Confinement remains the simplest measure to reduce roaming by pet cats

Hall, C. M., Bryant, K. A., Haskard, K., Major, T., Bruce, S., & Calver, M. C. (2016). Factors determining the home ranges of pet cats: A meta-analysis. Biological Conservation, 203, 313-320.

Highlights
• We assessed pet cats' roaming behaviour using meta-analyses and mixed linear models.
• Desexing, regular feeding and interaction with owners did not affect home range.
• Males had larger home ranges than females.
• Both sexes had larger home ranges at low housing densities.
• Confinement remains the simplest measure to reduce roaming by pet cats.

Abstract
Roaming pet cats Felis catus are a significant conservation issue because they may hunt, harass and compete with wildlife; spread disease, interbreed with cats in feral populations, and hybridise with wild native felids. Studies of the roaming behaviour of pet cats are often hampered by modest sample sizes and variability between cats, limiting statistical significance of the findings and their usefulness in recommending measures to discourage roaming. We resolved these difficulties through meta-analyses of 25 studies from 10 countries involving 469 pet cats to assess the influence of sex, whether a cat was desexed and housing density on roaming. A complementary linear mixed models approach used data on 311 individual animals from 22 studies and was also able to assess the influence of age and husbandry practices on roaming. This restricted sample gave greater statistical power than the meta-analyses.

Meta-analyses found that: male pet cats had larger home ranges than females, desexing did not influence home range, and cats had larger home ranges when housing densities were low. The linear mixed models supported those results. They also indicated that animals ≥ 8 years old had smaller home ranges than younger cats. Cats fed regularly, provided with veterinary care and socialised with humans had similar home ranges to cats living in association with households but not provided for in some of these ways. Short of confinement, there is no simple measure owners can adopt to reduce roaming by their cats and prevent the associated environmental problems.

Feral cats overlap with prey and competitors in primary and altered habitats

Bogdan, V., Jůnek, T., & Vymyslická, P. J. (2016). Temporal overlaps of feral cats with prey and competitors in primary and human-altered habitats on Bohol Island, Philippines. PeerJ, 4, e2288.

The vertebrate fauna of the Philippines, known for its diversity and high proportion of endemic species, comprises mainly small- to medium-sized forms with a few large exceptions. As with other tropical ecosystems, the major threats to wildlife are habitat loss, hunting and invasive species, of which the feral cat (Felis catus) is considered the most damaging. Our camera-trapping study focused on a terrestrial vertebrate species inventory on Bohol Island and tempo-spatial co-occurrences of feral cats with their prey and competitors. The survey took place in the Rajah Sikatuna Protected Landscape, and we examined the primary rainforest, its border with agricultural land, and rural areas in the vicinity of villages. Altogether, over 2,885 trap days we captured 30 species of vertebrates–10 mammals (including Sus philippensis), 19 birds and one reptile, Varanus cumingi. We trapped 81.8% of expected vertebrates. Based on the number of events, the most frequent native species was the barred rail (Gallirallus torquatus). The highest overlap in diel activity between cats and potential prey was recorded with rodents in rural areas (Δ = 0.62); the lowest was in the same habitat with ground-dwelling birds (Δ = 0.40). Cat activity was not recorded inside the rainforest; in other habitats their diel activity pattern differed. The cats’ activity declined in daylight in the proximity of humans, while it peaked at the transition zone between rainforest and fields. Both rodents and ground-dwelling birds exhibited a shift in activity levels between sites where cats were present or absent. Rodents tend to become active by day in cat-free habitats. No cats’ temporal response to co-occurrences of civets (Paradoxurus hermaphroditus and Viverra tangalunga) was found but cats in diel activity avoided domestic dogs (Canis lupus familiaris). Our first insight into the ecology of this invasive predator in the Philippines revealed an avoidance of homogeneous primary rainforest and a tendency to forage close to human settlements in heterogeneous habitats. A detailed further investigation of the composition of the cat’s diet, as well as ranging pattern, is still needed.

Spatial ecology and population genetics of cats living in or near conservation-sensitive areas

Cross, C. (2016). Spatial ecology and population genetics of cats (Felis catus) living in or near conservation-sensitive areas (Doctoral dissertation, University of Otago).


Human-mediated dispersal of organisms across the world has resulted in species introductions into many vulnerable ecosystems. Invasive mammalian predators have had detrimental impacts on native island biota, leading to declines and extinctions of many endemic prey species. Humans have transported cats (Felis catus) across the world as mousers on ships and as companion animals. The role cats (especially feral) have played in the decline and extinction of several island species is clear; however, different types of cats classified by their associations with humans has an influence on the public perception of cat impacts on wildlife and acceptance of appropriate management strategies.
I studied the spatial ecology of two different types of cats in two different conservation-sensitive areas (Te Anau Basin and Canterbury/North Otago) in the South Island of New Zealand. I conducted this research to gain an insight into companion cat spatial ecology and feral cat population genetics. Specifically, to investigate individual cat movement patterns and population level movements to discover putative geographic barriers to movement. Additionally, I intended to aid formulation and reinforcement of appropriate and current management strategies with respect to conservation-sensitive areas that support high levels of native biodiversity.

Cat capture rates in the Tasman Valley from March 2005 toFebruary 2013 (included as 2012).

In the Te Anau Basin, the township of Te Anau lies on the edge of Lake Te Anau, directly adjacent to Fiordland National Park. The Kepler Mire conservation area, also situated in the Te Anau Basin, is a nearby wetland that supports a diverse range of fauna. I GPS tracked 32 local companion cats (11F:21M) for a maximum of 10 to 14 days over the austral spring/summer. I recorded a total of 19,157 locations prior to filtering data for erroneous locations. Home range and habitat analysis were performed on a filtered dataset of 13,241 locations using 100% minimum convex polygons (MCP) and Objective-Restricted-Edge Polygons (OREP). Dispersal barriers might be acting to prevent movement of tracked cats into Fiordland National Park, but not the Kepler Mire conservation area. I found males (mean MCP: 22.13 ha, OREP: 1.05 ha) exhibited larger movements (home range and distance travelled from home) than females (mean MCP: 8.83 ha, OREP: 0.45 ha) and rural-living cats (mean MCP: 32.54 ha, OREP 1.33 ha) exhibited larger movements than urban-living cats (mean MCP: 5.90 ha, OREP: 0.46 ha).  Cats showed a tendency to preferentially select Built, Cover and Sealed habitat features.  Although there was great individual variation in the ranging behaviour, there was no sex or age-related difference observed in the cats’ resource selection.
To infer population movements, I used 10 microsatellite loci and a sexidentification marker, in a multiplex framework, to infer population structure of 157 feral cats in the upper Waitaki Basin (Tasman Valley, Ohau River and Ahuriri Valley) and Macraes Flat. I found some evidence of population connectivity between the sites based on migration rates and low FST values, indicating features in the landscape that act to facilitate dispersal. Bayesian clustering analysis noted the presence of three separate clusters; however, assignment rates were low for the Ohau River, Tasman Valley and Macraes Flat sites. Spatial autocorrelation and Mantel tests indicated rough terrain (i.e. mountain ranges) might limit dispersal. Macraes Flat and Ohau River might function as man-made sinks due to lower relatedness scores. Lower relatedness, genetic differentiation scores, and proximity to human habituation suggested there might be genetic input from nearby stray and companion cat populations. Due to large movements exhibited by feral cats in these areas, reinvasion into trapped areas seems likely; however, the Tasman Valley might be able to be managed as an eradication unit, if movement out of the Ohau River and surrounding area is reduced. Continued genetic monitoring of
these sites and sampling of local stray and companion cats might help to identify if there is connectivity between different types of cats (i.e. companion, stray and feral). Additionally, continued genetic monitoring might be able to determine if genetic differentiation increases between each site in response to trapping operations.
Tighter regulations regarding companion cat management might aid New Zealand conservation efforts by reducing and restricting movement and cat interactions with native wildlife. Stricter companion and stray cat regulations might also benefit feral cat control efforts; however, this aspect requires further analysis. 

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.

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.

Distribution and habitat use of invasive dogs in Colombia

Manjarrés Rodríguez, T. S. (2015). Distribución y uso de hábitat del perro (Canis familiaris) en la cuenca alta del río Otún (Risaralda-Colombia).Trabajo de grado presentado para optar al titulo de: Magister en Conservación y Uso de la Biodiversidad (Modalidad de investigación)
The dog (Canis familiaris) is a alien specie that when is present in natural areas get to interact with wildlife as a competitor, predator and transmitter of disease. The present study identified through the
tracking the dog abundance index and the dog selection of habitat types, its density with the probability density Kernel-ArcGis 10 and its potential distribution related with environmental
variables that limit or favor he dog presence through the MAXENT program. How results the dog
was found in both vegetation types studied (secondary forest and grassland). The dog got a high
density and abundance in the study area, surpassing the abundance of wildlife registered. The
Bonferroni interval showed that the dog and the fox (Cerdocyon thous) shared the same types of
habitat. The variables that favors their presence were the proximity to house and roads turning the
upper basin of the river Otun in vulnerable to the constant invasion of this specie.

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

Feral cat home‐range size varies predictably with landscape productivity and population density

Bengsen, A. J., Algar, D., Ballard, G., Buckmaster, T., Comer, S., Fleming, P. J. S., ... & Zewe, F. (2015). Feral cat home‐range size varies predictably with landscape productivity and population density. Journal of Zoology.

An understanding of the factors that drive inter-population variability in home-range size is essential for managing the impacts of invasive species with broad global distributions, such as the feral domestic cat (Felis catus). The assumption that home-range sizes scale negatively with landscape productivity is fundamental to many spatial behaviour models, and inter-site variation in landscape productivity has often been invoked to explain the vast differences in feral cat home-range sizes among different regions. However, the validity of this explanation has not been tested or described. We used regression models to examine the ability of remotely sensed landscape productivity data, average body weight and population density to explain differences in the size of feral cat home ranges estimated across a diverse collection of sites across the globe. As expected for a solitary polygynous carnivore, female cats occupied smaller home ranges in highly productive sites, and range sizes of male cats scaled positively with those of females. However, the relationship between range size and productivity broke down at highly seasonal sites. Home-range size also scaled negatively with population density, but there was no clear relationship with average body weight. The relationships we describe should be useful for predicting home-range sizes and for designing effective feral cat control and monitoring programmes in many situations. More generally, these results confirm the importance of landscape productivity in shaping the spatial distribution of solitary carnivores, but the nature of the relationship is more complicated than is often appreciated.

Corridors of introduced feral cats infringing ecologically sensitive areas in NZ

Recio, M. R., Seddon, P. J., & Moore, A. B. (2015). Niche and movement models identify corridors of introduced feral cats infringing ecologically sensitive areas in New Zealand. Biological Conservation, 192, 48-56.

The mitigation of the impact caused by introduced mammalian predators is a priority for conservation managers. Reducing predator population numbers is the most realistic strategy in mainland areas or large islands, and could be a feasible alternative to pest eradication. However, the success of control campaigns depends not only on removal of resident individuals, but also on managing reinvasions facilitated by connectivity with surrounding source populations. We combined niche analysis and fine-scale movement analyses of feral cats (Felis silvestris catus) to identify least-cost corridors from sources surrounding controlled areas of the ecologically sensitive area of Tasman Valley and Aoraki/Mt. Cook National Park, New Zealand. Intensive control of exotic predators has been executed during the last ten years in this area, where they pose a threat to native species such as endangered ground-nesting birds. Species distribution models revealed that cat distribution in the region was limited by its main prey, the European rabbit, and to mid-elevation (~ 1600 m) areas. Using GPS-tracking data and step-selection functions, we found that cats moved in an optimized fashion suggesting a maximum energy gain associated with high rabbit presence, while avoiding landscape obstacles such as rugged terrain. Connectivity between the high probability of cat presence in source and destination locations (in the control area) was facilitated by 1–3 corridors between valleys and multiple paths within valleys. Identification of least-cost paths, rooted in ecological and behavioral mechanisms underlying space use, can identify realistic putative corridors for focused implementation of control measures for introduced species in ecologically sensitive areas.

Density and home range of feral cats in NW Australia

McGregor, H. W., Legge, S., Potts, J., Jones, M. E., & Johnson, C. N. (2015). Density and home range of feral cats in north-western Australia. Wildlife Research.

Context: Feral cats (Felis catus) pose a significant threat to biodiversity in Australia, and are implicated in current declines of small mammals in the savannas of northern Australia. Basic information on population density and ranging behaviour is essential to understand and manage threats from feral cats.

Aims: In this study, we provide robust estimates of density and home range of feral cats in the central Kimberley region of north-western Australia, and we test whether population density is affected by livestock grazing, small mammal abundance and other environmental factors.

Methods: Densities were measured at six transects sampled between 2011 and 2013 using arrays of infrared cameras. Cats were individually identified, and densities estimated using spatially explicit capture–recapture analysis. Home range was measured from GPS tracking of 32 cats.

Key results: Densities were similar across all transects and deployments, with a mean of 0.18 cats km^-2(range = 0.09–0.34 /km²). We found no evidence that population density was related to livestock grazing or abundance of small mammals. Home ranges of males were, on average, 855 ha (±156 ha (95% CI), n = 25), and those of females were half the size at 397 ha (±275 ha (95% CI), n = 7). There was little overlap in ranges of cats of the same sex.

Conclusions: Compared with elsewhere in Australia outside of semiarid regions, feral cats occur at low density and have large home ranges in the central Kimberley. However, other evidence shows that despite this low density, cats are contributing to declines of small mammal populations across northern Australia.

Implications: It will be very difficult to reduce these already-sparse populations by direct control. Instead, land-management practices that reduce the impacts of cats on prey should be investigated.

Ecology and predation of free ranging farm cats

 Kitts-Morgan SE, Caires KC, Bohannon LA, Parsons EI, Hilburn KA (2015) Free-Ranging Farm Cats: Home Range Size and Predation on a Livestock Unit In Northwest Georgia. PLoS ONE 10(4): e0120513. doi:10.1371/journal.pone.0120513

This study’s objective was to determine seasonal and diurnal vs. nocturnal home range size, as well as predation for free-ranging farm cats at a livestock unit in Northwest Georgia. Seven adult cats were tracked with attached GPS units for up to two weeks for one spring and two summer seasons from May 2010 through August 2011. Three and five cats were tracked for up to two weeks during the fall and winter seasons, respectively. Feline scat was collected during this entire period. Cats were fed a commercial cat food daily. There was no seasonal effect (P > 0.05) on overall (95% KDE and 90% KDE) or core home range size (50% KDE). Male cats tended (P = 0.08) to have larger diurnal and nocturnal core home ranges (1.09 ha) compared to female cats (0.64 ha). Reproductively intact cats (n = 2) had larger (P < 0.0001) diurnal and nocturnal home ranges as compared to altered cats. Feline scat processing separated scat into prey parts, and of the 210 feline scats collected during the study, 75.24% contained hair. Of these 158 scat samples, 86 contained non-cat hair and 72 contained only cat hair. Other prey components included fragments of bone in 21.43% of scat and teeth in 12.86% of scat. Teeth were used to identify mammalian prey hunted by these cats, of which the Hispid cotton rat (Sigmodon hispidus) was the primary rodent. Other targeted mammals were Peromyscus sp., Sylvilagus sp. and Microtus sp. Invertebrates and birds were less important as prey, but all mammalian prey identified in this study consisted of native animals. While the free-ranging farm cats in this study did not adjust their home range seasonally, sex and reproductive status did increase diurnal and nocturnal home range size. Ultimately, larger home ranges of free-ranging cats could negatively impact native wildlife.

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.

Activity and exploration range of house cats in rural areas of central Poland

Goszczynski, J., Krauze, D., and Gryz, J. (2009). Activity and exploration range of house cats in rural areas of central Poland. Folia Zoologica 58, 363–371.  

Domestic cats are the most numerous predators in Poland. They are commonly kept at farms but hardly controlled, so penetrate freely wide range of habitats. The work aimed at determining the range of greatest impact of cats by identifying patterns of their activity and area searching, over daily, monthly and annual cycles. The density index, estimated from transect counts, performed along standard routes, proved to be dependent on temperature, precipitation and time of the day. In spring and summer, cats presented a two-peaked activity pattern, while in cold seasons it was more stable throughout the day. In warm months cats were registered at a further distance from the buildings than in colder ones. The animals were much less active when rain was falling. Cats’ responses on noticing an observer showed that the further they were from the edges of settlements the more timid and cautious they became. The results showed that the potential pressure that cats may exert on their prey is the biggest around dawn and dusk and in summer. During a daytime it is confined to the immediate vicinity of build-up areas.

A critical review of habitat use by feral cats

Doherty, T. S., Bengsen, A. J., & Davis, R. A. (2015). A critical review of habitat use by feral cats and key directions for future research and management. Wildlife Research, 41(5), 435-446.

Feral cats (Felis catus) have a wide global distribution and cause significant damage to native fauna. Reducing their impacts requires an understanding of how they use habitat and which parts of the landscape should be the focus of management. We reviewed 27 experimental and observational studies conducted around the world over the last 35 years that aimed to examine habitat use by feral and unowned cats. Our aims were to: (1) summarise the current body of literature on habitat use by feral and unowned cats in the context of applicable ecological theory (i.e. habitat selection, foraging theory); (2) develop testable hypotheses to help fill important knowledge gaps in the current body of knowledge on this topic; and (3) build a conceptual framework that will guide the activities of researchers and managers in reducing feral cat impacts. We found that feral cats exploit a diverse range of habitats including arid deserts, shrublands and grasslands, fragmented agricultural landscapes, urban areas, glacial valleys, equatorial to sub-Antarctic islands and a range of forest and woodland types. Factors invoked to explain habitat use by cats included prey availability, predation/competition, shelter availability and human resource subsidies, but the strength of evidence used to support these assertions was low, with most studies being observational or correlative. We therefore provide a list of key directions that will assist conservation managers and researchers in better understanding and ameliorating the impact of feral cats at a scale appropriate for useful management and research. Future studies will benefit from employing an experimental approach and collecting data on the relative abundance and activity of prey and other predators. This might include landscape-scale experiments where the densities of predators, prey or competitors are manipulated and then the response in cat habitat use is measured. Effective management of feral cat populations could target high-use areas, such as linear features and structurally complex habitat. Since our review shows often-divergent outcomes in the use of the same habitat components and vegetation types worldwide, local knowledge and active monitoring of management actions is essential when deciding on control programs.

Intergroup agonistic behaviour in free-ranging dog

Pal, S.K. 2014. Factors influencing intergroup agonistic behaviour in free-ranging domestic dogs (Canis familiaris). Acta ecologica.

We investigated the effects of sex, age, season and competitive context on the intergroup agonistic behaviour of free-ranging dogs (Canis familiaris). Data were collected in different places to record competitive cooperative behaviour during intergroup conflicts. Observations of 21 free-ranging dogs belonging to four neighbouring groups were made in Katwa town, India. Throughout the 12-month study period, 85 % of all intergroup agonistic interactions recorded were aggressive and 15 % submissive. Intergroup aggressive interactions were more frequent during the late monsoon months when the females were in oestrus, while submissive interactions reached a peak during the winter months when the females were lactating. Adult dogs, particularly males, displayed a higher rate of aggressive behaviour than other age classes, whereas juvenile dogs, particularly males, displayed the highest rate of submissive behaviour. Male dogs were observed to perform more agonistic behaviours in mating contexts and at the boundaries of their territories, whereas female dogs displayed more agonistic behaviours in feeding contexts and in the vicinity of the den. Both aggressive and submissive patterns displayed by the dogs varied with the competitive contexts. The most frequently observed category of aggressive behaviour was ‘barking, growling and snarling’ and submissive behavioural patterns were displayed frequently by ‘lips retracted in a submissive grin’. The striking feature of this study was that in most cases, more than one dog participated in aggressive conflicts. Such cooperative defense predominantly occurred at the boundaries of territory. Group home range size was largest during the late monsoon months and during the winter months.

Cat predation assessed through kitty-cams

Morling, F. (2014). Cape Town's cats: reassessing predation through kitty-cam. Mini Thesis.

Domestic cats (Felis catus) are abundant generalist predators that exploit a wide range of prey within and adjacent to the urban matrix. Cats are known to have contributed to the extinction and endangerment (mostly on islands) of a number of indigenous species, including birds, small mammals, reptiles and amphibians. Most research on this important topic has been carried out in the developed world, predominantly in Australia, New Zealand, the U.K., the U.S. and Canada with only four studies carried out in Africa. Of these, two studies in Cape Town suggest that domestic cats have a big impact on wildlife but these studies may have underestimated predation because they failed to account for the proportion of prey not returned to participants’ homes. In this study I used kitty-cams in an attempt to provide a prey correction factor for urban cats in Cape Town, South Africa. I investigated hunting of wildlife by free-ranging domestic cats in Newlands, a suburb of Cape Town, South Africa over 5 weeks in 2013. I monitored 13 cats (6 deep-urban and 7 urban-edge) by questionnaire survey, asking cat owners to record all prey items returned by their cats. A total of 43 prey items were returned, 42% of which were small mammals, 30% invertebrates, 12% reptiles, 9% amphibians and 7% birds. Combining these data with two similar survey studies carried out in Cape Town I estimated that a total of 118 cats caught an average of 0.04 prey items per cat per day. Ten of the 13 cats were also monitored for 3 weeks using kitty-cam video cameras. Participating cats wore a video camera and all activity was analysed for prey captures and behavioural activity patterns.

Ecology of stray dogs in the Republic of Karelia

Sedova, N. 2014. Ecology of stray dogs in the Republic of Karelia. 9th Baltic Theriological Conference. Book of Abstracts, p. 73. Daugavpils, 16 – 18 October, 2014

The study was carried out between 2002-2007 in three cities in Karelia: Petrozavodsk, Belomorsk and Kostamuksha. During this period 669 dogs were censused in Petrozavodsk, 162 dogs in Belomorsk and 82 dogs in Kostamuksha.
Depending on the nature of owner control and the degree of socialization we distinguished three types of stray dogs; these were «neglected pets», «homeless» and «feral». In Petrozavodsk there were 232 individuals of the first type, 669 of the second type and about 20 of the third type. In Kostamuksha and Belomorsk numbers of «neglected pets» were 148 and 40 individuals respectively. «homeless» dogs were 162 and 82 individuals respectively, and «feral» dogs were not found. In the research we have identified 135 morphotypes of dogs in Petrozavodsk, and of these the dominant type is so called «laykoid» of black color, medium height, short-haired, upstanding ears with a log-like form tail (wolf form). In Kostamuksha there were 48 morphotypes identified and 58 in Belomorsk. Comparing between these cities has explored the same morphotype of stray dogs – red colored «laykoid», medium height, short-haired, upstanding ears and log-like tail.
The spatial structure of the stray dogs’ population in Petrozavodsk is characterized by aggregated distribution. It is expressed as a formation of various groups with large unpopulated areas between. For the packs in the industrial territories, small home ranges size (0.02 - 0.1 km²) were typical, with a low degree of variability within this. In residential territories the home range sizes did not exceed the foresaid (0.02 - 0.1 km²). Grouped distribution is mostly typical in the industrial territories where 75% of all dogs were gregarious. For residential territories solitary individuals were mainly typical: in Petrozavodsk - 90%, in Kostamuksha - 100 %, and in Belomorsk - 100%. However, packs did sometimes occur.
All contact of stray dogs with other species can be reduced to direct contact and mediated interaction. By direct contact the dogs demonstrate active predatory behaviour, or research activity. Mediated interaction can be described as commensalism, for instance when dogs consume cats - the main predators of rats in towns, as well as improve access of rodents and birds to feed. Competitive relations of stray dogs with other animals have not been identified.
The average number of stray dogs in Petrozavodsk was about 36.8 ind/ km² (1300 individuals in total). Analysis of number dynamics (2003-2007) showed that annual differences are insignificant. Changes tended to be small, indicating numbers to be fairly stable. The average number of stray dogs in Kostamuksha is 1.22 ind/km², and in Belomorsk - 5.91 ind/ km².
Analysis of samples within 2003-2007 showed that in Petrozavodsk the overall sex ratio among adults is 1:1. In Belomorsk and Kostamuksha there is a predominance of males. One explanation behind this is that the number of stray dogs are replenished by negelected domestic dogs, which are dominated by males.
In general the stray dog population within the studied cities was characterised by low numbers. One can also note the dependence of dog number on the area and layout of the city. The high numbers of neglected dogs observed in the streets indicates a culture of low pet care.

Cat predation on Middle East wildlife

Brickner-Braun, I., Geffen, E., & Yom-Tov, Y. (2007). The domestic cat as a predator of Israeli wildlife. Israel Journal of Ecology & Evolution, 53(2), 129-142.

Predation of wildlife by domestic cats was studied in Israel. Analysis of stomach contents and data provided by observers revealed that many domestic cats enriched the diet provided by their owners with many species of wild animals, including 12 mammals, 26 birds, 18 reptiles, and one amphibian, and scavenged from garbage. The proportion of manufactured cat food and garbage dump food in the diet of urban cats decreased from 70% of stomach volume among those living in rural settlements to 44% among cats living in open areas, with the rest of the stomach contents consisting of wild animals. Of the wild animals hunted by cats, the most common category was mammals (75% of the stomach volume), followed by amphibians (10%), birds (9%), and reptiles (6%).

Most cats do not wander more than 200 m away from either a food source or cover. Female cats living in (southern) desert settlements do not leave the inhabited area and have very small home ranges, while those living in the Mediterranean region (central and northern) wander outside under the cover of trees and bushes and have significantly larger home ranges. The mean distance traveled daily by females from their center of activity was 51.3 m and 103.4 m for the southern and northern populations, respectively. Males were studied only in the Mediterranean region, and their travel distances were greater than those of females.

Although our results of predation are mainly qualitative, this study supports those done elsewhere in the world where the cat was shown to be a generalist predator whose potential impact on some species, especially endangered ones, may be considerable.

Roaming behaviour and home range estimation of domestic dogs in northern Australia

Dürr, S., & Ward, M. P. (2014). Roaming behaviour and home range estimation of domestic dogs in Aboriginal and Torres Strait Islander communities in northern Australia using four different methods. Preventive Veterinary Medicine.

Disease transmission parameters are the core of epidemic models, but are difficult to estimate, especially in the absence of outbreak data. Investigation of the roaming behaviour, home range (HR) and utilization distribution (UD) can provide the foundation for such parameter estimation in free-ranging animals. The objectives of this study were to estimate HR and UD of 69 domestic dogs in six Aboriginal and Torres Strait Islander communities in northern Australia and to compare four different methods (the minimum convex polygon, MCP; the location-based kernel density estimation, LKDE; the biased random bridge, BRB; and Time Local Convex Hull, T-LoCoH) for investigation of UD and estimating HR sizes. Global positioning system (GPS) collars were attached to community dogs for a period of 1–3 days and positions (fixes) were recorded every minute. Median core HRs (50% isopleth) of the 69 dogs were estimated to range from 0.2 to 0.4 ha and the more extended HR (95% isopleth) to range from 2.5 to 5.3 ha, depending on the method used. The HR and UD shapes were found to be generally circular around the dog owner's house. However, some individuals were found to roam much more with a HR size of 40–104 ha and cover large areas of their community or occasionally beyond. These far roaming dogs are of particular interest for infectious disease transmission. Occasionally, dogs were taken between communities and out of communities for hunting, which enables the contact of dogs between communities and with wildlife (such as dingoes). The BRB and T-LoCoH are the only two methods applied here which integrate the consecutiveness of GPS locations into the analysis, a substantial advantage. The recently developed BRB method produced significantly larger HR estimates than the other two methods; however, the variability of HR sizes was lower compared to the other methods. Advantages of the BRB method include a more realistic analytical approach (kernel density estimation based on movements rather than on locations), possibilities to deal with irregular time periods between consecutive GPS fixes and parameter specification which respects the characteristics of the GPS unit used to collect the data. The BRB method was therefore the most suitable method for UD estimation in this dataset. The results of this study can further be used to contact rates between the dogs within and between communities, a foundation for estimating transmission parameters for canine infectious disease models, such as a rabies spread model in Australia.