The impact of cats and foxes on the small vertebrate fauna of Heirisson Prong, Western Australia. I. Exploring potential impact using diet analysis

1999 ◽  
Vol 26 (5) ◽  
pp. 621 ◽  
Author(s):  
Jeff Short ◽  
Michael C. Calver ◽  
Danielle A. Risbey
Keyword(s):  
Western Australia ◽  
Prey Species ◽  
Food Type ◽  
Gut Contents ◽  
Frequency Of Occurrence ◽  
Feral Cats ◽  
Important Prey ◽  
Introduced Predators ◽  
Small Vertebrate ◽  
The Impact

The diets of cats (Felis catus) and foxes (Vulpes vulpes) killed during predator control at a semi-arid site in Western Australia were studied to see which prey species may be affected by predation from these introduced predators. The number of items, biomass and frequency of occurrence of each food type in the gut contents from 109 feral cats, 62 semi-feral cats and 47 foxes were used to calculate an Index of Relative Importance for each food category for each predator. Mammals were the most important prey group for all three predators, with rabbit being the most highly ranked prey species. The diets of feral and semi-feral cats were similar in dietary diversity but differed in the frequency of occurrence of some food categories. Native rodents, birds and reptiles occurred more frequently and were ranked higher in the diet of feral cats, and food scraps occurred more frequently in the diet of semi-feral cats. The diet of foxes was less diverse than that of either group of cats. Invertebrates and sheep carrion were more important prey categories for foxes than for cats. In the summer–autumn period, foxes ate more sheep carrion and invertebrates than they did in winter–spring. The diet of feral cats was more diverse in summer–autumn, including a greater range of invertebrates and more rodents, birds and reptiles than in the winter–spring period. We predict that cats are more likely to have an impact on small vertebrates at this site and that the control of cats could lead to recoveries in the populations of native rodents, birds and reptiles. By contrast, the control of foxes alone may lead to a rise in cat numbers and a consequent detrimental impact on small vertebrate populations.

The impact of cats and foxes on the small vertebrate fauna of Heirisson Prong, Western Australia. II. A field experiment

2000 ◽  
Vol 27 (3) ◽  
pp. 223 ◽  
Author(s):  
Danielle A. Risbey ◽  
Michael C. Calver ◽  
Jeff Short ◽  
J. Stuart Bradley ◽  
Ian W. Wright
Keyword(s):  
Small Mammals ◽  
Western Australia ◽  
Negative Impact ◽  
Sampling Period ◽  
Feral Cats ◽  
Predator Removal ◽  
Population Sizes ◽  
One Year ◽  
Small Vertebrate ◽  
The Impact

The hypothesis that predation by feral cats and introduced foxes reduces population sizes of small, native vertebrates was supported by results of a predator-removal experiment at Heirisson Prong, a semi-arid site in Western Australia. The methods of control used against cats and foxes to protect native mammals reintroduced to Heirisson Prong produced three broad ‘predator zones’: a low-cat and low-fox zone, where foxes were eradicated and spotlight counts of cats declined after intensive cat control; a high-cat and low-fox zone where spotlight counts of cats increased three-fold after foxes were controlled; and a zone where numbers of cats and foxes were not manipulated. Small mammals and reptiles were monitored for one year before and three years after predator control began. Captures of small mammals increased in the low-cat and low-fox zone, but where only foxes were controlled captures of small mammals declined by 80%. In the absence of cat and fox control, captures of small mammals were variable over the sampling period, lower than where both cats and foxes were controlled, yet higher than where only foxes were controlled. The capture success of reptiles did not appear to be related to changes in predator counts. This study presents the first experimental evidence from mainland Australia that feral cats can have a negative impact on populations of small mammals.

scholarly journals Prey consumed by Guiana dolphin Sotalia guianensis (Cetacea, Delphinidae) and franciscana dolphin Pontoporia blainvillei (Cetacea, Pontoporiidae) in an estuarine environment in southern Brazil

2012 ◽  
Vol 102 (2) ◽  
pp. 131-137 ◽  
Author(s):  
Marta J. Cremer ◽  
Pedro C. Pinheiro ◽  
Paulo C. Simões-Lopes
Keyword(s):  
Prey Species ◽  
Stomach Contents ◽  
Frequency Of Occurrence ◽  
Teleost Fishes ◽  
Southern Brazil ◽  
Sympatric Populations ◽  
Sotalia Guianensis ◽  
Important Prey ◽  
Pontoporia Blainvillei ◽  
Lolliguncula Brevis

The present study provides information about the diet of sympatric populations of small cetaceans in the Babitonga Bay estuary. This is the first study on the diet of these species in direct sympatry. The stomach contents of seven Guiana dolphins Sotalia guianensis and eight franciscanas Pontoporia blainvillei were analyzed. The prey of both cetaceans was mostly teleost fishes, followed by cephalopods. We identified 13 teleost fishes as part of the diet of the franciscanas, and 20 as part of the diet of Guiana dolphins. Lolliguncula brevis was the only cephalopod recorded, and was the most important prey for both cetaceans. Stellifer rastrifer and Gobionellus oceanicus were also important for franciscana, so as Mugil curema and Micropogonias furnieri were important for Guiana dolphins. Stellifer rastrifer and Cetengraulis edentulus were the fishes with the highest frequency of occurrence for franciscana (50%), while Achirus lineatus, C. edentulus, S. brasiliensis, Cynoscion leiarchus, M. furnieri, M. curema, Diapterus rhombeus, Eugerres brasilianus and G. oceanicus showed 28.6% of frequency of occurrence for Guiana dolphins. Franciscanas captured greater cephalopods than the Guiana dolphins in both total length (z= -3.38; n= 40; p< 0.05) and biomass (z = -2.46; n = 40; p<0.05). All of the prey species identified occur inside the estuary, which represents a safe habitat against predators and food availability, reinforcing the importance of the Babitonga Bay for these cetacean populations.

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.

Impact of rabbit haemorrhagic disease on introduced predators in the Flinders Ranges, South Australia

2002 ◽  
Vol 29 (6) ◽  
pp. 615 ◽  
Author(s):  
C. Holden ◽  
G. Mutze
Keyword(s):  
Population Dynamics ◽  
Physical Condition ◽  
South Australia ◽  
Feral Cats ◽  
Flinders Ranges ◽  
Introduced Predators ◽  
Rabbit Haemorrhagic Disease ◽  
Haemorrhagic Disease ◽  
The Impact

The impact of rabbit haemorrhagic disease (RHD) on the population dynamics and diet of foxes and feral cats was studied in the Flinders Ranges, South Australia. Populations of both foxes and cats decreased substantially some 6–10 months after the advent of RHD, when rabbit numbers were reduced by 85%. The diet of foxes changed as a result of reduced rabbit numbers, with much less rabbit and more invertebrates and carrion being eaten. The physical condition of foxes showed little change after RHD. The diet of cats did not change markedly, but their physical condition was substantially poorer than before RHD. Total predation on native fauna is considered to have decreased after RHD.

Predation by feral cats key to the failure of a long-term reintroduction of the western barred bandicoot (Perameles bougainville)

2016 ◽  
Vol 43 (1) ◽  
pp. 38 ◽  
Author(s):  
Jeff Short
Keyword(s):  
Prey Species ◽  
Local Extinction ◽  
Contributing Factors ◽  
Feral Cats ◽  
European Rabbits ◽  
Threatening Processes ◽  
The Impact ◽  
Methods Of Control

Context Reintroduction of endangered species potentially places them back in contact with putative factors of historical decline, inadvertently providing the opportunity to evaluate their impact. Aims To monitor the long-term progress of a population of western barred bandicoot reintroduced to mainland Australia and to assess factors involved in its eventual local extinction. Methods Bandicoots were reintroduced from offshore Dorre Island to the nearby mainland peninsula of Heirisson Prong in 1995. The narrow neck of the peninsula was fenced to exclude foxes and feral cats from a 1200 ha area, but the area was subject to periodic incursions. There was parallel management of a confined but unsupported population in an in situ 17-ha predator refuge. Bandicoots were assessed for abundance, body condition and reproduction two to four times annually between 1995 and 2010. In addition, perceived threatening processes (drought, disease and the abundance of cats, foxes and rabbits) were monitored. Key results Bandicoots became well established at the site, spreading to all available habitat. Numbers fluctuated strongly, peaking at ~250 in 1999 and then declining to apparent local extinction (with subsequent re-establishment from the refuge), and at ~470 animals in 2006, followed again by extinction. Conclusions Predation by feral cats was implicated as the primary cause of both free-range extinctions and the eventual elimination of all bandicoots from the predator refuge. Other contributing factors in one or more of the declines were a reduction in reproduction and recruitment in bandicoots during a one-in-100-year drought, the impact of overabundant European rabbits on vegetation used by bandicoots for nesting shelter and brief fox incursions at key times. Implications Existing methods of control of feral cats are rendered ineffective in the presence of abundant and diverse native fauna and abundant exotic species (particularly European rabbits). In addition, episodic drought in arid Australia intensifies the impact of predation by restricting reproduction of prey species. These factors hamper the attempts of conservation managers to re-establish vulnerable species at sites other than those with the infrastructure and/or management intensity to largely exclude exotic predators (and preferably European rabbits) over the long-term.

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.

Reintroduction of the greater stick-nest rat (Leporillus conditor) to Heirisson Prong, Shark Bay: an unsuccessful attempt to establish a mainland population

2018 ◽  
Vol 40 (2) ◽  
pp. 269 ◽  
Author(s):  
Jeff Short ◽  
Jacqui D. Richards ◽  
Sally O'Neill
Keyword(s):  
Western Australia ◽  
Natural Vegetation ◽  
Birds Of Prey ◽  
Unsuccessful Attempt ◽  
Mainland Population ◽  
Feral Cats ◽  
Shark Bay ◽  
Introduced Predators ◽  
Source Site

Greater stick-nest rats were reintroduced to Heirisson Prong from Salutation Island at Shark Bay to establish the first mainland population in Western Australia in over 60 years. Forty-eight animals were transferred over two years from August 1999 to a 17-ha enclosure of natural vegetation that excluded foxes and feral cats. This refuge from introduced predators was located within a larger 1200-ha area where these predators were controlled. Stick-nest rats were able to disperse from the refuge to the wider area. The reintroduction was unsuccessful, with the last record in August 2007. Rats were reproducing in most years, yet only 28 recruits were detected over the reintroduction. Mean condition of rats was better at the reintroduction site relative to the source site. Survivorship of successive translocation cohorts was poorer than that of their predecessors, and survivorship of recruits was poorer than that of translocated animals. The most likely explanations for the decline are predation from monitors and small birds of prey within the refuge, and from monitors, small birds of prey and feral cats outside the refuge. An irruption of other rodents immediately before and coinciding with the reintroduction and building rabbit numbers likely contributed to elevated levels of predation from predators.

Assessment of Lamprey and Fish Stocks in the Great Lakes in Relation to Control of the Sea Lamprey (Petromyzon marinus): Report from the SLIS Assessment Measurements Task Force

1980 ◽  
Vol 37 (11) ◽  
pp. 2197-2201 ◽  
Author(s):  
P. S. Maitland
Keyword(s):  
Great Lakes ◽  
Prey Species ◽  
Task Force ◽  
Stock Assessment ◽  
Control Program ◽  
Sea Lamprey ◽  
Nontarget Organisms ◽  
Fish Stocks ◽  
Important Prey ◽  
The Impact

Available and potential methodology for assessing lamprey and prey fish populations is related to existing and future requirements of the sea lamprey control program of the Great Lakes Fishery Commission (GLFC). For lamprey, we recommend that the classification of Great Lakes tributaries according to their potential for larval production and the quality of lamprey attack data should be improved and standardized; standardized collections of spawning run adults should be continued; research should be encouraged on attractants and repellents, a male sterilization program, and the biology of parasitic phase animals. For fish, we recommend that more emphasis be given to the precision and standardization of estimates to allow better comparison between places and years, and the assessment of fish stocks other than major prey species; the GLFC support an evaluation program of an important prey species; and that other assessment methods (e.g. acoustic; counts of entrained fish) be explored. Because lamprey control is a long-term process that may span periods of environmental change, monitoring of physical, chemical, and biotic factors should be encouraged. Research on the impact of lampricides on nontarget organisms should be expanded. We also discuss and offer suggestions on the future of sea lamprey control.Key words: stock assessment, fishery surveys, methodology, populations control, proposed research

scholarly journals Using Genetics to Evaluate the Success of a Feral Cat (Felis catus) Control Program in North-Western Australia

Animals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1050
Author(s):  
Saul Cowen ◽  
Lucy Clausen ◽  
Dave Algar ◽  
Sarah Comer
Keyword(s):  
Western Australia ◽  
Control Program ◽  
Small Sample ◽  
Sample Sizes ◽  
Natural Habitats ◽  
Feral Cat ◽  
Feral Cats ◽  
Animal Populations ◽  
The Impact ◽  
North Western

The feral cat has been implicated in the decline and extinction of many species worldwide and a range of strategies have been devised for its control. A five-year control program using the aerial broadcast of toxic Eradicat® baits was undertaken at Fortescue Marsh in the Pilbara region of north-western Australia, for the protection of biodiversity in this important wetland area. This program has been shown to have had a significant detrimental effect on cats in this landscape, but the long-term impact is difficult to ascertain. We assessed population genetics across three cohorts of feral cats sampled as part of the control program. We also compared cat populations in natural habitats and around human infrastructure. A key challenge in any study of wild animal populations is small sample sizes and feral cats are particularly difficult to capture and sample. The results of this study superficially appear to suggest promising trends but were limited by sample size and many were not statistically significant. We find that the use of genetic techniques to monitor the impact of invasive species control programs is potentially useful, but ensuring adequate sample sizes over a long enough time-frame will be critical to the success of such studies.

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