Predation of wildlife by domestic cats Felis catus in Great Britain

Abstract

1. A questionnaire survey of the numbers of animals brought home by domestic cats Felis catus was conducted between 1 April and 31 August 1997. A total of 14 370 prey items were brought home by 986 cats living in 618 households. Mammals made up 69% of the items, birds 24%, amphibians 4%, reptiles 1%, fish < 1%, invertebrates 1% and unidentified items 1%. A minimum of 44 species of wild bird, 20 species of wild mammal, four species of reptile and three species of amphibian were recorded. 2. Of a sample of 696 individual cats, 634 (91%) brought home at least one item and the back‐transformed mean number of items brought home was 11.3 (95% CI 10.4–12.2). The back‐transformed means and number of cats retrieving at least one item from each prey group were: 8.1 (7.4–8.9) mammals for 547 (79%) cats, 4.1 (3.8–4.5) birds for 506 (73%) cats, 2.6 (2.2–3.0) herpetofauna for 145 (21%) cats and 2.2 (1.8–2.7) other items for 98 (14%) cats. 3. The number of birds and herpetofauna brought home per cat was significantly lower in households that provided food for birds. The number of bird species brought home was greater in households providing bird food. The number of birds and herpetofauna brought home per cat was negatively related to the age and condition of the cat. The number of mammals brought home per cat was significantly lower when cats were equipped with bells and when they were kept indoors at night. The number of herpetofauna brought home was significantly greater when cats were kept in at night. 4. Based on the proportion of cats bringing home at least one prey item and the back‐transformed means, a British population of approximately 9 million cats was estimated to have brought home in the order of 92 (85–100) million prey items in the period of this survey, including 57 (52–63) million mammals, 27 (25–29) million birds and 5 (4–6) million reptiles and amphibians. 5. An experimental approach should be taken to investigate the factors found by this descriptive survey to influence the numbers of prey brought home by cats. In particular, investigation of potential management practices that could reduce the numbers of wild animals killed and brought home by cats will be useful for wildlife conservation, particularly in suburban areas.

Annual variation in prey composition of domestic cats in rural and urban environment

“…The number of knots for the spline fit was estimated to 5 to maintain a relatively simple fit. In each GAMM, site and year were used as random effects (the latter was fitted with a ridge penalty spline, which acts as a random effect but improves the robustness of the model, Wood 2006). Moreover, the total number of all preys varied between the monthly collections from different sites and years, reflecting both the willingness of the cats to hunt and the owners to cooperate with us.…”

“…In case of GAMM 5 (for which the total number of preys was used as response variable), the number of hunting cats in a given site, month and year was instead used as an offset (i.e., it was assumed to be a proxy of sampling effort). We based the parameter estimation on the full models computed using the Bmgcvp ackage (Wood 2006) in R (R Core Team 2015). The seasonal variation in prey was described according to four seasons: winter (December -February), spring (March -May), summer (June -August), autumn (September -November).…”

“…We used two explanatory variables in each GAMM: month (continuous variable, range: 1-12) and environment (categorical variable with two levels: rural vs. urban). The effect of month was fitted with a cyclic penalized cubic regression spline, i.e., splines whose ends match (Wood 2006), following the assumption that the response variable has similar values on the 31st of December and the 1st of January. We fitted the effect of month separately for the two environments (rural vs. urban) because the temporal dynamics of cat prey composition can differ between two environments.…”

“…Most of the studies focused on the diet of free-ranging house cats have been conducted in the USA (Kays and DeWan 2004;Lepczyk et al 2004), Australia and Oceania (Barrat 1997;Gillies and Clout 2003;Morgan et al 2009;van Heezik et al 2010). In Europe, where there is a relationship between high-density human populations and a high abundance of domestic cats, previous investigations were mainly located in the United Kingdom (i.e., Churcher and Lawton 1987;Woods et al 2003;Baker et al 2005;Thomas et al 2012) but also in Sweden (Liberg 1984), Switzerland (Weber and Daily 1998;Tschanz et al 2010), Poland (KrauzeGryz et al 2012a) and Finland (Kauhala et al 2015). However, this topic has never been investigated in many central and eastern European countries.…”

Public health risk analysis of European bat lyssavirus infection in The Netherlands

“…From a survey of domestic cats in Denmark it was estimated that 1-3 % of cats were EBLV seropositive [10]. Domestic cats do, indeed, prey on numerous small animals, including bats [11]. Although probably rare, indirect transmission of EBLV to humans via domestic and wild mammals might be possible.…”