Control of Feral Cats for Nature Conservation. II. Population Reduction by Poisoning

1997 ◽  
Vol 24 (6) ◽  
pp. 703 ◽  
Author(s):  
Jeff Short ◽  
Bruce Turner ◽  
Danielle A. Risbey ◽  
Reg Carnamah
Keyword(s):  
Prey Species ◽  
Control Programme ◽  
Laboratory Mice ◽  
Timing Control ◽  
Feral Cat ◽  
Feral Cats ◽  
Track System ◽  
Population Reduction ◽  
Before And After ◽  
Semi Arid

A feral cat population was substantially reduced by poisoning at a semi-arid site in Western Australia. The control programme was designed to protect two species of endangered native mammals that had recently been reintroduced to the site. Feral cats were poisoned with carcasses of laboratory mice, each impregnated with 4.5 mg of sodium monofluoroacetate (1080). Baits were placed at 100-m intervals along the track system each night for four consecutive nights. Kill rates were assessed by monitoring survival of radio- collared cats and by spotlight counts of cats before and after baiting. All radio-collared cats were killed and there was a 74% reduction in spotlight counts of cats after baiting. Bait removal varied with the abundance of rabbits, the primary prey item for cats in this area. Effectiveness of control operations against feral cats is maximised by baiting at times of low prey abundance. Monitoring the changing abundance of the primary prey species provides important information for timing control operations against feral cats.

Evidence of significantly higher island feral cat abundance compared with the adjacent mainland

2019 ◽  
Vol 46 (5) ◽  
pp. 378 ◽  
Author(s):  
Patrick L. Taggart ◽  
Bronwyn A. Fancourt ◽  
Andrew J. Bengsen ◽  
David E. Peacock ◽  
Patrick Hodgens ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Spatial Model ◽  
Native Species ◽  
Prey Species ◽  
South Australia ◽  
Camera Trap ◽  
Feral Cat ◽  
Feral Cats ◽  
Continental Scale ◽  
Scale Models

Context Feral cats (Felis catus) impact the health and welfare of wildlife, livestock and humans worldwide. They are particularly damaging where they have been introduced into island countries such as Australia and New Zealand, where native prey species evolved without feline predators. Kangaroo Island, in South Australia, is Australia’s third largest island and supports several threatened and endemic species. Cat densities on Kangaroo Island are thought to be greater than those on the adjacent South Australian mainland, based on one cat density estimate on the island that is higher than most estimates from the mainland. The prevalence of cat-borne disease in cats and sheep is also higher on Kangaroo Island than the mainland, suggesting higher cat densities. A recent continental-scale spatial model of cat density predicted that cat density on Kangaroo Island should be about double that of the adjacent mainland. However, although cats are believed to have severe impacts on some native species on the island, other species that are generally considered vulnerable to cat predation have relatively secure populations on the island compared with the mainland. Aims The present study aimed to compare feral cat abundance between Kangaroo Island and the adjacent South Australian mainland using simultaneous standardised methods. Based on previous findings, we predicted that the relative abundance of feral cats on Kangaroo Island would be approximately double that on the South Australian mainland. Methods Standardised camera trap surveys were used to simultaneously estimate the relative abundance of feral cats on Kangaroo Island and the adjacent South Australian mainland. Survey data were analysed using the Royle–Nichols abundance-induced heterogeneity model to estimate feral cat relative abundance at each site. Key results Cat abundance on the island was estimated to be over 10 times greater than that on the adjacent mainland. Conclusions Consistent with predictions, cat abundance on the island was greater than on the adjacent mainland. However, the magnitude of this difference was much greater than expected. Implications The findings show that the actual densities of cats at local sites can vary substantially from predictions generated by continental-scale models. The study also demonstrates the value of estimating abundance or density simultaneously across sites using standardised methods.

An evaluation of two methods of assessing feral cat and dingo abundance in central Australia

2000 ◽  
Vol 27 (2) ◽  
pp. 143 ◽  
Author(s):  
G. P. Edwards ◽  
N. D. de Preu ◽  
B. J. Shakeshaft ◽  
I. V. Crealy
Keyword(s):  
Relative Abundance ◽  
Population Change ◽  
Feral Cat ◽  
Feral Cats ◽  
Central Australia ◽  
Semi Arid ◽  
Arid Rangeland

We evaluated the efficacy of spotlight surveys and passive track surveys conducted along roads for assessing the relative abundance of feral cats and dingoes in a semi-arid rangeland environment in central Australia. Track surveys were more time-efficient than spotlight surveys and offered higher precision. We cover a range of issues that need to be considered when using track-based surveys to assess population change. We also discuss the merits of other techniques used to monitor the abundance of mammalian carnivores.

Aerial baiting for feral cats is unlikely to affect survivorship of northern quolls in the Pilbara region of Western Australia

2020 ◽  
Vol 47 (8) ◽  
pp. 589
Author(s):  
M. Cowan ◽  
D. Moro ◽  
H. Anderson ◽  
J. Angus ◽  
S. Garretson ◽  
...  
Keyword(s):  
Western Australia ◽  
Reproductive Output ◽  
Reference Area ◽  
Acute Effects ◽  
Feral Cat ◽  
Feral Cats ◽  
Introduced Predators ◽  
Before And After ◽  
Wild Dog ◽  
High Level

Abstract ContextFeral cats (Felis catus) are known predators of northern quolls (Dasyurus hallucatus). Management to suppress feral cat densities often uses the poison sodium monofluoroacetate (compound 1080) in baits broadcast aerially. Eradicat® baits have demonstrated efficacy at reducing feral cat densities in some environments. However, these are not registered for use in northern Australia because their risk to non-target northern quolls remains unknown. AimsWe investigated the risks of aerially deployed feral cat Eradicat® baits containing 4.5mg of the poison 1080 on the survival of free-ranging northern quolls. MethodsThe study was conducted over a 20000-ha area in the Pilbara bioregion in Western Australia. Twenty-one wild northern quolls from a baited area and 20 quolls from a nearby reference area were fitted with radio-collars, and their survivorship was compared following the aerial deployment of over 9700 feral cat baits. Survivorship of quolls was assessed before and after the baiting campaign. Key resultsFive radio-collared quolls died at the baited area; four mortalities were due to feral cat predation, and the cause of one death was uncertain. At the reference area, seven radio-collared quolls were confirmed dead; three mortalities were due to feral cat predation, two from wild dog predation, and the cause of death of two could not be determined. Evidence for sublethal poison impacts on quolls, inferred by monitoring reproductive output, was lacking; average litter size was higher in quolls from the baited area than in those from the unbaited area, and within range of litters reported elsewhere, suggesting that acute effects of 1080 (if ingested) on reproductive success were unlikely. ConclusionsRadio-collared northern quolls survived the trial using Eradicat® baits, and females showed no acute effects of sublethal poisoning on the basis of reproductive output. A lack of quoll deaths attributed to 1080 poisoning suggests that the use of Eradicat® poses a low risk to northern quolls in the Pilbara. Importantly, the high level of mortalities associated with predation by feral cats, and to a lesser extent, canids, validates the threats of these introduced predators on quolls, suggesting that their control in areas where quolls are present is likely to be beneficial for the recovery of this species. ImplicationsLand managers aiming to conserve northern quolls in the Pilbara would see conservation benefits if they introduced an operational landscape-scale feral cat baiting program using Eradicat® baits, with appropriate monitoring.

Feral cat diet and predation on endangered endemic mammals on a biodiversity hot spot (Amami–Ohshima Island, Japan)

2015 ◽  
Vol 42 (4) ◽  
pp. 343 ◽  
Author(s):  
Kazumi Shionosaki ◽  
Fumio Yamada ◽  
Takuya Ishikawa ◽  
Shozo Shibata
Keyword(s):  
Prey Item ◽  
Prey Species ◽  
Hot Spot ◽  
Rattus Rattus ◽  
Active Management ◽  
Term Survival ◽  
Scat Analysis ◽  
Feral Cat ◽  
Feral Cats ◽  
Main Prey

Context There has been concern that feral cats have negative impacts on the endangered endemic mammals of Amami-Ohshima Island, Japan, including the Amami rabbit, Pentalagus furnessi, Ryukyu long-tailed giant rat, Diplothrix legata, and Amami spiny rat, Tokudaia osimensis. However, no diet study of feral cat has been conducted to support the necessity of an urgent feasible feral-cat management for the island. Aims The aims of the present study were to analyse feral-cat diet on Amami-Ohshima Island by using scat analysis and estimate the potential predation impact of feral cats on endangered mammals on the island. Methods The diet of feral cats was studied using scat analysis. We estimated the number of prey, percentage of prey, frequency of occurrence (the percentage of scats in a sample containing a particular prey item), percentage of biomass (biomass of the same prey item divided by the total consumed biomass ×100) and daily consumed biomass (DCB). Key results Three endangered endemic mammals were the main prey species of the feral cat diet (65% of total DCB). The percentage contributions of these species on DCB were long-tailed giant rat (34.7%), Amami spiny rat (21.9%) and Amami rabbit (12%). Conclusions Mammals, especially endangered endemic mammals, were main prey species of feral cat on Amami Island. In Amami Island, where native and invasive rodents coexisted, feral cats consumed more native (56.6%) than invasive (22.2% for Rattus rattus) species. Implications Feral cats are likely to be having a significant impact on endangered endemic mammals on the island. To ensure the long-term survival of these endemic species, active management of the feral-cat population should be considered.

Management of invasive mesopredators in the Flinders Ranges, South Australia: effectiveness and implications

2020 ◽  
Vol 47 (8) ◽  
pp. 720
Author(s):  
Alyson M. Stobo-Wilson ◽  
Robert Brandle ◽  
Christopher N. Johnson ◽  
Menna E. Jones
Keyword(s):  
Prey Species ◽  
South Australia ◽  
Short Time Period ◽  
Short Term ◽  
Feral Cat ◽  
Feral Cats ◽  
Flinders Ranges ◽  
Time Period ◽  
Short Time ◽  
The Impact

Abstract ContextSignificant resources have been devoted to the control of introduced mesopredators in Australia. However, the control or removal of one pest species, such as, for example, the red fox (Vulpes vulpes), may inadvertently benefit other invasive species, namely feral cats (Felis catus) and rabbits (Oryctolagus cuniculus), potentially jeopardising native-species recovery. AimsTo (1) investigate the impact of a large-scale, long-term fox-baiting program on the abundance of foxes, feral cats and introduced and native prey species in the Flinders Ranges, South Australia, and (2) determine the effectiveness of a short time period of cat removal in immediately reducing feral cat abundance where foxes are absent. MethodsWe conducted an initial camera-trap survey in fox-baited and unbaited sites in the Flinders Ranges, to quantify the impact of fox baiting on the relative abundance of foxes, feral cats and their prey. We then conducted a secondary survey in sites where foxes were absent, following an intensive, but short, time period of cat removal, in which 40 cats were shot and killed. Key resultsNo foxes were detected within baited sites, but were frequently detected in unbaited sites. We found a corresponding and significant increase in several native prey species in fox-baited sites where foxes were absent. Feral cats and rabbits were also more frequently detected within baited sites, but fox baiting did not singularly predict the abundance of either species. Rather, feral cats were less abundant in open habitat where foxes were present (unbaited), and rabbits were more abundant within one predominantly open-habitat site, where foxes were absent (fox-baited). We found no effect of short-term cat removal in reducing the local abundance of feral cats. In both camera-trap surveys, feral cat detections were positively associated with rabbits. ConclusionsLong-term fox baiting was effective in fox removal and was associated with a greater abundance of native and introduced prey species in the Flinders Ranges. To continue to recover and conserve regional biodiversity, effective cat control is required. ImplicationsOur study showed fox removal has likely resulted in the local release of rabbits and an associated increase in cats. Because feral cat abundance seemingly fluctuated with rabbits, we suggest rabbit control may provide an alternative and more effective means to reduce local feral cat populations than short-term removal programs.

Toxic Trojans: can feral cat predation be mitigated by making their prey poisonous?

2015 ◽  
Vol 42 (8) ◽  
pp. 689 ◽  
Author(s):  
J. L. Read ◽  
D. Peacock ◽  
A. F. Wayne ◽  
K. E. Moseby
Keyword(s):  
Threatened Species ◽  
Disease Transmission ◽  
Prey Species ◽  
Selective Predation ◽  
Live Prey ◽  
Feral Cat ◽  
Feral Cats ◽  
Wildlife Species ◽  
Baited Traps

Predation, along with competition and disease transmission from feral domestic cats (Felis catus), poses the key threat to many in situ and reintroduced populations of threatened species globally. Feral cats are more challenging to control than pest canids because cats seldom consume poison baits or enter baited traps when live prey are readily available. Novel strategies for sustainably protecting threatened wildlife from feral cats are urgently required. Emerging evidence suggests that once they have successfully killed a challenging species, individual feral cats can systematically eradicate threatened prey populations. Here we propose to exploit this selective predation through three targeted strategies to improve the efficacy of feral cat control. Toxic collars and toxic implants, fitted or inserted during monitoring or reintroduction programs for threatened species, could poison the offending cat before it can effect multiple kills of the target species. A third strategy is informed by evidence that consumption of prey species that are relatively tolerant to natural plant toxins, can be lethal to more sensitive cats. Within key habitats of wildlife species susceptible to cat predation, we advocate increasing the accessibility of these toxins in the food chain, provided negative risks can be mediated. Deliberate poisoning using live and unaffected ‘toxic Trojan prey’ enables ethical feral cat management that takes advantage of cats’ physiological and behavioural predilection for hunting live prey while minimising risks to many non-targets, compared with conventional baiting.

Feeding ecology and population dynamics of the feral cat (Felis catus) in relation to the availability of prey in central-eastern New South Wales

1999 ◽  
Vol 26 (5) ◽  
pp. 593 ◽  
Author(s):  
Robyn Molsher ◽  
Alan Newsome ◽  
Chris Dickman
Keyword(s):  
Oryctolagus Cuniculus ◽  
Prey Species ◽  
New South ◽  
New South Wales ◽  
Felis Catus ◽  
House Mice ◽  
Minor Components ◽  
Feral Cat ◽  
South Wales ◽  
Central Eastern

The diet of feral cats (Felis catus) was studied at Lake Burrendong, central-eastern New South Wales, from July 1994 to June 1997. Mammals were the major prey in 499 scats that were analysed. Rabbits (Oryctolagus cuniculus) were the staple prey, while carrion was an important secondary food. Invertebrates, other mammalian prey, vegetation, birds and reptiles were generally minor components of the diet. Few significant seasonal differences in diet were found; however, invertebrates contributed less and possums more to the diet in winter and summer respectively. A significant dietary response was found to changes in rabbit abundance, but not for the other prey types. Cats continued to prey heavily on rabbits even after a 90% decline in rabbit abundance occurred, which coincided with the advent of Rabbit Calicivirus Disease (RCD). House mice (Mus domesticus) increased in importance in the diet ten months post-RCD. Although the abundance of cats was correlated with the abundance of some prey species, other factors may have influenced the observed patterns; these are discussed.

Biology of the Feral Cat, Felis Catus (L.), On Macquarie Island.

1985 ◽  
Vol 12 (3) ◽  
pp. 425 ◽  
Author(s):  
NP Brothers ◽  
IJ Skira ◽  
GR Copson
Keyword(s):  
Sex Ratio ◽  
Breeding Season ◽  
Felis Catus ◽  
Feral Cat ◽  
Feral Cats ◽  
Macquarie Island ◽  
Pregnant Females

246 feral cats were shot on Macquarie Island, Australia, between Dec. 1976 and Feb. 1981. The sex ratio ( males : females ) was 1:0.8. The percentages of animals with tabby, orange and black coats were 74, 26 and 2 resp. [sic]. Of the 64 orange cats, 56 were males . The breeding season was Oct.-Mar., with a peak in Nov.-Dec. The number of embryos in the 14 pregnant females averaged 4.7 (range = 1-9). The size of the 23 litters that were observed averaged 3 (range = 1-8). Kitten survival to 6 months of age was estimated to be <43%.

Effectiveness of the Felixer grooming trap for the control of feral cats: a field trial in arid South Australia

2020 ◽  
Vol 47 (8) ◽  
pp. 599
Author(s):  
K. E. Moseby ◽  
H. McGregor ◽  
J. L. Read
Keyword(s):  
Field Trial ◽  
South Australia ◽  
Camera Traps ◽  
Specific Method ◽  
Density Estimates ◽  
Live Prey ◽  
Feral Cats ◽  
Before And After ◽  
Remote Camera ◽  
Track Counts

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.

scholarly journals Seasonal and spatial shifts in feral cat predation on native seabirds vs. non-native rats on Mikura Island, Japan

2020 ◽  
Author(s):  
Sarara Azumi ◽  
Yuya Watari ◽  
Nariko Oka ◽  
Tadashi Miyashita
Keyword(s):  
Native Species ◽  
Control Strategies ◽  
Interspecific Interactions ◽  
Rattus Rattus ◽  
Large Body ◽  
Effective Control ◽  
Alternative Prey ◽  
Feral Cat ◽  
Feral Cats ◽  
Invasive Predators

Abstract Understanding how invasive predators impact native species is essential for the development of effective control strategies, especially in insular environments where alternative non-native prey species exist. We examined seasonal and spatial shifts in diet of feral cat Felis silvestris catus focusing on the predation on native streaked shearwaters, Calonectris leucomelas, and introduced rats, Rattus rattus and R. norvegicus, which are alternative prey to shearwaters, on Mikura Island, Japan. Streaked shearwaters breed at low elevations on the island from spring to autumn, whereas rats inhabit the island throughout the year, which makes them an alternative prey when native shearwaters are absent. Fecal analysis revealed that feral cats dramatically shifted their diets from introduced rats in winter to streaked shearwaters in seabird-season in low elevation areas of the island, while cats preyed on rats throughout the year at high altitudes on the island. This finding suggests that feral cats selectively prey on shearwaters. This is probably because of their large body size and less cautious behavior, and because introduced rats sustain the cat population when shearwaters are absent. The number of streaked shearwaters killed was estimated to be 313 individuals per cat per year, which represents an indication of top-down effects of feral cats on streaked shearwaters. Further studies on the demographic parameters and interspecific interactions of the three species are required to enable effective cat management for the conservation of streaked shearwaters on this island.

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