Belled collars reduce catch of domestic cats in New Zealand by half

Context. As evidence accumulates implicating domestic cats as significant predators of urban wildlife, the need for effective mitigation of potentially negative impacts becomes more pressing. Belled collars are probably one of the cheapest and least intrusive methods, although the opinion of a proportion of members of the public in New Zealand is that they are not effective. Aims. We aimed to determine whether belled collars reduced prey catch. Methods. Prey caught and brought back home by cats that were regular hunters during 6 weeks when they wore a belled collar was compared with prey caught during 6 weeks when they did not wear a collar. Key results. Predation of birds and rodents was reduced by 50% and 61%, respectively. The number of rats, lizards and insects was not significantly reduced; however, these constituted a small proportion of the total catch. Sex and age of cats, as well as time did not affect catch rates, with the exception that older cats were more likely to catch rats (Rattus spp.) than were younger cats. Most of the cats in the study were young, reflecting our selection criteria that cats be regular and frequent hunters. Conclusions. The degree to which catch of birds and rodents was reduced is similar to that reported in two experimental studies in the UK, and confirms that belled collars are effective in the New Zealand environment. Implications. In New Zealand, small mammals are introduced pests and hunters of native wildlife; predation by cats may regulate their populations in urban areas and so care should be taken when instituting cat-control measures. It is also possible that a 50% reduction in predation may be insufficient to ensure viability for some urban wildlife populations.