Vertebrate Pesticides Research Articles

Sub-lethal exposure to a mammalian pesticide bait alters behaviour in an orthopteran

Pesticides are a crucial tool to control introduced pest species, facilitating restoration of native ecosystems and reducing mortality risk in endemic species. However, non-target species, including many invertebrates, consume pesticides. Although lethal effects on these non-target species are often documented, sub-lethal effects are poorly understood. New Zealand presents a unique case study in this field, with a range of introduced mammalian pest species that threaten a large proportion of endemic fauna. Current research suggests that vertebrate pesticide baits do not cause mortality in invertebrate consumers, but few studies investigate sub-lethal behavioural effects. In this study, we tested whether consumption of a widely dispersed anticoagulant rodenticide, brodifacoum, influenced the expression and repeatability of behaviour in a known consumer of the bait, Wellington tree weta (Hemideina crassidens) over a 40-day treatment period. We compared refuge emergence, activity, refuge-seeking tendencies and defensive responses of brodifacoum-exposed and untreated control weta. Bait-exposed individuals showed increased emergence but decreased activity, boldness and aggression compared to untreated controls. These results show that brodifacoum, although not directly causing mortality, may alter behaviours directly related to foraging, mating, competitive interactions and anti-predator responses, which could be detrimental to fitness and survival. More research should be undertaken to investigate the capacity for H. crassidens to tolerate exposure, and to determine any age- or duration-related responses. These results should also be a catalyst for further research on non-target behavioural effects in other pesticide-exposed insect species.

Technology Advances for Vertebrate Pest Eradication

Author(s): Eason, Charles; Shapiro, Lee; Ross, James; Murphy, Elaine; Ogilvie, Shaun; MacMorran, Duncan; Jackson, Michael; Irie, Kenji; Inder, Shane; Clout, Mick; Rennison, David; Brimble, Margaret | Abstract: Internationally, over the last 20 years the number of tools available for the control of small mammals has declined. Through the efforts of research we have bucked this trend and retained and developed new tools. Three new toxins have been extensively researched and registered, namely para-aminopropiophenone (PAPP) in 2011 for stoats and feral cats; zinc phosphide for possums in 2012; and encapsulated sodium nitrite (ESN) in 2013, for possums and feral pigs. The development of PAPP and ESN, coined red blood cell toxins, developed for humaneness, represent the first new vertebrate pesticides registered for field control of mammalian pests anywhere in the world for g30 years. Research on rodenticides including diphacinone with the additive cholecalciferol (D+C) and a palatable form of norbormide continues. A New Zealand EPA application for D+C was filed in June 2015. More effective killing systems are being researched, and the first successful field trials of resetting toxin delivery devices for possum and stoat control were completed in 2013 and 2014. Improved deployment strategies, integration of humane and selective toxins, lures of greater potency, and improved killing devices aided by species’ recognition will transform ground control for endangered species protection. Sodium fluoroacetate (1080) and other important tools have been retained as new tools are emerging from a research and development pipeline. It is important for the future of New Zealand’s biodiversity that this focused research continues and we continue to learn and advance new technologies. Our goals are shifting to enable reduction in density of rat, stoat, and possum populations to zero over large scales (i.e., elimination at landscape scale), and to hold these at zero through detection and response, including the use of new technologies for perimeter control as part of barrier systems for conservation.

Nontarget mortality of New Zealand lesser short-tailed bats (Mystacina tuberculata) caused by diphacinone.

Primary and secondary poisoning of nontarget wildlife with second-generation anticoagulant rodenticides has led to restrictions on their use and to increased use of first-generation anticoagulants, including diphacinone. Although first-generation anticoagulants are less potent and less persistent than second-generation compounds, their use is not without risks to nontarget species. We report the first known mortalities of threatened New Zealand lesser short-tailed bats (Mystacina tuberculata) caused by diphacinone intoxication. The mortalities occurred during a rodent control operation in Pureora Forest Park, New Zealand, during the 2008-09 Austral summer. We observed 115 lesser short-tailed bat deaths between 9 January and 6 February 2009, and it is likely that many deaths were undetected. At necropsy, adult bats showed gross and histologic hemorrhages consistent with coagulopathy, and diphacinone residues were confirmed in 10 of 12 liver samples tested. The cause of mortality of pups was diagnosed as a combination of the effects of diphacinone toxicity, exposure, and starvation. Diphacinone was also detected in two of 11 milk samples extracted from the stomachs of dead pups. Eight adults and 20 pups were moribund when found. Two adults and five pups survived to admission to a veterinary hospital. Three pups responded to treatment and were released at the roost site on 17 March 2009. The route of diphacinone ingestion by adult bats is uncertain. Direct consumption of toxic bait or consumption of poisoned arthropod prey could have occurred. We suggest that the omnivorous diet and terrestrial feeding habits of lesser short-tailed bats make them susceptible to poisoning with the bait matrix and the method of bait delivery used. We recommend the use of alternative vertebrate pesticides, bait matrices, and delivery methods in bat habitat.

Para-aminopropiophenone and its Registration and Use as a Vertebrate Pesticide in New Zealand

Author(s): Eason, Charles; Murphy, Elaine; MacMorran, Duncan | Abstract: PAPP is short for para-aminopropiophenone and is a new vertebrate pesticide. It is a compound with the formula C9H11NO, it is comparative humane, has low secondary poisoning risk, and has an antidote. PAPP was originally trialed in the 1960s as an antidote for human radiation and cyanide poisoning. In the USA, it has been investigated as a tool for coyote control and was found to be specifically much more toxic to carnivores than to birds and humans. In Australia, it will be used for field control of foxes, wild dogs, and feral cats. In New Zealand, PAPP was registered in 2011 for the control of stoats and feral cats, following the completion of pen and field trials and submission of extensive dossiers covering its effectiveness as a pest control agent and on its ecotoxicology, toxicology, and metabolism.

Innovative developments for long‐term mammalian pest control

Invasive mammalian pests have inflicted substantial environmental and economic damage on a worldwide scale. Over the last 30 years there has been minimal innovation in the development of new control tools. The development of new vertebrate pesticides, for example, has been largely restricted due to the costly and time-consuming processes associated with testing and registration. In this article we discuss recent progress and trends in a number of areas of research aimed to achieve long-term population suppression or eradication of mammalian pest species. The examples discussed here are emerging from research being conducted in New Zealand, where invasive mammalian pests are one of the greatest threats facing the national environment and economy.

A review of recent non-target toxicity testing of vertebrate pesticides: establishing generic guidelines

An analysis of the range, extent and importance of New Zealand-based ecotoxicology studies has been completed to better understand the hazards and non-target risks associated with new toxins and baits. This review focuses on compounds that have been recently developed for incorporation into bait for terrestrial vertebrate pest control, namely cholecalciferol, para-aminopropiophenone (PAPP) and zinc phosphide and the effects of these toxins on non-target species. Testing of these compounds has included cage and pen toxicity and bait acceptance studies. Locally conducted acute toxicity studies clarify overseas data and enhance risk assessments. Consistency in approach and selection of surrogate species, and careful selection of native non-target species for acute toxicity testing in cage and pen trials are recommended as important steps before field trials. We propose a systematic approach to cage and pen trials and offer guidelines on species selection.

Reference concentrations of cholecalciferol in animals: a basis for establishing non-target exposure

Cholecalciferol (vitamin D3) is widely used as a vertebrate pesticide in New Zealand. However, cholecalciferol also occurs naturally in animals. Therefore, when trying to determine whether a non-target animal has been exposed to cholecalciferol baits, knowledge of the baseline cholecalciferol concentrations in the animal's plasma and tissue is required. We analysed cattle, sheep, pig, deer, dog and cat plasma and liver samples for the vitamin D3 metabolite 25-hydroxycholecalciferol (25-OHD), a sensitive biomarker for cholecalciferol. Based on these data and a literature search we present 25-OHD reference ranges. We also examined the literature for 25-OHD concentrations in poisoned animals and compared these to the reference ranges. Where plasma and liver samples have 25-OHD concentrations at least four times higher than our reference ranges it is likely that the animal has been exposed to cholecalciferol baits. 25-OHD concentrations 10 times higher than the reference range indicate ingestion of abnormally high amounts of cholecalciferol.

Protecting Nontarget Wildlife from Effects of Vertebrate Pesticides

Author(s): McMillin, Stella C. | Abstract: The California Department of Fish and Game (DFG) recognizes the need for the availability of a variety of tools for vertebrate pest control and has a strong interest in ensuring that these tools are used in a way that minimizes impacts to nontarget wildlife. From 1992 to 2011, the DFG has investigated 44 cases of wildlife kills caused by vertebrate pesticides, resulting in the loss of 258 animals. While anticoagulant rodenticides were responsible for the loss of the highest number of incidents, incidents involving acute toxicants, such as strychnine and zinc phosphide, typically involved a greater number of animals per incident. Incidents of intentional poisoning of wildlife usually involved strychnine. There were no documented losses due to fumigants; however, such incidents are likely to go unnoticed because the carcasses remain underground.

Is sodium fluoroacetate (1080) a humane poison? The influence of mode of action, physiological effects, and target specificity

Abstract1080 (sodium fluoroacetate)-baiting programmes are an important and often the only option for reducing the impact of invasive vertebrate pests on biodiversity and agricultural production in Australia and New Zealand. These programmes are generally recognised as being target specific, and environmentally and user safe. Nevertheless, although 1080 has few recognised long-term side-effects, its potential to disrupt endocrine systems has been recently raised, and there is some conjecture regarding the humaneness of 1080 for certain target species. However, the assessment of the humaneness of any vertebrate pesticide must be commensurate with its mode of action, metabolism, target specificity, and operational use. This has not always occurred with 1080, particularly regarding these aspects, and its overall effects. The actual risk faced by non-target species during baiting operations is not accurately reflected simply by their sensitivity to 1080. 1080 is not endocrine-disrupting or carcinogenic, and because of the lag phase before signs of poisoning occur, the time from ingestion to death is not a reliable indicator of its humaneness. Moreover, functional receptors and neurological pathways are required to experience pain. However, as 1080 impairs neurological function, mainly through effects on acetylcholine and glutamate, and as this impairment includes some pain receptors, it is difficult to interpret the behaviour of affected animals, or to assess their ability to experience discomfort and pain. This has implications for assessing the merits of including ameliorative agents in 1080 baits aimed at further improving welfare outcomes. We also suggest that the assessment of the humaneness of any vertebrate pesticide should follow the ethical pest control approach, and on this basis, believe that the use of 1080 to reduce the detrimental impacts of invasive vertebrates is ethical, particularly with respect to the expectations of the wider community.

Alternatives to brodifacoum and 1080 for possum and rodent control—how and why?

The risks of vertebrate pesticides to non-target animals are determined by intrinsic susceptibility, the toxicokinetics of the compounds used, and the degree and frequency of exposure. Metabolism and persistence studies coupled with field surveys have provided us with an improved understanding of the toxicokinetics and non-target effects of different anticoagulants. This has enabled improved choice of tools for island versus mainland use in New Zealand, and has stimulated the development of low-residue tools. Brodifacoum is a potent second-generation rodenticide used worldwide for commensal rodent control, and has been widely used to eradicate rodents from islands. The risks associated with ‘one-off’ application of baits containing second-generation anticoagulants for rodent eradication on islands are considered to be outweighed by the potential benefits to their ecosystems. Possums are susceptible to bait containing brodifacoum, but not to first-generation anticoagulants, hence brodifacoum has been the only alternative to 1080 that effectively targets both possums and rodents. On the mainland, contamination of wildlife and game species and secondary poisoning of non-target species has been substantial where brodifacoum has been used repeatedly. We are extending the current range of low residue alternatives to reduce reliance on brodifacoum and sodium fluoroacetate (1080). Currently, suitable alternatives available include encapsulated cyanide Feratox® and cholecalciferol paste Feracol®. Other compounds being developed as alternatives include micro-encapsulated zinc phosphate and low dose cholecalciferol and coumatetralyl, or C+C.

A review of existing and potential New World and Australasian vertebrate pesticides with a rationale for linking use patterns to registration requirements

Registration is a necessarily sophisticated evaluation process applied to vertebrate pesticide products. Although conducted to minimise any potential impacts upon public health, the environment and food production, the all-encompassing process of registration can stifle innovation. Vertebrate pesticides are rarely used to control pest animals in food crops. In contrast to agrochemicals, relatively small amounts of vertebrate pesticides are used (<0.1%), usually in solid or paste baits, and generally by discrete application methods rather than by broad-scale spray applications. We present a hierarchy or sliding scale of typical data requirements relative to application techniques, to help clarify an evolving science-based approach which focuses on requiring data to address key scientific questions while allowing waivers where additional data have minor value. Such an approach will facilitate the development and delivery of increasingly humane, species-targeted, low residue pesticides in the New World, along with the phasing out of less desirable chemicals that continue to be used due to a lack of alternatives.

Vertebrate pesticide risk assessment by indigenous communities in New Zealand

In New Zealand, the vertebrate pesticide sodium fluoroacetate (Compound 1080) is aerially applied in baits for control of the brush-tailed possum Trichosurus vulpecula (Kerr, 1792). Maori, the indigenous people of New Zealand, have raised concerns about 1080 impacts on culturally-important species. Here, we outline two steps taken to help Maori assess 1080 risk. First, field research was undertaken to determine if naturally-occurring plants utilized by a Maori community for food and medicine would take up 1080 from baits. Single baits were placed at the base of individual plants of two species, pikopiko (Asplenium bulbiferum) and karamuramu (Coprosma robusta). Plants were sampled at various times up to 56 days, and samples were analyzed for 1080 content. No 1080 was detected in any of the pikopiko samples, whereas 1080 was detected in karamuramu, at a maximum concentration of 5 ppb after seven days, and 2.5 ppb after 14 days. This concentration decreased to 0 at 28 days, indicating that 1080 was not persistent. The results of the present study suggest there is negligible risk of humans being poisoned by consuming plants that have taken up 1080 from baits. To allay community concerns that minute concentrations of 1080 might influence the medicinal properties of plants, it is suggested that a withholding period of 30 days after 1080 control operations could be adopted. Second, after further consultation we undertook a review of the scientific literature relating to 1080 impacts on additional non-target species of cultural importance to Maori. The information was presented on an interactive foodweb database that allowed the collection and presentation of a large volume of complex information about 1080 in a holistic and pictorial fashion. This database was presented to many Maori communities throughout New Zealand, and feedback was overwhelmingly positive. The database is likely to play a key role in informing these communities about 1080, and is seen as an important new tool to help these communities make their own risk assessments.

Trends in Vertebrate Pesticide Use and New Developments: New Zealand Initiatives and International Implications

Author(s): Eason, Charles; Murphy, Elaine; Ogilvie, Shaun; Blackie, Helen; Ross, James; Kavermann, Mathew; Sam, Shona; Statham, Mick; Statham, Helen; Lapidge, Steven; Humphrys, Simon; Henderson, Ray; MacMorran, Duncan; Gibson, Troy; Gregory, Neville; Harrison, Joanne; Giles, Gregory; Sammut, Ivan; Jansen, Paul; Conole, Daniel; Rennison, David; Brimble, Margaret | Abstract: In New Zealand, sodium fluoroacetate (1080) has been used for vertebrate pest control for several decades. Since the 1990s, some 1080 users have switched to brodifacoum for possum and rodent control because of its ready availability and ease of use. An awareness that field use of brodifacoum results in persistent residues provides the impetus to develop alternatives and provide new tools and greater flexibility. Looking to the future, we seek toxins which increasingly combine “low-residue” characteristics with humaneness, and more selective bait and delivery systems enabling better and more acceptable control of possums, wallabies, mustelids, rodents, feral cats, and rabbits. Experience gained in the 1990s with the introduction of cholecalciferol (Feracol®) and a cyanide pellet (Feratox®), which both kill possums without secondary poisoning, underpins the extension in 2009 of the Feratox® registration to include introduced Dama wallabies. To date, zinc phosphide has not been registered in NZ, despite its field use in Australia and the U.S. and low secondary poisoning risk compared with 1080. Research and registration dossiers are being assessed in 2009-10 for zinc phosphide containing products for possum and rodent control. Registration documents are also being prepared for a combination of cholecalciferol and coumatetralyl to provide a slow-acting alternative to brodifacoum for the field control of possums, rodents, and rabbits with low risk of bio-accumulation. Anticipated timelines for product availability are 2010 (zinc phosphide) and 2011-13 (cholecalciferol and coumatetralyl). Our intention now is to move beyond these conventional rodenticides and develop new vertebrate pesticides. For example, we are pursuing the registration of para-aminopropiophenone (PAPP) for humane control of stoats and feral cats, and a series of related novel toxins and other compounds that target the red blood cell for other pest species including rodents. PAPP products should be available in 2010, subject to registration approvals. New research initiatives in 2010 will increasingly result in a shift in focus to the development of novel rodenticides aided by new international research collaborations.

Para-aminopropiophenone (PAPP) Research, Development, Registration, and Application for Humane Predator Control in New Zealand

Feral cat and stoat control is conducted in New Zealand to protect a number of threatened native species, including kiwi, from predation. Para-aminopropiophenone (PAPP) is being developed for predator control. Previously reported cage trials have shown PAPP presented in a meat bait was palatable and effective, while symptoms observed demonstrated PAPP to be humane. Subsequent field trials on stoats were undertaken in two blocks of native forest and achieved 83% and 87% reductions in the stoat abundance index, and a field trial on a population of radio-collared feral cats had an 84% kill. PAPP represents one compound from a new class of active ingredients, which we are calling red blood cell toxins. These vertebrate pesticides have humaneness, and low secondary and non-target poisoning risks, as their primary consideration. The dose is optimised to be effective in the field and reduces oxygen supply to the brain such that animals become lethargic, sleepy and unconscious prior to death within 1-2 hours. Results from these field trials on stoats and feral cats indicate that PAPP will be a useful additional tool for predator control.

Uptake of the Vertebrate Pesticide 1080 (Sodium Fluoroacetate) by Watercress, a Culturally Important Food Plant

Author(s): Ogilvie, Shaun C.; Miller, Aroha; Ataria, James M.; Waiwai, James; Doherty, James | Abstract: A field-based experiment was carried out to determine if watercress, commonly harvested by Māori, the indigenous people of New Zealand, could take up the vertebrate pesticide sodium fluoroacetate (Compound 1080), often applied aerially in New Zealand for the control of introduced vertebrate pests. Single toxic baits were placed within seven watercress stands, while three stands received non-toxic controls. Water and plant tissue samples were taken out to 17 days after bait placement, and samples analysed for 1080 content. 1080 was recorded from treatment watercress samples, with a maximum concentration of 63 ppb recorded on Day 7. Subsequent sampling did not show any 1080 in watercress tissue. It is concluded that there is a negligible secondary poisoning risk to humans via consumption of watercress after exposure to 1080.

A review of chemical, biological and fertility control options for the camel in Australia

Since their introduction to Australia in 1840 the one-humped camel, Camelus dromedarius, has gone from the colonist’s companion to a conservationist’s conundrum in the fragile arid ecosystems of Australia. Current management techniques are failing to curb present population growth and alternatives must be sought. This review assess the applicability of currently registered and developmental vertebrate pesticides and fertility control agents for camel control, as well as examining the potential usefulness of known C. dromedarius diseases for biological control. Not surprisingly, little is known about the lethality of most vertebrate pesticides used in Australia to camels. More has been published on adverse reactions to pharmaceuticals used in agriculture and the racing industry. An examination of the literature on C. dromedarius diseases, such as camel pox virus, contagious ecthyma and papillomatosis, indicates that the infections generally result in high morbidity but not necessarily mortality and this alone may not justify their consideration for use in Australia. The possibility exists that other undiscovered or unstudied biological control agents from other camilid species may offer greater potential for population control. As a long-lived species the camel is also not ideally suited to fertility control. Notwithstanding, anti-fertility agents may have their place in preventing the re-establishment of camel populations once they have been reduced through mechanical, biological or chemical means. Delivery of any generic chemical or fertility control agent will, however, require a species-tailored pathway and an appropriate large-scale deployment method. Accordingly, we put forward avenues of investigation to yield improved tools for camel control.

Vertebrate Pest Control Research Advisory Committee (VPCRAC): California’s Approach to Supporting Vertebrate Pest Control

As a result of increasing concern over rodenticide registration, in 1990, the California Legislature passed a law to collect $0.50 per pound surcharge on all vertebrate pest control materials sold by county agricultural commissioners in the state of California. Monies collected are used to fund research required to maintain the state’s current vertebrate pesticide registrations, to improve existing rodenticides, and to find new materials and methods to solve California’s vertebrate pest problems. A Vertebrate Pest Control Research Advisory Committee was established to administer this fund and set research priorities. To date, the program has raised more than $9 million to meet its objectives. The history, operation, and accomplishments of the surcharge fund are discussed in this report. A summary of projects funded is presented.

Assuring that 1080 toxicosis in the red fox (Vulpes vulpes) is humane. II. Analgesic drugs produce better welfare outcomes

Fluoroacetic acid (1080) is a widely used vertebrate pesticide in Australia and New Zealand. In Australia it is used in meat baits as the primary method of control for the introduced red fox (Vulpes vulpes). Subsequent to the onset of initial signs, collapse and convulsions are associated with central nervous system disruptions where the animal is unresponsive to external stimuli, making an assessment of humaneness difficult. Prior to collapse and unconsciousness it would appear that there is potential for suffering to occur although its extent and nature during the entire toxicosis remains unclear. We investigated various formulations of 1080 with either analgesic or anxiolytic drugs in order to manage possible suffering experienced during 1080 poisoning of red foxes. Oral doses of 0.5 mg kg−1 1080 alone produced no visible signs for a mean of 205.3 min (±28 min, P &lt; 0.05), but were lethal after signs that lasted a mean of 103 min (±16 min, P &lt; 0.05). Combinations of 0.5 mg kg−1 1080 with either 10 mg kg−1 carprofen (CA), 0.4 mg kg−1 copper indomethacin (CI) or 10 mg kg−1 buspirone (BS) were assessed in pen trials and compared with a group that received 0.5 mg kg−1 1080 only and one that received the drug dose only. CI reduced the time between the onset of signs and death (P &lt; 0.01) and CA reduced the overall intensity of activity from dosage to death (P &lt; 0.05). A significant reduction in the incidence of retching during the onset of signs was observed in foxes that were coadministered CA (P &lt; 0.05) or CI (P &lt; 0.01) with 1080 compared with 1080 alone. The combination of BS and 1080 halved the mean activity from first signs to death, but was not statistically significant. In a separate trial, drug and 1080 combinations were delivered to penned foxes using an M-44 ejector. Neither 70 mg CA nor 2.8 mg CI appeared to affect the lethality of 1080 doses, although 70 mg BS produced a result that was equivocal and warrants further investigation. Coadministration of 70 mg diazepam was associated with the survival of six of nine foxes and suggests that there may be the potential for diazepam to act in the treatment of accidentally poisoned domestic dogs and this is discussed briefly. Given evidence for both central and peripheral analgesia, its potential to reduce the duration of signs and incidence of retching, CI shows immediate potential to be used with 1080 fox baits and to assist in delivering better welfare outcomes in fox control.

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

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.

Delivering and registering species-tailored oral antifertility products: a review

Technologies that induce infertility in wildlife are advancing rapidly. This is due largely to our increasing understanding of reproductive physiology, as well as the demand for management techniques that reduce fertility rather than increase mortality. However, transferring wildlife fertility control from the laboratory into landscape-scale utility for free-ranging animal populations will be highly dependent on products possessing oral activity and cost-effectiveness. A significant challenge to the delivery process is providing the international regulators in each jurisdiction with the most relevant data packages they need to assess new products. An essential part of any product registration for free-ranging animals will be the development of species-tailored delivery systems, especially so for non-specific antifertility actives. This review examines the current range of orally deliverable antifertility options, broadly classifies them according to overall risk compared with alternative vertebrate pesticides, outlines a species-tailoring process that reduces identified risks, and encompasses the data requirements for their registration for sale in Australasia, the USA and Europe.