The use of poison baits to control feral cats and red foxes in arid South Australia II. Bait type, placement, lures and non-target uptake

2011 ◽  
Vol 38 (4) ◽  
pp. 350 ◽  
Author(s):  
K. E. Moseby ◽  
J. L. Read ◽  
B. Galbraith ◽  
N. Munro ◽  
J. Newport ◽  
...  

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.


2018 ◽  
Vol 45 (6) ◽  
pp. 518 ◽  
Author(s):  
Jaime Heiniger ◽  
Skye F. Cameron ◽  
Graeme Gillespie

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.



2011 ◽  
Vol 38 (4) ◽  
pp. 338 ◽  
Author(s):  
K. E. Moseby ◽  
B. M. Hill

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.



2011 ◽  
Vol 38 (1) ◽  
pp. 39 ◽  
Author(s):  
Paul J. de Tores ◽  
Duncan R. Sutherland ◽  
Judy R. Clarke ◽  
Robert F. Hill ◽  
Sean W. Garretson ◽  
...  

Context The CURIOSITY® bait is the name coined for a variation of the existing sausage-style cat bait, ERADICAT®. The latter is used under experimental permit in Western Australia for research associated with cat control. The CURIOSITY bait differs from ERADICAT by providing a pH-buffered (less acidic) medium and has been proposed to reduce the risk to non-target species by encapsulating a toxin in a pellet. We trialled a prototype pellet proposed for encapsulation of 1080 and/or alternative toxins, with delivery proposed through the CURIOSITY bait. Aim Our aim was to determine whether the pellet was consumed by non-target native species from south-west of Western Australia. Methods Trials involved use of a non-toxic biomarker, Rhodamine B, encapsulated within the pellet and inserted into the CURIOSITY® bait. Uptake of the encapsulated biomarker was assessed in captive trials for the target species, the feral cat (Felis catus) and two non-target species of varanid lizard, Rosenberg’s goanna (Varanus rosenbergi) and Gould’s goanna (V. gouldii) and the non-target mammal species chuditch (Dasyurus geoffroii) and southern brown bandicoot (Isoodon obesulus). Uptake of the encapsulated biomarker was also assessed in field trials for a range of native species. Key results Captive trials demonstrated feral cats will consume the CURIOSITY bait and pellet. However, results from captive and field trials indicated several non-target species also consumed the bait and pellet. We also found the pellet itself was not sufficiently robust for use in a bait. As with previously reported studies, we found Rhodamine B to be an effective biomarker for use in cats. We also developed a technique whereby Rhodamine B can be used as a biomarker in reptiles. However, its use as a biomarker in other mammalian species was confounded by what appeared to be background, or pre-existing, levels of fluorescence, or banding, in their whiskers. Conclusion The prototype pellet is unsuitable in its current form for use with the CURIOSITY bait. We caution that the CURIOSITY bait has non-target issues in south-west of Western Australia and any proposed variations to this bait, or the ERADICAT® bait, need to be rigorously assessed for their potential risk to non-target species and assessed for the level of uptake by cats, irrespective of their suitability/unsuitability as a medium for delivery of an encapsulated toxin. We believe the threat to biodiversity-conservation values from unmitigated feral-cat predation of native fauna poses a significant and real threat and we recommend urgent investment of resources to address the issue of cat predation in a coordinated and collaborative manner within Australia and New Zealand.



PLoS ONE ◽  
2014 ◽  
Vol 9 (9) ◽  
pp. e107788 ◽  
Author(s):  
Tony Buckmaster ◽  
Christopher R. Dickman ◽  
Michael J. Johnston


2020 ◽  
Vol 47 (8) ◽  
pp. 599
Author(s):  
K. E. Moseby ◽  
H. McGregor ◽  
J. L. Read

Abstract ContextFeral cats pose a significant threat to wildlife in Australia and internationally. Controlling feral cats can be problematic because of their tendency to hunt live prey rather than be attracted to food-based lures. The Felixer grooming trap was developed as a targeted and automated poisoning device that sprays poison onto the fur of a passing cat, relying on compulsive grooming for ingestion. AimsWe conducted a field trial to test the effectiveness of Felixers in the control of feral cats in northern South Australia where feral cats were present within a 2600-ha predator-proof fenced paddock. MethodsTwenty Felixers were set to fire across vehicle tracks and dune crossings for 6 weeks. Cat activity was recorded using track counts and grids of remote camera traps set within the Felixer Paddock and an adjacent 3700-ha Control Paddock where feral cats were not controlled. Radio-collars were placed on six cats and spatial mark–resight models were used to estimate population density before and after Felixer deployment. Key resultsNone of the 1024 non-target objects (bettongs, bilbies, birds, lizards, humans, vehicles) that passed a Felixer during the trial was fired on, confirming high target specificity. Thirty-three Felixer firings were recorded over the 6-week trial, all being triggered by feral cats. The only two radio-collared cats that triggered Felixers during the trial, died. Two other radio-collared cats appeared to avoid Felixer traps possibly as a reaction to previous catching and handling rendering them neophobic. None of the 22 individually distinguishable cats targeted by Felixers was subsequently observed on cameras, suggesting death after firing. Felixer data, activity and density estimates consistently indicated that nearly two-thirds of the cat population was killed by the Felixers during the 6-week trial. ConclusionsResults suggest that Felixers are an effective, target-specific method of controlling feral cats, at least in areas in which immigration is prevented. The firing rate of Felixers did not decline significantly over time, suggesting that a longer trial would have resulted in a higher number of kills. ImplicationsFuture studies should aim to determine the trade-off between Felixer density and the efficacy relative to reinvasion.



2020 ◽  
Vol 47 (8) ◽  
pp. 686
Author(s):  
Michael Johnston ◽  
Dave Algar ◽  
Michael O'Donoghue ◽  
Jim Morris ◽  
Tony Buckmaster ◽  
...  

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.



2020 ◽  
Vol 47 (8) ◽  
pp. 557 ◽  
Author(s):  
Michael L. Wysong ◽  
Gwenllian D. Iacona ◽  
Leonie E. Valentine ◽  
Keith Morris ◽  
Euan G. Ritchie

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).



2020 ◽  
Vol 47 (8) ◽  
pp. 547
Author(s):  
Rosemary Hohnen ◽  
Brett P. Murphy ◽  
Sarah M. Legge ◽  
Chris R. Dickman ◽  
John C. Z. Woinarski

Abstract ContextPredation by feral cats (Felis catus) threatens a range of vertebrate species across Australia, and cat-free islands increasingly act as safe havens for biodiversity. A feral cat eradication program has begun on Kangaroo Island (4405km2) in South Australia, and poison baiting is likely to be one of the main methods used. Aims Here, we trial a non-toxic version of a cat bait, ‘Eradicat’, on western Kangaroo Island, to examine its potential impact on non-target species. MethodsNon-toxic baits containing the biomarker Rhodamine B were deployed across four sites in early August and late November in 2018, with bait take and consumption assessed both by remote cameras and by the presence of Rhodamine B in mammalian whisker samples taken post-baiting. Key resultsCats encountered baits on very few occasions and took a bait on only one occasion in August (<1% of 576 baits deployed). Non-target species accounted for over 99% of identifiable bait takes. In both seasons, >60% of all baits laid was taken by either the common brushtail possum (Trichosurus vulpecula), bush rat (Rattus fuscipes) or Australian raven (Corvus coronoides). In November, Rosenberg’s goanna (Varanus rosenbergi) and southern brown bandicoot (south-eastern subspecies; Isoodon obesulus obesulus), listed nationally as Endangered, also took baits (3% and 1% respectively). The Kangaroo Island dunnart (Sminthopsis fuliginosus aitkeni), listed nationally as endangered, approached a bait on only one occasion, but did not consume it. Evidence of bait consumption was visible in the whiskers of captured common brushtail possums (100% of post-baiting captured individuals in August, 80% in November), bush rats (59% in August and 50% in November), house mice (Mus musculus) (45% in November) and western pygmy-possums (Cercartetus concinnus) (33% in November). ConclusionsAlthough feral cat baiting has the potential to significantly benefit wildlife on Kangaroo Island, impacts on non-target species (particularly the bush rat and common brushtail possum) may be high. ImplicationsAlternative cat baits, such as those containing a toxin to which native species have a higher tolerance or that are less readily consumed by native wildlife, will be more appropriate.



2017 ◽  
Vol 4 (9) ◽  
pp. 170317 ◽  
Author(s):  
Emma E. Spencer ◽  
Thomas M. Newsome ◽  
Christopher R. Dickman

Predators often display dietary shifts in response to fluctuating prey in cyclic systems, but little is known about predator diets in systems that experience non-cyclic prey irruptions. We tracked dietary shifts by feral cats ( Felis catus ), red foxes ( Vulpes vulpes ) and dingoes ( Canis dingo ) through a non-cyclic irruption of small mammalian prey in the Simpson Desert, central Australia. We predicted that all three predators would alter their diets to varying degrees as small mammals declined post irruption, and to test our predictions we live-trapped small mammals through the irruption event and collected scats to track predator diets. Red foxes and dingoes included a broader variety of prey in their diets as small mammals declined. Feral cats did not exhibit a similar dietary shift, but did show variable use and selectivity of small mammal species through the irruption cycle. Results were largely consistent with prior studies that highlighted the opportunistic feeding habits of the red fox and dingo. They also, however, showed that feral cats may exhibit less dietary flexibility in response to small mammal irruptions, emphasizing the importance of tracking predator diets before, during and after irruption events.



2020 ◽  
Vol 47 (8) ◽  
pp. 747
Author(s):  
J. Anthony Friend ◽  
Robert Hill ◽  
Brian Macmahon ◽  
Louisa Bell ◽  
Tim Button ◽  
...  

Abstract ContextFeral cats have benefitted from effective control of foxes in south-western Australia and, consequently, their impact on some threatened mammal species has increased. Control of feral cats in the region can be enhanced by use of the Eradicat® cat bait, but its impact on non-target animal populations requires investigation before widespread use. AimsThe aim of the present study was to determine through field trials whether consumption of Eradicat® baits by resident red-tailed phascogales, following a broadscale baiting operation to control feral cats, was sufficiently frequent to cause significant rates of mortality in wild populations of phascogales. MethodsNine radio-tagged red-tailed phascogales were monitored through an Eradicat® baiting event to determine their survival. Removal and consumption of toxic and non-toxic rhodamine B-labelled baits by a range of species were monitored with camera traps and by subsequent trapping of red-tailed phascogales and other mammals to sample whiskers for evidence of rhodamine uptake. Key resultsAlthough some phascogales showed interest in baits and sometimes moved them from the deposition site, all radio-tagged phascogales survived for at least 1 week after baiting, by which time very few or no baits remained. Examination of whiskers sampled from individuals exposed to rhodamine-labelled baits showed that consumption of non-toxic Eradicat® baits by phascogales was negligible; only one phascogale of 62 sampled showed any rhodamine banding. ConclusionsThe present study provided no evidence that red-tailed phascogales in the study region are at risk from an Eradicat® baiting episode in autumn. ImplicationsThe risk to red-tailed phascogale populations through the use of Eradicat® baiting to control cats in their habitat in the Great Southern region of Western Australia is likely to be low. Further research to elucidate any impact of repeated baiting on populations of this species at several locations is recommended.



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