Fearing the feline: domestic cats reduce avian fecundity through trait-mediated indirect effects that increase nest predation by other species
Article first published online: 30 JAN 2013
© 2013 The Authors. Journal of Applied Ecology © 2013 British Ecological Society
Journal of Applied Ecology
Volume 50, Issue 1, pages 15–24, February 2013
How to Cite
Bonnington, C., Gaston, K. J., Evans, K. L. (2013), Fearing the feline: domestic cats reduce avian fecundity through trait-mediated indirect effects that increase nest predation by other species. Journal of Applied Ecology, 50: 15–24. doi: 10.1111/1365-2664.12025
- Issue published online: 30 JAN 2013
- Article first published online: 30 JAN 2013
- Manuscript Accepted: 1 NOV 2012
- Manuscript Received: 28 MAR 2012
- Natural Environment Research Council
- chick growth rate;
- gray squirrel;
- nest defence;
- non-native species;
- provisioning rate;
- Skutch's hypothesis;
- Urban areas contain high densities of non-native species, which in the UK include the domestic cat Felis catus (Linnaeus 1758) and the grey squirrel Sciurus carolinensis (Gmelin 1788). The direct predation effects of domestic cats on prey populations attract intense debate, and such influences of the nest-predatory grey squirrel are receiving increasing attention. In contrast, theory predicts that sublethal and indirect effects are more important, but empirical evidence is currently lacking.
- We conducted controlled model presentation experiments at active urban blackbird Turdus merula (Linnaeus 1758) nests to provide the first empirical evidence that quantifies the potential sublethal and indirect effects of predators (domestic cat and grey squirrel) on avian reproductive success.
- Domestic cat models reduced subsequent parental provisioning rates, a strong indicator of sublethal effects, by one-third relative to a nonpredatory rabbit Oryctolagus cuniculus (Linnaeus 1758) control. There was no compensatory increase in food load size. Previous experiments demonstrate that this magnitude of reduced food delivery will reduce nestling growth rates by c. 40%. The grey squirrel model induced similar but weaker effects.
- Following the brief presence of the domestic cat model, subsequent daily nest predation rates, chiefly by corvids, increased by an order of magnitude relative to the squirrel and rabbit models. The intensity of parental nest defence elicited in response to model presentations predicts the probability of such third-party predator predation events, and the domestic cat model generated significant increases in nest defence behaviour.
- Synthesis and applications. The brief presence of a domestic cat at avian nest sites reduces subsequent provisioning rates and induces lethal trait-mediated indirect effects. We provide the first robust evidence for these latter effects in any avian predator–prey system, although they are likely to be common in many avian assemblages with high predator densities. It is imperative that future assessments of the impact of predatory species on avian prey species take lethal trait-mediated indirect effects into account, as so doing will prevent biased estimates of predator effects and facilitate the design of more effective control strategies. Full mitigation of the sublethal and indirect effects of domestic cats would problematically require permanent indoor housing.