Assessing Risks to Non-Target Species during Poison Baiting Programs for Feral Cats

Context Poison baits are often used to control both foxes and feral cats but success varies considerably. Aims This study investigated the influence of bait type, placement and lures on bait uptake by the feral cat, red fox and non-target species to improve baiting success and reduce non-target uptake. Methods Six short field trials were implemented during autumn and winter over a five-year period in northern South Australia. Key results Results suggest that poison baiting with Eradicat or dried kangaroo meat baits was inefficient for feral cats due to both low rates of bait detection and poor ingestion rates for baits that were encountered. Cats consumed more baits on dunes than swales and uptake was higher under bushes than in open areas. The use of auditory or olfactory lures adjacent to baits did not increase ingestion rates. Foxes consumed more baits encountered than cats and exhibited no preference between Eradicat and kangaroo meat baits. Bait uptake by native non-target species averaged between 14 and 57% of baits during the six trials, accounting for up to 90% of total bait uptake. Corvid species were primarily responsible for non-target uptake. Threatened mammal species investigated and nibbled baits but rarely consumed them; however, corvids and some common rodent species ingested enough poison to potentially receive a lethal dose. Conclusions It is likely that several factors contributed to poor bait uptake by cats including the presence of alternative prey, a preference for live prey, an aversion to scavenging or eating unfamiliar foods and a stronger reliance on visual rather than olfactory cues for locating food. Implications Further trials for control of feral cats should concentrate on increasing ingestion rates without the requirement for hunger through either involuntary ingestion via grooming or development of a highly palatable bait.

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Efficacy and welfare assessment of an encapsulated para-aminopropiophenone (PAPP) formulation as a bait-delivered toxicant for feral cats (Felis catus)

Wildlife Research ◽

10.1071/wr19171 ◽

2020 ◽

Vol 47 (8) ◽

pp. 686

Author(s):

Michael Johnston ◽

Dave Algar ◽

Michael O'Donoghue ◽

Jim Morris ◽

Tony Buckmaster ◽

...

Keyword(s):

Controlled Release ◽

Clinical Signs ◽

Management Technique ◽

Target Species ◽

Feral Cats ◽

Invasive Predators ◽

Scale Population ◽

Poison Baiting ◽

Decision Making Processes ◽

Management Techniques

Abstract ContextFeral cats are invasive predators of small and medium-sized fauna throughout Australia. The only broad-scale population-management technique for feral cats currently available in Australia is poison baiting. As poison baits for feral cats must be surface-laid, this can lead to the unintended exposure of non-target species consuming the baits. Encapsulation of a toxin within a robust, controlled-release pellet implanted within the meat lure (the combination of which is termed the Curiosity® bait) substantially reduces the potential risk to non-target species. Para-aminopropiophenone (PAPP) has been shown to be an effective toxin to which cats are highly susceptible. AimsThe present study aimed to measure the efficacy of encapsulating PAPP toxin in a controlled-release pellet on feral cats in a pen situation and to document the observed behaviours through the toxication process. MethodsPen trials with captive cats were undertaken to document efficacy of encapsulating PAPP toxin in a controlled-release pellet and to assess the behaviours during toxicosis. These behaviours inform an assessment of the humaneness associated with the Curiosity bait using a published relative humaneness model. Key resultsThe trials demonstrated a 95% consumption of the toxic pellet and observed the pattern of behaviours exhibited during the intoxication process. There was a definitive delay in the onset of clinical signs and death followed at ~185min after the first definitive sign. The humaneness using the relative humaneness model was scored at ‘mild suffering’. ConclusionsThe encapsulating PAPP toxin in a controlled-release pellet for feral cats is effective. The feral cats display a range of behaviours through the toxication process, and these have been interpreted as mild suffering under the relative humaneness model. ImplicationsThe documented efficacy and behaviours of encapsulating PAPP toxin in a controlled-release pellet provides knowledge of how the PAPP toxin works on feral cats, which may assist in decision-making processes for conservation land managers controlling feral cats and whether to incorporate the use of the Curiosity® bait into existing management techniques.

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On the right track: placement of camera traps on roads improves detection of predators and shows non-target impacts of feral cat baiting

Wildlife Research ◽

10.1071/wr19175 ◽

2020 ◽

Vol 47 (8) ◽

pp. 557 ◽

Cited By ~ 1

Author(s):

Michael L. Wysong ◽

Gwenllian D. Iacona ◽

Leonie E. Valentine ◽

Keith Morris ◽

Euan G. Ritchie

Keyword(s):

Survey Design ◽

Camera Traps ◽

Apex Predator ◽

Target Species ◽

Ecological Consequences ◽

Large Herbivores ◽

Feral Cat ◽

Feral Cats ◽

Detection Probabilities ◽

Poison Baiting

Abstract ContextTo understand the ecological consequences of predator management, reliable and accurate methods are needed to survey and detect predators and the species with which they interact. Recently, poison baits have been developed specifically for lethal and broad-scale control of feral cats in Australia. However, the potential non-target effects of these baits on other predators, including native apex predators (dingoes), and, in turn, cascading effects on lower trophic levels (large herbivores), are poorly understood. AimsWe examined the effect that variation in camera trapping-survey design has on detecting dingoes, feral cats and macropodids, and how different habitat types affect species occurrences. We then examined how a feral cat poison baiting event influences the occupancy of these sympatric species. MethodsWe deployed 80 remotely triggered camera traps over the 2410-km2 Matuwa Indigenous Protected Area, in the semiarid rangelands of Western Australia, and used single-season site-occupancy models to calculate detection probabilities and occupancy for our target species before and after baiting. Key resultsCameras placed on roads were ~60 times more likely to detect dingoes and feral cats than were off-road cameras, whereas audio lures designed to attract feral cats had only a slight positive effect on detection for all target species. Habitat was a significant factor affecting the occupancy of dingoes and macropodids, but not feral cats, with both species being positively associated with open woodlands. Poison baiting to control feral cats did not significantly reduce their occupancy but did so for dingoes, whereas macropodid occupancy increased following baiting and reduced dingo occupancy. ConclusionsCamera traps on roads greatly increase the detection probabilities for predators, whereas audio lures appear to add little or no value to increasing detection for any of the species we targeted. Poison baiting of an invasive mesopredator appeared to negatively affect a non-target, native apex predator, and, in turn, may have resulted in increased activity of large herbivores. ImplicationsManagement and monitoring of predators must pay careful attention to survey design, and lethal control of invasive mesopredators should be approached cautiously so as to avoid potential unintended negative ecological consequences (apex-predator suppression and herbivore release).

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Potential impacts of poison baiting for introduced house mice on native animals on islands in Jurien Bay, Western Australia

Wildlife Research ◽

10.1071/wr15126 ◽

2016 ◽

Vol 43 (1) ◽

pp. 61 ◽

Cited By ~ 1

Author(s):

Clifford Bennison ◽

J. Anthony Friend ◽

Timothy Button ◽

Harriet Mills ◽

Cathy Lambert ◽

...

Keyword(s):

Western Australia ◽

Rhodamine B ◽

Native Species ◽

House Mice ◽

Mus Domesticus ◽

Target Species ◽

Island Populations ◽

Delivery Technique ◽

Poison Baiting ◽

Competition For Resources

Context House mice (Mus domesticus) are present on Boullanger and Whitlock islands, Western Australia, and could potentially threaten populations of the dibbler (Parantechinus apicalis) and grey-bellied dunnart (Sminthopsis griseoventer) through competition for resources. A workshop in 2007 recommended a study to assess the feasibility of eradicating house mice from the islands by using poison baits and of the risk posed to non-target native species. Aim We aimed to assess the risk to non-target native species if poison baiting was used to eradicate house mice on Boullanger and Whitlock islands. Methods Non-toxic baits containing the bait marker rhodamine B were distributed on Boullanger Island and on the mouse free Escape Island to determine the potential for primary poisoning. Acceptance of baits by mammals was measured through sampling and analysis of whiskers, and by reptiles through observations of dye in faeces. To determine the potential for secondary exposure to poison, the response of dibblers to mouse carcasses was observed using motion-activated cameras. Bait acceptance was compared using two methods of delivery, namely, scattering in the open and delivery in polyvinyl chloride (PVC) tubes. A cafeteria experiment of bait consumption by dibblers was also undertaken using captive animals held at the Perth Zoo. Ten dibblers were offered non-toxic baits containing rhodamine B in addition to their normal meals; consumption of bait and the presence of dye in whiskers were measured. Key results Bait acceptance on the islands was high for house mice (92% of individuals) and dibblers (48%) and it was independent of bait-delivery technique. There was no evidence of bait acceptance by grey-bellied dunnarts. Dibblers may consume mice carcasses if available; however, no direct consumption of mice carcasses was observed with movement sensor cameras but one dibbler was observed removing a mouse carcass and taking it away. During the cafeteria experiment, 9 of 10 captive dibblers consumed baits. Conclusions This investigation demonstrated that dibblers consume baits readily and island populations would experience high mortality if exposed to poison baits. Poison baiting could effectively eradicate mice from Boullanger and Whitlock islands but not without mortality for dibblers. Implications Toxic baits could be used to eradicate mice from Boullanger and Whitlock islands, provided that non-target species such as dibblers were temporarily removed from the islands before the application of baits.

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Movement patterns of feral predators in an arid environment – implications for control through poison baiting

Wildlife Research ◽

10.1071/wr08098 ◽

2009 ◽

Vol 36 (5) ◽

pp. 422 ◽

Cited By ~ 64

Author(s):

K. E. Moseby ◽

J. Stott ◽

H. Crisp

Keyword(s):

Home Range ◽

Sand Dunes ◽

Activity Patterns ◽

Movement Patterns ◽

Home Range Size ◽

Range Size ◽

Home Ranges ◽

Feral Cats ◽

Poison Baiting ◽

Specific Variation

Control of introduced predators is critical to both protection and successful reintroduction of threatened prey species. Efficiency of control is improved if it takes into account habitat use, home range and the activity patterns of the predator. These characteristics were studied in feral cats (Felis catus) and red foxes (Vulpes vulpes) in arid South Australia, and results are used to suggest improvements in control methods. In addition, mortality and movement patterns of cats before and after a poison-baiting event were compared. Thirteen cats and four foxes were successfully fitted with GPS data-logger radio-collars and tracked 4-hourly for several months. High intra-specific variation in cat home-range size was recorded, with 95% minimum convex polygon (MCP) home ranges varying from 0.5 km2 to 132 km2. Cat home-range size was not significantly different from that of foxes, nor was there a significant difference related to sex or age. Cats preferred habitat types that support thicker vegetation cover, including creeklines and sand dunes, whereas foxes preferred sand dunes. Cats used temporary focal points (areas used intensively over short time periods and then vacated) for periods of up to 2 weeks and continually moved throughout their home range. Aerial baiting at a density of 10 baits per km2 was ineffective for cats because similar high mortality rates were recorded for cats in both baited and unbaited areas. Mortality was highest in young male cats. Long-range movements of up to 45 km in 2 days were recorded in male feral cats and movement into the baited zone occurred within 2 days of baiting. Movement patterns of radio-collared animals and inferred bait detection distances were used to suggest optimum baiting densities of ~30 baits per km2 for feral cats and 5 per km2 for foxes. Feral cats exhibited much higher intra-specific variation in activity patterns and home-range size than did foxes, rendering them a potentially difficult species to control by a single method. Control of cats and foxes in arid Australia should target habitats with thick vegetation cover and aerial baiting should ideally occur over areas of several thousand square kilometres because of large home ranges and long-range movements increasing the chance of fast reinvasion. The use of temporary focal points suggested that it may take several days or even weeks for a cat to encounter a fixed trap site within their home range, whereas foxes should encounter them more quickly as they move further each day although they have a similar home-range size. Because of high intra-specific variability in activity patterns and home-range size, control of feral cats in inland Australia may be best achieved through a combination of control techniques.

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Evaluation of risks for two native mammal species from feral cat baiting in monsoonal tropical northern Australia

Wildlife Research ◽

10.1071/wr17171 ◽

2018 ◽

Vol 45 (6) ◽

pp. 518 ◽

Cited By ~ 3

Author(s):

Jaime Heiniger ◽

Skye F. Cameron ◽

Graeme Gillespie

Keyword(s):

Rhodamine B ◽

Native Species ◽

Field Trials ◽

Camera Traps ◽

Northern Australia ◽

Target Species ◽

Mammal Species ◽

Feral Cat ◽

Feral Cats ◽

Dry Tropics

Context Feral cats are a significant threat to native wildlife and broad-scale control is required to reduce their impacts. Two toxic baits developed for feral cats, Curiosity® and Hisstory®, have been designed to reduce the risk of baiting to certain non-target species. These baits involve encapsulating the toxin within a hard-shelled delivery vehicle (HSDV) and placing it within a meat attractant. Native animals that chew their food more thoroughly are predicted to avoid poisoning by eating around the HSDV. This prediction has not been tested on wild native mammals in the monsoonal wet–dry tropics of the Northern Territory. Aim The aim of this research was to determine whether northern quolls (Dasyurus hallucatus) and northern brown bandicoots (Isoodon macrourus) would take feral cat baits and ingest the HSDV under natural conditions on Groote Eylandt. Methods We hand-deployed 120 non-toxic baits with a HSDV that contained a biomarker, Rhodamine B, which stains animal whiskers when ingested. The species responsible for bait removal was determined with camera traps, and HSDV ingestion was measured by evaluating Rhodamine B in whiskers removed from animals trapped after baiting. Key results During field trials, 95% of baits were removed within 5 days. Using camera-trap images, we identified the species responsible for taking baits on 65 occasions. All 65 confirmed takes were by native species, with northern quolls taking 42 baits and northern brown bandicoots taking 17. No quolls and only one bandicoot ingested the HSDV. Conclusion The use of the HSDV reduces the potential for quolls and bandicoots to ingest a toxin when they consume feral cat baits. However, high bait uptake by non-target species may reduce the efficacy of cat baiting in some areas. Implications The present study highlighted that in the monsoonal wet–dry tropics, encapsulated baits are likely to minimise poisoning risk to certain native species that would otherwise eat meat baits. However, further research may be required to evaluate risks to other non-target species. Given the threat to biodiversity from feral cats, we see it as critical to continue testing Hisstory® and Curiosity® in live-baiting trials in northern Australia.

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The use of poison baits to control feral cats and red foxes in arid South Australia I. Aerial baiting trials

Wildlife Research ◽

10.1071/wr10235 ◽

2011 ◽

Vol 38 (4) ◽

pp. 338 ◽

Cited By ~ 33

Author(s):

K. E. Moseby ◽

B. M. Hill

Keyword(s):

Arid Zone ◽

South Australia ◽

Red Foxes ◽

Local Conditions ◽

Feral Cats ◽

Wildlife Species ◽

Delivery Times ◽

Poison Baiting ◽

Dry Conditions

Context Feral cats and foxes pose a significant threat to native wildlife in the Australian arid zone and their broadscale control is required for the protection of threatened species. Aims The aim of this research was to trial aerial poison baiting as a means of controlling feral cats and foxes in northern South Australia. Methods Eradicat baits or dried meat baits containing 1080 poison were distributed by air over areas of 650 to 1800 km2 in trials from 2002 to 2006. Different baiting density, frequency, bait type and area were trialled to determine the optimum baiting strategy. Baiting success was determined through mortality of radio-collared animals and differences in the track activity of cats and foxes in baited and unbaited areas. Key results Quarterly aerial baiting at a density of 10 baits per square km successfully controlled foxes over a 12-month period, while annual baiting led to reinvasion within four months. Despite the majority of radio-collared cats dying after baiting, a significant decline in cat activity was only recorded during one of the eight baiting events. This event coincided with extremely dry conditions and low rabbit abundance. Rabbit activity increased significantly in baited areas over the study period in comparison with control areas. Conclusions Despite trialling different baiting density, frequency and area over a five-year period, a successful long-term baiting strategy for feral cats could not be developed using Eradicat baits or dried meat baits. Implications Broadscale control of feral cats in the arid zone remains a significant challenge and may require a combination of control methods with flexible delivery times dependent on local conditions. However, it is doubtful that current methods, even used in combination, will enable cat numbers to be reduced to levels where successful reintroductions of many threatened wildlife species can occur.

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An analysis of bait-take and non-target impacts during a fox-control exercise

Wildlife Research ◽

10.1071/wr97020 ◽

1998 ◽

Vol 25 (2) ◽

pp. 147 ◽

Cited By ~ 25

Author(s):

Nick Dexter ◽

Paul Meek

Keyword(s):

New South ◽

New South Wales ◽

The Other ◽

Target Species ◽

South Wales ◽

Poison Baiting ◽

Heath Forest ◽

Free Feeding ◽

Fox Control ◽

Control Exercise

The effectiveness of a fox-control exercise at the Beecroft Peninsula, New South Wales, was evaluated by examining the change in proportion of baits taken during free-feeding and after lethal baiting in four different habitats (heath, forest, coastal scrub, beach), and the change in number of radio-collared foxes alive during the course of the baiting exercise. The change in proportion of baits taken by non-target species was also examined over the course of the study. Bait take declined by 97% from the initiation of poison baiting to the final day of poison baiting eight days later with significantly more baits being taken in heath than in any other habitat. Four out of six radio-collared foxes died on the first day of poison baiting while the other two foxes died within ten days of the start of the poison-baiting session. Black rats, currawongs and ravens took a small number of baits throughout the baiting exercise.

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Bait consumption by, and 1080-based control of, feral pigs in the Mediterranean climatic region of south-western Australia

Wildlife Research ◽

10.1071/wr06084 ◽

2007 ◽

Vol 34 (2) ◽

pp. 125 ◽

Cited By ~ 7

Author(s):

Laurie E. Twigg ◽

Tim Lowe ◽

Gary Martin

Keyword(s):

Western Australia ◽

Sus Scrofa ◽

Native Species ◽

Target Species ◽

Variable Response ◽

Feral Pigs ◽

Poison Baiting ◽

The Mediterranean ◽

Bait Stations ◽

Minimal Evidence

The consumption of five non-toxic, grain-based baits, and the effectiveness of the preferred baits when treated with 1080 in reducing pig numbers, were determined for feral pigs (Sus scrofa) in several areas in the Mediterranean agricultural region of Western Australia. Fermented wheat with added blood and bone proved an effective attractant for feral pigs, and for determining areas of pig activity. Wheat and malted barley were the preferred baits, there was a variable response to lupins, and commercial pig pellets were consumed least. Malted barley, barley, and wheat treated with 1080 gave good reductions in pig numbers at the localised scale. Where pigs would eat lupins, 1080-treated lupins were usually effective in reducing pig abundance. In some instances, further evidence of feral pig activity was not seen on several sites for several months after poison-baiting occurred. The addition of a small amount of unpoisoned grain to mask the presence of 1080 did not increase the take of treated bait (P < 0.05). Although finding poisoned pigs was difficult owing to the terrain and the presence of bush remnants, the poisoned pigs found (n = 90) were often within 200 m of active bait stations. 1080-poisoned pigs included both adult (≥25 kg) and non-adult pigs of both sexes. Body mass of these pigs ranged from 4 to 90 kg. In all, 42% of poisoned adults found (n = 50) were 50 kg or more. There was minimal evidence of bait take by non-target species, and, where this occurred, it generally involved the consumption of the fermented wheat attractant by kangaroos (Macropus spp.) and foxes (Vulpes vulpes). Six foxes were known to have been poisoned with 1080-treated grain (4 with malted barley, 2 with wheat). Excluding foxes, no other non-target animals, including native species, were found dead during the intensive searches for poisoned pigs.

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Target-specificity of feral pig baits under different conditions in a tropical rainforest

Wildlife Research ◽

10.1071/wr11023 ◽

2011 ◽

Vol 38 (5) ◽

pp. 370 ◽

Cited By ~ 9

Author(s):

Andrew J. Bengsen ◽

Luke K.-P. Leung ◽

Steven J. Lapidge ◽

Iain J. Gordon

Keyword(s):

Seasonal Variation ◽

Functional Groups ◽

Tropical Rainforests ◽

Target Species ◽

Novel Foods ◽

Different Types ◽

Poison Baiting ◽

Consumption Rates ◽

Presentation Methods ◽

Feral Pig

Context The mitigation of feral pig (Sus scrofa) impacts in north Queensland’s World Heritage tropical rainforests is constrained by the lack of an effective and target-specific poison baiting method. Aims This study aimed to determine whether easily implemented bait presentation methods or seasonal variation in bait acceptability could be used to selectively reduce the consumption of feral pig baits by non-target species. Methods We exposed manufactured feral pig baits to pigs and non-target species in the field, and compared bait encounter, sampling and consumption rates for different functional groups of species among three different types of bait presentation and composition. We then exposed baits under different seasonal conditions and related bait encounter and consumption by different functional groups to seasonally variable phenomena. Key results Shallow burial greatly reduced bait consumption by most non-target species, but not dingoes (Canis lupus dingo). Nocturnal bait distribution and seasonal baiting were less useful. Pigs showed substantial seasonal variation in physiological condition, suggesting that pigs should be more susceptible to consuming novel foods, such as baits, after periods of low rainfall. However, few pigs consumed the manufactured baits used in this study. Conclusions Manufactured baits are not currently suitable for widespread use in the region. However, shallow burial should provide an effective method of reducing non-target bait-take if baits can be made more attractive and acceptable to pigs and less acceptable to dingoes. Implications Future efforts to enable effective feral pig control in the region should focus on developing baiting materials that are more attractive to pigs and unappealing to dingoes.

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