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1
Giffney, R. A., T. Russell e J. L. Kohen. "Age of road-killed common brushtail possums (Trichosurus vulpecula) and common ringtail possums (Pseudocheirus peregrinus) in an urban environment". Australian Mammalogy 31, n. 2 (2009): 137. http://dx.doi.org/10.1071/am09016.
Testo completoAbstract (sommario):
Road-associated mortality has been identified as having major ecological effects on small, fragmented and declining populations. Both the common brushtail possum (Trichosurus vulpecula) and common ringtail possum (Pseudocheirus peregrinus) appear to be in decline in some regions across their natural ranges. Urban populations may be an exception; however, little is known of their population ecology. This study investigates age trends in a subset of road-killed brushtail and ringtail possums collected along eight northern Sydney roads between March 2004 and March 2006. From a total of 591 recorded road-killed possums, 86 were collected for use in this study (36 brushtails, 50 ringtails). Age was estimated using tooth wear patterns on cleaned skulls. Both species showed trends associated with age, and younger possums of both species were more likely to be killed on roads than older animals. Male-biased dispersal of subadult possums is considered a major contributing factor to the over-representation of young brushtail possums in this road-kill sample.
2
Russell, Tracey Catherine, Ellen Geraghty e Sarah Wilks. "Brushtail possums: do present law, policy and management approaches meet the needs of this species in all its contexts?" Australian Journal of Zoology 61, n. 1 (2013): 95. http://dx.doi.org/10.1071/zo12125.
Testo completoAbstract (sommario):
Brushtail possums (Trichosurus vulpecula) have been variously described as endangered, pests, prized native wildlife and, recently, as a potential meat export. This article reports information on the increasing decline of the brushtail possum and on attitudes towards these animals. The ‘fit’ between values and attitudes and prevailing governance arrangements is assessed. While the range of this animal is certainly shrinking, areas do exist where the brushtail possum is present at high or very high densities. It is in these areas of high possum density (some urban areas and certain agricultural regions) that conflicts arise, both over the ‘identity’ of the brushtail possum and as to what would be appropriate management. It is argued that although brushtail possums enjoy significant legal protection, these provisions are treated as a nuisance to be circumvented by many residents in areas where possums are in high abundance. Existing policies on possum management somewhat unhelpfully focus attention on situations where possums are overabundant, thus overshadowing situations where active management of declining possum populations would be appropriate.
3
Russell, Tracey C., Catherine A. Herbert e James L. Kohen. "High possum mortality on urban roads: implications for the population viability of the common brushtail and the common ringtail possum". Australian Journal of Zoology 57, n. 6 (2009): 391. http://dx.doi.org/10.1071/zo09079.
Testo completoAbstract (sommario):
Animal–vehicle collisions impact wildlife populations and in the northern suburbs of Sydney, both the common brushtail possum (Trichosurus vulpecula) and the common ringtail possum (Pseudocheirus peregrinus) are killed in large numbers. Over a two-year period almost 600 road-killed possums were observed from 217 road surveys covering over 7800 km, equating to 5.45 possums per week over the 36-km study area. Surveys were conducted along roads where the environment ranged from low-rise suburban to continuous sclerophyll forest. Significantly more ringtail possums were observed as road-kill, outnumbering brushtail possums by almost three to one. No sex bias was found amongst road-killed ringtail possums; however, seasonal trends and weight fluctuations were significant, with both males and females being at their lowest weights during the autumn breeding season. For brushtail possums a bias towards young males was observed. Sex and weight of road-killed brushtail possums were comparable to live-trap data from a previous study in the same location. In areas of such high possum mortality, wildlife managers may need to take action to mitigate possum road-kill.
4
Isaac, JL. "Possums: The Brushtails, Ringtails and Greater Glider. Anne Kerle. A Review by Joanne L Isaac." Australian Mammalogy 24, n. 2 (2002): 249. http://dx.doi.org/10.1071/am02249.
Testo completoAbstract (sommario):
DESPITE their almost ubiquitous presence across Australia, contemporary research on the biology, ecology and conservation status of the so-called 'common' possums is scant and inadequate. The majority of possum studies have been a result of the huge research effort in New Zealand to control and eradicate the common brushtail possum, a notorious introduced pest, and have concentrated primarily upon reproductive physiology. The conspicuous lack of ecological data on the larger possums across their native Australian range is particularly disturbing since evidence suggests that a number of these species are disappearing from large tracts of Australia. However, Possums: the brushtails, ringtails and greater glider, part of the Australian Natural History Series, provides a long overdue summary of up-to-date research on these familiar and intriguing marsupials.
5
Harper, Michael J. "Home range and den use of common brushtail possums (Trichosurus vulpecula) in urban forest remnants". Wildlife Research 32, n. 8 (2005): 681. http://dx.doi.org/10.1071/wr04072.
Testo completoAbstract (sommario):
The common brushtail possum (Trichosurus vulpecula) is an arboreal marsupial that has adapted well to urban landscapes. Fifteen adult possums (12 female, 3 male) caught in small patches of indigenous vegetation (remnants) in the south-east of metropolitan Melbourne were radio-tracked over a three-month period to investigate nocturnal behaviour and den use. Minimum convex polygon (100%) home-range estimates of both female (1.02 ± 0.28 ha) and male (1.19 ± 0.33 ha) urban brushtail possums trapped in urban forest remnants appear to be smaller than those previously reported for urban brushtail possums. All the brushtail possums foraged extensively in remnants but made repeated forays into adjacent residential areas. The use of few dens, by both female (2.21 ± 0.35 ha) and male (2.51 ± 1.45 ha) brushtail possums, in close proximity to their nocturnal ranges is similar to the behaviour of non-urban brushtail possums
6
Kerle, J. A. "The population dynamics of a tropical possum, Trichosurus vulpecula arnhemensis Collett". Wildlife Research 25, n. 2 (1998): 171. http://dx.doi.org/10.1071/wr96113.
Testo completoAbstract (sommario):
The population ecology of Trichosurus vulpecula has been studied extensively in temperate Australia and in New Zealand. This paper provides the results of a trapping study of a population of the northern brushtail possum (T. vulpecula arnhemensis Collett 1897) in the wet–dry tropics of Australia’s Northern Territory. Possums were readily trapped and the population had a comparatively high density for Australian brushtails of around 3 per hectare. The core home-range size and range length for males was 1.12 ha and 165 m; this was a little larger than for females (0.89 ha and 155 m). The possums were not very agressive when handled and were apparently quite socially tolerant. The ready availability of nutritious food sources throughout the year enables them to breed continuously, producing 1.7 young per year per adult female. If environmental conditions become unfavourable with a series of poor wet seasons or frequent fires, the habitat will resemble the less-productive eucalypt forest not occupied by possums. Mortality of pouch young and immatures will increase under these conditions but with a potential reproductive rate of nearly two per year, populations of the northern brushtail can readily recover from short periods of unfavourable conditions.
7
Harper, Michael J., Michael A. McCarthy e Rodney van der Ree. "The use of nest boxes in urban natural vegetation remnants by vertebrate fauna". Wildlife Research 32, n. 6 (2005): 509. http://dx.doi.org/10.1071/wr04106.
Testo completoAbstract (sommario):
Nest boxes are routinely installed as a substitute for natural tree hollows to provide den and nest sites for a range of hollow-utilising fauna. We installed 120 nest boxes in 20 patches of indigenous vegetation (remnants) across the urban/suburban landscape of Melbourne, south-eastern Australia, and investigated their use by indigenous and exotic vertebrate species over a period of 12 months. Nest-box use was dominated by the common brushtail possum (Trichosurus vulpecula), the common ringtail possum (Pseudocheirus peregrinus) and the common myna (Acridotheres tristis), an aggressive introduced bird. We found that brushtail and ringtail possums utilised nest boxes all year round but more frequently in cooler months (May–August). Common mynas dominated nest-box use during spring/summer, potentially reducing the availability of this resource to indigenous species. We found evidence that the probability of a nest box being occupied by either species of possum was greater in remnants with abundant possum populations. Brushtail possums preferred thick-walled pine nest boxes over thin-walled plywood nest boxes, most likely owing to differences in their thermal insulation properties. Although considerable economic costs would be involved in using nest boxes as a long-term substitute for hollow-bearing trees, nest boxes may provide a temporary hollow resource until hollow-bearing trees are recruited in urban remnants.
8
Kerle, JA, e CJ Howe. "The Breeding Biology of a Tropical Possum, Trichosurus-Vulpecula-Arnhemensis (Phalangeridae, Marsupialia)". Australian Journal of Zoology 40, n. 6 (1992): 653. http://dx.doi.org/10.1071/zo9920653.
Testo completoAbstract (sommario):
The breeding biology of Trichosurus vulpecula has been studied in some detail for temperate populations but not for the northern brushtail possum (T. v. arnhemensis), the tropical form of this species. Data for the distribution of births and sex ratio of the young, growth and development of the young and reproductive cycles of both males and females were obtained. Most data were collected from a captive breeding colony of northern brushtails and supplemented with data from wild populations. The reproduction, growth and development of T. v. arnhemensis are very similar to those already described for other populations of T vulpecula. The observed differences can be explained by variation in the size of the animals and the absence of a restricted breeding season. Neither males nor females showed any periodicity in their reproductive strategy. This continuous breeding cycle can be attributed directly to their tropical environment. These tropical possums occupy a stable habitat, mature early and have a higher reproductive effort than populations in more seasonal and unpredictable environments. This suggests that the northern brushtail has a stochastic or 'bet-hedging' reproductive strategy.
9
Eason, CT, D. Batcheler e CM Frampton. "Comparative Pharmacokinetics of Iophenoxic Acid in Cats and Brushtail Possums." Wildlife Research 21, n. 3 (1994): 377. http://dx.doi.org/10.1071/wr9940377.
Testo completoAbstract (sommario):
The comparative plasma pharmacokinetics of iophenoxic acid was studied in the cat and brushtail possum (Trichosurus vulpecula) to evaluate the suitability of this compound as a bait marker in these species. In cats, a mean peak plasma concentration of 946 micro g per 100 ml was obtained after administration of 1.5 mg/kg of iophenoxic acid. However, at the same dose level in possums, mean peak plasma concentration was only 157 micro g per 100 ml. Even after administration of 10 mg/kg of iophenoxic acid, the maximum peak plasma concentration in possums was only 459 micro g per 100 m/litre. The plasma elimination half-life for iophenoxic acid was 107 days in cats and close to one day in possums. Iophenoxic acid is therefore a suitable marker for cats but is unsuitable for use as a long-term or quantitative bait marker for possums. Differences between the possum and other mammals in gastrointestinal physiology and plasma protein configuration by account for the poor absorption and rapid elimination of iophenoxic acid in the possum.
10
Moore, L. G., W. Ng Chie, S. Lun, S. B. Lawrence, D. A. Heath e K. P. McNatty. "Isolation, characterization and radioimmunoassay of luteinizing hormone in the brushtail possum". Reproduction, Fertility and Development 9, n. 4 (1997): 419. http://dx.doi.org/10.1071/r97004.
Testo completoAbstract (sommario):
Luteinizing hormone (LH) was purified from brushtail possum (Trichosurus vulpecula) pituitary glands. The purification procedure consisted of ammonium sulfate precipitation followed by triazinyl-dye chromatography, hydrophobic interaction chromatography and gel filtration. A yield of 10 µg LH g-1 pituitary with a recovery of 20% was obtained from 1400 pituitary glands (20·3 g). Contamination with possum follicle-stimulating hormone (FSH) was ≤0.05%. The amino acid analysis and the N-terminal sequencing for 10 cycles revealed close homology with LH from other mammals. Minor amounts of LH that had been truncated near the N-terminal were also detected. No contaminating proteins were found by amino acid sequencing. The potency of possum LH was 20% that of ovine LH in a receptor assay using possum testicular receptors and 4% that of ovine LH when bovine corpora lutea receptors were used. Possum LH was able to stimulate production of cyclic adenosine 3′ ,5′-monophosphate by bovine granulosa cells. A radioimmunoassay (RIA) for possum LH using 125I-possum LH and an antiserum raised against ovine LH was developed. The RIA has a sensitivity of 0·15 ng mL-1 , a 50% displacement of 1·9 ng mL-1 and a cross-reactivity of <0 · 02% against possum FSH. Plasma concentrations were 0·24 ± 0· 04 ng mL-1 (n = 8) and 0·39 ± 0·12 ng mL-1 (n = 8) in female and male possums respectively. Administration of mammalian gonadotrophin-releasing hormone (GnRH) and chicken GnRH II stimulated increases in plasma LH concentrations in male and female possums. When comparing LH responses with administration of mammalian GnRH or chicken GnRH II, plasma LH concentrations remained elevated for a longer period of time in males than in females (P < 0· 01); plasma LH concentrations also remained elevated for longer after mammalian GnRH than after chicken GnRH II (P < 0· 01). Gonadectomy stimulated an increase in plasma concentrations of LH in both male (P < 0· 01) and female (P < 0· 05) possums. The rate of increase in plasma LH concentrations in males was faster than that in females. In summary, we have purified, partially characterized, and developed a RIA for possum LH.
11
Chen, Yuqing, Bruce Doran, Sharyn Sinclair-Hannocks, John Mangos e Philip Gibbons. "Building selection by the common brushtail possum (Trichosurus vulpecula)". Wildlife Research 47, n. 2 (2020): 186. http://dx.doi.org/10.1071/wr19106.
Testo completoAbstract (sommario):
Abstract ContextThe common brushtail possum (Trichosurus vulpecula) is a protected native species in Australia that can access buildings in urban areas and cause considerable damage or disruption to building occupants. Although several strategies to discourage this species from entering buildings have been recommended, few have been evaluated empirically. AimsOur study aims to analyse how landscaping and building construction influence occupancy of buildings by the common brushtail possum. MethodsWe collated reports of possums occupying 134 buildings over 12 years on the campus of The Australian National University (ANU), in the Australian Capital Territory (ACT). We used generalised linear modelling (GLM) to identify associations between the total number of reported possum-related incidents for buildings and a range of landscape and building characteristics. Key resultsControlling for the effect of building size, we found that the number of reported possum-related incidents in buildings was positively associated with the percentage of tree and shrub canopy cover within the calculated home-range buffer distance of 49m from buildings, length of canopy overhanging roofs and building age, and negatively associated with tree species richness and number of trees with natural hollows and nest boxes within 49m of buildings. There were likely to be more possum-related reports from buildings in areas where the dominant tree genus was native, buildings with parapets (walls extending above the roof), buildings with structures penetrating from the roof, buildings with tile roofs and gable roofs. ConclusionsA combination of suitable habitat surrounding buildings, suitable access to the roofs of buildings and weak points in building roofs (e.g. parapets, roof penetrations), makes them more vulnerable to occupancy by the common brushtail possum. Implications Our results provided clues for managing existing buildings, or designing new buildings, in a way that may reduce the likelihood of occupancy by the common brushtail possum. Our study also demonstrated how building-maintenance records can be used to address human–wildlife conflict over time.
12
Mackintosh, C. G., J. L. Crawford, E. G. Thompson, B. J. McLeod, J. M. Gill, e J. S. O'Keefe. "A newly discovered disease of the brushtail possum: Wobbly possum syndrome". New Zealand Veterinary Journal 43, n. 3 (6 gennaio 1995): 126. http://dx.doi.org/10.1080/00480169.1995.35869.
Testo completo
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Arthur, A., D. Ramsey e M. Efford. "Impact of bovine tuberculosis on a population of brushtail possums (Trichosurus vulpecula Kerr) in the Orongorongo Valley, New Zealand". Wildlife Research 31, n. 4 (2004): 389. http://dx.doi.org/10.1071/wr03097.
Testo completoAbstract (sommario):
Brushtail possums are the main wildlife vectors of bovine tuberculosis (Tb) in New Zealand. Possum–Tb models form the basis of possum control aimed at eradicating the disease, and yet competing models show different behaviour, and are highly sensitive to parameters about which there is considerable uncertainty. One area of great uncertainty is the impact of the disease on possum populations. We investigated the impact of Tb on a local population of brushtail possums in the Orongorongo Valley, Wellington. Bovine Tb was first detected in 1997 at one site within an intensively studied population, but has not been detected in another intensively studied population 3 km away since the early 1980s. Using a Before-After-Control-Impact (BACI) analysis, detection of Tb coincided with a 42% (95% CI = 23–56%) reduction in the odds of apparent yearly survival of a possum >17 months of age, i.e. a decrease in yearly survival from 0.85 to 0.77 in 'good' years, and a decrease from 0.71 to 0.60 in 'bad' years. This suggests that Tb had a significant impact on overall survival. However, there was no impact on local population density in September each year due to compensatory recruitment.
14
Frankenberg, Stephen, e Lynne Selwood. "Ultrastructure of oogenesis in the brushtail possum". Molecular Reproduction and Development 58, n. 3 (2001): 297–306. http://dx.doi.org/10.1002/1098-2795(200103)58:3<297::aid-mrd8>3.0.co;2-c.
Testo completo
15
Cooke, M. M. "Lipopigments in the brushtail possum,Trichosurus vulpecula". New Zealand Veterinary Journal 42, n. 2 (3 gennaio 1994): 66–69. http://dx.doi.org/10.1080/00480169.1994.35789.
Testo completo
16
Carman, RM, e KD Klika. "Partially Racemic Compounds as Brushtail Possum Urinary Metabolites". Australian Journal of Chemistry 45, n. 4 (1992): 651. http://dx.doi.org/10.1071/ch9920651.
Testo completoAbstract (sommario):
The hydroxycineole (2) and cineolic acid (3) obtained as urinary metabolites from the brushtail possum (Trichosurus vulpecula) after the ingestion of l,8-cineole (1), are partial racemates. The compounds have been examined by gas chromatographic analysis over chiral stationary phases, and by the synthesis of optically pure enantiomers. Female possums show different enantiomeric ratios from males. Possible advantages to the animal in the use of a partial racemate as a pheromone are discussed.
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Emami-Khoyi, Arsalan, Shilpa Pradeep Parbhu, James G. Ross, Elaine C. Murphy, Jennifer Bothwell, Daniela M. Monsanto, Bettine Jansen van Vuuren, Peter R. Teske e Adrian M. Paterson. "De Novo Transcriptome Assembly and Annotation of Liver and Brain Tissues of Common Brushtail Possums (Trichosurus vulpecula) in New Zealand: Transcriptome Diversity after Decades of Population Control". Genes 11, n. 4 (17 aprile 2020): 436. http://dx.doi.org/10.3390/genes11040436.
Testo completoAbstract (sommario):
The common brushtail possum (Trichosurus vulpecula), introduced from Australia in the mid-nineteenth century, is an invasive species in New Zealand where it is widespread and forms the largest self-sustained reservoir of bovine tuberculosis (Mycobacterium bovis) among wild populations. Conservation and agricultural authorities regularly apply a series of population control measures to suppress brushtail possum populations. The evolutionary consequence of more than half a century of intensive population control operations on the species’ genomic diversity and population structure is hindered by a paucity of available genomic resources. This study is the first to characterise the functional content and diversity of brushtail possum liver and brain cerebral cortex transcriptomes. Raw sequences from hepatic cells and cerebral cortex were assembled into 58,001 and 64,735 transcripts respectively. Functional annotation and polymorphism assignment of the assembled transcripts demonstrated a considerable level of variation in the core metabolic pathways that represent potential targets for selection pressure exerted by chemical toxicants. This study suggests that the brushtail possum population in New Zealand harbours considerable variation in metabolic pathways that could potentially promote the development of tolerance against chemical toxicants.
18
Hufschmid, J., K. A. Handasyde e I. Beveridge. "The role of host and environmental factors in the epidemiology of rumpwear in brushtail possums". Australian Journal of Zoology 58, n. 4 (2010): 250. http://dx.doi.org/10.1071/zo10030.
Testo completoAbstract (sommario):
Rumpwear is a common, but poorly defined and understood disease of brushtail possums (Trichosurus spp.) in Australia and New Zealand, resulting in varying degrees of fur loss. Populations of Trichosurus cunninghami (mountain brushtail possum) and T. vulpecula (common brushtail possum) were studied over two years at Boho South (Victoria), to describe the disease, investigate its prevalence and explore its epidemiology. The main type of lesion observed was coat damage in the lumbo-sacral region, and increased severity of rumpwear was related to decreased coat length and increased hair breakage. Significant skin lesions were rare and hair breakage patterns suggested mechanical damage. Rumpwear was very prevalent in both T. cunninghami and T. vulpecula, but very severe rumpwear was rare. There was no true seasonal pattern to the prevalence of rumpwear in T. cunninghami and sex and habitat did not affect prevalence or severity. Prevalence and severity of rumpwear did, however, increase with age. There were no significant relationships between the number of previous captures or body condition index with rumpwear.
19
Mella, Valentina S. A., Jordan Krucler, Lakshmi Sunderasan, Jason Hawkins, Anushika P. H. M. Herath, Kyla C. Johnstone, Sandra M. Troxell-Smith, Peter B. Banks e Clare McArthur. "Effective field-based methods to quantify personality in brushtail possums (Trichosurus vulpecula)". Wildlife Research 43, n. 4 (2016): 332. http://dx.doi.org/10.1071/wr15216.
Testo completoAbstract (sommario):
Context There is growing recognition of the importance of animal personality in wildlife ecology and management. Individuals that differ consistently in their behaviours from others of the same population are considered to exhibit different personalities. Personality can be easily quantified with repeat tests on animals held in captivity. However, captive-based tests may not always be possible for logistical reasons and tests conducted in captivity can alter naturally occurring behaviours. Development of methods to assess personality in the field over short-term capture is an important alternative to long-term captive tests. Aims To develop and refine field-based tests that can be used to easily define personality traits of wild common brushtail possum (Trichosurus vulpecula), eliminating the need to bring individuals into captivity for an extended period of time. Methods We developed a series of short-term capture protocols to quantify personality traits of the common brushtail possum in the field, using handling-bag tests, modified open-field tests, trap-behaviour tests and release tests. Key results Personality traits of brushtail possums could be measured in several different ways, but refining methods was crucial to reveal traits efficiently. Behaviours related to several personality traits (boldness, docility and activity/exploration) could be measured rapidly in the field with our methods, and were repeatable over time. Conclusions Rapid, reliable and easy-to-perform quantification of personality of brushtail possums in the field is possible. This may sometimes be the only available option, and has advantages over long captive trials in terms of animal welfare and cost. Implications The present study provides a baseline for future research on the personality of common brushtail possums and its application to management and control strategies for the species.
20
Eymann, J., C. A. Herbert e D. W. Cooper. ". Management issues of urban common brushtail possums Trichosurus vulpecula: a loved or hated neighbour." Australian Mammalogy 28, n. 2 (2006): 153. http://dx.doi.org/10.1071/am06025.
Testo completoAbstract (sommario):
The common brushtail possum (Trichosurus vulpecula) has readily adapted to the expanding urban settings of its native Australian environment. This has lead to conflict with humans due to T.�vulpecula?s seemingly bold behaviour in suburbia. Current management strategies encourage people to live harmoniously with possums. However, despite the cooperation of many residents, some object to this policy and illegally remove T.�vulpecula from their properties. Wildlife managers are seeking alternative management options that aim to reduce conflict with people. These include fertility control methods which may be used to adjust possum numbers in a publicly acceptable way. Nest boxes are frequently recommended as alternative den sites for T.�vulpecula which reside in man-made structures. The disease status of possums may alter the rationale for their management in urban areas, due to the potential consequences for humans, domestic animals and possum conservation. Understanding the biology and behaviour of T.�vulpecula can greatly enhance the ability to select and successfully utilise adequate methods and solve outstanding issues. As such, this paper aims to review the scientific knowledge on possum populations as well as urban possum management policies and potential management tools.
21
Whyte, Belinda I., James G. Ross e Helen M. Blackie. "Differences in brushtail possum home-range characteristics among sites of varying habitat and population density". Wildlife Research 40, n. 7 (2013): 537. http://dx.doi.org/10.1071/wr13063.
Testo completoAbstract (sommario):
Context In New Zealand, the Australian brushtail possum is a pest, because this species preys on native birds and transmits bovine tuberculosis (bTB) to livestock. Previous studies on possums have shown that home-range characteristics differ depending on habitat and/or population density. However, direct comparisons between studies are limited because of the use of differing monitoring techniques, some of which are now out-dated and imprecise. Understanding how possum ranging behaviour varies in response to habitat and density may allow the development of more effective and site-specific control operations. For example, variations in home-range characteristics (e.g. home-range overlap with conspecifics) among populations may mean that bTB transmission risk is not uniform among populations, resulting in the need for some sites to be prioritised for control over others. Aims To investigate whether home-range characteristics varied among three sites of differing habitat and population density, and investigate whether possum home-range characteristics varied between males and females. Methods Global Positioning System (GPS)- and VHF-tracking were used to compare possum home-range characteristics among three sites. Two sites were within pine (Pinus radiata) habitat and had low-density possum populations, and one site was within oak (Quercus robur) and sycamore (Acer pseudoplatanus) habitat, and had a higher-density possum population. Key results Possum home-range characteristics did not vary between the two low-density sites. However, these populations exhibited considerably larger home-range sizes and home-range overlap between pairs of collared possums than did the high-density population. In addition, the low-density populations used more dens and changed these more often. Across all sites, there were generally no intersexual differences in home-range characteristics. Key conclusions The present research highlights that the home-range characteristics of possums can vary among populations, depending on habitat and/or population density. Implications Further research into the drivers of possum home-range characteristics would be beneficial to allow identification of how spatial behaviour is likely to vary depending on habitat and density. This would allow the design of more targeted and therefore effective control strategies that account for these variations in behaviour, such as using a larger spatial scale of control devices where possums are known to range further.
22
Gemmell, R. T. "Breeding Biology of Brushtail Possums Trichosurus vulpecula (Marsupialia, Phalangeridae) in Captivity." Australian Mammalogy 18, n. 1 (1995): 1. http://dx.doi.org/10.1071/am95001.
Testo completoAbstract (sommario):
The brushtail possum is a common arboreal marsupial that is well adapted to the Australian urban environment and to rearing in captivity. Data obtained from 100 female possums housed in a semi-captive colony over a 7 year period demonstrate the reproductive capability of this marsupial. The main breeding season is from March to June with a declining number of births occurring from July to October. The possums gave birth to 259 single young and one set of twins. The range of the lactation period was from 177 to 200 days with the birth of the subsequent young occurring at 188.4 ± 4.1 days post partum (SD, n = 5). The growth rate of the young female possum varied greatly after day 100 post partum, the mean body weight of possums at day 172, being 753.0 ± 76.2g (SD, n = 5) with a range of 685 to 851 g. Female possums, with a mean body weight of 2171 ± 388g, gave birth to their first litter on day 345.9 ± 69.3 days postpartum (mean, SD, n = 7). Although two female possums trapped in the wild were held in captivity for 64 and 63.4 months and one possum bred in captivity had a life span of 51.5 months, the mean life span was 21.0 ± 12.5 months (SD, n =3D 8), with a range of 14.3 to 51.5 months. This life span is very variable and it is of interest to determine if this is an artefact of captivity or is also observed in the wild.
23
Deakin, Janine E., Katherine Belov, Natalie C. Curach, Peter Green e Desmond W. Cooper. "High levels of variability in immune response using antigens from two reproductive proteins in brushtail possums". Wildlife Research 32, n. 1 (2005): 1. http://dx.doi.org/10.1071/wr03107.
Testo completoAbstract (sommario):
Immune-based fertility control is being considered as an effective long-term approach for controlling the pest brushtail possum (Trichosurus vulpecula) population in New Zealand. This relies heavily on the immune response of each immunised possum. A strong and lasting immune response in the majority of individuals in a population is essential. In this study, possums and the model macropod species, the tammar wallaby (Macropus eugenii) were immunised with either a luteinising hormone or androgen receptor synthetic peptide coupled to the carrier molecule KLH (keyhole limpet haemocyanin). The antibody response of wallabies to the antigens was relatively uniform. In contrast, the possum immunoglobulin response to both synthetic peptides and KLH was variable. The apparent high level of variation in the immune response of possums raises questions about the feasibility of using these two antigens to control possum numbers in New Zealand.
24
Signal, T. D., W. Temple e T. M. Foster. "Visual discrimination in the brushtail possum (Trichosurus vulpecula )". Australian Journal of Psychology 53, n. 3 (dicembre 2001): 152–54. http://dx.doi.org/10.1080/00049530108255138.
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25
McLean, Stuart, Noel W. Davies e Natasha L. Wiggins. "Scent Chemicals of the Brushtail Possum, Trichosurus vulpecula". Journal of Chemical Ecology 38, n. 10 (14 settembre 2012): 1318–39. http://dx.doi.org/10.1007/s10886-012-0188-5.
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26
Richardson, K. S., C. Rouco, C. Jewell, N. P. French, B. M. Buddle e D. M. Tompkins. "Investigating brushtail possum (Trichosurus vulpecula) home-range size determinants in a New Zealand native forest". Wildlife Research 44, n. 4 (2017): 316. http://dx.doi.org/10.1071/wr16215.
Testo completoAbstract (sommario):
Context The Australian brushtail possums (Trichosurus vulpecula) introduction to New Zealand has exacted a heavy toll on native biodiversity and presented the country with its greatest wildlife reservoir host for bovine tuberculosis (TB). Management efforts to control both possums and TB have been ongoing for decades, and the biology of possums has been studied extensively in Australia and New Zealand over the past 50 years; however, we still do not have a clear understanding of its home-range dynamics. Aims To investigate determinants of home range size by using a uniquely large dataset in the Orongorongo Valley, a highly monitored research area in New Zealand and compare our findings with those of other studies. Methods Possum density was estimated, for subpopulations on four 13-ha cage-trap grids, by the spatially explicit capture–mark–recapture analysis of trapping data from 10 consecutive months. Home ranges were estimated from trap locations using a 100% minimum convex polygon (MCP) method for 348 individuals and analysed with respect to grid, age and sex. Key results Mean (standard error) possum density, estimated as 4.87 (0.19), 6.92 (0.29), 4.08 (0.21) and 4.20 (0.19) ha–1 for the four grids, was significantly negatively correlated with mean MCP home-range size. Grid, age, and the interaction of age and sex were significantly related to home-range size. Older possums had larger home ranges than did younger possums. When ‘juvenile cohort’ and ‘adult cohort’ data were analysed separately, to investigate the significant interaction, males in the ‘adult cohort’ had significantly larger home ranges than did females, with the grid effect still being apparent, whereas neither sex nor grid effects were significant for the ‘juvenile cohort’. Conclusions Our findings indicate that, in addition to density, age and sex are likely to be consistent determinants of possum home-range size, but their influences may be masked in some studies by the complexity of wild-population dynamics. Implications Our findings have strong implications regarding both disease transmission among possums and possum management. The fact that adult males occupy larger home ranges and the understanding that possum home range increases as population density decreases are an indication that males may be the primary drivers of disease transmission in possum populations. The understanding that possum home range increases as population density decreases could be a direct reflection of the ability of TB to persist in the wild that counteracts current management procedures. If individuals, and particularly males, infected with TB can withstand control measures, their ensuing home-range expansion will result in possible bacteria spread in both the expanded area of habitation and new individuals becoming subjected to infection (both immigrant possums and other control survivors). Therefore, managers should consider potential approaches for luring possum males in control operations.
27
O'Keefe, J. S., W. L. Stanislawek e D. D. Heath. "Pathological studies of wobbly possum disease in New Zealand brushtail possums (Trichosurus vulpecula)". Veterinary Record 141, n. 9 (30 agosto 1997): 226–29. http://dx.doi.org/10.1136/vr.141.9.226.
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28
Cown, PE, e DS Rhodes. "Restricting the movements of brushtail possums (Trichosurus vulpecula) on farmland with electric fencing". Wildlife Research 19, n. 1 (1992): 47. http://dx.doi.org/10.1071/wr9920047.
Testo completoAbstract (sommario):
A trial was conducted to test whether an electric fence would limit local movements of brushtail possums (Trichosurus vulpecula) on farmland in the central North I. of New Zealand. If effective, such a system could be used to reduce possum and cattle interactions and the spread of bovine tuberculosis. A 3-km-long, 9-strand electric fence was erected from ridge to ridge across a valley catchment of about 160 ha. Possums were live-trapped and released at bush patches within the study area and in open areas immediately adjacent to the electric fence. Only about 30% of possums caught at local bush patches were ever retrapped at the fence, and most were caught only once at the fence. About a third of possums caught at the fence were trapped at least once on both sides of the fence. The electric fence reduced possum movements through the fenced area by about 60-80%. Most possums trapped at the fence had come from bush patches within 200 m of the fence. When the fence was switched off, possum captures on the outside increased rapidly. The effectiveness of the fence was reduced because of frequent voltage reduction by earthing from a wide variety of causes, and because possums learned to move around the ends of the fence and the fences along the farm roads. Improvements to fence design are discussed.
29
Eymann, Jutta, Catherine A. Herbert, Brian P. Thomson, Tim E. Trigg, Desmond W. Cooper e Douglas C. Eckery. "Effects of deslorelin implants on reproduction in the common brushtail possum (Trichosurus vulpecula)". Reproduction, Fertility and Development 19, n. 8 (2007): 899. http://dx.doi.org/10.1071/rd07046.
Testo completoAbstract (sommario):
The present study investigated the effects of slow-release implants containing the gonadotrophin-releasing hormone (GnRH) agonist deslorelin on reproduction in the common brushtail possum (Trichosurus vulpecula). Captive female brushtail possums were assigned to control (placebo implant), low dose (4.7 mg deslorelin) or high dose (9.4 mg deslorelin) groups; males were assigned to control or high dose (9.4 mg deslorelin) groups. The acute effects of deslorelin treatment at the level of the pituitary gland were similar between the two sexes, where a transient rise in luteinising hormone concentration was induced over the first 24 h. In females, this was associated with the disruption of the normal oestrous cycle and mating within 2–10 days in some treated individuals, but no young were subsequently detected. By 3 weeks after treatment, treated females became anoestrus and remained infertile for at least one breeding season. The effects of treatment were reversible in a subset of females that had their implants removed, although the time taken to produce offspring was variable. Paradoxically, male brushtail possums remained fertile during chronic deslorelin exposure. Despite significant declines in basal follicle-stimulating hormone and testosterone concentrations, as well as an inability to respond to a GnRH challenge, treated males sired as many offspring as control males and there was no evidence of testicular regression. In conclusion, there is potential to control reproduction in female brushtail possums by using chronic GnRH agonist treatment.
30
Duckworth, J. A., X. Cui, F. C. Molinia, W. Lubitz e P. E. Cowan. "208.Zona pellucida vaccines for fertility control of brushtail possums in New Zealand". Reproduction, Fertility and Development 16, n. 9 (2004): 208. http://dx.doi.org/10.1071/srb04abs208.
Testo completoAbstract (sommario):
Introduced marsupial brushtail possums (Trichosurus vulpecula) are a major pest in New Zealand because of their impacts on conservation values and agricultural production. Immunologically-based fertility control (immunocontraception) offers an effective and humane alternative approach to possum management. The zona pellucida (ZP) is an extracellular coat around all mammalian eggs and an attractive target for the development of immunocontraceptive vaccines. Antibodies against ZP are ovary-specific and act by preventing sperm from binding and penetrating the ova and/or by disrupting the development of follicles or early embryo. The aim of these studies was to test the efficacy of possum-derived ZP antigens for their ability to elicit sustained immune responses and cause infertility, and to assess a range of options for development of a bait-delivered contraceptive vaccine. Alloimmunisation with possum ZP2 and ZP3 proteins showed that self-ZP antigens elicited strong humoral immune responses and reduced the fertility of female possums by 72-80%. Several potentially possum-specific immunocontraceptive peptides have been identified by linear epitope mapping and amino acid alignment and are being tested for their ability to reduce fertility. Recent trials have demonstrated that possums mount immune responses against ZP antigens delivered in transgenic plants and bacterial ghosts. Research on antigen and specific peptide identification, non-target effects and delivery systems is ongoing. Research supported by NZ Foundation for�Research Science & Technology, Marsupial CRC and NZ Animal Health Board.
31
Warburton, Bruce, Richard Barker e Morgan Coleman. "Evaluation of two relative-abundance indices to monitor brushtail possums in New Zealand". Wildlife Research 31, n. 4 (2004): 397. http://dx.doi.org/10.1071/wr03018.
Testo completoAbstract (sommario):
Population monitoring of brushtail possums (Trichosurus vulpecula) is an essential part of their management in New Zealand, with a trap-catch removal method being used most commonly. An alternative monitoring method (bait-interference), using bite marks on wax blocks, has been promoted as a more cost-effective alternative to using traps. However, neither of these methods has been validated. We assessed the utility of these two methods regarding their accuracy (unbiasedness and precision) in detecting changes in possum abundance by comparing the estimates of relative change in possum density following control obtained from both methods with the kill rate among radio-collared possums in the same study areas. In each of seven control operations, 48–50 possums were collared with mortality-sensing radio-transmitters, and trap-catch and wax-block lines were assessed before and after control. The correlation between trap-catch and radio-transmitter kill estimates (R2 = 0.91) suggests that trap catch, as currently used to monitor relative possum abundance, appears to be sufficiently accurate to manage these pests, with any bias being small. The kill estimates based on the wax-block monitoring were correlated less strongly with the radiotransmitter estimates than the trap-catch estimates (R2 = 0.66), although still significant. Until the extent of the potential bias in the wax-block estimates is known, we recommend that traps continue to be used as the main method to monitor possum abundance.
32
Duckworth, Janine A., Kathryn Wilson, Xianlan Cui, Frank C. Molinia e Phil E. Cowan. "Immunogenicity and contraceptive potential of three infertility-relevant zona pellucida 2 epitopes in the marsupial brushtail possum (Trichosurus vulpecula)". Reproduction 133, n. 1 (gennaio 2007): 177–86. http://dx.doi.org/10.1530/rep-06-0088.
Testo completoAbstract (sommario):
In a previous study, three infertility-relevant epitopes of possum ZP2 (Pep12 (amino acids 111–125), Pep31 (amino acids 301–315), and Pep44 (amino acids 431–445)) were identified using sera from possums (Trichosurus vulpecula) immunized with recombinant possum zona pellucida 2 (ZP2) constructs, and a synthetic peptide library of possum ZP2 protein. In this study, the three peptides were conjugated to keyhole limpet hemocyanin and 300 μg of each conjugated peptide were administered subcutaneously to female possums (n = 20 per peptide) in complete Freund’s adjuvant. Immunogen doses were repeated 3 and 6 weeks later using incomplete Freund’s adjuvant. Control animals were immunized with either phosphate-buffered saline only (n = 10) or 300 μg keyhole limpet hemocyanin (n = 10), administered with the same adjuvants. Serum antibodies from animals immunized against these three epitopes bound to the corresponding possum ZP2 peptides, recombinant possum ZP2 protein constructs, and native zona. Possum fertility was assessed following superovulation and artificial insemination. Peptides Pep12 and Pep31 had no significant effects on fertility parameters (P > 0.05). However, animals immunized with Pep44 had lower egg fertilization rates (immunized 19.5% versus control 60.5%, P < 0.05) and produced significantly fewer embryos than control animals (immunized 0.5 embryos versus control 2.4 embryos, P < 0.05). The number of Pep44-immunized females that produced embryos was reduced by 64%. Identification and characterization of possum infertility-relevant epitopes on possum ZP2 protein will assist development of safe, humane, and possum-specific immunocontraceptive vaccines for controlling the introduced possums in New Zealand.
33
Baillie, Gregory J., e Richard J. Wilkins. "Endogenous Type D Retrovirus in a Marsupial, the Common Brushtail Possum (Trichosurus vulpecula)". Journal of Virology 75, n. 5 (1 marzo 2001): 2499–507. http://dx.doi.org/10.1128/jvi.75.5.2499-2507.2001.
Testo completoAbstract (sommario):
ABSTRACT We have sequenced and characterized an endogenous type D retrovirus, which we have named TvERV(D), from the genome of an Australian marsupial, the common brushtail possum (Trichosurus vulpecula). Intact TvERV(D) gag, pro, pol, andenv open reading frames were detected in the possum genome. TvERV(D) was classified as a type D retrovirus, most closely related to those of Old World monkeys, New World monkeys, and mice, based on phylogenetic analyses and genetic organization. Approximately 30 TvERV(D) proviruses are present in the genomes of possums, as detected by Southern hybridization. However, variability in fragment patterns between possums was observed and suggests recent (or ongoing) retrotranspositional activity.
34
Caley, P., N. J. Spencer, R. A. Cole e M. G. Efford. "The effect of manipulating population density on the probability of den-sharing among common brushtail possums, and the implications for transmission of bovine tuberculosis". Wildlife Research 25, n. 4 (1998): 383. http://dx.doi.org/10.1071/wr97029.
Testo completoAbstract (sommario):
Common brushtail possums (Trichosurus vulpecula) act as a reservoir of bovine tuberculosis (Mycobacterium bovis) in New Zealand and the simultaneous sharing of dens may result in the transmission of Tb between possums. The effect of manipulating population density on the per capita probability of simultaneous den-sharing among possums was investigated at a site near Dunedin, New Zealand. Den characteristics that could affect the probability of simultaneous sharing were also investigated, though none were found to be significant. The daily probability of a possum sharing a den was estimated to be 0.07 for possums denning within uncontrolled areas of the study area. Den-sharing was most common between female pairs, though sharing was also recorded between male–female and male–male pairs. The highest number of possums recorded sharing a single den was four. Reducing population density significantly lowered the probability of possums simultaneously sharing dens within the study area, with greater than 60% reductions estimated to eliminate simultaneous den-sharing altogether. The relationship between the contact rate arising from den-sharing and population density was convex-down, rather than convex-up, as often hypothesised for animal–animal disease contact processes. The implications of simultaneous den-sharing for the transmission and control of bovine tuberculosis in brushtail possum populations are discussed.
35
Anderson, Hannah, Leonie E. Valentine, Giles E. St J. Hardy e Patricia A. Fleming. "Relationship between the common brushtail possum (Trichosurus vulpecula) and tuart (Eucalyptus gomphocephala) tree decline in Western Australia". Australian Mammalogy 42, n. 1 (2020): 67. http://dx.doi.org/10.1071/am18019.
Testo completoAbstract (sommario):
Forest canopy loss due to plant pathogens, insect or abiotic factors significantly alters habitat and resource availability for animals, which has flow-on effects for whole ecosystems. The tuart (Eucalyptus gomphocephala) has been in decline throughout its geographic range; this is likely associated with watertable and salinity changes, although a plant pathogen (Phytophthora multivora) has also been implicated. We examined the relative abundance of common brushtail possums (Trichosurus vulpecula) across 12 sites (each 0.72 ha) selected on the basis of the health of dominant tuart trees (six ‘healthy’ and six ‘declining’ sites). Habitat variables (understorey, tuart dimensions and density, tree hollows, tree-to-trap distance) and tuart tree health (crown loss, epicormic regrowth) were compared with possum abundance. Possums were detected at most sites. There was no significant difference between brushtail possum numbers at ‘healthy’ or ‘declining’ sites, although marginally more possums were recorded at declining sites (5.7 ± 1.5 (s.e.), n = 6 sites) compared with healthy sites (3.3 ± 0.7; Cohen’s effect size d = 0.80). Slightly higher abundance of possums was associated with sites that had a greater density of smaller-diameter but taller tuart trees. ‘Declining’ sites, with more epicormic regrowth and greater tree densities, may provide more palatable food resources for possums.
36
Duckworth, Janine A., Xianlan Cui, Susie Scobie, Jane Arrow e Phil E. Cowan. "Development of a contraceptive vaccine for the marsupial brushtail possum (Trichosurus vulpecula): lack of effects in mice and chickens immunised with recombinant possum ZP3 protein and a possum ZP3 antifertility epitope". Wildlife Research 35, n. 6 (2008): 563. http://dx.doi.org/10.1071/wr07139.
Testo completoAbstract (sommario):
Zona pellucida fertility-control vaccines are being developed in New Zealand to control an introduced marsupial pest, the brushtail possum (Trichosurus vulpecula). In this study recombinant possum ZP3 protein (rZP3) and a possum ZP3 peptide (amino acids 334–361) (both known to block fertility in possums) were examined for their potential to induce species-specific, or at least marsupial-specific, infertility. Laboratory mice (a ‘model’ eutherian mammal species) and domestic chickens (a ‘model’ bird species) immunised with possum rZP3 or possum-infertility ZP3 peptide in Freund’s adjuvants showed no reduction in a range of parameters indicative of reproductive performance. The lack of contraceptive effects on mouse and chicken fertility is an encouraging result in terms of rZP3 and ZP3 peptide specificity, and these promising antigens are to be expressed in a bacterial ghost vaccine system for mucosal delivery to possums and the effects on possum fertility evaluated. Ultimately, a much wider range of non-target species will need to be screened and tested once the antigens have been successfully formulated in their final delivery vehicle.
37
Holland, O. J., P. E. Cowan, D. M. Gleeson e L. W. Chamley. "413. Genetic diversity of the major histocompatibility complex and response to immunocontraceptives in the brushtail possum". Reproduction, Fertility and Development 20, n. 9 (2008): 93. http://dx.doi.org/10.1071/srb08abs413.
Testo completoAbstract (sommario):
The brushtail possum (Trichosurus vulpecula) is a major invasive pest in New Zealand. One option for its control is the use of an immunocontraceptive vaccine, a method of fertility control that employs the immune system to attack reproductive cells or proteins. Initial trials of immunocontraceptive vaccines have shown individual variation in immune response. Concerns have been raised that the use of such a vaccine on wild populations could result in selection for possums that remain fertile because of low or no response, and subsequently negate the efficacy of the vaccine. Therefore, it is important to establish the basis of this variation. The major histocompatibility complex (MHC) is an important component of the immune system which influences the nature of immune responses. This study aimed to document genetic variation in MHC loci of New Zealand possums, and investigate whether there was a relationship between MHC haplotypes and individual immune responses to immunocontraceptive vaccines. We used known marsupial (possum, red-necked wallaby, tammar wallaby, opossum) MHC sequences to design PCR primers for possum MHC loci. The variability of these loci was screened in populations of possums from locations throughout New Zealand, and between individuals with known responses to immunocontraceptive vaccines. We identified 71 novel class I and class II MHC alleles and observed significant variation in allele identity and frequency between geographically separate possum populations in New Zealand. Comparisons of MHC haplotype and immunocontraceptive vaccine response showed that some of these alleles differ between high-responding and low-responding possums. The considerable variation we have found in the possum MHC, combined with differences in the occurrence of MHC genes at locations around New Zealand, provide a potential basis for the observed variability of individual possum's responses to immunocontraceptive vaccines.
38
Veitch, Colleen E., John Nelson e Robert T. Gemmell. "Birth in the brushtail possum, Trichosurus vulpecula (Marsupialia : Phalangeridae)". Australian Journal of Zoology 48, n. 6 (2000): 691. http://dx.doi.org/10.1071/zo00033.
Testo completoAbstract (sommario):
Birth has been observed and described in a number of marsupials. However, the ability of the newborn marsupial to move from the uterus to the pouch and locate the teat is still not fully understood. Birth and the path taken by the newborn from the urogenital sinus to the teat within the pouch were filmed in the brushtail possum, Trichosurus vulpecula. Prior to birth, females began to lick the pouch and urogenital sinus vigorously. The young took approximately 2 min to transfer from the urogenital sinus to the pouch and attached to the teat within 10–15 min. To determine the senses used by the newborn possum to reach the pouch, young were removed from the anaesthetised mothers immediately after birth and placed outside the pouch. From the subsequent observations, the newborn possum instinctively crawled upwards. However, when the newborn was in the vicinity of the pouch, odours emanating from the pouch presumably attracted the young. Thus, the senses of gravity and of olfaction were used by the newborn to reach the teat and probably the sense of touch, via the mechanoreceptor Merkel cells around the mouth, allowed the young to attach to the teat.
39
Cowan, PE. "Possum biocontrol: prospects for fertility regulation". Reproduction, Fertility and Development 8, n. 4 (1996): 655. http://dx.doi.org/10.1071/rd9960655.
Testo completoAbstract (sommario):
Research has begun recently into biocontrol of brushtail possums as the only long-term, cost-effective solution to the possum problem in New Zealand, where possums cause significant damage to native forests, threaten populations of native plants and animals, and infect cattle and deer with bovine tuberculosis. Fertility regulation as a means of biocontrol has the support of major animal welfare and conservation groups in New Zealand. Systems are being investigated, mostly in reproduction and development, with the ultimate aim of developing immunologically-based fertility regulation (immunocontraception), but much basic information essential to such an approach for possums is lacking. The key components for the success of this approach--suitable vectors expressing possum-specific reproductive antigens sufficiently to block reproduction--are reviewed. The social and political issues of local, national and international risk and acceptability arising from such an approach are also discussed.
40
Wallis, I. R., M. L. Watson e W. J. Foley. "Secondary metabolites in Eucalyptus melliodora: field distribution and laboratory feeding choices by a generalist herbivore, the common brushtail possum". Australian Journal of Zoology 50, n. 5 (2002): 507. http://dx.doi.org/10.1071/zo02029.
Testo completoAbstract (sommario):
We studied the influence of a group of plant secondary compounds, the sideroxylonals, on feeding by the common brushtail possum (Trichosurus vulpecula), a generalist herbivore. Possums were offered synthetic diets either with or without sideroxylonals or, in separate experiments, foliage from 28 individual Eucalyptus melliodora trees. Possums ate less of the synthetic diet at sideroxylonal concentrations of 4 and 7 mg g–1 when offered a choice or no choice, respectively. Possums fed foliage in no-choice protocols ate 12–61 g of dry matter per day. Sideroxylonal concentration was an essential determinant of feeding on foliage but the wide variation, particularly at intermediate sideroxylonal concentrations, suggests that other secondary plant chemicals, e.g. tannins, are important also. The normal distribution of sideroxylonal concentrations (mean = 27.7, s.d. = 7.85 mg sideroxylonals per g dry leaf) in a natural population of 150 E. melliodora trees shows that brushtail possums will rarely encounter highly palatable trees (<10 mg sideroxylonals per g dry leaf) nor highly unpalatable foliage (>40 mg sideroxylonals per g dry leaf). When foraging on E. melliodora, brushtail possums must contend with intermediate sideroxylonal concentrations (20–30 mg per g dry leaf), where variability in food intake is most noticeable.
41
Corner, LAL, MA Stevenson, DM Collins e RS Morris. "The re-emergence ofMycobacterium bovisinfection in brushtail possums (Trichosurus vulpecula) after localised possum eradication". New Zealand Veterinary Journal 51, n. 2 (aprile 2003): 73–80. http://dx.doi.org/10.1080/00480169.2003.36343.
Testo completo
42
Loxley, Grace M., David O. Hooks, Aristotelis Antonopoulos, Anne Dell, Stuart M. Haslam, Wayne L. Linklater, Jane L. Hurst e Robert J. Beynon. "Vulpeculin: a novel and abundant lipocalin in the urine of the common brushtail possum, Trichosurus vulpecula". Open Biology 10, n. 10 (ottobre 2020): 200218. http://dx.doi.org/10.1098/rsob.200218.
Testo completoAbstract (sommario):
Lipocalins are a family of secreted proteins. They are capable of binding small lipophilic compounds and have been extensively studied for their role in chemosignalling in rodent urine. Urine of the common brushtail possum ( Trichosurus vulpecula ) contains a prominent glycoprotein of 20 kDa, expressed in both sexes. We have isolated this protein and determined its primary sequence by mass spectrometry, including the use of metabolic labelling to resolve the leucine/isoleucine isobaric ambiguity. The protein sequence was identified as a lipocalin, and phylogenetic analysis grouped the protein with other marsupial lipocalin sequences in a phylogenetic clade distinct from established cross-species lipocalin sub-families. The pattern of expression in possum urine and the similarity in sequence and structure to other lipocalins suggests this protein may have a role in brushtail possum chemosignalling.
43
Holland, Olivia J., Philip E. Cowan, Lawrence W. Chamley e Dianne M. Gleeson. "MHC population structure in the New Zealand brushtail possum". Veterinary Immunology and Immunopathology 128, n. 1-3 (marzo 2009): 308. http://dx.doi.org/10.1016/j.vetimm.2008.10.209.
Testo completo
44
Cowan, P. E. "Advances in New Zealand mammalogy 1990–2000: Brushtail possum". Journal of the Royal Society of New Zealand 31, n. 1 (marzo 2001): 15–29. http://dx.doi.org/10.1080/03014223.2001.9517636.
Testo completo
45
McLean, S. "Scent glands of the common brushtail possum (Trichosurus vulpecula)". New Zealand Journal of Zoology 41, n. 3 (3 luglio 2014): 193–202. http://dx.doi.org/10.1080/03014223.2014.899506.
Testo completo
46
Buaboocha, W., e R. T. Gemmell. "Thyroid gland development in the brushtail possum,Trichosurus vulpecula". Anatomical Record 243, n. 2 (ottobre 1995): 254–60. http://dx.doi.org/10.1002/ar.1092430212.
Testo completo
47
Tompkins, Daniel M., e David Ramsey. "Optimising bait-station delivery of fertility control agents to brushtail possum populations". Wildlife Research 34, n. 1 (2007): 67. http://dx.doi.org/10.1071/wr05109.
Testo completoAbstract (sommario):
Introduced Australian brushtail possums (Trichosurus vulpecula) are a major pest in New Zealand. Alternatives to current management by trapping and poisoning are being actively explored. The most effective scenario for the deployment of fertility control vaccines is the use of bait stations to maintain possum populations at low densities following their initial knockdown from high densities using conventional control tools. However, three field trials that estimated population coverage achievable by differing station layouts using dyed baits have produced conflicting results. To assess optimal vaccine-delivery strategies adequately we need meaningful a priori expectations of the level of population coverage achievable by differing bait station layouts and densities. To this end, we collated data on field operations in which bait stations were used to deliver acute toxins for lethal control of possum populations and constructed an individual-based spatially explicit stochastic model to simulate encounter rates between possums and bait stations. The model provided a reasonable fit to the data from both the acute toxin operations and two of the three dyed-bait trials. The third trial likely overestimated typical possum movement distances. Simulating vaccine delivery in the model demonstrated that grid densities of 0.6 bait stations ha–1 are predicted to be optimal, and prefeeding may not be necessary. The model strongly indicates that the effective delivery of fertility control will not be limited by our ability to deliver vaccine baits to possums. However, the exact strategy to employ will depend on three key characteristics of any vaccine – its expense relative to existing tools, its longevity in the field, and its efficacy at reducing female breeding success.
48
Nugent, G., I. J. Yockney, E. J. Whitford e M. L. Cross. "Assessing the Effectiveness of Tuberculosis Management in Brushtail Possums (Trichosurus vulpecula), through Indirect Surveillance ofMycobacterium bovisInfection Using Released Sentinel Pigs". Veterinary Medicine International 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/361634.
Testo completoAbstract (sommario):
In New Zealand, wild pigs acquireMycobacterium bovisinfection by scavenging tuberculous carrion, primarily carcasses of the main disease maintenance host, the brushtail possum (Trichosurus vulpecula). We investigated the utility of captive-reared, purpose-released pigs as sentinels for tuberculosis (TB) following lethal possum control and subsequent population recovery. Within 2-3 years of possum control by intensive poisoning, TB prevalence and the incidence rate ofM. bovisinfection in released sentinel pigs were lower than in an adjacent area where possums had not been poisoned. Unexpectedly, TB did not decline to near zero levels among pigs in the poisoned area, a fact which reflected an unanticipated rapid increase in the apparent abundance of possums. Monitoring infection levels among resident wild pigs confirmed that TB prevalence, while reduced due to possum control, persisted in the poisoned area at >20% among pigs born 2-3 years after poisoning, while remaining >60% among resident wild pigs in the nonpoisoned area. When fitted with radio-tracking devices, purpose-released pigs provided precise spatial TB surveillance information and facilitated effective killing of wild pigs when employed as “Judas” animals to help locate residents. Sentinel pigs offer value for monitoring disease trends in New Zealand, as TB levels in possums decline nationally due to large-scale possum control.
49
Sernia, Conrad, Tang Zeng e Robert T. Gemmell. "Ontogeny of thyroid hormone receptors in the brushtail possum (Trichosurus vulpecula)". Reproduction, Fertility and Development 9, n. 5 (1997): 489. http://dx.doi.org/10.1071/r97014.
Testo completoAbstract (sommario):
Newborn marsupials do not have a thyroid gland at birth. The gland develops while the young marsupial is in the mother’s pouch. The young brushtail possum initiates secretion of thyroid hormones from its own thyroid at about Day 65 post partum. However, during the first three weeks of pouch life thyroxine is passed from the mother to the young via the milk. To determine if this maternal thyroxine can effect organ development in the young possum before it initiates secretion of thyroxine from its own thyroid, the ontogeny of thyroid hormone receptors was determined in nuclear extracts of lung, liver and kidney by radioreceptor assay, using125I-labelled tri-iodothyronine as ligand. Receptor density was calculated for tissues removed from young possums at Days 25 (n = 5), 50 (n = 4), 100 (n = 3) and 150 (n = 4) and from adults (n = 5). Receptors were found in possums of all age groups, including the small 25-day pouch young. Significant differences were not found in the receptor density between different tissues or at various ages. The association constant Ka (4 ·0 ± 2· 6 L nmol-1 for lung) was similar in different tissues and at the various ages examined. The passage of thyroid hormones from the mother to the developing marsupial via the milk may have a role in the slow development of organ systems early in pouch life by acting on thyroid receptors in the pouch young. However, the functional maturation of the thyroid gland of the young possum, not an increase in receptors, appears to coincide with the rapid increase in the rate of growth and development which occurs in later pouch life.
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Caley, P., G. J. Hickling, P. E. Cowan e D. U. Pfeiffer. "Effects of sustained control of brushtail possums on levels ofMycobacteriumbovis infection in cattle and brushtail possum populations from Hohotaka, New Zealand". New Zealand Veterinary Journal 47, n. 4 (agosto 1999): 133–42. http://dx.doi.org/10.1080/00480169.1999.36130.
Testo completo