Optimising bait size and 1080 concentration (sodium monofluoroacetate) for the control of brushtail possums Trichosurus vulpecula)

1999 ◽  
Vol 26 (1) ◽  
pp. 53 ◽  
Author(s):  
C. M. Frampton ◽  
B. Warburton ◽  
R. Henderson ◽  
D. R. Morgan
Keyword(s):  
New Zealand ◽  
Weight Distribution ◽  
Lethal Dose ◽  
Distribution Data ◽  
Trichosurus Vulpecula ◽  
Toxic Concentration ◽  
The Mean ◽  
Quantitative Assessments

A method is presented for quantitatively assessing the likely effectiveness of specific bait size and 1080 concentration for controlling brushtail possums with a known weight distribution. Data from aerial 1080 operations for the control of brushtail possums in New Zealand show that estimates of the bait size and toxic concentration required derived from the mean parameters [pest weight, bait size, and lethal dose (LD 95)] will not be accurate. This inaccuracy is most likely to lead to an underestimate of the amount of toxin presented to each animal, so that many operations currently run the risk of sub-lethally dosing possums and thereby possibly inducing some degree of poison shyness. On the basis of more accurate quantitative assessments of bait effectiveness we recommend that the 1080 concentration be increased to 0.15% and that baits less than 5 g be excluded to ensure that when mean possum weights are less than 3 kg more than 95% of possums are lethally dosed by a single bait.

Behaviour and time to unconsciousness of brushtail possums (Trichosurus vulpecula) after a lethal or sublethal dose of 1080

2009 ◽  
Vol 36 (8) ◽  
pp. 709 ◽  
Author(s):  
Kate E. Littin ◽  
Neville G. Gregory ◽  
Andrea T. Airey ◽  
Charles T. Eason ◽  
David J. Mellor
Keyword(s):  
New Zealand ◽  
Animal Welfare ◽  
Lethal Dose ◽  
Total Loss ◽  
Sublethal Dose ◽  
Loss Of Consciousness ◽  
Trichosurus Vulpecula ◽  
Welfare Impacts ◽  
Behavioural Changes ◽  
H 26

Context. Sodium fluoroacetate (1080) is a vertebrate pesticide used in several countries, including New Zealand, where it is the main pesticide for controlling brushtail possums (Trichosurus vulpecula) – a significant agricultural and conservation pest. There is growing concern internationally about the impacts of vertebrate pesticides, including 1080, on pest animal welfare. Aims. Behavioural changes and time to loss of consciousness of possums after 1080 ingestion in carrot baits were determined to compare the animal welfare impacts with other possum pesticides. Methods. Eight lethally dosed possums and eight that consumed a dose intended to be sublethal were observed until death or recovery but not handled. Another nine lethally dosed possums were handled to determine responses to stimuli, indicating time to loss of consciousness. Key results. Unhandled, lethally dosed possums died after 11 h 26 min ± 1 h 55 min (mean ± s.e.m.). Half had abnormal appearances and postures 1 h 50 min ± 9 min after consuming baits. Seven showed retching, and three vomited, over 27 ± 12 min from 2 h 53 min ± 13 min. Lack of coordination began 3 h 37 min ± 32 min after dosing, then possums spent most of the time until death lying, showing spasms and tremors. Five showed seizures while lying prostrate. Possums receiving a nominally sublethal dose all showed signs of poisoning, including abnormal postures, lethargy, lack coordination, retching, spasms or tremors, and a cessation of grooming, feeding and activity. One died 18 h 15 min after dosing, experiencing two seizures within 30 min of death. Response to handling, indicating total loss of consciousness, was lost in two possums before death. Conclusions. Possums ingesting a lethal dose of 1080 experienced ~9.5 h of changed behaviour and lost consciousness close to death, although awareness was likely reduced sometime beforehand. Possums ingesting a nominally sublethal dose experienced some effects of poisoning. Implications. These impacts are intermediate compared with other possum pesticides in New Zealand. Nevertheless, the potential for consciousness during and after retching and seizures is undesirable for animal welfare. Further work is encouraged on alternatives to 1080 and means of reducing its impact on animal welfare.

Effect of prefeeding on foraging patterns of brushtail possums (Trichosurus vulpecula) about prefeed transects

2009 ◽  
Vol 36 (8) ◽  
pp. 659 ◽  
Author(s):  
B. Warburton ◽  
R. Clayton ◽  
G. Nugent ◽  
G. Graham ◽  
G. Forrester
Keyword(s):  
New Zealand ◽  
Agricultural Production ◽  
Lethal Dose ◽  
Trichosurus Vulpecula ◽  
Gradual Decline ◽  
Foraging Patterns ◽  
Major Pest ◽  
Number Of Visits ◽  
The Wire ◽  
Free Feeding

Context. Brushtail possums (Trichosurus vulpecula) are a major pest of native biodiversity and agricultural production in New Zealand. To maximise the effectiveness of control operations, prefeeding (free-feeding) of non-toxic bait before poison is often used, but the mechanisms by which it does so, remain unclear. One possibility is that prefeeding changes foraging patterns and space use in ways that increase the likelihood of possums finding and eating a lethal dose of poison bait. Aim. To determine whether prefeeding along transects increases possum activity on the transect, and if so, how long the effect lasts. Methods. We monitored the time that radio-collared possums spent within a few metres of 350 m of aerial wire laid along a transect. Key results. Initially, possums spent only 2.6 min per night in the vicinity of the wire, but after 20 kg of bait per kilometre were placed along the wire, that time increased 20-fold on the first night and remained high for the next four nights (by which time all of the bait had been consumed). After that there was a gradual decline in time spent near the wire over a further 18 days. The increased amount of time spent near the wire was the product of both an increase in the number of visits and the duration of those visits. Conclusions. We conclude that sowing prefeed in concentrated strips is likely to greatly increase the probability of possums rapidly encountering toxic bait sown along the same strips, especially where the toxin can be sown immediately after all of the prefeed has been eaten. Implications. Possum control operations can now be designed to apply much smaller quantities of toxic bait that will potentially reduce concerns about 1080 poisoning because of a move away from broadcast sowing operations that are intuitively disliked by many, to much more localised baiting regimes.

Chronopharmacological studies of phenylbutazone in the rat

1983 ◽  
Vol 61 (6) ◽  
pp. 649-652 ◽  
Author(s):  
G. Labrecquf ◽  
P. M. Bélanger ◽  
F. M. Doré
Keyword(s):  
Lethal Dose ◽  
Circadian Variation ◽  
Temporal Variations ◽  
Paw Edema ◽  
Lethal Effects ◽  
Ulcerogenic Effect ◽  
Small Doses ◽  
The Mean ◽  
Anti Inflammatory ◽  
Inflammatory Action

Temporal variations in the anti-inflammatory action and in the ulcerogenic and lethal effects of phenylbutazone were studied in rats. The results indicate that small doses of the drug produced a larger reduction of paw edema in the morning than in the evening. At 0900, doses of 10, 30, and 100 mg/kg of phenylbutazone reduced the carrageenan-induced paw edema by 23, 44, and 66%, respectively. At 2000, the same doses of the drug decreased the paw edema by 9, 22, and 62%, respectively. No circadian variation was observed in the ulcerogenic effect of phenylbutazone. The mean lethal dose (LD50) of the drug was larger in the morning than in the evening and the values obtained were 710 ± 24 (SE) mg/kg at 0900 in comparison to 525 ± 38 (SE) mg/kg at 2000.

scholarly journals On some continuous observations of the rate of dissipation of electric charges in the open air

1905 ◽  
Vol 76 (508) ◽  
pp. 152-159 ◽  
Keyword(s):  
New Zealand ◽  
Individual Values ◽  
Similar Work ◽  
Maximum Value ◽  
Variable Quantity ◽  
The Mean ◽  
Atmospheric Conductivity ◽  
Rate Of Dissipation ◽  
The Individual ◽  
Sea Coast

During the latter part of 1902 and the early months of 1903 I resolved to take as many observations of the rates of dissipation of positive and negative electric charges as possible, and to continue them over the whole 24 hours of the day, and, when opportunity offered, over longer periods. There appeared to be little information regarding the rate of dispersion during the night hours. At about the same time that these observations were being made, Nilsson was doing similar work at Upsala, and found a noticeable maximum value for atmospheric conductivity at about midnight. The observations were made on the Canterbury Plains of New Zealand, at a station about 20 feet above sea-level and about five miles due west from the sea coast. The apparatus used was Elster and Geitel’s Zerstreuungs- apparat , and the formula of reduction used was that given by them, viz:- E = 1/ t log V 0 /V- n / t ' log V' 0 /V' . In this formula E is proportional to the conductivity of the gas surrounding the instrument—for positive or negative charges, as the case may be. The constant “ n ” = ratio of capacity without cylinder ____________________________________ capacity with cylinder was determined by me to be 0·47, as the instrument was always used, with the protecting cover. The cover was always at one height above the base of the instrument, and was set so as to be as nearly co-axial with the discharging cylinder as could be judged by eye. No attempt was made to determine the actual capacity of the condenser cylinder and protecting cover, which would be a somewhat variable quantity owing- (1) to the differences on different days in attempting to cause the two to be co-axial; (2) to a certain amount of looseness in the fit of the shank of the cylinder on to its hole. The value above given for “ n "is the mean of several deter­minations made with different settings of the cover and cylinder. The individual values of “ n ” varied over about 0.03.

Methane emissions from young and mature dairy cattle

2016 ◽  
Vol 56 (11) ◽  
pp. 1897 ◽  
Author(s):  
C. A. Ramírez-Restrepo ◽  
H. Clark ◽  
S. Muetzel
Keyword(s):  
New Zealand ◽  
Emission Factor ◽  
Dry Matter ◽  
Sulfur Hexafluoride ◽  
Dry Matter Intake ◽  
Tracer Technique ◽  
Ch4 Emissions ◽  
Dairy Heifers ◽  
Age Related ◽  
The Mean

Daily methane (CH4) emissions (g) and CH4 yield (g/kg dry matter intake) were measured from 10 dairy heifers (<1 year old) and nine rumen-fistulated cows (>6 years old) fed ryegrass (Lolium perenne) chaffage indoors. The CH4 emissions were estimated using the sulfur hexafluoride tracer technique in four ~5-day periods beginning in June 2008 and repeated 4, 6 and 7 months later. Respiratory chambers were used in four ~13-day periods beginning in November 2008 and repeated 2, 5 and 6 months later. Third and fourth sulfur hexafluoride tracer periods overlapped with the first and second chamber measurement periods, respectively. Averaged over the four measurement periods the CH4 yields determined using both techniques were similar for heifers and cows. The mean CH4 yield estimated by the sulfur hexafluoride tracer technique was 25.3 ± 0.52 for heifers and 24.1 ± 0.55 for mature cows, whereas the mean CH4 yield measured in respiratory chambers was 23.7 ± 0.66 for heifers and 23.6 ± 0.66 for mature cows. Averaged over the eight measurements irrespective of technique, CH4 yields for heifers (24.5 ± 0.42) and cows (23.8 ± 0.43) were similar. There was also no difference between CH4 methods for assessing CH4 yield during the overlapping measurement periods. It was concluded that no consistent differences in CH4 yield existed between heifers and mature cows. Therefore, we do not recommend adoption of an age-related emission factor for cattle in the national inventory calculations for New Zealand.

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.

scholarly journals Antibody level of New Zealand children immunized with the triple vaccine DTP (diphtheria-tetanus-pertussis)

1988 ◽  
Vol 101 (2) ◽  
pp. 405-410 ◽  
Author(s):  
R. C. H Lau
Keyword(s):  
New Zealand ◽  
Immunosorbent Assay ◽  
Antibody Level ◽  
Herd Immunity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Immunization Strategy ◽  
The Mean ◽  
Antibody Levels

SUMMARYEnzyme-linked immunosorbent assay (ELISA) tests were used to measure IgG antibody levels in 2638 New Zealand children who had been immunized with the triple vaccine DTP. The percentage of children immune to diphtheria decreased with age. The percentage of children immune to tetanus varied from 67.1 to 55.0%. The percentage of children with measurable antibody to pertussis increased with age. The mean percentages of children with measurable antibody or immunity to one or more DTP components were 34.2% (with 3 components), 34.4% (2 components), and 78.1% (1 component). It appears the immunization strategy for diphtheria and tetanus is satisfactory for herd immunity in New Zealand children. However, the current pertussis strategy may not be providing adequate immunity to 5-year-olds in this country.

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
Sign in / Sign up

Export Citation Format

Share Document