Variability in the seasonality of breeding by the common brushtail possum, Trichosurus vulpecula: its possible causes and management implications

2014 ◽  
Vol 36 (2) ◽  
pp. 131 ◽  
Author(s):  
Phil Cowan
Keyword(s):  
New Zealand ◽  
Secondary Compounds ◽  
Future Research ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Plant Secondary Compounds ◽  
Food Quantity ◽  
Introduced Range ◽  
The Common ◽  
Common Brushtail Possum

Across its native range in Australia and its introduced range in New Zealand the common brushtail possum, Trichosurus vulpecula, demonstrates significant flexibility in reproduction from breeding once a year in autumn, breeding in both autumn and spring, or breeding year round. Understanding variation in the seasonality of breeding has relevance to the management of possum populations for both management as a pest and their conservation. The success of possums as a colonising species in New Zealand has been attributed in part to their flexible breeding behaviour. Review of available evidence suggests that photoperiod and food quantity/quality influence the variation in seasonality of breeding and their effects are modulated by interactions with factors such as density, body weight and, possibly, genetics and plant secondary compounds. Future research is suggested to tease apart the relative contributions of these various factors to the observed variation.

Secondary metabolites in Eucalyptus melliodora: field distribution and laboratory feeding choices by a generalist herbivore, the common brushtail possum

2002 ◽  
Vol 50 (5) ◽  
pp. 507 ◽  
Author(s):  
I. R. Wallis ◽  
M. L. Watson ◽  
W. J. Foley
Keyword(s):  
Dry Matter ◽  
Secondary Compounds ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Plant Secondary Compounds ◽  
Generalist Herbivore ◽  
Plant Chemicals ◽  
The Common ◽  
Common Brushtail Possum ◽  
Feeding Choices

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.

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.

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