Dogs in Lombok Island, Indonesia

Mustiana A, Toribio J-A, Abdurrahman M, Suadnya IW, Hernandez-Jover M, Putra AAG, et al. (2015) Owned and Unowned Dog Population Estimation, Dog Management and Dog Bites to Inform Rabies Prevention and Response on Lombok Island, Indonesia. PLoS ONE 10(5): e0124092. doi:10.1371/journal.pone.0124092

Although Indonesia has been rabies-infected since at least the 1880s, some islands remain rabies-free, such as Lombok. However, due to its adjacency to rabies-infected islands such as Bali and Flores, there is considerable risk of a rabies incursion. As part of a rabies risk assessment project, surveys were conducted to estimate the size of the dog population and to describe dog management practices of households belonging to different ethnic groups. A photographic-recapture method was employed and the number of unowned dogs was estimated. A total of 400 dog owning households were interviewed, 300 at an urban site and 100 at a rural site. The majority of the interviewed households belonged to the Balinese ethnic group. Owned dogs were more likely male, and non-pedigree or local breed. These households kept their dogs either fully restricted, semi-free roaming or free-roaming but full restriction was reported only at the urban site. Dog bite cases were reported to be higher at the urban site, and commonly affected children/young adults to 20 years old and males. A higher number of unowned dogs was observed at the urban site than at the rural site. Data generated within these surveys can inform rabies risk assessment models to quantify the probability of rabies being released into Lombok and resulting in the infection of the local dog population. The information gained is critical for efforts to educate dog owners about rabies, as a component of preparedness to prevent the establishment of rabies should an incursion occur.

Prevalence of T. gondii depends on household effect

Fromont, E. G., Riche, B., & Rabilloud, M. (2009). Toxoplasma seroprevalence in a rural population in France: detection of a household effect. BMC infectious diseases, 9(1), 76.

Background

Toxoplasma gondii, the agent of toxoplasmosis, has a complex life cycle. In humans, the parasite may be acquired either through ingestion of contaminated meat or through oocysts present in the environment. The importance of each source of contamination varies locally according to the environment characteristics and to differences concerning human eating habits and the presence of cats; thus, the risk factors may be determined through fine-scale studies. Here, we searched for factors associated with seropositivity in the population of two adjacent villages in Lorraine region, France.

Methods
All voluntary inhabitants filled out a questionnaire and gave a blood sample. The seroprevalence was estimated globally and according to the inhabitants' ages using a cubic spline regression. A mixed logistic regression model was used to quantify the effect of individual and household factors on the probability of seropositivity.

Results

Based on serological results from 273 persons, we estimated seroprevalence to be 47% (95% confidence interval: 41 to 53%). That seroprevalence increased with age: the slope was the steepest up to the age of 40 years (OR = 2.48 per 10-year increment, 95% credibility interval: [1.29 to 5.09]), but that increase was not significant afterwards. The probability of seropositivity tended to be higher in men than in women (OR = 2.01, 95% credibility interval: [0.92 to 4.72]) and in subjects eating raw vegetables at least once a week than in the others (OR = 8.4, 95% credibility interval: [0.93 to 72.1]). These effects were close to statistical significance. The multivariable analysis highlighted a significant seroprevalence heterogeneity among households. That seroprevalence varied between 6 and 91% (5th and 95th percentile of the household seropositivity distribution).

ConclusionThe major finding is the household effect, with a strong heterogeneity of seroprevalence among households. This effect may be explained by common exposures of household members to local risk factors. Future work will quantify the link between the presence of oocysts in the soil and the seroprevalence of exposed households using a spatial analysis.

FIV epidemiology in rural cats

Courchamp, F., N. Yoccoz, M. Artois & D. Pontier. 1998. At-risk individuals in Feline Immunodeficiency Virus epidemiology: evidence from a multivariate approach in a natural population of domestic cats (Felis catus). Epidemiology and Infection. 121: 227-236.

Prevalence of Feline Immunodeficiency Virus (FIV) infection was measured during 6 consecutive years in a natural rural population of domestic cats. Sex, age, weight, origin, group size and presence of antibodies to FIV were recorded for each sampled cat. Logistic regressions were used to estimate the influence of the recorded parameters on infection. FIV prevalence rates are as high as 19.6% in the total population, and do not statistically change between years, after controlling for changes in samples' age structure. FIV infection is characterized by risk factors linked to aggressive behaviour: old mature male adults having dispersed are more likely to be infected. A study of the cats group size and of the spatial distribution of infected individuals indicates the absence of infection clusters in males, and suggests the importance of roaming in the spreading of FIV. In conclusion, FIV infection spreads, with low contagiousness, mainly between particularly aggressive individuals, and the virus is endemic in this population.

Spacing patterns in a rural cat population in Sweden

Liberg, O. (1980). Spacing patterns in a population of rural free roaming domestic cats. Oikos, 336-349.

Spacing patterns in a population of domestic and feral cats in a rural area in southern Sweden were investigated by visual observations, trapping and radio tracking. Females lived alone or in groups around human households. Within each female group the home ranges almost completely overlapped, but between different female groups there was little or no overlap. Most females remained in the same place all their lives, but a few individuals moved and became established at new households, invariably one where there were no other female cats. There were always six to eight feral, well established males in the area, with moderately overlapping home ranges. These ranges were considerably larger than those of females, and one male might include several female groups within his home range. Young males, born in the area, stayed with the female group, where they were born until they were 1.5-3 yr old. They then left and tried to settle somewhere else. Spacing patterns in this cat population can be explained by the influence of proximate and ultimate factors, among which intraspecific aggression and adaptation to living in human households are the most important. Parallel evolution of lion and house cat social organizations is discussed.

Ecology of a feral cat population in rural Northern Italy

Genovesi, P., Besa, M., & Toso, S. (1995). Ecology of a feral cat Felis catus population in an agricultural area of northern Italy. Wildlife Biology, 1: 233-237.

The ecology of a feral cat population in an intensively cultivated region of northern Italy was studied. The study area is a land accretion territory, reclaimed in the early 1970s, characterised by the absence of any food source of human origin (e.g. garbage dumps, farms, houses) and surrounded by a continuous irrigation channel that is likely to limit immigration/emigration of cats. The cat population was censused for two successive years using the sighting-resighting method; spacing patterns were studied by means of radio-telemetry; hunting behaviour was assessed by observation. Feral cats avoided any direct contact with humans, and reproduced in the wild. The density of the population remained stable throughout the study period. Turnover appeared very high, and was remarkably higher than that of cats regularly fed by humans. Very low densities, large home range sizes, solitary habits, territorial patterns similar to those of the wildcat, seasonal parturition, and prevalence of hunting activity were found. We speculate that these patterns are related to the peculiar conditions of resource availability and dispersion in the study area. Our results indicate that feral cats, even in agricultural areas and in the absence of any food provided by humans, have solitary habits and low densities, thus confirming a key role of resource availability and dispersion on the ecology of carnivores.

Farm dogs aroung protected areas: problem or solution?

Sepúlveda, M. A., Singer, R. S., Silva-Rodríguez, E., Stowhas, P., & Pelican, K. (2014). Domestic Dogs in Rural Communities around Protected Areas: Conservation Problem or Conflict Solution?. PLOS ONE, 9(1), e86152.

Although domestic dogs play many important roles in rural households, they can also be an important threat to the conservation of wild vertebrates due to predation, competition and transmission of infectious diseases. An increasing number of studies have addressed the impact of dogs on wildlife but have tended to ignore the motivations and attitudes of the humans who keep these dogs and how the function of dogs might influence dog-wildlife interactions. To determine whether the function of domestic dogs in rural communities influences their interactions with wildlife, we conducted surveys in rural areas surrounding protected lands in the Valdivian Temperate Forests of Chile. Sixty percent of farm animal owners reported the use of dogs as one of the primary means of protecting livestock from predators. The probability of dog–wild carnivore interactions was significantly associated with the raising of poultry. In contrast, dog–wild prey interactions were not associated with livestock presence but had a significant association with poor quality diet as observed in previous studies. Dog owners reported that they actively encouraged the dogs to chase off predators, accounting for 25–75% of the dog–wild carnivore interactions observed, depending on the predator species. Humans controlled the dog population by killing pups and unwanted individuals resulting in few additions to the dog population through breeding; the importation of predominantly male dogs from urban areas resulted in a sex ratios highly dominated by males. These results indicate that dog interactions with wildlife are related to the role of the dog in the household and are directly influenced by their owners. To avoid conflict with local communities in conservation areas, it is important to develop strategies for managing dogs that balance conservation needs with the roles that dogs play in these rural households.

Domestic dogs in Wildlife habitats

Sime, C. A. 1999. Domestic Dogs in Wildlife Habitats. Pages 8.1-8.17 in G. Joslin and H. Youmans, coordinators. Effects of recreation on Rocky Mountain wildlife: A Review for Montana. Committee on Effects of Recreation on Wildlife, Montana Chapter of The Wildlife Society. 307pp.

It is difficult to segregate human demographic trends from trends in rural development and outdoor recreational participation in settings like the West where they appear to be interrelated. One extension of human recreation in wildlife habitats is the effect of disturbance, harassment, displacement, or direct mortality of wildlife attributable to domestic dogs that accompany recreationists. At some level, domestic dogs still maintain instincts to hunt and/or chase. Given the appropriate stimulus, those instincts can be triggered in many different settings. Even if the chase instinct is not triggered, dog presence in and of itself has been shown to disrupt many wildlife species. Authors of many wildlife disturbance studies concluded that dogs with people, dogs on-leash, or loose dogs provoked the most pronounced disturbance reactions from their study animals. During winter, concerns are primarily related to human activity on ungulate winter ranges. Dogs extend the zone of human influence when off-leash. Many ungulate species demonstrated more pronounced reactions to unanticipated disturbances, as a dog off-leash would be until within very close range. In addition, dogs can force movement by ungulates (avoidance or evasion during pursuit), which is in direct conflict with overwinter survival strategies which promote energy conservation. During summer, concerns are primarily related to the birth and rearing of young for all wildlife species. Dogs are noted predators for various wildlife species in all seasons. Domestic dogs can potentially introduce diseases (distemper, parvovirus, and rabies) and transport parasites into wildlife habitats. While dog impacts to wildlife likely occur at the individual scale, the results may still have important implications for wildlife populations. For most wildlife species, if a “red flag” is raised by pedestrian-based recreational disturbance, there could also be problems associated with the presence of domestic dogs. Managers may consider the following when evaluating recreational impacts of dogs in wildlife habitats: species biology, reproductive potential, abundance, density, distribution, degree of habitat specificity or reliance on certain habitat components, and predisposition and sensitivity to disturbance by other agents. This information is intended to increase awareness among natural resource professionals and the public about the potential implications of uncontrolled domestic dogs in wildlife habitats and to encourage responsible outdoor recreation ethics.

Diet of feral cats on farmland in New Zealand

Langham, N. P. E. (1990). The diet of feral cats (Felis catus L.) on Hawke’s Bay farmland, New Zealand. New Zealand journal of zoology, 17(2), 243-255.

Food remains were analysed in 361 cat faeces (scats) collected from September 1983 to May 1987 on farmland in southern Hawke’s Bay. Mammals were the most important food items in scats, both by occurrence (76%) and by weight (74%). House mice were the most frequently (50%) encountered remains, and comprised only 12% of the total prey identified by weight; rats were less frequently found (20%) but the most important item by weight (39%). Other mammals found were scavenged possums (13% by weight), sheep (7%), and lagomorphs (3%). Birds, consisting mainly of introduced species, including turkeys, were both frequent (24%) and important by weight (24%). Invertebrate remains consisted mainly of cicada nymphs (Homoptera) (10% by frequency), grass grubs (Coleoptera) (8%), and black field crickets (Orthoptera) (7%) contributed less than 2% by weight. Cicada nymphs were recorded only in willow/ swamp habitat. No significant differences were found between vertebrate prey recorded in scats from willows and swamps and vertebrate prey from bams and pasture. There were no consistent local or seasonal changes in frequency of occurrence of rats, but mice were found more frequently in scats collected in winter. Possum remains were found mainly in winter. Birds were the main items in scats collected in the spring and summer months. Eggs of Toxocari cati (64%) were the only identifiable internal parasite frequently found in the scats.

Cat predation on rural and urban landscapes

Lepczyk, C.A., Mertig, A.G. & Liu, J. (2003) Landowners and cat predation across rural-to-urban landscapes. Biological Conservation 115: 191–201

Fluctuations of bird abundances have been attributed to such factors as supplemental feeding, landscape change, and habitat fragmentation. Notably absent from consideration, however, is the role of private landowners and their actions, such as owning free-ranging domestic cats (Felis catus; cats allowed free access to the outdoors). To understand the impacts of cat predation on birds, we surveyed all 1694 private landowners living on three breeding bird survey (BBS) routes (∼120 km) that represent a continuum of rural-to-urban landscapes in Southeastern Michigan, where the majority (>90%) of land is privately owned. Our data indicate that among the 58.5% of landowners that responded, one quarter of them owned outdoor cats. On average a cat depredated between 0.7 and 1.4 birds per week. A total of 23+ species (12.5% of breeding species) were on the list of being killed, including two species of conservation concern (Eastern Bluebirds and Ruby-throated Hummingbirds). Across the three landscapes there were ∼800 to ∼3100 cats, which kill between ∼16,000 and ∼47,000 birds during the breeding season, resulting in a minimum of ∼1 bird killed/km/day. While the number and density (no./ha) of free-ranging cats per landowner differed across the rural to urban landscapes, depredation rates were similar. Landowner participation in bird feeding showed no relationship with the number of free-ranging cats owned. Similarly, selected demographic characteristics of landowners were not significantly related to the number of free-ranging cats owned. Our results, even taken conservatively, indicate that cat predation most likely plays an important role in fluctuations of bird populations and should receive more attention in wildlife conservation and landscape studies.

Birds' choice of song posts

Møller, A. P. (2011). Song post height in relation to predator diversity and urbanization. Ethology, 117(6), 529-538.

Birds may sing from positions in the vegetation (song posts) to allow efficient transmission of sexual and territorial vocal displays while simultaneously minimizing the risk of predation because of avian and mammalian predators. Because urban areas are deficient in specialized avian predators, but have many cats while the opposite is the case for nearby rural areas, urban birds should display higher in the vegetation. In a comparison of the abundance of predators in three cities (Oslo, Brønderslev, Orsay), I show that avian predators are more common in rural areas, while mammalian predators are more common in urban areas. Singing birds sang from higher positions in the vegetation of urban than nearby rural areas. Differences in song post heights between urban and rural areas were consistent among cities, suggesting inherent specific difference in microhabitat choice. Bird species that have become urbanized recently had similar song post heights in urban and rural habitats, while species that have been urbanized for a long time sang from relatively higher song posts in urban areas. These findings suggest that urban and rural birds differ in habitat use when singing. These differences in song post choice between urban and rural habitats may have a number of consequences for vocal displays in the two different habitats.

Escape behaviour related to different predators in urban or rural habitats

Møller, A. P., & Ibáñez-Álamo, J. D. (2012). Escape behaviour of birds provides evidence of predation being involved in urbanization. Animal Behaviour, 84 (2): 341–348

Altered predation risk in urban environments may contribute to animals becoming successfully urbanized by individuals from rural habitats. Escape behaviour has evolved to allow an individual to escape once captured by a predator. We tested whether altered predation risk in urban environments is associated with colonization of such habitats by comparing escape behaviour of 1132 individual birds belonging to 15 species from nearby rural and urban populations when captured by a human. Raptors (of which the Eurasian sparrowhawk, Accipiter nisus, was one of the most common species) were more common in rural than in urban habitats, whereas cats, Felis catus, showed the opposite pattern. There were consistent differences in escape behaviour between habitats, showing divergence in behaviour from the ancestral rural state. Urban birds wriggled less, showed higher tonic immobility, more often lost feathers, were less aggressive by biting less often, and emitted fear screams and alarm calls more often than rural birds. Furthermore, differences in escape behaviour between habitats were related to susceptibility to predation by sparrowhawks, as expected if differences in behaviour were due to differences in predation risk. Finally, an analysis of differences in escape behaviour between rural and urban birds revealed a significant relationship with time since urbanization, suggesting that escape behaviour has changed in urban environments over time. These findings suggest that release from predation and change in predator community associated with urbanization has altered the antipredator behaviour of birds colonizing towns and cities.

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Highlights

► We investigated escape behaviour of urban and rural birds. ► Urban birds tried to escape less actively and gave more alarm calls than rural birds. ► These differences were related to susceptibility to predation by sparrowhawks. ► The degree of divergence was related to time since urbanization. ► Predation is an important selection force driving adaptation to urban habitats.

Diet of feral cats and dogs in suburban Brazil

Campos, C. B., Esteves, C. F., Ferraz, K. M. P. M. B., Crawshaw, P. G., & Verdade, L. M. (2007). Diet of free‐ranging cats and dogs in a suburban and rural environment, south‐eastern Brazil. Journal of Zoology, 273(1), 14-20.

In spite of the worldwide occurrence of domestic cats and dogs, and their close relationship with humans, the number of published papers on free-ranging cats Felis catus and dogs Canis familiaris, is small. The diet of both species was estimated in a suburban and rural environment in July 2002 and January 2003. Visual observations and scat collection of both species were accomplished along a 10 km transect line in the Campus ‘Luiz de Queiroz’, University of São Paulo, Piracicaba, south-eastern Brazil. The diet of both species was determined by analysis of sterilized, washed, dried and sorted scats. Estimated abundances of free-ranging cats and dogs in the sampled area were 81 (±4.32) and 42 (±2.96), respectively. Cats and dogs were more abundant in the suburban than in the rural environment (t=3.78, P<0.001, N=55; t=8.38, P<0.001, N=55, respectively) and cats were more abundant than dogs in the suburban environment (t=6.76, P<0.001, N=55), even though there was no significant difference between the abundance of both species in the rural environment (t=0.82, P=0.46, N=55). Invertebrates were the most commonly consumed item by both species, followed by mammals (cats: 63.24 and 20.51%; dogs: 57.05 and 25.15%, respectively). Niche breadth was 0.4892 for cats and 0.4463 for dogs. Niche overlap was almost complete (0.97108). The consumption of mammals was estimated to be between 16.76 and 25.42 kg individual−1year−1 for dogs and between 2.01 and 2.9 kg individual−1year−1 for cats. These data might be useful to establish a management program to minimize the predation pressure of free-ranging cats and dogs on wildlife.

Up to 31% of recoveries of banded birds killed by cats

Mead, C. J. (1982). Ringed birds killed by cats. Mammal Review, 12(4), 183-186.

Mead examined the fate of banded birds in Britain and discovered that for six species more than 25 percent of the recoveries were of birds caught by cats. He ascribed 31% of recoveries of ringed robins and dunnocks to cat predation, but believed that there was no evidence that cats affected the overall populations of these species. Catchability is very different in different species, depending on gregarious habits, terrestrial feeding, avoidance of potential hiding places, etc. but some cats are even able to catch aerial species.
He emphasised that birds in rural and suburban parts of Britain have co-existed with cats for hundreds of generations and may now be under less pressure from cats than they were in the past from assorted 'natural' predators.

Predation by house cat in Canberra

Barratt, D. G. (1997). Predation by house cats, Felis catus (L.), in Canberra, Australia. I. Prey composition and preference. Wildlife Research, 24(3), 263-277.

This paper attempts to apply theory from more than 100 years of scientific experience and experimentation in predator-prey ecology and introduced species ecology to predict the likely effects of predation by domestic cats (Felis catus) on prey populations and community structure. Those aspects of the predatory behaviour of domestic cats which are of most importance in predicting their impact on prey populations: I) the degree of prey selectivity or 'dietary preference'; 2) the exhibition of switching behaviour; 3) changes in predatory activity in response to changes in prey density; and 4) the extent to which high and constant densities of the predator are ameliorated by reduced prey consumption rates as a result of dietary supplement.

In suburban environments, the influence of predation by domestic cats on prey abundance and community structure probably increases, relative to the influence of habitat change, with increasing suburb age, particularly in the absence of physical disturbances such as fire. However, it may never be as important as habitat availability and indeed may never be significant at all. Removal of the predator may allow some animal species to increase in abundance but others may decline. The details of these changes are very difficult to predict. Similarly, following predator removal, total species diversity is as likely to decline due to increased inter-specific competition, as it is to increase due to the invasion of species previously excluded by predation.

In remnant habitat, the impact of predation by domestic cats is probably less likely to be important in determining the relative abundance of the more common species than in suburban environments, but more likely to contribute to local extinctions of rare species. As in suburban environments, predation on introduced species in remnant habitat may reduce predation on native species. However, the ability of domestic cats to control introduced species which prey on, or compete with, native species will be difficult to demonstrate. In light of this uncertainty, any attempt to prevent domestic cats hunting in remnant habitat patches should be integrated with a program to eliminate or control populations of other introduced species, such as black rats and rabbits, which are preyed upon by domestic cats and are known to prey on or compete with native species

Barratt, D. G. (1998). Predation by house cats, Felis catus (L.), in Canberra, Australia. II. Factors affecting the amount of prey caught and estimates of the impact on wildlife. Wildlife Research, 25(5), 475-487.

Information on the amount of vertebrate prey caught by house cats in Canberra was collected by recording prey deposited at cat owners’ residences over 12 months. The amount of prey taken was not significantly influenced by cat gender, age when neutered, or cat breed. Nor did belling or the number of meals provided per day have a significant influence on the amount of prey caught. The age of the cat and the proportion of nights spent outside explained approximately 11% of the variation in the amount of prey caught by individual cats. In all, 43% of variation in predation on introduced species (predominantly rodents) was explained by distance from potential prey source areas (i.e. rural/grassland habitat) and cat density. The mean number of prey reported per cat over 12 months (10.2) was significantly lower than mean predation per cat per year based on estimates made by cat owners before the prey survey began (23.3). Counts of the amount of prey caught by house cats were highly positively skewed. In all, 70% of cats were observed to catch less than 10 prey over 12 months, but for 6% of cats, more than 50 prey were recorded. Estimates of predation by house cats, particularly extrapolated estimates, should be treated with caution. The total number of prey caught by house cats in Canberra estimated using the sample median was approximately half the estimate based on the sample mean. Predation estimates alone do not prove that prey populations are detrimentally affected, especially in highly disturbed and modified environments such as suburbs. Impacts on native fauna are likely to be most significant in undisturbed habitat adjacent to new residential developments.



Read a short review about belling effectiveness

Predation by domestic cat in a British village

Churcher , P.B. & J.H. Lawton. 1987. Predation by domestic cats in an English (UK) village. Journal of Zoology. (London.) 212: 439-455

We studied predation by approximately 70 domestic cats (Felis catus L.) in the Bedfordshire village of Felmersham over a one-year period. All the prey items brought home by virtually all the cats in the village were recorded and, where possible, identified. A total of 1090 prey items (53i5 mammals, 297 birds and 258 unidentified animals) were taken, an average of about 14 per cat per year. Twenty two species of birds and 15 species of mammals were identified. The most important items were woodmice (17%), house sparrows (16%) and bank voles (14%).

Old cats of both sexes caught fewer prey over the year than young cats. Female cats on the edge of the village also caught more prey than female cats in intermediate or central areas of the village; male cats showed no such effect. The type of prey caught also varied with position in the village; ‘core’ cats caught proportionately more birds than ‘edge’ cats. There was some indication in the data that cats caught fewer prey in areas where cat density was highest, but this effect was impossible to disentangle from position in the village. Weather apparently influenced hunting success. Temperature had no direct influence, but fewer prey were caught in winter; cats also caught less on wet days and windy days.

Estimates of the number of house sparrows in the village at the start of the breeding season, and the number of sparrows known to have been caught by the cats, suggest that at least 30% of the sparrow deaths in the village were due to cats. Domestic cats would appear to be major predators in this typical English village.

Feral cats' diet in Australia

Another pair of articles and a review on cats' diet in Australia.

Paltridge, R., D. Gibson & G. Edwards. 1997. Diet of the Feral Cat (Felis catus) in Central Australia. Wildlife Research 24(1) 67 - 76

Feral cats (Felis catus) occur throughout central Australia. In this study, we analysed the stomach contents of 390 feral cats collected between 1990 and 1994 from the southern half of the Northern Territory. Cats fed on a wide variety of invertebrates, reptiles, birds and mammals, including animals up to their own body mass in size. Mammals were the most important prey but reptiles were regularly eaten in summer and birds were important in winter. Invertebrates were present in the diet in all seasons. Carrion appeared in stomach samples during dry winters only and this has implications for future control of feral cats.

Martin, G.R., L.E. Twigg & DJ Robinson. 1996. Comparison of the Diet of Feral Cats From Rural and Pastoral Western Australia. Wildlife Research 23(4): 475 - 484

The stomach contents of 93 cats from rural and pastoral Western Australia were compared using the number and biomass of food items, and by calculating an Index of Relative Importance for each food category. Species of small native mammals (e.g. dasyurids, rodents) and geckos were significantly (P < 0.03) more prevalent in the diet of pastoral cats, and rural cats consumed greater (P < 0.03) quantities of introduced rodents and rabbits. Several other groups of native animals (e.g. snakes, skinks, agamids) were also more prevalent in the stomachs of pastoral cats (P < 0.10). Birds and orthopterans were important food items to cats from both habitats. There was reasonable dietary overlap (mean = 0.71) between the cats from both habitats, but the dietary breadth of the pastoral cats (mean = 0.44) was two-fold greater than that of the rural cats (mean = 0.21). These findings are compared with previous studies, and are discussed with respect to possible implications for future management strategies for feral cats.

Major prey of prey of feral cats in Australia (from Dickman, C. R. 1996)

Data collected from 22 studies of feral cats in mainland Australia suggest that mammals comprise the major prey of feral cats in most localities. Introduced rabbits (Oryctolagus cuniculus) and house mice (Mus domesticus) predominate in semi-arid to arid habitats, whereas marsupials (especially the common ringtail possom (Pseudocheirus peregrinus) are predominant in temperate forest, urban and suburban habitats (Dickman 1996). Brushtail possoms (Trichosurus vulpecula), sugar gliders (Petaurus breviceps), greater gliders (Petauroides volans) and smaller prey such as brown antechinus (Antechinus stuartii), brush rat (Rattus fuscipes) and swamp rat (Rattus lutreolus) are consistently part of the diet of feral cats in the temperate forests of Australia. In wet-dry tropical habitats where rabbits do not occur native Rattus spp. become more important, including the pale field rat (Rattus tunneyi), dusky rat (R. colletti) and the long-haired rat (Rattus villosissimus).
Smaller rodents such as the spinifex hopping mouse (Notomys alexis) and the sandy inland mouse (Pseudomys hermannburgensis) may also be preyed upon. Birds are represented most highly in
temperate forest, urban and suburban habitats. Small species such as wrens (Malurus spp.), robins (Petroica spp.) and thornbills (Acanthiza spp.) have all been recorded, as have larger species such as galahs (Cacatua roseicapilla), magpies (Gymnorhina tibicen) species of parrots (Psephotus spp.). Species such as geckos and flap-footed lizards and diurnal species of skinks, dragons, goannas and snakes have often been recorded in the feral cat's diet (Dickman 1996).
Reviews of the diet of feral cats in mainland areas in other parts of the world reveal great similarities with the situation in Australia (Corbett, 1979, Fitzgerald and Karl 1979, Liberg 1984, Fitzgerald 1988, Kitchener 1991, in Dickman 1996). In all studies, mammals have consistently comprised the major part of the diet throughout the year, with other vertebrates, especially birds, comprising only a minor component. Rabbits
and murid rodents, especially Rattus species, appear to be favoured prey, and together comprise the bulk of the diet of feral cats in some localities over long periods.

Gestión de perros y gatos en zonas rurales

De Iván Parrillo (Fundación Gypaetus)
Una vez más y siguiendo en nuestra tarea de poder minimizar a la mínima expresión los casos de envenenamiento, hemos montado esta jornada de trabajo: Gestión de perros y gatos en zonas rurales, una herramienta contra el VENENO.

Para ello se ha contado con la Estrategia Andaluza para la erradicación de cebos envenandos de la Consejería de Agricultura, Pesca y Medio Ambiente de la Junta de Andalucía, Consejo Andaluz de Veterinarios de Andalucía, la Diputación de Córdoba, el Ayuntamiento de Alcaracejos, la empresa ABECOR-Aplicaciones Medioambientales y la Mancomunidad de Municipios de Los Pedroches.

En algunas ocasiones una de las motivaciones del uso ilegal de cebos envenenados que se ha detectado está relacionado con el objetivo de la eliminación de las molestias derivadas como consecuencia de perros y gatos domésticos y asilvestrados. Este hecho, lejos de ser residual, se presenta de forma relativamente habitual en zonas rurales y urbanas. Desde el proyecto Life+ y en el marco la Red Europea de Municipios contra el veneno, pretendemos poner nuestro granito de arena para poder atajar este problema y por ello hemos desarrollado esta jornada.

La asistencia es libre, hasta completar aforo y la cita será el día 9 de abril en el Salón de Convivencia del Ayuntamiento de Alcaracejos

Cat's diet and prey impact in Sweden

Liberg, O. 1984. Food habits and prey impact by feral and house-based domestic cats in a rural area in southern Sweden. Journal of Mammalogy, 65(3): 424-432

Natural prey of domestic cats in the Revinge area in southern Sweden during 1974-79 was related to prey abundance, annual production, and availability. Of 1437 scats collected, 996 contained remains of vertebrate prey. Most cats (80-85%) were house-based and obtained from 15 to 90% of their food from natural prey, depending on abundance and availability of the latter. Wild rabbits (Oryctolagus cuniculus) were the most important prey, and cats responded functionally to changes in abundance and availability of this prey. Prolonged snow cover made rabbits vulnerable to cats irrespective of abundance. Small rodents were the second most important cat prey, while brown hares (Lepus europeus) and birds were less important. In a period with high rabbit abundance, cat predation corresponded to 4% of annual production of rabbits and to about 20% of annual production of field voles (Microtus agrestis) and wood mice (Apodemus silvaticus). Prey choice of feral cats was similar to that of house-based cats, but as the former subsisted almost completely on natural prey, their absolute intake (294g/day during years with high rabbit abundance) was 4 times that of an average house-based cat (66 g/day).

Intraguild interactions between dogs and wild carnivores

Vanak, A.T. 2008. Intraguild interactions between native and domestic carnivores in Central India. PhD. University of Missoury

I determined the various factors affecting the resource selection and spatial ecology of the Indian fox Vulpes bengalensis, a small canid endemic to the Indian subcontinent. Despite being widespread throughout India, and commonly occurring in many dry grassland habitats, little is known about the ecology of this species. I investigated habitat selection by the Indian fox in a grassland region in central India that represents a mix of natural and human-dominated habitats to discern if and how foxes respond to human encroachment on native habitats. I collected home range and habitat selection data on 32 radio-collared Indian foxes in the Great Indian Bustard Wildlife Sanctuary, Nannaj, Maharashtra over a one year period. Adult Indian fox 95% kernel density home-range sizes varied between sexes and among seasons. Males had consistently larger home-ranges than females across all seasons but there was no interseasonal variation. Females had smaller home-range sizes during the cool-dry season which is also the denning period, than during any other season. Compositional analysis of Indian fox selection of home-ranges at the landscape level showed heavy influence of the presence of grasslands, plantations and fallow land. Indian foxes avoided humanmodified habitat such as agricultural land and human settlements. The presence of grasslands was also the dominant predictor of Indian fox habitat selection across seasons within the home-range as determined by AIC ranked discrete-choice models. The results indicate that Indian foxes select for natural grasslands and avoid human-modified habitat.
The distribution, abundance and resource selection patterns of meso-carnivores such as the Indian fox are also heavily influenced by the effects of top-down intraguild competition with sympatric larger carnivores. Competitive dynamics among carnivores are asymmetric and interference competition and the associated occurrence of intraguild predation are unidirectional, with larger carnivores negatively influencing smaller carnivores. Competition can affect the subordinate competitor in several ways: by limiting spatial distributions resulting in scattered interspecies territories, constraining habitat selection, reducing prey encounter rates and food intake, or requiring increased hunting effort.
In my study area, the domestic dog Canis familiaris, is the most common midsized carnivore. As the world’s most common carnivore, dogs are known to interact with wildlife as predators, prey, competitors, and disease reservoirs or vectors. Despite these varied roles in the community, the interaction of dogs with sympatric carnivores is not well understood. Dogs have the potential to be exploitative, interference and apparent competitors with sympatric carnivores.
I examined competition for food between dogs and the Indian fox through dietary analysis. Dogs subsisted largely on human derived material from direct feeding, and scavenging on garbage, crop residue and livestock carcasses (83% relative occurrence).

Wild caught foods constituted only 11% relative occurrence of dog diet. Indian foxes are omnivorous and included a wide variety of food types in their diet. The majority of  Indian fox diet consisted of invertebrates (33% relative occurrence), rodents (20% relative occurrence) and fruits of Zizyphus mauritiana (18.5% relative occurrence). Indian foxes did not include any human derived material, nor did they scavenge from large mammal carcasses, and included only a small portion of agricultural produce in their diet. The diet of free-ranging dogs is typical of dogs from other parts of the world. However, the low contribution of human-derived food sources to the diet of Indian foxes was surprising since the species is a generalist carnivore. Although there was limited dietary overlap between dogs and foxes in this study, dogs may actually be preventing foxes from accessing agricultural lands and human associated foods by interference competition.

Dogs have the potential to be effective interference competitors, especially with medium and small-sized carnivores, and may fulfill the role of a mid-sized canid, especially in areas where the native large carnivore community is depauperate. I experimentally examined the behavioral responses of the Indian fox to the presence of dogs and dog odors. Since resource competition between dogs and foxes is low, it is unclear whether foxes perceive dogs as interference competitors. To test this I exposed foxes to neutral, live dog, and animal odor cues at food trays and recorded the amount of food eaten, time spent at food trays, and vigilance and non-vigilance behaviors. When dogs were visible, foxes continued to visit the food trays, but reduced the amount of time spent (by 83%) and food eaten (by 70%) at those trays. Foxes were 10 times more vigilant during dog trials than during neutral and odor trials and also exhibited lower levels of non-vigilance behavior (resting, playing) when dogs were visible. In contrast, dog odors did not affect fox foraging and activity. These results show that vigilance/foraging tradeoffs due to interference competition can occur between native and domestic carnivores, despite low dietary overlap.

To avoid the effects of interference competition and intraguild predation, subordinate competitors such as the Indian fox can alter space use patterns which may result in a reduction of foraging opportunities. To determine if interference competition between dogs and foxes influences the space use patterns of foxes at a landscape level, I conducted a radio-telemetry study of 32 Indian foxes and 25 free-ranging dogs in and around the Great Indian Bustard Wildlife Sanctuary in central India. Using a logistic regression analysis in an information theoretic framework, I determined the effects of landcover type, primary prey abundance (rodents) and dog presence on the landscape on the space use of foxes. As expected, Indian foxes showed low overlap with dogs based on the volume of intersection index. Top AIC ranked models showed a positive influence of grasslands and a negative influence of agricultural land and dog presence. Rodent abundance only had a weak positive effect. This suggests that fox space use is determined not only by habitat type, but also influenced by the presence of a mid-sized carnivore, the dog.

These results suggest that the competitive intraguild dynamics that are seen among wild carnivores can also occur between wild and domestic carnivores, despite a seeming lack of competition for food and other resources. The role of dogs as intraguild competitors of wild carnivores has thus far been under-recognized. Dogs are among the world’s most common carnivores and are heavily subsidized by humans. As a result, they can occur at high densities even in rural areas, where they tend to range freely into wild habitats. Therefore, dogs can pose threats to native carnivore communities, and extend the edge of anthropogenic disturbance well beyond the borders of human settlements.

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Disease impact of dogs

Vanak, A. T., Belsare, A. V. & Gompper, M. E. 2007. Survey of Disease Prevalence in Free-Ranging Domestic Dogs and Possible Spill-Over Risk for Wildlife – A Case Study from the Great Indian Bustard Sanctuary, Maharashtra - India. Final report submitted to the Rufford Small Grants Foundation, UK. Pp 1-13

Domestic dogs are the world’s most common carnivore, and yet the ecology of free-ranging  dogs has rarely been investigated. Many dog populations are subsidized by humans resulting in  high population density, which presumably also have contact rates above the critical threshold  that allows diseases to persist enzootically within the population. Domestic dogs are the  reservoir of infectious diseases that have led to epidemics of rabies, canine distemper and  canine parvovirus in several wild carnivore species, yet little is known about the disease ecology  of domestic dogs in India, and the potential for spill-over risk to wildlife. This project was carried out to assess the disease exposure and health status of free-ranging domestic dogs in the vicinity of a wildlife reserve in central India. We carried out a sero-prevalence survey of canine distemper virus (CDV), canine parvovirus (CPV) and rabies in the dog population surrounding the Great Indian Bustard Sanctuary in Nannaj, Maharashtra. We sampled 74 dogs from four villages surrounding the wildlife reserve and obtained blood samples for testing for IgM and IgG antibodies to CDV and CPV. We also collected salivary swabs from 31 dogs to test for rabies antigen. Antibodies to CPV were detected in 93.3% of the sampled dogs, while 90.7% of dogs had evidence for recent or past exposure to CDV. This suggests that these diseases are enzootic in the dog population, and may pose a significant threat to wild carnivores if disease control measures are not implemented. Rabies was also detected in 2 (6%) of the dogs tested, raising human health concerns as well. We recommend a comprehensive vaccination and dog population control policy as well as an education campaign on responsible dog ownership among villagers.