Dietary changes in response to population reduction in the possum Trichosurus vulpecula in New Zealand

2013 ◽  
Vol 40 (7) ◽  
pp. 561 ◽  
Author(s):  
Peter J. Sweetapple ◽  
Wendy A. Ruscoe ◽  
Graham Nugent
Keyword(s):  
New Zealand ◽  
Pest Control ◽  
Population Control ◽  
Stomach Contents ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Dietary Changes ◽  
Before And After ◽  
Per Capita ◽  
Indigenous Forest

Context Efforts to protect or restore degraded plant communities by population control of invasive herbivores frequently fail to achieve their goals. Aims We seek to quantify changes in diet of an introduced herbivore, the brushtail possum (Trichosurus vulpecula), following population control, and determine how these may contribute to variable responses in plant condition. Methods Stomach contents of possums from five areas of indigenous forest in northern New Zealand were analysed to measure diet before and after the application of possum control. Key results The contribution of fruit, and foliage of some early successional forest species, to total possum diet increased up to 27-fold following possum population control. This was accompanied by declines in consumption of the main pre-control possum foods (foliage from common canopy trees). Dietary changes were a combination of an immediate response to control (1 year) and a strengthening of these initial changes with increasing time since control. Conclusions Possums in the study areas changed diet following population control, from a diet dominated by foliage of common canopy tree species to one dominated by fruits, and foliage of uncommon early successional plants. Pest control instantaneously increased the per capita availability of all foods, and probably permitted absolute increases in some foods through plant recovery, enabling possums to substitute scarce, high-preference foods for abundant but less preferred canopy foliage. Implications Following control of a pest herbivore, dietary changes reduce benefits for the most vulnerable preferred plant foods, but enhance benefits for less favoured plants. Intense pest control can permit some recovery of highly preferred foods, despite increased per capita consumption of these foods by survivors of control.

scholarly journals 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 ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 436 ◽  
Author(s):  
Arsalan Emami-Khoyi ◽  
Shilpa Pradeep Parbhu ◽  
James G. Ross ◽  
Elaine C. Murphy ◽  
Jennifer Bothwell ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
New Zealand ◽  
Metabolic Pathways ◽  
De Novo ◽  
Population Control ◽  
Transcriptome Assembly ◽  
Control Measures ◽  
Genomic Diversity ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula

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.

scholarly journals De novo Transcriptome Assembly and Annotation of Liver and Brain Tissues of New Zealand brushtail possums (Trichosurus vulpecula): Transcriptome Diversity after Decades of Population Control

2020 ◽  
Author(s):  
Arsalan Emami-Khoyi ◽  
Shilpa Parbhu ◽  
James Ross ◽  
Elaine Murphy ◽  
Jennifer Bothwell ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
New Zealand ◽  
Metabolic Pathways ◽  
Population Control ◽  
Transcriptome Assembly ◽  
Control Measures ◽  
Genomic Diversity ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Hepatic Cells

The New Zealand brushtail possum (Trichosurus vulpecula), introduced from Australia in the 1850s, is an invasive species that is widespread throughout New Zealand and forms the largest self-sustained reservoir of bovine tuberculosis (Mycobacterium bovis) in the wild. 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 for the species. 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 in hepatic cells and cerebral cortex, 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 levels of variation in metabolic pathways that could potentially promote the development of tolerance against chemical toxicants.

Reduced spillover transmission ofMycobacterium bovisto feral pigs (Sus scofa) following population control of brushtail possums (Trichosurus vulpecula)

2011 ◽  
Vol 140 (6) ◽  
pp. 1036-1047 ◽  
Author(s):  
G. NUGENT ◽  
J. WHITFORD ◽  
I. J. YOCKNEY ◽  
M. L. CROSS
Keyword(s):  
New Zealand ◽  
Disease Transmission ◽  
Population Control ◽  
Mammalian Species ◽  
Oral Route ◽  
Poison Control ◽  
Brushtail Possum ◽  
Infection Prevalence ◽  
Trichosurus Vulpecula ◽  
Feral Pigs

SUMMARYIn New Zealand, bovine tuberculosis (bTB) is present in domestic cattle and deer herds primarily as the result of on-going disease transmission from the primary wildlife host, the brushtail possum (Trichosurus vulpecula). However, bTB is also present in other introduced free-ranging mammalian species. Between 1996 and 2007, we conducted a series of studies to determine whether poison control of possum populations would have any effect on the prevalence ofMycobacterium bovisinfection in sympatric feral pigs (Sus scrofa). We compared trends in the prevalence of bTB infection in feral pigs in six study areas: possum numbers were reduced in three areas, but not in the other three, effectively providing a thrice-replicated before-after-control-intervention design. Before possum control, the overall prevalence of culture-confirmedM. bovisinfection in feral pigs was 16·7–94·4%, depending on area. Infection prevalence varied little between genders but did vary with age, increasing during the first 2–3 years of life but then declining in older pigs. In the areas in which possum control was applied,M. bovisprevalence in feral pigs fell to near zero within 2–3 years, provided control was applied successfully at the whole-landscape scale. In contrast, prevalence changed much less or not at all in the areas with no possum control. We conclude that feral pigs in New Zealand acquireM. bovisinfection mainly by inter-species transmission from possums, but then rarely pass the disease on to other pigs and are end hosts. This is in contrast to the purported role of pigs as bTB maintenance hosts in other countries, and we suggest the difference in host status may reflect differences in the relative importance of the oral route of infection in different environments. Despite harbouringM. bovisinfection for a number of years, pigs in New Zealand do not sustain bTB independently, but are good sentinels for disease prevalence in possum populations.

scholarly journals Implications of prefeeding for the development of bait aversions in brushtail possums (Trichosurus vulpecula)

1998 ◽  
Vol 25 (2) ◽  
pp. 133 ◽  
Author(s):  
Zane N. Moss ◽  
Cheryl E. O'Connor ◽  
Graham J. Hickling
Keyword(s):  
New Zealand ◽  
Pest Control ◽  
Subsequent Development ◽  
Sublethal Dose ◽  
Trichosurus Vulpecula ◽  
Management Procedure

Development of aversions, or learned ‘bait-shyness’, in frequently poisoned possum (Trichosurus vulpecula) populations is becoming increasingly detrimental to the efficacy of pest-control operations in New Zealand. This experiment aimed to identify the effects of prefeeding, a common management procedure, on the subsequent development of aversions in possums. Wild possums (n = 96) were captured and acclimatised, then allocated to one of three treatments groups that for seven days received either (i) no prefeed, (ii) plain RS5 cereal baits, or (iii) green-dyed and cinnamon-lured RS5 cereal baits. The possums were then offered a standard green-dyed and cinnamon-lured RS5 bait that contained a sublethal dose (0.4 mg kg-1) of the toxin sodium monofluoroacetate (1080). The possums were tested for development of an aversion towards a toxic RS5 1080 bait, a prefeed bait, and a prefeed bait containing an alternative toxin, brodifacoum. Most (96%) of the non-prefed possums became averse to the 1080 bait after two exposures, compared with only 55% and 9% of the two prefed groups. Similarly, 90% and 92% of the non-prefed possums were averse to prefeed and brodifacoum baits, respectively, compared with 8% and 14% of the prefed possums. This suggests that pest managers can reduce the risk of ‘bait shyness’ by prefeeding. A further advantage of prefeeding is that if poison shyness develops, use of an alternative toxin such as brodifacoum in the original bait base may still be successful.

scholarly journals Ecology of a brushtail possum (Trichosurus vulpecula) population at Castlepoint in the Wairarapa, New Zealand

2019 ◽  
Vol 43 (2) ◽  
Author(s):  
Ron Jackson ◽  
D.U. Pfeiffe ◽  
T Porphyre ◽  
C Sauter-Louis ◽  
L.A.L. Corner ◽  
...  
Keyword(s):  
New Zealand ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula

Morphological trends in the Common brushtail possum, Trichosurus vulpecula, in New Zealand

2009 ◽  
Vol 208 (4) ◽  
pp. 583-593 ◽  
Author(s):  
Y. Yom-Tov ◽  
W. O. Green ◽  
J. D. Coleman
Keyword(s):  
New Zealand ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
The Common ◽  
Common Brushtail Possum

Cholecalciferol Toxicity and Its Enhancement by Calcium Carbonate in the Common Brushtail Possum.

1995 ◽  
Vol 22 (5) ◽  
pp. 579 ◽  
Author(s):  
SE Jolly ◽  
RJ Henderson ◽  
C Frampton ◽  
CT Eason
Keyword(s):  
New Zealand ◽  
Calcium Carbonate ◽  
Confidence Interval ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Toxic Material ◽  
Introduced Pest ◽  
The Common ◽  
Common Brushtail Possum ◽  
The Cost

The common brushtail possum (Trichosurus vulpecula), an introduced pest in New Zealand, is susceptible to cholecalciferol (vitamin D3), which is marketed as a rodenticide in many countries. To evaluate cholecalciferol for possum control we offered 242 caged adult possums cereal pellets containing cholecalciferol on its own or with calcium carbonate. Mortality was recorded for two weeks after presentation. For cholecalciferol on its own the LD50 was 16.8 mg kg-1 (95% confidence interval 11.6-21.9 mg kg-1), but the addition of calcium carbonate reduced this to 9.8 mg kg-1 (95% confidence interval 7.0-12.7 mg kg-1). When the sexes were analysed separately, the reduction of the LDS0 by the addition of calcium carbonate was significant only in females. The addition of calcium carbonate appeared to result in a more predictable outcome as shown by the reduced confidence intervals. For possum control, adding calcium carbonate to cholecalciferol bait would improve the bait's efficacy, decrease the amount of toxic material needed, and reduce the cost of bait production.

Serving two masters: Reconciling economic and biodiversity outcomes of brushtail possum (Trichosurus vulpecula) fur harvest in an indigenous New Zealand forest

2012 ◽  
Vol 153 ◽  
pp. 143-152 ◽  
Author(s):  
Christopher Jones ◽  
Mandy Barron ◽  
Bruce Warburton ◽  
Morgan Coleman ◽  
Philip O’B. Lyver ◽  
...  
Keyword(s):  
New Zealand ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula

Spatial prediction of brushtail possum (Trichosurus vulpecula) distribution using a combination of remotely sensed and field-observed environmental data

2013 ◽  
Vol 40 (7) ◽  
pp. 578 ◽  
Author(s):  
Thibaud Porphyre ◽  
Joanna McKenzie ◽  
Andrea E. Byrom ◽  
Graham Nugent ◽  
James Shepherd ◽  
...  
Keyword(s):  
Pest Control ◽  
Relative Abundance ◽  
Forest Cover ◽  
Remotely Sensed ◽  
Environmental Data ◽  
Effective Control ◽  
Brushtail Possum ◽  
Mean Annual Temperature ◽  
Trichosurus Vulpecula ◽  
Remotely Sensed Data

Context In New Zealand, the introduced brushtail possum, Trichosurus vulpecula, is a reservoir of bovine tuberculosis and as such poses a major threat to the livestock industry. Aerial 1080 poisoning is an important tool for possum control but is expensive, creating an ongoing need for ever more cost-effective ways of using this technique. Aims To develop geographic information system (GIS) models to better predict spatial variation in the distribution of unmanaged possum populations, to facilitate better targeting of control activities. Methods Relative abundance of possums and their distribution among habitat types were surveyed in a dry high-country area of the northern South Island. Two GIS-based models were developed to predict the relative abundance of possums on trap lines. The first model used remotely sensed (digital) environmental data; the second complemented the remotely sensed data with fine-scale habitat and topographic data collected on the ground. Key results Digital environmental factors and habitat features proved to be key predictors of relative possum abundance. In both GIS models, height above valley floor, presence of forest cover and mean annual temperature were the strongest predictors. Conclusions Predictive maps (projections) of relative possum abundance produced from these models can provide useful decision-support tools for pest-control managers, by enabling possum control to be targeted spatially. Implications Spatially targeted pest control could allow effective control activities for invasive species or disease vectors to be applied at a lower cost for the same benefit.

A live-trapping of Australian brush-tailed possums, Trichosurus vulpecula (Kerr), in the Orongorongo Valley, Wellington, New Zealand

1973 ◽  
Vol 21 (1) ◽  
pp. 75 ◽  
Author(s):  
MC Crawley
Keyword(s):  
New Zealand ◽  
Home Ranges ◽  
Trichosurus Vulpecula ◽  
Adult Males ◽  
Adult Females ◽  
Capture Site ◽  
Live Trapping ◽  
Indigenous Forest ◽  
Autumn And Winter ◽  
Initial Capture

A live-trapping study of a population of Australian brush-tailed possums, Trichosurus vulpecula (Kerr), in indigenous forest of the Orongorongo Valley, Wellington, N.Z., was carried out from March 1966 to November 1968. In 14 ha of podocarp-mixed broadleaf forest, 301 possums (150; 151) were individually marked and repeatedly captured in a series of trapping periods. The population comprised residents and transients of both sexes with sub- adults forming the bulk of the latter, particularly in spring. The estimated population density varied from 10.6 per ha in November 1966 to 6.4 per ha in August 1968. There was one well-defined season of births each autumn and a few births in winter. On average, 73% (67-92%) of mature females produced pouch young each year. Females resident throughout the study had the highest breeding success (79%). Achievement of sexual maturity was delayed; no females bred until they were 2 yr old, and some not even at 3 yr. Losses occurred at all stages of the life history and averaged 62% between the pouch young and subadult stages; thus only 28 subadults per 100 females were recruited. Adult losses averaged 26% per annum. Adult males (mean weight 2.46 kg) were heavier than adult females (2.33 kg). Weights varied seasonally, with males heaviest in summer and lightest in spring, and females heaviest in winter and lightest in summer. Possums of both sexes were rather sedentary, with males (95% of captures within 115 m of the initial capture site) being less so than females (95 % of captures within 90 m of the initial capture site). More than half of the captures (55% for males, 62% for females) were made within 30 m of the site of initial capture. Males moved farther in autumn and summer than in other seasons, while females did so in autumn and winter. Subadults were apparently more sedentary than adults. Home ranges of adult males (mean 0.81 ha) were significantly larger than those of adult females (0.46 ha). Considerable overlapping of the ranges of both sexes occurred, and territorial behaviour was not conspicuous. The dispersion of the population remained the same throughout the study although the component individuals changed. The results of the present study are compared with those of similar studies in New Zealand and Australia, and the dynamics of the Orongorongo Valley possum population are discussed with reference to variable rates of reproduction and mortality.

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