Anticoagulant effects and the persistence of brodifacoum in possums ( Trichosurus vulpecula )

Ship rats in a North Island podocarphardwood forest were poisoned using brodifacoum in cereal baits presented in bait stations. Livers from 68% of 25 rats captured during and up to three months after poisoning contained brodifacoum residues. Following a rat-and possum-poisoning operation in another podocarp forest, 78% of 40 stoats, 71% of 14 weasels, and 56% of 16 ferrets trapped contained brodifacoum residues. Residue levels in stoats were greater during the three months following the removal of baits than during the poison operation. Female stoats were more likely to contain brodifacoum residues than males, perhaps the result of differences in the dietary habits of the sexes. Brodifacoum was also detected in the livers of the only morepork and in two out of 10 magpies Received 15 December 1997; accepted 1 May 1998 sampled by shooting, but was absent from the livers of four robins, five tomtits, six whiteheads, one bellbird, one fantail, one harrier and four red deer. All five pigs and two cats either shot, caught or found dead contained the toxin residues. This study emphasises the potential ecological and human health risks that flow-on from the use of anticoagulant poisons in New Zealand forests. Z97044

Section: Discussionmentioning

confidence: 98%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Brodifacoum residues in target and non‐target animals following large‐scale poison operations in New Zealand podocarp‐hardwood forests

Murphy¹,

Clapperton²,

Bradfield³

et al. 1998

“…Originally we had planned to use brodifacoum as our rat control toxin for at least another year, but when the results from the toxin assays revealed traces of this persistent and cumulative poison (Eason et al 1996;Eason 1999) in the livers of the kiwi chicks, we decided to opt for less persistent toxins to reduce any risks to native fauna. The difficulty was that we were trialling toxins and bait formulations that had, with the exception of 1080, rarely (if ever) been used to control rodents in New Zealand before.…”

Section: Pest Controlmentioning

confidence: 99%

Six years of intensive pest mammal control at Trounson Kauri Park, a Department of Conservation “mainland island”, June 1996—July 2002

Gillies¹,

Leach²,

Coad³

et al. 2003

Trounson Kauri Park is a 445-ha fragment of kauri-podocarp forest located in western Northland, New Zealand, and is one of a series of "mainland island" ecosystem restoration projects managed by the Department of Conservation. One of the main objectives at Trounson is to reduce introduced mammalian pest numbers to a level that would allow recovery of those native species still present in the park and allow the reintroduction of local or regionally extinct species.Brushtail possums (Trichosurus vulpecula) and rodents (ship rats, Rattus rattus, Norway rats, R. norvegicus, and mice, Mus musculus) were targeted in poison baiting operations using 1080, various anticoagulants, cholecalciferol or cyanide pellets laid in bait stations within the park. These operations suppressed possum and rat numbers to low levels, but mouse numbers were reduced only for short periods. The reduction in possum and rat numbers allowed significant seasonal increases in kukupa (New Zealand wood pigeon, Hemiphaga novaeseelandiae) abundance. Feral cats (Felis catus) and mustelids (stoats, Mustela erminea, weasels, M. nivalis, and ferrets, M.furo) were trapped around the forest boundaries and at key locations within and around the park.The predator trapping consistently provided predation relief for North Island brown kiwi (Apteryx australis mantelli) chicks, which are extremely vulnerable to predation by stoats, such that enough survived in order to sustain and increase the size of the adult population. Attempts were made to reestablish breeding populations of North Island robins (Petroica australis longipes), North Island kokako (Callaeas cinerea wilsoni), and brown teal (Anas aucklandica chlorotis) (three species of locally extinct native birds) to Trounson, but these were only partially successful at best.

“…Compound Sample Eason et al 1996. Wairarapa in June 1994 (Meenken & Booth 1997). To assess the risk of secondary poisoning, samples of the stomach and their contents from 1080-poisoned possum carcasses were collected up to and including 75 days after the control operation.…”

Section: Speciesmentioning

confidence: 99%

Secondary poisoning risks from 1080-poisoned carcasses and risk of trophic transfer—a review

Eason¹,

Ross²,

Miller

2013

In New Zealand, sodium fluoroacetate (1080) is used for the control of unwanted terrestrial vertebrate pests, some of which are carriers of bovine TB, and for the conservation of native flora and fauna. One key advantage of 1080 used for animal pest control is that it is biodegradable. In this short review, we focus on the persistence of 1080 in carcasses and the risk of 1080-poisoned carcasses to dogs, and the possible risk of toxicity in other non-target species via trophic transfer. The slower breakdown of 1080 in poisoned carcasses under certain conditions (e.g. cold, dry conditions), and the risks of secondary poisoning, have to be understood and managed following use of this toxin in conservation or as part of TB eradication programs. Poisoned possum carcasses can pose a risk to dogs even up to 75 days after the control operation. Lower, less hazardous concentrations have been found in deer bone marrow after 213 days. When other species (e.g. insects or birds) come into contact with 1080 in carcasses, sublethal poisoning is more likely. In these cases, as with sub-lethal poisoning in any non-target animals, any 1080 ingested will be metabolised and excreted, and trophic transfer will be minimal when compared to more persistent poisons.