Free-ranging pet cats (Felis catus) frequently kill wildlife but also return live prey to their owners. This raises welfare concerns if live animals released by cat owners subsequently die, since this is preventable, eg through prompt euthanasia. To estimate the mortality rate of birds released alive by cat owners, we examined the fates of 3,597 cat-attacked individuals submitted to four RSPCA wildlife centres in the UK. Individuals from 64 species were received but most cases (77%) involved just seven species commonly found in urban areas. The overall mortality rate (based on all individuals received at centres, ie including those which perished in transport, those which were euthanased on arrival and those which were admitted for care after having been triaged) was 78%; the post-admittance mortality rate (n = 2,070 birds admitted for care) was 62%. On average, individuals that perished (n = 2,798) survived for 3.0 days before dying or being euthanased. Juveniles were more likely to survive to release than adults, possibly because their small size means they are less likely to receive injuries that are ultimately fatal. Extrapolating from the limited data currently available, and applying conservative estimates at each stage, we estimate that a minimum of 0.3 million birds are released annually by cat owners but subsequently die. Substantial welfare improvements could be achieved if owners were more prepared to adopt strategies to limit hunting behaviour (eg fitting cats with collars and bells) and if owners and rehabilitators were able to effectively identify individuals with fatal injuries. The latter will require studies that quantify the effects of identifiable physical injuries on the likelihood of survival to release, in order to establish effective triage criteria.

Collar-worn deterrents reduce predation by cats while collar-mounted ID enhances return of lost animals. A perception that collars are hazardous limits their use. We defined cases as ‘collar incidents’ (cat snagged its collar or caught a paw), ‘collar injuries’ (veterinary treatment needed for a collar incident), and ‘collar deaths’ (cat died), before integrating data from veterinarians, owners from the general public and owners from a welfare society. Despite biases associated with each of these groups, taken together, the results from these indicated that collar injuries or deaths are rare. Interviews with one hundred and seven veterinarians indicated an average rate of one collar injury observed per 2.3 years of veterinary practice. At one practice, over three years, only 0.33% of 4,460 cat cases were collar injuries, while 180 cat cases at four clinics during August and November 2011 included none. The 63 owners from the general public reported only one collar injury and no deaths in a lifetime of ownership, although 27% experienced collar incidents. In contrast, 22% reported cats needing treatment following road accidents, 53% reported cats needing treatment for fighting injuries and 62% had owned cats killed on the road. Most (62%) of the 55 respondents from a cat welfare society had experienced a collar incident, but only two cats needed treatment. One died. In contrast, 31 and 58% reported cats needing treatment for road accidents and fighting, respectively, and 41% had owned cats killed on the road. Fighting and road accidents are greater hazards to roaming cats than collars, which offer the compensatory benefits of mounting predation deterrents and ID tags.

The aim of this study was to analyse the spatio-temporal dynamics of Toxoplasma gondii infection in long-term monitoring of domestic cats (8–15 years) in three populations living in rural France. Overall seroprevalence was 52·7% (modified agglutination test ⩾1:40). Incidence was 0·26–0·39 seroconversions/cat per year, and the estimated rate of soil contamination by T. gondii oocysts ranged between 31 and 3600 oocysts/m2 per year, depending on the population. Incidence risk in cats was related to mean precipitation, explaining both the spatial and temporal variability in risk: local conditions explained differences between the three study sites and incidence risk increased during rainy years. This study brings rare quantitative information on the level of contamination of the environment by T. gondii oocysts, and suggests that the spatio-temporal distribution of incidence risk in cats may reflect both the influence of rain on prey populations and infectivity of T. gondii oocysts.

The prey brought in by 80 cats Felis catus over 1 year was monitored in two suburbs of Auckland, New Zealand: one suburb was completely urban, the other on the urban/forest fringe. Cat owners were asked to record and, if possible, keep the prey that their cats brought in. Rodents were the main prey brought in by domestic cats in the urban/forest fringe habitat, whereas invertebrates were the main prey in the fully urban habitat. Birds were caught in similar numbers by cats in both areas and were the second most important prey group at both study sites. However, more native birds were caught by cats in the urban/forest fringe area than in the fully urban habitat. Lizards were caught in similar numbers and were the third most important prey group in both study areas.

Twenty-one cat owners from a 100 km2 area, centred on Carnforth, Lancashire, England, recorded each dead prey item delivered by their cat or cats during an 8-week period, following one of three experimental schedules, each of which required each cat to have a bell on a collar for only half of the time. The mean number of items each cat delivered to the owner was 2.9 in the 4 weeks when the cats had a bell attached, compared to 5.5 for the equivalent time when the bell was absent. The bell had no effect on the relative numbers of different prey types delivered, and there was no evidence that the cats adapted their hunting behaviour to reduce the effect of the bell over time.