Brushtail possums (Trichosurus vulpecula) in metropolitan Sydney: population biology and response to Suprelorin contraceptive implants

2013 ◽  
Vol 61 (1) ◽  
pp. 78 ◽  
Author(s):  
J. Eymann ◽  
D. W. Cooper ◽  
C. A. Herbert
Keyword(s):  
Urban Areas ◽  
Population Biology ◽  
Local Population ◽  
Fertility Control ◽  
Main Peak ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Management Options ◽  
Contraceptive Implants ◽  
Over Time

The cohabitation of the common brushtail possum (Trichosurus vulpecula) with people in urban areas often causes conflict. Basic biological parameters are needed to evaluate potential new management options such as fertility control. This study investigated the biology of an urban brushtail possum population and the effects of Suprelorin contraceptive implants on individual females within that population. Trapping success remained constant over time, with 2.8 ± 0.2 individuals trapped per residential property. Recapture rates for males declined rapidly over time, with only 30% of males recaptured on the same property 12 months after initial capture (n = 30) and no males recaptured after 18 months (compared with female recapture rates of 58% after 18 months, n = 33). These data, combined with the preponderance of males observed within the lower age classes, suggests that male possum turnover is high within urban areas. This may be partially compensated for by the male-bias (1.8 : 1) observed in pouch young. Breeding was seasonal with the main peak of births in autumn, and a secondary smaller peak in spring. Suprelorin contraceptive treatment effectively inhibited reproduction in adult females for a minimum duration of 519 ± 7 (n = 5) and ≥700 ± 20 (n = 5) days after administration of one or two 4.7-mg implants, respectively, with no negative side-effects obvious. The concurrent collection of data on contraceptive efficacy and population-specific life-history parameters provides a unique opportunity to highlight the importance of understanding local population dynamics when evaluating the likely efficacy and implementation of fertility control programs to manage problem wildlife.

. Management issues of urban common brushtail possums Trichosurus vulpecula: a loved or hated neighbour.

2006 ◽  
Vol 28 (2) ◽  
pp. 153 ◽  
Author(s):  
J. Eymann ◽  
C. A. Herbert ◽  
D. W. Cooper
Keyword(s):  
Urban Areas ◽  
Management Strategies ◽  
Disease Status ◽  
Fertility Control ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Management Options ◽  
Management Tools ◽  
Nest Boxes ◽  
Management Issues

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.

Building selection by the common brushtail possum (Trichosurus vulpecula)

2020 ◽  
Vol 47 (2) ◽  
pp. 186
Author(s):  
Yuqing Chen ◽  
Bruce Doran ◽  
Sharyn Sinclair-Hannocks ◽  
John Mangos ◽  
Philip Gibbons
Keyword(s):  
Urban Areas ◽  
Native Species ◽  
Canopy Cover ◽  
Brushtail Possum ◽  
Suitable Habitat ◽  
Trichosurus Vulpecula ◽  
Building Maintenance ◽  
National University ◽  
The Common ◽  
Common Brushtail Possum

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.

scholarly journals Prevalence and Genetic Characterization of Cryptosporidium Isolates from Common Brushtail Possums (Trichosurus vulpecula) Adapted to Urban Settings

2008 ◽  
Vol 74 (17) ◽  
pp. 5549-5555 ◽  
Author(s):  
Nichola J. Hill ◽  
Elizabeth M. Deane ◽  
Michelle L. Power
Keyword(s):  
Urban Areas ◽  
White Blood Cells ◽  
Urban Setting ◽  
Urban Habitat ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Sympatric Populations ◽  
Cryptosporidium Hominis ◽  
Urban Settings ◽  
Zoo Animals

ABSTRACT The common brushtail possum (Trichosurus vulpecula) is one of the most abundant native marsupials in urban Australia, having successfully adapted to utilize anthropogenic resources. The habituation of possums to food and shelter available in human settlements has facilitated interaction with people, pets, and zoo animals, increasing the potential for transmission of zoonotic Cryptosporidium pathogens. This study sought to examine the identity and prevalence of Cryptosporidium species occurring in possums adapted to urban settings compared to possums inhabiting remote woodlands far from urban areas and to characterize the health of the host in response to oocyst shedding. Findings indicated that both populations were shedding oocysts of the same genotype (brushtail possum 1 [BTP1]) that were genetically and morphologically distinct from zoonotic species and genotypes and most closely related to Cryptosporidium species from marsupials. The urban population was shedding an additional five Cryptosporidium isolates that were genetically distinct from BTP1 and formed a sister clade with Cryptosporidium parvum and Cryptosporidium hominis. Possums that were shedding oocysts showed no evidence of pathogenic changes, including elevated levels of white blood cells, diminished body condition (body mass divided by skeletal body length), or reduced nutritional state, suggesting a stable host-parasite relationship typical of Cryptosporidium species that are adapted to the host. Overall, Cryptosporidium occurred with a higher prevalence in possums from urban habitat (11.3%) than in possums from woodland habitat (5.6%); however, the host-specific nature of the genotypes may limit spillover infection in the urban setting. This study determined that the coexistence of possums with sympatric populations of humans, pets, and zoo animals in the urban Australian environment is unlikely to present a threat to public health safety.

Genetic structure infers generally high philopatry and male-biased dispersal of brushtail possums (Trichosurus vulpecula) in urban Australia

2006 ◽  
Vol 33 (5) ◽  
pp. 409 ◽  
Author(s):  
A. J. Stow ◽  
N. Minarovic ◽  
J. Eymann ◽  
D. W. Cooper ◽  
L. S. Webley
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Adult Male ◽  
Urban Areas ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Dispersal Patterns ◽  
Sample Average ◽  
Natural Range ◽  
Dispersal Distances

The brushtail possum (Trichosurus vulpecula) is in decline throughout much of its natural range with the notable exception of urban areas and a few islands. In some urban areas, its density can be high enough to cause conflict with householders. We provide the first genetic-based study of dispersal for T. vulpecula in the urban environment. Seven microsatellite markers were used to investigate genetic structure of adult male (n = 53) and female (n = 39) possums sampled from mainland suburbs of Sydney, and on nearby Scotland Island. Samples from Scotland Island also provide an opportunity to assess the effect of isolation on genetic variability, which, as theory would predict, was significantly lower than observed in mainland samples. Male-biased dispersal was inferred from patterns of relatedness between individuals of each sex. Average relatedness was significantly higher between adult female possums than between adult male possums sampled within the same garden area. In addition, males were genotypically more similar to one another at substantially greater geographic distances than females. Along with male-biased dispersal, strong localised genetic structure for both sexes infers generally high philopatry. Dispersal distances were greatest for adult male possums sampled from mainland locations. However, even for these males, genotypic similarity between possums separated by distances further than ~900 m was lower than the sample average, suggesting infrequent dispersal beyond this distance. Knowledge of dispersal patterns is important to managing the density levels of overabundant T. vulpecula in urban areas.

Long-term efficacy of levonorgestrel implants for fertility control of eastern grey kangaroos (Macropus giganteus)

2008 ◽  
Vol 35 (6) ◽  
pp. 520 ◽  
Author(s):  
Graeme Coulson ◽  
Christopher D. Nave ◽  
Geoff Shaw ◽  
Marilyn B. Renfree
Keyword(s):  
Urban Areas ◽  
Fertility Control ◽  
The Other ◽  
Control Group ◽  
Acceptable Alternative ◽  
Term Efficacy ◽  
Adult Females ◽  
Free Ranging ◽  
Over Time

Overabundant populations of kangaroos pose substantial management problems in small parks on the fringe of urban areas in Australia. Translocation is impractical and culling is often not publicly acceptable, but fertility control offers an acceptable alternative. One potential contraceptive is levonorgestrel, which provides effective long-term contraception in women, and prevents births in some marsupials for up to five years. We evaluated the long-term efficacy of levonorgestrel in free-ranging eastern grey kangaroos (M. giganteus) at two sites in Victoria, Australia. We trapped 25 adult females at one site (Portland Aluminium), treating 18 with two subcutaneous 70-mg levonorgestrel implants and seven with control (inert) implants. We darted 25 adult females at the other site (Woodlands Historic Park), treating all with two 70-mg levonorgestrel implants. We monitored the reproductive status of the kangaroos, as indicated by the obvious presence of a pouch young, in spring each year for up to seven years. In the first three years at Portland, 81–86% of levonorgestrel-treated females were infertile, compared with 12–29% in the control group, but the effectiveness of fertility control declined over time. At this site, the proportions of treated females breeding in the fourth, fifth, sixth and seventh years of the trial were 36%, 50%, 67% and 100% respectively. Fecundity at Woodlands was similar. Although this protocol achieved fertility control for several years, it was likely that more than one treatment or a higher dose rate would be required for effective fertility control in this long-lived species.

Brushtail possums: do present law, policy and management approaches meet the needs of this species in all its contexts?

2013 ◽  
Vol 61 (1) ◽  
pp. 95 ◽  
Author(s):  
Tracey Catherine Russell ◽  
Ellen Geraghty ◽  
Sarah Wilks
Keyword(s):  
Urban Areas ◽  
Legal Protection ◽  
Active Management ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Focus Attention ◽  
Management Approaches ◽  
Agricultural Regions ◽  
Very High ◽  
Governance Arrangements

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.

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

2008 ◽  
Vol 35 (6) ◽  
pp. 563 ◽  
Author(s):  
Janine A. Duckworth ◽  
Xianlan Cui ◽  
Susie Scobie ◽  
Jane Arrow ◽  
Phil E. Cowan
Keyword(s):  
Bird Species ◽  
Fertility Control ◽  
Eutherian Mammal ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Mammal Species ◽  
Peptide Specificity ◽  
Contraceptive Vaccine ◽  
Bacterial Ghost ◽  
Species Specific

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.

scholarly journals Mapping 20 Years of Urban Expansion in 45 Urban Areas of Sub-Saharan Africa

2021 ◽  
Vol 13 (3) ◽  
pp. 525
Author(s):  
Yann Forget ◽  
Michal Shimoni ◽  
Marius Gilbert ◽  
Catherine Linard
Keyword(s):  
Case Studies ◽  
Urban Areas ◽  
Urban Expansion ◽  
Local Population ◽  
Sub Saharan Africa ◽  
Annual Growth Rate ◽  
Urban Dynamics ◽  
Mapping Approach ◽  
Sub Saharan ◽  
The Impact

By 2050, half of the net increase in the world’s population is expected to reside in sub-Saharan Africa (SSA), driving high urbanization rates and drastic land cover changes. However, the data-scarce environment of SSA limits our understanding of the urban dynamics in the region. In this context, Earth Observation (EO) is an opportunity to gather accurate and up-to-date spatial information on urban extents. During the last decade, the adoption of open-access policies by major EO programs (CBERS, Landsat, Sentinel) has allowed the production of several global high resolution (10–30 m) maps of human settlements. However, mapping accuracies in SSA are usually lower, limited by the lack of reference datasets to support the training and the validation of the classification models. Here we propose a mapping approach based on multi-sensor satellite imagery (Landsat, Sentinel-1, Envisat, ERS) and volunteered geographic information (OpenStreetMap) to solve the challenges of urban remote sensing in SSA. The proposed mapping approach is assessed in 17 case studies for an average F1-score of 0.93, and applied in 45 urban areas of SSA to produce a dataset of urban expansion from 1995 to 2015. Across the case studies, built-up areas averaged a compound annual growth rate of 5.5% between 1995 and 2015. The comparison with local population dynamics reveals the heterogeneity of urban dynamics in SSA. Overall, population densities in built-up areas are decreasing. However, the impact of population growth on urban expansion differs depending on the size of the urban area and its income class.

Protected Areas: offering security to whom, when and where?

2016 ◽  
Vol 43 (2) ◽  
pp. 172-180 ◽  
Author(s):  
ALICE B. KELLY ◽  
A. CLARE GUPTA
Keyword(s):  
Protected Areas ◽  
Environmental Conditions ◽  
Protected Area ◽  
Spatial Scales ◽  
Local Population ◽  
Well Being ◽  
Economic Context ◽  
Term Management ◽  
Over Time

SUMMARYThis study considers the issue of security in the context of protected areas in Cameroon and Botswana. Though the literature on issues of security and well-being in relation to protected areas is extensive, there has been less discussion of how and in what ways these impacts and relationships can change over time, vary with space and differ across spatial scales. Looking at two very different historical trajectories, this study considers the heterogeneity of the security landscapes created by Waza and Chobe protected areas over time and space. This study finds that conservation measures that various subsets of the local population once considered to be ‘bad’ (e.g. violent, exclusionary protected area creation) may be construed as ‘good’ at different historical moments and geographical areas. Similarly, complacency or resignation to the presence of a park can be reversed by changing environmental conditions. Changes in the ways security (material and otherwise) has fluctuated within these two protected areas has implications for the long-term management and funding strategies of newly created and already existing protected areas today. This study suggests that parks must be adaptively managed not only for changing ecological conditions, but also for shifts in a protected area's social, political and economic context.

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