Home range of feral cats on Rota Is.

Leo, B. T., Anderson, J. J., Brand Phillips, R., & Ha, R. R. (2016). Home range estimates of feral cats (Felis catus) on Rota Island and determining asymptotic convergence 1. Pacific Science, 70(3), 323-331.

Feral cats (Felis catus) have been shown to be a main contributor to species decline throughout the world and are especially threatening to insular species that lack appropriate defense characteristics. To mitigate the impact of feral cats on threatened species, space-use data are commonly used to design control strategies. In this article we report on the performance of GPS datalogging collars and provide baseline information on daily space use and home ranges of feral cats that threaten an endangered species on Rota Island in the Commonwealth of the Northern Mariana Islands. Using 100% Minimum Convex Polygon (MCP), average adult male home range was 1.32 km²(n = 2) and average adult female home range was 0.22 km²(n = 3). Home ranges were deemed fully revealed if asymptotes were approached using incremental analysis. Currently, there is no objective method for assessing where an asymptote is approached. Here, we describe a methodology to do so with the application of a Michaelis-Menten model to incremental data. We conclude that GPS datalogging collars are a viable tool for feral cat location data collection on Rota Island and that the Michaelis-Menten model is useful for determining asymptotic convergence of incremental location data.

Dogs vs camera traps: a comparison of techniques for detecting feral cats

Glen, A. S., Anderson, D., Veltman, C. J., Garvey, P. M., & Nichols, M. (2016). Wildlife detector dogs and camera traps: a comparison of techniques for detecting feral cats. New Zealand Journal of Zoology, 1-11.

A major challenge in controlling overabundant wildlife is monitoring their populations, particularly as they decline to very low density. Camera traps and wildlife detector dogs are increasingly being used for this purpose. We compared the costeffectiveness of these two approaches for detecting feral cats (Felis catus) on two pastoral properties in Hawke’s Bay, North Island, New Zealand. One property was subject to intensive pest removal, while the other had no recent history of pest control. Camera traps and wildlife detector dogs detected cats at similar rates at both sites. The operating costs of each method were also comparable. We identify a number of advantages and disadvantages of each technique, and suggest priorities for further research.

An examination of feral cats control techniques for the protection of critically endangered species

Leo, B. T. (2016). An examination of predator control techniques for the protection of critically endangered species (Doctoral dissertation).

Feral cats (Felis catus) have been shown to be a main contributor to species decline throughout the world and are especially threatening to insular species that lack adequate defense characteristics. Feral cat control programs have been implemented on islands throughout the world with varied success. Many islands present unique limitations and therefore require custom control strategies. Furthermore, the adaptive nature of feral cat populations makes it difficult to predict space use and the effect of control on population size. To mitigate the impact of feral cats on threatened species, space use data are commonly used to design control strategies. With the use of GPS data logging collars, chapter two describes daily space use and home ranges of feral cats that threaten an endangered species on Rota Island in the Commonwealth of the Northern Mariana Islands. Using 100% Minimum Convex Polygon (MCP), average adult male home range was 1.32 km² and average adult female home range was 0.22 km². Home ranges were deemed fully revealed if asymptotes were reached using incremental analysis. A Michaelis-Menten model was applied to predict home ranges of cats with datasets that did not show convergence. The ability of the model to estimate home ranges of cats with limited location datasets was evaluated by comparing predictions derived from truncations of the full time series of complete datasets. Findings suggest that cat management on Rota should be multifaceted in order to maximize the protection of endangered species and that the Michaelis-Menten model is a useful tool for home range analysis. Chapter three examines the Rota hunting strategy to determine its impacts on the population. A discrete form of the Schaefer model was applied to a 29-month time series of control data. A likelihood framework was used to determine maximum likelihood parameter estimates and calculate population projections to compare control strategies. Model results suggest that the hunting strategy on Rota was effective at initially reducing the cat population, however an unfeasible amount of effort would be required to maintain such a rate of decline. Findings show that it is feasible to maintain cat abundance at lower levels and suggest that a concentrated-effort strategy is preferable to a fixed-effort strategy. While more complex population model forms are available, the Schaefer model is well suited for assessing the impacts of limited predator control programs, such as the one conducted on Rota Island.

Spatial ecology and prey choice of tagged feral cats

van der Ende, J. M. (2015). Spatial ecology and prey choice of tagged feral cats on Schiermonnikoog. M.Sc. Dissertation.  Master of Science in Geographical Information Systems (UNIGIS) Faculty of Economics and Business Administration Vrije Universiteit Amsterdam
The Netherlands

Feral cats (Felis catus) inhabiting the island Schiermonnikoog, The Netherlands, are a potential threat for local prey species populations. To improve the understanding and retrieve more insight in the spatial ecology of this invasive predator, ten feral cats (5 male : 5 female; 5 adult : 5 subadult) were equipped with GPS tags and followed from May till July 2014. Spatio-temporal analyses were used. The home ranges we calculated using Minimum Convex Polygon and Kernel density estimators and tested for differences in sex, age and time. The displacement distance and habitat use was compared between day and night. Locomotive behaviour was compared between subjects using a pre-defined dimension dyad with daily movement variables. In addition, scats were collected and analysed on prey remains and compared with the prey present in the area.
Average 3-month home ranges were found to be 81 and 158ha using Kernel density 95% and Minimum Convex Polygon 95% home ranges respectively. Home range sizes were not significantly different between sexes or age classes. However, nocturnal home range sizes were bigger than the diurnal ones. The nocturnal habitat use did differ from the diurnal use, suggesting a small preference for short salt marsh vegetation during the night. The cats showed a higher nightly displacement (M=45m/15min) compared to during the day (M=22m/15min). The cats were very variable in their daily migration (range M=198-528m) and cumulative daily displacement (range M=1.5-4.1km). A new visualisation technique was proposed to identify differences and similarities between the feral cats and seemed to work well. Hares (Lepus europaeus) contributed the most to the diet in terms of relative prey volume, but Common vole (Microtus arvalis) was the most numerous prey item found in the scats.
In conclusion this study describes the spatial ecology of feral cats and give new insights in the behaviour of feral cats in a natural part of a Dutch Waddensea island. The home ranges of males are not necessarily bigger than female ones. They tend to use short salt marsh vegetation more during the night which could indicate they hunt on the nocturnal species foraging there like hares and rabbits. Bird remains are found in the scats which indicate a potential threat for the bird population by this invasive introduced predator. However in this research no indication is found they actively search and hunt on birds. Further research using acceleration data might be useful to better quantify their hunting behaviour.

Movement and diet of domestic cats on Stewart Island/Rakiura, NZ

Wood, V., Seddon, P. J., Beaven, B., & van Heezik, Y. (2016). Movement and diet of domestic cats on Stewart Island/Rakiura, New Zealand. New Zealand Journal of Ecology, 40(1), 0-0.

Domestic cats (Felis catus) in Halfmoon Bay, Stewart Island/Rakiura, were tracked to assess the
potential for incursions into native forest around the township, and into Rakiura National Park c. 5 km away.
During February and April 2005, 15 and 4 radio-collared cats were tracked, respectively. During a six-month period, cat-owners logged prey brought home by 11 cats. Cats were at home >90% of the time. Of the six cats that left home, movements were small: home range was between 0.05 and 16.6 ha (100% minimum convex polygon). Four cats brought prey home, comprising rats (Rattus spp.; 67% of prey items), and birds (four species, one native; 33%). Cats sampled at Halfmoon Bay were unlikely to enter the national park; however, many locations were within native forest patches, indicating that native birds within Halfmoon Bay were vulnerable to predation. The high proportion of rats caught could have benefits for native species.

Monitoring techniques in the capture and adoption of dogs and cats

Galvis, J. O. A., Baquero, O. S., Dias, R. A., Ferreira, F., Chiozzotto, E. N., & Grisi-Filho, J. H. H. (2015). Monitoring techniques in the capture and adoption of dogs and cats. Geospatial health, 10(2).

The continuous improvement of the information systems of organizations that work toward the control of stray dog and cat populations facilitates the implementation of programs aimed at reducing the number of animals that roam free in public streets. This study aimed to present techniques to improve the understanding of the spatial distribution of stray dogs and cats and of people who adopt these animals and the fate of these animals in zoonosis control centers (ZCC). Ripley’s K function was used with a Euclidean distance graph to detect the distribution pattern of dogs and cats captured and of the people who adopted these animals. An estimate of the kernel density was used to allow a better assessment of the spatial distribution of the phenomenon studied. The results showed that the distribution of captured animals and of the people who adopted these animals form a spatial cluster (p = 0.01). Most of the animals were captured near the premises of the ZCC and near the downtown area. Factors such as the abandonment of animals near animal control agencies and the availability of food sources are the main hypotheses associated to the distribution of the captures. The awareness of the people who live in places where there is a greater number of stray animals and the distribution of the urban population are the main hypotheses to explain the distribution of the adoptions. The results will help to implement control measures over these populations in the most problematic areas.

Monitoring feral cats' movements at important seabird colony

Bonnaud, E., Berger, G., Zarzoso-Lacoste, D., Bourgeois, K., Palmas, P., & Vidal, É. (2015). First steps in studying cat movement behaviour through VHF tracking at a major world breeding site for the Mediterranean endemic Yelkouan shearwater. Revue d'Ecologie, 70 (12)

Cats are considered one of the most harmful invasive predators of island native species, particularly adult shearwaters, which are highly vulnerable to predation. Populations of Yelkouan shearwater, an endemic species of the Mediterranean basin with only a few large breeding colonies, are predicted to decline in response to feral or free-roaming cats. In a previous study, the impact of introduced cats on the Yelkouan shearwater population of Le Levant Island was assessed through the analysis of cat diet over a two-year period. The study showed that cats prey upon three staple species: rabbits, rats, and shearwaters, with a peak of predation on shearwaters immediately upon their arrival at colonies (prospecting period). Here, we supplement this previous work by conducting a preliminary study on the movement patterns of four free-roaming cats (three feral and one domestic) using very high frequency (VHF) tracking to analyse individual behaviour and home ranges on Le Levant Island, one of the Yelkouan shearwater’s major breeding sites. Our results show that two of the three feral cats were recorded inside and in close vicinity to the shearwater colonies, mainly during the prospecting period, while the domestic cat was never recorded inside the colonies. This suggests that some feral cats could show movement behavioural patterns linked to the shearwater presence as soon as these seabirds arrive at the colonies. The monitored domestic cat also showed a relatively small home range, while feral cats covered larger distances and with overlapping territories. Based on these preliminary results of cat movement behaviour, in addition to the previous results of cat predation, it is evident that cat impact must be reduced. This may be achieved through accurate management strategy that takes cat movement behaviour into account to avoid exhausting one of the most important breeding sites for this Mediterranean endemic species

Studying cat movement behaviour through VHF tracking on Mediterranean island

Bonnaud, E., Berger, G., Zarzoso-Lacoste, D., Bourgeois, K., Palmas, P., & Vidal, É. (2015). First steps in studying cat movement behaviour through VHF tracking at a major world breeding site for the Mediterranean endemic Yelkouan shearwater. Revue d'Écologie, 70  Sup.12

Le chat représente un des prédateurs invasifs les plus menaçants pour les espèces natives des îles et particulièrement pour les oiseaux marins adultes qui sont fortement vulnérables à la prédation. Les populations du Puffin Yelkouan, espèce endémique du bassin méditerranéen, sont réparties en quelques grandes colonies de reproduction et sont en voie de déclin, notamment du fait de l’impact des chats harets et errants. Dans une étude précédemment publiée, l’impact des chats introduits sur la population de puffins de l’île du Levant a été évalué au travers du régime alimentaire du chat sur une période de deux ans. Cette étude a mis en évidence que les chats consommaient trois proies principales : le Lapin, le Rat noir et le Puffin Yelkouan, et qu’un pic de prédation de puffins était observé dès leur arrivée sur les colonies (période de prospection). Nous avons donc cherché à compléter ce travail par une étude préliminaire visant à étudier les patrons de mouvement de quatre chats (trois chats harets et un chat domestique) via un suivi VHF (very high frequency), dans le but d’analyser leurs comportements individuels et leurs domaines vitaux sur l’île du Levant, qui est l’un des principaux sites de reproduction du Puffin Yelkouan. Nos résultats montrent que deux des trois chats harets ont été détectés dans les colonies de puffins durant les périodes de prospection et de reproduction de cet oiseau marin alors que le chat domestique n’a jamais été détecté dans ces colonies. Cela suggère que les patrons de déplacement des quatre chats suivis puissent être liés à la présence des puffins dès que ces oiseaux marins arrivent à la colonie. Les chats suivis montrent des domaines vitaux de taille relativement réduite, plus larges pour les chats harets qui couvrent de plus grandes distances, et avec des territoires chevauchants, que pour le chat domestique. Ces résultats préliminaires de patrons de déplacements, couplés aux résultats précédents de prédation du chat sur le Puffin Yelkouan, nous indiquent que l’impact du chat haret se doit d’être limité. Cet objectif doit être atteint en effectuant une stratégie de gestion efficace qui tiendrait compte des patrons de déplacements des chats afin d’éviter l’épuisement d’un des sites de reproduction les plus importants pour cette espèce de puffin endémique de Méditerranée


Cats are considered one of the most harmful invasive predators of island native species, particularly adult shearwaters, which are highly vulnerable to predation. Populations of Yelkouan shearwater, an endemic species of the Mediterranean basin with only a few large breeding colonies, are predicted to decline in response to feral or free-roaming cats. In a previous study, the impact of introduced cats on the Yelkouan shearwater population of Le Levant Island was assessed through the analysis of cat diet over a two-year period. The study showed that cats prey upon three staple species: rabbits, rats, and shearwaters, with a peak of predation on shearwaters immediately upon their arrival at colonies (prospecting period). Here, we supplement this previous work by conducting a preliminary study on the movement patterns of four free-roaming cats (three feral and one domestic) using very high frequency (VHF) tracking to analyse individual behaviour and home ranges on Le Levant Island, one of the Yelkouan shearwater’s major breeding sites. Our results show that two of the three feral cats were recorded inside and in close vicinity to the shearwater colonies, mainly during the prospecting period, while the domestic cat was never recorded inside the colonies. This suggests that some feral cats could show movement behavioural patterns linked to the shearwater presence as soon as these seabirds arrive at the colonies. The monitored domestic cat also showed a relatively small home range, while feral cats covered larger distances and with overlapping territories. Based on these preliminary results of cat movement behaviour, in addition to the previous results of cat predation, it is evident that cat impact must be reduced. This may be achieved through accurate management strategy that takes cat movement behaviour into account to avoid exhausting one of the most important breeding sites for this Mediterranean endemic species

Smartphone and GPS for free-roaming dog population monitoring

Barnard, S., Ippoliti, C., Di Flaviano, D., De Ruvo, A., Messori, S., Giovannini, A., & Dalla Villa, P. (2015). Smartphone and GPS technology for free-roaming dog population surveillance-a methodological study. Veterinaria italiana, 51(3), 165-172.

Free-roaming dogs (FRD) represent a potential threat to the quality of life in cities from an ecological, social and public health point of view. One of the most urgent concerns is the role of uncontrolled dogs as reservoirs of infectious diseases transmittable to humans and, above all, rabies. An estimate of the FRD population size and characteristics in a given area is the first step for any relevant intervention programme. Direct count methods are still prominent because of their non-invasive approach, information technologies can support such methods facilitating data collection and allowing for a more efficient data handling. This paper presents a new framework for data collection using a topological algorithm implemented as ArcScript in ESRI^® ArcGIS software, which allows for a random selection of the sampling areas. It also supplies a mobile phone application for Android^®  operating system devices which integrates Global Positioning System (GPS) and Google Maps^TM. The potential of such a framework was tested in 2 Italian regions. Coupling technological and innovative solutions associated with common counting methods facilitate data collection and transcription. It also paves the way to future applications, which could support dog population management systems.

Spatial ecology of feral cats on San Clemente Island

Bridges, A. S., Sanchez, J. N., & Biteman, D. S. (2015). Spatial ecology of invasive feral cats on San Clemente Island: implications for control and management. Journal of Mammalogy, 96(1), 81-89.

Feral cats, Felis catus, inhabiting San Clemente Island, California, are both predators and competitors of multiple sympatric endemic species. To improve our understanding and management of these invasive predators, we used GPS-equipped radiocollars to track 11 (6F:5M) cats for a total of 3,108 days, resulting in 15,419 GPS locations. Average 100% minimum convex polygon, 95% kernel density, and 50% kernel density estimates were 229, 132, and 33 ha, respectively. The point estimate for average male home-range size was larger than the average for females, but there was substantial variation among individuals of both sexes. Overlap indices indicated similar usage areas during nocturnal and diurnal time periods. Sample size limited our ability to definitively detect habitat preference, but data suggested areas within 50 m of roads were avoided, and that thicker land cover was preferred over open grasslands. Three test collars deployed within active cat home ranges indicated GPS locations were precise, with 96% of locations having < 10-m error estimates, and that horizontal dilution of precision indices were not useful in screening data. Our results describe feral cat spatial ecology on a semiarid island and can be used to inform population estimation, control, and mitigation programs.

Pet cat home-range sizes may be underestimates in some studies

Coughlin, C. E., & van Heezik, Y. (2015). Weighed down by science: do collar-mounted devices affect domestic cat behaviour and movement?. Wildlife Research, 41(7), 606-614.

Context: Animals carrying tracking and logging devices are subject to a range of instrument effects that negatively affect survival, reproduction and behaviour. The common recommendation is that device weight should not exceed 5% body mass (BM) for terrestrial species; however, this rule-of-thumb has little empirical basis. Modelling indicates that devices weighing less than 3% BM may still have impacts. Several studies have used telemetry and data loggers on domestic cats (Felis catus) with instruments ranging in weight from 30 g to 125 g, but there has been no quantitative evaluation of instrument effects. In addition, inexpensive GPS tags such as iGotU are increasingly being used to track domestic cats, but often with little acknowledgement of habitat-related location error.

Aims: We evaluated the impact of wearing devices of different weights on domestic cat movements, and quantified location error across typical suburban habitats.

Methods: We recorded movements of cats wearing three different GPS collar weights for a week at a time: light, 30 g (<1% BM); medium, 80 g (~2% BM); and heavy, 130 g (~3% BM). Location error (LE) and fix success rates (FSR) were compared between backyard habitats and up- or downward orientation of the GPS tags on collars.

Key results: Home-range size and distance travelled from home were smaller when cats wore the heaviest collar. LE was lower and FSR higher for GPS tags with direct-line-of-sight to satellites (e.g. on lawns), but there was no difference between tags placed in dense vegetation (hedges) or more open vegetation (trees), or tags oriented up or down.

Conclusions: Collars carrying instruments on cats should be no more than 2% BM (medium-weight collar). LE was large relative to typical urban habitat size, indicating that misclassification of locations into habitats could easily occur in habitat-selection studies.

Implications: Some published accounts of cat home-range sizes may be underestimates, resulting in underestimates of the extent of impacts on prey species. Habitat-use studies should acknowledge the error associated with GPS tags and incorporate it into analyses using techniques such as Brownian Bridges.

A new technique for monitoring the detailed behaviour of domestic cat

Watanabe, S., Izawa, M., Kato, A., Ropert-Coudert, Y., & Naito, Y. (2005). A new technique for monitoring the detailed behaviour of terrestrial animals: a case study with the domestic cat. Applied Animal Behaviour Science, 94(1), 117-131.

For many animal species that are difficult to access, the behaviour of free-ranging individuals cannot be assessed by direct observation. In order to remedy this, we developed a new technique using a motion detector (acceleration data-logger) for monitoring the activity and behaviour of free-ranging vertebrates and tested its efficiency on a domestic cat, Felis catus. A total of 3615 min of surging acceleration was measured along the longitudinal body axis of an adult male cat. The cat's behaviour was also filmed for 113 min, these video data being used to correlate the logger's signals with the cat's behaviour. Acceleration data-loggers attached on the cat's collar recorded acceleration signals which were influenced by both the gravitational acceleration resulting from the body posture and the dynamic acceleration resulting from the dynamic behaviour of the cat. By applying spectral analysis based on a fast Fourier Transform to acceleration signals, body postures and some of the dynamic behaviours of the cat such as drinking, eating, and several paces of travelling were efficiently determined. The present study shows that acceleration data-loggers represent a useful and reliable system for accurately recording the activities and detail behaviours of the terrestrial animals.

Feral cat behaviour influence monitoring techniques and control methods

Fisher, P., Algar, D., Murphy, E., Johnston, M., & Eason, C. (2014). How does cat behaviour influence the development and implementation of monitoring techniques and lethal control methods for feral cats?. Applied Animal Behaviour Science.

Highlights
•Feral cats utilise the ‘wild’ end of the predatory and social behavioural spectrum of Felis catus.
•Efficacy in lethal control of feral cats is strongly influenced by prey resources.
•Cryptic habits and low densities in large remote areas make feral cat behaviour difficult to study.

Abstract
The need for lethal control of feral cats will remain in some contexts and potentially increase in others, alongside an obligation to develop and apply methods that are as cost-effective, humane and target-specific as possible. Drawing on practices particularly used in Australia, New Zealand and on offshore islands we review current lethal techniques applied for feral cat removal, such as shooting, trapping and poison baiting, and how our understanding of feral cat behaviour has influenced their development and application.