Leptospiral Infection in Common Brushtail Possums (Trichosurus Vulpecula) From Lowland Podocarp/Mixed Hardwood Forest in New Zealand.

1991 ◽  
Vol 18 (6) ◽  
pp. 719 ◽  
Author(s):  
PE Cowan ◽  
DK Blackmore ◽  
RB Marshall
Keyword(s):  
New Zealand ◽  
Breeding Season ◽  
Sexual Maturity ◽  
Hardwood Forest ◽  
Leptospira Interrogans ◽  
Trichosurus Vulpecula ◽  
Males And Females

A survey of 261 common brushtail possums (Trichosurus vulpecula) from New Zealand lowland podocarp/mixed hardwood forest showed 34% of possums with antibodies to Leptospira interrogans serovar balcanica, 35% with antibodies to serovar hardjo, and isolation of balcanica leptospires from 23% of kidney cultures. One possum showed a titre to serovar ballum, leptospires of which were subsequently isolated in culture. Seroprevalences and isolation rates were similar in mature males and females, and increased with age. Sexually immature possums were rarely infected, but recently matured animals had significant rates of infection. Seroprevalence was elevated during the breeding season, suggesting that primary infections were generally acquired in association with sexual maturity and mating. There was no significant association between prevalence of infection and genotype, based on 8 polymorphic proteins. Infection had no significant effect on various indices of possum condition. In their response to infection, possums displayed characteristics typical of a maintenance host.

Den Sites of Possums, Trichosurus-Vulpecula, and Frequency of Use in Mixed Hardwood Forest in Westland, New-Zealand

1987 ◽  
Vol 14 (3) ◽  
pp. 285 ◽  
Author(s):  
WQ Green ◽  
JD Coleman
Keyword(s):  
New Zealand ◽  
Bovine Tuberculosis ◽  
Ground Level ◽  
Root Systems ◽  
Hardwood Forest ◽  
Trichosurus Vulpecula ◽  
Frequency Of Use ◽  
Below Ground ◽  
Males And Females

Forty-seven common brushtail possums, Trichosurus vulpecula, were radiotracked to 282 dens on 546 occasions. Just over half of all dens were in living trees; the remainder were evenly distributed between dead standing stems (including short stumps) and logs, with a few (3%) in banks and rock fissures. Of all the den entrances, 73% were at, or below, ground level amongst root systems or in logs. Although dead standing stems (over 25 cm d.b.h.) made up only 4% of standing stems in forest below 500 m altitude, they contained 41% of the dens. Each possum probably used between 10 and 15 dens each year. There were no differences in den choice and frequency of use between mature males and females. Den choice by matures and immatures was similar, but mature possums used dens in 'dead' sites more than did immatures. The implications of dens in the transmission of bovine tuberculosis are discussed.

Reproduction in the Ningbing Antechinus (Marsupialia, Dasyuridae) - Field and Laboratory Observations

1988 ◽  
Vol 15 (2) ◽  
pp. 149 ◽  
Author(s):  
PA Woolley
Keyword(s):  
Breeding Season ◽  
Western Australia ◽  
Sexual Maturity ◽  
Males And Females

The ningbing antechinus is a species of small dasyurid marsupial found in the Kimberley region of Western Australia. Observations on reproduction have been made on newly captured and laboratory maintained specimens. The breeding season is short and mating occurs in June. The young are born after a long gestation, estimated to be between 45 and 52 days, in late July and early August. They are weaned in November when about 16 weeks old and they reach sexual maturity at 10-11 months, in the first breeding season after birth. Both males and females are potentially capable of breeding in a second season.

Age, Sex and Season: Factors which Determine the Trap Response of the European Wild Rabbit, Oryctolagus cuniculus

1980 ◽  
Vol 7 (3) ◽  
pp. 421 ◽  
Author(s):  
JC Daly
Keyword(s):  
Individual Differences ◽  
Natural Population ◽  
Breeding Season ◽  
Sexual Maturity ◽  
Oryctolagus Cuniculus ◽  
Adult Population ◽  
Late Summer ◽  
Wild Rabbit ◽  
Males And Females ◽  
Probability Of Capture

Factors determining the trap-response of the rabbit, investigated in a natural population at Urana, N.S.W., included the age and the sex of the rabbit and the season in which it was trapped. Differences were also observed between rabbits living in two adjacent habitats. Mark-recapture data, derived from 52 trips undertaken over 30 months, did not show a uniform probability of capture within the adult population. Adult rabbits were most trappable when they were not breeding (late summer to midwinter); at this time males and females were equally trappable but individual differences were noted. During the breeding season all adults were difficult to trap, males more so than females. Trappability increased with age in young rabbits and declined at sexual maturity. Trap-response was random with respect to the animal's genotype as determined by four polymorphic enzyme loci. Markrecapture- analysis is unlikely to be an accurate means of estimating the parameters of rabbit populations; full enumeration of the population is necessary.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

Variation within and between Rivers in Adult Size and Sea Age at Maturity of Anadromous Brown Trout, Salmo trutta

1991 ◽  
Vol 48 (6) ◽  
pp. 1015-1021 ◽  
Author(s):  
Jan Henning L'Abée-Lund
Keyword(s):  
Brown Trout ◽  
Sexual Maturity ◽  
Salmo Trutta ◽  
Adult Size ◽  
Age At Maturity ◽  
Migration Distance ◽  
Spawning Area ◽  
Brown Trout Salmo Trutta ◽  
Males And Females ◽  
The Mean

I compared adult size and sea age at sexual maturity among nine populations of anadromous brown trout, Salmo trutta, in two Norwegian rivers to determine the extent of inter- and intrariverine variations. Variation in the mean length of spawners and in the mean sea age at sexual maturity were mainly dependent on the variations found within rather than between rivers. Mean lengths and mean age at maturity of males increased significantly with increasing altitude of the spawning area and with migration distance in freshwater. In females, positive significant correlations were found with mean lengths and altitude of the spawning area and with mean sea age at maturity and both spawning site altitude and migration distance. Mean lengths and ages of males and females were not significantly correlated with the rate of water discharge in the streams during spawning. The size of gravel substrate for spawning was of minor importance in explaining interpopulation variation in mean female size. The increase noted in mean length and in mean sea age at maturity of both males and females is probably an adaptation to greater energy expenditure to reach the uppermost natal spawning areas.

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.

A systematic approach to evaluating and ranking the relative animal welfare impacts of wildlife control methods: poisons used for lethal control of brushtail possums (Trichosurus vulpecula) in New Zealand

2016 ◽  
Vol 43 (7) ◽  
pp. 553 ◽  
Author(s):  
N. J. Beausoleil ◽  
P. Fisher ◽  
K. E. Littin ◽  
B. Warburton ◽  
D. J. Mellor ◽  
...  
Keyword(s):  
New Zealand ◽  
Animal Welfare ◽  
Policy Development ◽  
Management Decision ◽  
Pest Species ◽  
Control Methods ◽  
Trichosurus Vulpecula ◽  
Welfare Impacts ◽  
Wildlife Control ◽  
Management Decision Making

Context Control of unwanted wildlife (‘pest’ animals) is undertaken for conservation and economic reasons, and when such animals are considered a nuisance. Such control should be undertaken using approaches that minimise, as far as possible, detrimental impacts on the welfare of the animals. Using a scientific framework based on the Five Domains model, the relative welfare impacts of pest control methods can be compared across methods and pest species. Aims We demonstrate the application of a modified version of this framework to evaluate the relative impacts of seven Vertebrate Toxic Agents (VTAs) used to control brushtail possums (Trichosurus vulpecula) in New Zealand. The evaluation is used to produce a ranking of the seven VTAs based on their relative impacts on possum welfare. Methods Scientific literature describing mode of toxic action, specific effects in possums or other animals and reports from human poisonings was collated as reference material for a panel of six experts. The panel produced a median welfare impact score (‘none’ to ‘extreme’) for each of the Five Domains. The ‘Overall Grade’ (1 to 8) reflected the intensity and duration of all impacts of a VTA on possums. Key results All VTAs evaluated have at least moderate impacts on possum welfare, lasting for at least minutes. Cyanide was assessed as having the lowest welfare impacts (median grade 4), and cholecalciferol and the anticoagulants the highest impacts (7.5 to 8). Zinc phosphide was assigned an intermediate grade (6) with high confidence. While the overall impacts of sodium fluoroacetate (1080) and phosphorus were also assessed as intermediate (6), the panel’s confidence in these scores was low. Conclusions From an animal welfare perspective, anticoagulant poisons and cholecalciferol should be the least preferred options for controlling possums in New Zealand, as VTAs with less severe welfare impacts are available. Implications The results of such assessments allow animal welfare impacts to be integrated with other factors in wildlife management decision-making and policy development, and are thus useful for managers, researchers, regulators and operators. Evaluation of welfare impacts aligns with the goals and mandates of ethical wildlife control and may also be valuable in wider wildlife research and management activities.

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