How Does a Carnivore Guild Utilise a Substantial but Unpredictable Anthropogenic Food Source? Scavenging on Hunter-Shot Ungulate Carcasses by Wild Dogs/Dingoes, Red Foxes and Feral Cats in South-Eastern Australia Revealed by Camera Traps

Abstract ContextWild dogs, including dingoes and dingo cross-breeds, are vertebrate pests when they cause financial losses and emotional costs by harming livestock or pets, threaten human safety or endanger native fauna. Tools for lethal management of these animals currently include aerial baiting with poisoned baits. In New South Wales (NSW), Australia, aerial baiting was previously permitted at a rate of 40 baits km−1 but a maximum rate of 10 baits km−1 was subsequently prescribed by the Australian Pesticides and Veterinary Medicines Authority. The efficacy of these baiting rates has not been quantified in eastern Australia, undermining the value of the policy and rendering adaptive management efforts difficult, at best. AimTo quantify the mortality rate of wild dogs exposed to aerial baiting at historic and currently approved rates, i.e. 40 baits per kilometre and 10 baits per kilometre, respectively. MethodsWild dog mortality rates were measured at sites in mesic north-eastern NSW, where aerial baiting was applied to control wild dogs and contrasted with sites and individuals where no baiting was undertaken. In total, 132 wild dogs were trapped and fitted with GPS-VHF telemetry collars before annual aerial baiting programs. Collars were used to locate animals after aerial baiting and to determine the fates of individuals. Key results90.6% of collared wild dogs exposed to aerial baiting at 40 baits km−1 died, whereas only 55.3% of those exposed to 10 baits km−1 died (Welsh’s t=4.478, P=0.004, v=6.95). All wild dogs that were not exposed to toxic baits survived during the same periods. ConclusionManagers using aerial baiting to maximise wild dog mortality in mesic south-eastern Australia should use 40 baits km−1 rather than 10 baits km−1. ImplicationsWild dog population reduction for mitigation of livestock and faunal predation requires the application of efficacious control. The currently prescribed maximum aerial baiting rate of 10 baits km−1 is inadequate for controlling wild dog populations in mesic forest environments in NSW.

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Bait-delivered cabergoline for the reproductive control of the red fox (Vulpes vulpes): estimating mammalian non-target risk in south-eastern Australia

Reproduction Fertility and Development ◽

10.1071/rd01076 ◽

2001 ◽

Vol 13 (8) ◽

pp. 499 ◽

Cited By ~ 10

Author(s):

Clive A. Marks

Keyword(s):

Vulpes Vulpes ◽

Post Partum ◽

Mammalian Species ◽

Limited Range ◽

Mammary Development ◽

Red Foxes ◽

South Eastern ◽

Eastern Australia ◽

High Doses ◽

South Eastern Australia

Cabergoline (CAB) is a potent dopamine agonist and an inhibitor of prolactin (PRL). In red foxes (Vulpes vulpes), a single oral dose of 100 g kg–1 CAB can cause abortions and postnatal cub mortality from at least Day 21 of the 52-day pregnancy. The abortifacient activity of CAB is owing to the suppression of PRL, which is essential for luteotrophic support in some eutherian species. Postnatal cub mortality probably results from a reduction in the development of the mammary ductile system, which is also partially dependant on PRL during pregnancy. This paper investigates the potential risks faced by non-target mammalian species that may consume CAB baits intended for fox control. Baiting with CAB is proposed from 1 August until 1 October each year, to correspond with the time that most vixens are pregnant in south-eastern Australia. Thirty-four endemic mammals in south-eastern Australia (9 eutherians and 25 marsupials) are considered to be potentially bait-consuming (PBC) species. The percentage overlap of pregnancy and birth periods for each PBC species was compared with the duration of the proposed CAB baiting period. Only Antechinus (3 species) and Sminthopsis leucopushave greater than 40% overlap, whereas overlap in endemic rodents ranges from 0% to 22%. Overall, most PBC rodent populations appear to face little risk from CAB baiting, as their period of pregnancy does not overlap significantly with the proposed CAB baiting period. The Antechinus species, Phascogale tapoatafa and Dasyurus maculatus are the only PBC mammals that are seasonally mono-oestrous and are thus probably more susceptible to disruption of breeding compared with polyoestrous species that may breed many times a year. At a baiting density of 8 baits km–2, theoretical bait availability for small dasyurids, rodents and peramelids is low. This suggests a low potential for affecting these populations if CAB was indiscriminate in affecting reproductive success in all mammal groups. Presently, studies in a limited range of marsupials suggest that, unlike eutherians, the marsupial corpus luteum is independent of pituitary control and thus suppression of PRL is not likely to cause abortions in marsupials. As yet, CAB has not been shown to be orally active in any PBC species other than rodents and carnivores. Oral doses of CAB given post partum have not been found to affect lactation in Sminthopsis crassicaudata,Trichosurus vulpecula, Macropus eugenii andSetonix brachyurus. Further studies are required in order to assess the potential for high doses of oral CAB to affect pre-partum mammary development and early lactation post partum, especially in peramelids and larger dasyurids. Highly target-specific baiting techniques, may eliminate most PBC species from being exposed to CAB and these are briefly discussed.

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The Effect on Wild Dogs, Canis-F-Familiaris, of 1080-Poisoning Campaigns in Kosciusko-National-Park, Nsw

Wildlife Research ◽

10.1071/wr9860535 ◽

1986 ◽

Vol 13 (4) ◽

pp. 535 ◽

Cited By ~ 21

Author(s):

JC Mcilroy ◽

RJ Cooper ◽

EJ Gifford ◽

BF Green ◽

KW Newgrain

Keyword(s):

National Park ◽

Home Ranges ◽

Rapid Loss ◽

Grazing Land ◽

Control Zone ◽

South Eastern ◽

Eastern Australia ◽

Radio Transmitters ◽

Wild Dogs ◽

South Eastern Australia

Nine wild dogs, Canis f. familiaris, radio-tracked over periods of 28-61 days in Kosciusko National Park, N.S.W., occupied home ranges of 220-5420 ha (mean 2193 ha). These home ranges were similar in size to those observed for dingoes, C. f. dingo, in other areas of south-eastern Australia. The maximum distance that any of the nine dogs moved between successive daily locations was 11.2 km. On the basis of this information and that obtained by others, we suggest that the control of wild dogs on Crown Land in south-eastern Australia should be confined to those areas adjacent to private grazing land. Furthermore, a control zone 12-20 km wide should be adequate. Two successive trail-baiting campaigns with 1080 poison in March and April 1982 killed only two (22%) of the nine wild dogs carrying radio transmitters. Traps, in comparison, caught 15 out of 27 (56%) of the dogs known to be in the area. The main factors which reduced the success of the poisoning campaign were the rapid loss of toxicity of the baits after their distribution, the rapid rate at which they were removed by other animals, particularly foxes Vulpes vulpes and birds, and the dogs' apparent preference for natural prey.

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