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

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.

2020 ◽  
Author(s):  
Sarara Azumi ◽  
Yuya Watari ◽  
Nariko Oka ◽  
Tadashi Miyashita

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.


2019 ◽  
Vol 46 (5) ◽  
pp. 378 ◽  
Author(s):  
Patrick L. Taggart ◽  
Bronwyn A. Fancourt ◽  
Andrew J. Bengsen ◽  
David E. Peacock ◽  
Patrick Hodgens ◽  
...  

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.


1978 ◽  
Vol 5 (1) ◽  
pp. 75 ◽  
Author(s):  
GR Friend

In Gippsland, Victoria, in pine plantations and the adjacent native eucalyptus forest, mammal population was estimated by the usual methods and by analysis of ffaeces of predators. Predators were fox (Vulpes vulpes), feral cat (Felis catus), dog and dingo. Prey species found in faeces included 1 monotreme, 18 marsupial and 10 placental mammals, including the predators. Remains of cattle and sheep were found, presumably eaten as carrion. Remains of plants, or of animals other than the groups noted, were not required to be identified for the purpose of the study, nor were prey species attributed to each species of predator.


1997 ◽  
Vol 24 (6) ◽  
pp. 703 ◽  
Author(s):  
Jeff Short ◽  
Bruce Turner ◽  
Danielle A. Risbey ◽  
Reg Carnamah

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.


2020 ◽  
Vol 47 (8) ◽  
pp. 720
Author(s):  
Alyson M. Stobo-Wilson ◽  
Robert Brandle ◽  
Christopher N. Johnson ◽  
Menna E. Jones

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.


2015 ◽  
Vol 42 (8) ◽  
pp. 689 ◽  
Author(s):  
J. L. Read ◽  
D. Peacock ◽  
A. F. Wayne ◽  
K. E. Moseby

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.


1999 ◽  
Vol 26 (5) ◽  
pp. 593 ◽  
Author(s):  
Robyn Molsher ◽  
Alan Newsome ◽  
Chris Dickman

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.


1985 ◽  
Vol 12 (3) ◽  
pp. 425 ◽  
Author(s):  
NP Brothers ◽  
IJ Skira ◽  
GR Copson

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%.


2019 ◽  
Vol 97 (3) ◽  
pp. 225-231
Author(s):  
T.D. Williams ◽  
A. Cornell ◽  
C. Gillespie ◽  
A. Hura ◽  
M. Serota

Diet specialization has important consequences for how individuals or species deal with environmental change that causes changes in availability of prey species. We took advantage of a “natural experiment” — establishment of a commercial insect farm — that introduced a novel prey item, black soldier flies (Hermetia illucens (Linnaeus, 1758)), to the diet-specialist European Starling (Sturnus vulgaris Linnaeus, 1758). We investigated evidence for individual diet specialization (IDS) and the consequences of diet specialization and exploitation of novel prey on breeding productivity. In all 4 years of our study, tipulid larvae were the most common prey item. Soldier flies were not recorded in diets in 2013–2014; however, coincident with the establishment of the commercial insect farming operation, they comprised 22% and 30% of all prey items in the diets of European Starling females and males, respectively, in 2015. There was marked individual variation in use of soldier flies (4%–48% and 2%–70% in females and males, respectively), but we found little evidence of dichotomous IDS, i.e., where only some individuals have a specialized diet. We found no evidence for negative effects of use of soldier flies on breeding productivity: brood size at fledging and chick quality (mass, tarsus length) were independent of the number and proportion (%) of soldier flies returned to the nest.


Behaviour ◽  
1976 ◽  
Vol 56 (1-2) ◽  
pp. 44-67 ◽  
Author(s):  
Glenn Hausfater

Abstract1. A group of 32 yellow baboons (Papio cynocephalus) in the Masai-Amboseli National Park, Kenya, caught and ate 45 vertebrate prey items during 2519.19 hours of observation. 2. Eighty percent of the prey items were mammals and the most frequently eaten species were African hares (Lepus capensis), vervet monkeys (Cercopithecus aethiops) and neonate gazelle (Cazella granti and G. thomsoni) in that order. The details of predatory behavior for each prey species are described. 3. Rates of predation were significantly higher during the long dry season than during other months of the year, although no correlation was found between total monthly rainfall and monthly rates of predation. A lognormal model however provided a good fit to the monthly rate of predation data suggesting that the rate of predation by Amboseli baboons was affected by several factors that acted multiplicatively with respect to each other and were themselves related to rainfall or dryness. 4. A mean of 2.3 individuals fed directly from the carcass of each prey item. A mean of 3.5 individuals per prey item fed directly or indirectly, i.e., on scraps, from each carcass. In general, both the number of individuals who fed from each carcass and the duration of their feeding bouts was dependent upon the gross body size of the prey item. Adult males fed directly from the carcass of prey items for about three times more minutes than expected from their number in the group; other classes of individuals fed directly from prey carcasses for only one-fourth as many minutes as expected. In general, an adult male would be expected to feed on each category of vertebrate prey at least once per year, while individuals of all other age-sex classes would be expected to feed on most prey categories only once every two years. 5. The most frequent social behavior around prey items was agonistic bouts; no cooperation, simultaneous feeding or specific begging gestures were observed. 6. Estimates of the total number of prey killed annually by Amboseli baboons indicate that baboon predation probably has a negligible effect on prey populations other than vervet monkeys. 7. It is speculated that the need for vitamin B12 underlies baboon predatory behavior, and perhaps that of other primate species as well.


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