released to the 12 km2 peninsula where introduced predators (foxes Vulpes vulpes and feral cats Felis catus) had been controlled, but European rabbits Oryctolagus cuniculus had not. Despite a small founder number and high mortality of free-range bandicoots in the presence of a low-density feral cat population, the bandicoot population successfully established. The reintroduced population of western barred bandicoots provided an opportunity to study the biology of the species, and to compare it with the remnant island populations and other species of Australian bandicoot. Many population parameters were similar between the island and mainland western barred bandicoot populations, as well as between the western barred bandicoot and other bandicoot species, suggesting that the habitat at the reintroduction site is suitable for long-term persistence of the population. However, there were some notable differences. The western barred bandicoot is the smallest extant species of bandicoot, with fewer young per litter than recorded for other bandicoot species, adult sex ratios were closer to parity, animals reached sexual maturity later, and it is the only species of bandicoot where females are larger than males. Home range size is larger also than recorded for other species. Some of these differences may be explained in part by trade-offs between island dwarfism, lactational pressures, and nest defence. The nesting biology of the western barred bandicoot was studied at Heirisson Prong, including during periods of high and low densities of rabbits. Individuals of the species constructed and utilised nests in a similar fashion to other species of Australian bandicoot, nesting amongst litter underneath shrubs. The western barred bandicoot appeared to favour particular shrub species, especially when vegetation condition was poor due to rabbit damage, but displayed flexibility in being able to construct nests under a variety of shrub species where at least some surface litter was present. Grasses were used in nest construction only when rabbit density was low. Nests appear important for protection against temperature extremes and diurnal predators. Vegetation exclosures around three of the shrub species most commonly used by the western barred bandicoot for nest sites (Acacia ligulata, A. tetragonophylla and Melaleuca cardiophylla) were used to examine the impact of rabbits on vegetation on Heirisson Prong. A high-density rabbit population over the summer of 1997/98 caused in a decrease in canopy cover and the death of mature A. ligulata. Subsequent rainfall and low-density rabbit populations allowed A. tetragonophylla shrubs to recover their former structure, and M. cardiophylla to recover, but not to the same degree. The flexibility of western barred bandicoots in use of nest materials and their omnivorous diet may enable the species to survive in the face of habitat modification by rabbits. Population viability analysis was used to examine future options for the recovery of the endangered western barred bandicoot. Biological data from the Dorre Island and Heirisson Prong populations were input to the computer simulation program VORTEX. The western barred bandicoot populations were modelled under a variety of scenarios to examine the possible effects of changes in carrying capacity, founder population size, inbreeding depression, and the occurrence of drought and cat predation as catastrophes, on the probability of population extinction. This analysis highlighted the need for eradication of feral cats, above all other management actions. Cat predation was particularly potent when it acted through high loss of juveniles, as well as adult bandicoots. Predator control is considered critical for the long-term persistence of reintroduced populations of the western barred bandicoot. This study documents the first reintroduction of the endangered western barred bandicoot to mainland Australia. The population had been extant for four years at the completion of data collection for this thesis, in late 1999 and for over eight years at the finalisation of this thesis in July 2004. The knowledge gained from the reintroduction was used to discuss management recommendations and future options for the recovery of the species. The primary concern for reintroductions of this, and other species of bandicoots, remains the control of introduced predators. For long-term persistence of small, isolated populations, such as those of the western barred bandicoot at Heirisson Prong and the Arid Recovery Project at Roxby Downs in South Australia, and the eastern barred bandicoot Perameles gunnii at a range of sites in Victoria, the complete eradication of introduced predators is essential.

For more than a decade, community groups, scientific organizations and government agencies have collaborated to repopulate the endangered western barred bandicoot (Perameles bougainville). While initially successful, the unexpected discovery of a papillomatosis and carcinomatosis syndrome in captive and wild populations of P. bougainville exposed a dearth of knowledge regarding their diseases. This dissertation addresses this issue through study of the clinical pathology, immunology, parasitology, and virology of P. bougainville. To facilitate the detection and understanding of diseases in P. bougainville, guidelines for interpreting haematology and clinical chemistry results were developed, including calculated species-specific reference intervals for plasma aspartate transaminase activity (20–283 U/L), haemoglobin (122-165 g/L), haematocrit (0.36-0.49 L/L), total leukocytes (2.9-14.9 x10^9/L), monocytes (0-0.6 x10^9/L), eosinophils (0-0.9 x10^9/L) and total protein (47-63 g/L) estimated by refractometry. P. bougainville immunoglobulin was also fractionated from plasma and inoculated into sheep to derive antiserum for serological screening assays. Arthropods, helminths and protozoa parasitic on P. bougainville were catalogued and Eimeria kanyana n. sp. was formally described. The pathogenic and zoonotic potential of bacteria detected in ticks parasitic on P. bougainville was also considered. The association between bandicoot papillomatosis carcinomatosis virus type 1 (BPCV1) and the western barred bandicoot papillomatosis and carcinomatosis syndrome was investigated using PCR, in situ hybridization and virus isolation. Optimized in situ hybridization techniques demonstrated BPCV1 DNA within keratinocyte and sebocyte nuclei, and BPCV1 mRNA within the cytoplasm. BPCV1 virions were isolated by ultracentrifugation and visualized with negative stain transmission electron microscopy revealing icosahedral, non-enveloped viral capsids ~47 nm in diameter, comparable to viruses classified within Papillomaviridae and Polyomaviridae. A novel virus, tentatively named bandicoot papillomatosis carcinomatosis virus type 2 (BPCV2) was discovered in papillomatous lesions from a southern brown bandicoot (Isoodon obesulus). It had a circular double-stranded DNA genome of 7277 bp, and encoded two papillomavirus-like structural proteins, L1 and L2, and two polyomavirus-like putative transforming proteins, large T antigen and small t antigen. DNA and RNA in situ hybridization confirmed the presence of BPCV2 nucleic acids within lesion biopsies. The discovery of the bandicoot papillomatosis carcinomatosis viruses has provoked reassessment of the established virus taxonomy paradigm, theories of virus-host co-speciation and bandicoot population management strategies.