Pre-eradication assessment of feral cat density and population size across Kangaroo Island, South Australia

2020 ◽  
Vol 47 (8) ◽  
pp. 669
Author(s):  
Rosemary Hohnen ◽  
Karleah Berris ◽  
Pat Hodgens ◽  
Josh Mulvaney ◽  
Brenton Florence ◽  
...  
Keyword(s):  
Habitat Type ◽  
South Australia ◽  
Habitat Types ◽  
Feral Cat ◽  
Feral Cats ◽  
Order Of Magnitude ◽  
Capture Recapture ◽  
Remote Camera ◽  
Camera Arrays ◽  
The Relationship

Abstract Context Feral cats (Felis catus) are a significant threat to wildlife in Australia and globally. In Australia, densities of feral cats vary across the continent and also between the mainland and offshore islands. Densities on small islands may be at least an order of magnitude higher than those in adjacent mainland areas. To provide cat-free havens for biodiversity, cat-control and eradication programs are increasingly occurring on Australian offshore islands. However, planning such eradications is difficult, particularly on large islands where cat densities could vary considerably. Aims In the present study, we examined how feral cat densities vary among three habitats on Kangaroo Island, a large Australian offshore island for which feral cat eradication is planned. Methods Densities were compared among the following three broad habitat types: forest, forest–farmland boundaries and farmland. To detect cats, three remote-camera arrays were deployed in each habitat type, and density around each array was calculated using a spatially explicit capture–recapture framework. Key results The average feral cat density on Kangaroo Island (0.37 cats km−2) was slightly higher than that on the Australian mainland. Densities varied from 0.06 to 3.27 cats km−2 and were inconsistent within broad habitat types. Densities were highest on farms that had a high availability of macropod and sheep carcasses. The relationship between cat density and the proportion of cleared land in the surrounding area was weak. The total feral cat population of Kangaroo Island was estimated at 1629±661 (mean±s.e.) individuals. Conclusions Cat densities on Kangaroo Island are highly variable and may be locally affected by factors such as prey and carrion availability. Implications For cat eradication to be successful, resources must be sufficient to control at least the average cat density (0.37 cats km−2), with additional effort around areas of high carcass availability (where cats are likely to be at a higher density) potentially also being required.

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.

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.

scholarly journals Effect of Habitat Type on Parasitism ofEctatomma ruidumby Eucharitid Wasps

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Aymer Andrés Vásquez-Ordóñez ◽  
Inge Armbrecht ◽  
Gabriela Pérez-Lachaud
Keyword(s):  
Habitat Type ◽  
Immature Stages ◽  
Habitat Types ◽  
First Instar ◽  
Ectatomma Ruidum ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
And Behavior ◽  
Host Parasite ◽  
The Relationship

Eucharitidae are parasitoids that use immature stages of ants for their development.KapalaCameron is the genus most frequently collected in the Neotropics, but little is known about the biology and behavior of any of the species of this genus. We aimed to evaluate the effect of habitat type on eucharitid parasitism and to contribute to the knowledge of the host-parasite relationship betweenKapalasp. and the poneromorph antEctatomma ruidum(Roger) in Colombia. TwentyE. ruidumcolonies were extracted from two different habitat types (woodland and grassland), and larvae and cocoons (pupae) were examined in search for parasitoids in different stages of development. Globally, 60% of the colonies were parasitized, with 1.3% of larvae and 4% of pupae parasitized. Planidia (first-instar larvae), pupae, and adults of the parasitoid were observed. All of the pupae and adult parasitoids belonged toKapala iridicolorCameron. All the colonies collected in the woodlands were parasitized and contained more parasitized larvae (2%) and parasitized cocoons (8%) than those collected in grasslands (4/12 parasitized colonies, 0.5% parasitized larvae, 0.8% parasitized cocoons). The relationship observed between habitat type and parasitism prevalence is a novel aspect of the study of eucharitid impact on ant host populations.

Applying home-range and landscape-use data to design effective feral-cat control programs

2012 ◽  
Vol 39 (3) ◽  
pp. 258 ◽  
Author(s):  
Andrew J. Bengsen ◽  
John A. Butler ◽  
Pip Masters
Keyword(s):  
Home Range ◽  
Habitat Preferences ◽  
South Australia ◽  
Gps Tracking ◽  
Feral Cat ◽  
Feral Cats ◽  
Small Areas ◽  
Control Programs ◽  
Spatial Coverage ◽  
Landscape Use

Context Effective feral-cat (Felis silvestris catus) management requires a sound understanding of the ways cats use their environment. Key characteristics of landscape use by cats vary widely among different regions and different conditions. Aims The present study aimed to describe the most important characteristics of landscape use by feral cats on a large, human-populated island, and to use this information to guide the development of feral-cat management programs. Methods We used GPS tracking collars to record the movements of 13 feral cats at two sites on Kangaroo Island, South Australia, for between 20 and 106 days. We described home-range extents by using local convex hulls, and derived management suggestions from examination of home-range and movement data. Key results Median feral-cat home range was 5.11 km2, and this did not differ between sexes or sites. Cats at a fragmented pastoral site tended to favour woody vegetation over open paddocks, but habitat preferences were less clear at a bushland site. Cats that preferentially used treelines at the pastoral site were almost twice as likely to be recorded close to a tree-line junction as expected. Conclusions Control programs for feral cats on Kangaroo Island should deploy control devices at a density no less than 1.7 devices km–2. Spatial coverage should be as large as practicable or repeated frequently. Infrequent programs covering small areas can be expected only to provide short-term reductions in cat abundance. Implications The information gained from the present study will contribute to the development of strategic sustained management plans for feral cats on Kangaroo Island. The principles from which we inferred management guidelines are applicable to other regions and species.

The effect of stand structure and stand density on the leaf area–sapwood area relationship of lodgepole pine

1989 ◽  
Vol 19 (3) ◽  
pp. 392-396 ◽  
Author(s):  
Dan C. Thompson
Keyword(s):  
Leaf Area ◽  
Stand Structure ◽  
Lodgepole Pine ◽  
Habitat Type ◽  
Ring Width ◽  
Stand Density ◽  
Habitat Types ◽  
Sapwood Area ◽  
Relationship Of ◽  
The Relationship

The relationship of sapwood area to leaf area in lodgepole pine was examined across a variety of habitat types and stand densities in northwest Montana. No statistical differences were found between plots with regard to either habitat type or stand density. A nonlinear relationship was found between leaf area and sapwood area. Increasing amounts of sapwood were associated with a decrease in the leaf area–sapwood area ratio. A large amount of within-plot variation in the sapwood area–leaf area relationship was explained by differences between dominant trees and trees of other crown classes. Leaf area (LA) was best estimated by the equation LA = 0.12 × S − 0.0003 × S2 + 0.06 × S × D, where LA is leaf area, S is sapwood area, and D is the crown class (dominant). Differences between dominant and subdominant trees appear to be related to ring width and its associated permeability. Differences in sapwood area–leaf area equations among different studies may be due in part to differences in stand structure.

scholarly journals Comparación entre ensambles de Phyllophaga (Coleoptera: Melolonthidae) del Occidente de Cuba

2017 ◽  
Vol 65 (1) ◽  
pp. 351
Author(s):  
Annery Serrano Rodríguez ◽  
Miguel Ángel Morón Ríos ◽  
Alejandro Barro Cañamero ◽  
Gabriela Molina
Keyword(s):  
Light Trap ◽  
Habitat Type ◽  
Abundant Species ◽  
Total Abundance ◽  
Plant Structure ◽  
Habitat Types ◽  
Composition And Structure ◽  
Human Habitat ◽  
Intermediate Degree ◽  
The Relationship

The Cuban archipelago has 79 Phyllophaga species with a 98.6 % of endemism, which makes the group ecologically and economically important, as some species are classified as crop pests. The aim of this study was to determine the relationship between the composition and structure of the Phyllophaga assemblages with their habitat type, considering both plant structure and level of human habitat disturbance. A total of 17 locations were sampled in Western Cuba during the rainy seasons of the period from 2011 to 2015; these differed in habitat types (forests and agroecosystems). Samplings followed standard methods and were made once with a light trap screen in each locality. A total of 1153 individuals of 24 Phyllophaga species were collected. The total abundance of collected individuals varied between 10 and 306, and species richness between two and nine species. The most abundant species was Phyllophaga dissimilis (Chevrolat) which also had the highest frequency of occurrence. Generally, less anthropized sites reflected richer and equitative communities; although these characteristics appeared in two sites that showed intermediate degree of disturbance. The non-metric multidimensional scaling showed that the most similar samples were those of the very anthropized sites; this similarity was given mainly by the abundance of Phyllophaga dissimilis, P. insualepinorum and P. puberula. Besides, the geographical distance was not related to the similarity of these assemblages.

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.

scholarly journals An Evaluation of Systematic Versus Strategically-Placed Camera Traps for Monitoring Feral Cats in New Zealand

Animals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 687 ◽  
Author(s):  
Margaret Nichols ◽  
James Ross ◽  
Alistair S. Glen ◽  
Adrian M. Paterson
Keyword(s):  
New Zealand ◽  
Model Selection ◽  
Habitat Type ◽  
Camera Traps ◽  
Type Model ◽  
Feral Cat ◽  
Feral Cats ◽  
Forest Margin ◽  
Detection Probabilities ◽  
Forest Habitats

We deploy camera traps to monitor feral cat (Felis catus) populations at two pastoral sites in Hawke’s Bay, North Island, New Zealand. At Site 1, cameras are deployed at pre-determined GPS points on a 500-m grid, and at Site 2, cameras are strategically deployed with a bias towards forest and forest margin habitat where possible. A portion of cameras are also deployed in open farmland habitat and mixed scrub. We then use the abundance-induced heterogeneity Royle–Nichols model to estimate mean animal abundance and detection probabilities for cameras in each habitat type. Model selection suggests that only cat abundance varies by habitat type. Mean cat abundance is highest at forest margin cameras for both deployment methods (3 cats [95% CI 1.9–4.5] Site 1, and 1.7 cats [95% CI 1.2–2.4] Site 2) but not substantially higher than in forest habitats (1.7 cats [95% CI 0.8–3.6] Site 1, and 1.5 cats [95% CI 1.1–2.0] Site 2). Model selection shows detection probabilities do not vary substantially by habitat (although they are also higher for cameras in forest margins and forest habitats) and are similar between sites (8.6% [95% CI 5.4–13.4] Site 1, and 8.3% [5.8–11.9] Site 2). Cat detections by camera traps are higher when placed in forests and forest margins; thus, strategic placement may be preferable when monitoring feral cats in a pastoral landscape.

Prey selectivity by feral cats at central Australian rock-wallaby colonies

2019 ◽  
Vol 41 (1) ◽  
pp. 132 ◽  
Author(s):  
J. L. Read ◽  
E. Dagg ◽  
K. E. Moseby
Keyword(s):  
Conservation Status ◽  
South Australia ◽  
Prey Selectivity ◽  
Pitfall Trapping ◽  
Short Term ◽  
Feral Cat ◽  
Feral Cats ◽  
Recovery Programs ◽  
Fast Running ◽  
Sustainable Recovery

Threatened warru, or black-footed rock-wallaby (Petrogale lateralis MacDonnell Ranges race), populations in northern South Australia continued to decline despite baiting for foxes (Vulpes vulpes), which improved their short-term conservation status elsewhere. To investigate whether feral cats (Felis catus) also represent a risk to warru we compared frequencies of prey occurrence in 103 feral cat and 14 fox stomachs shot near warru colonies in northern South Australia during 2001–17 with measures of prey abundance from pitfall trapping and opportunistic searches. We hypothesise that one fresh adult warru kill and the presence of warru remains in four other cats suggests predation by cats on adult and juvenile warru. Small reptiles and invertebrates were the most frequently recorded prey of cats in summer, whereas rodents and small dasyurids were the most frequent prey items in winter. Small mammals, small snakes and pygopodid lizards were over-represented in the diet of cats compared with estimated encounter frequencies, whereas fast-running dragons, knob-tailed geckoes (Nephrurus) and echidnas (Tachyglossus aculeatus) were not recorded from cat stomachs despite being relatively abundant. Rabbits (Oryctolagus cuniculus), rodents and fruits were the most frequently recorded items in fox stomachs. This study reinforces that targeted management of feral cat populations should be considered in concert with control of canids in sustainable recovery programs for warru and other cat-vulnerable species.

An Adaptive Strategy for Reducing Feral Cat Predation on Endangered Hawaiian Birds

2009 ◽  
Vol 15 (1) ◽  
pp. 56 ◽  
Author(s):  
Steven C. Hess ◽  
Paul C. Banko ◽  
Heidi Hansen
Keyword(s):  
Linear Models ◽  
Habitat Type ◽  
Adaptive Strategy ◽  
The West ◽  
Feral Cat ◽  
Feral Cats ◽  
Ranking Criteria ◽  
Control Programmes ◽  
Herpestes Auropunctatus ◽  
History Of

Despite the long history of Feral Cats Felis catus in Hawai?i, there has been little research to provide strategies to improve control programmes and reduce depredation on endangered species. Our objective was to develop a predictive model to determine how landscape features on Mauna Kea, such as habitat, elevation, and proximity to roads, may affect the number of Feral Cats captured at each trap. We used log-link generalized linear models and QAICc model ranking criteria to determine the effect of these factors. We found that the number of cats captured per trap was related to effort, habitat type, and whether traps were located on the West or North Slope of Mauna Kea. We recommend an adaptive management strategy to minimize trapping interference by non-target Small Indian Mongoose Herpestes auropunctatus with toxicants, to focus trapping efforts in Mamane Sophora chrysophylla habitat on the West slope of Mauna Kea, and to cluster traps near others that have previously captured multiple cats.

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