Cats "protecting" birds

Courchamp F, Langlais M, Sugihara G. 1999. Cats protecting birds: Modelling the mesopredator release effect. Journal of Animal Ecology, 68: 282–292

1- Introduced predators account for a large part of the extinction of endemic insular species, which constitutes a major component of the loss of biodiversity among vertebrates. Eradication of alien predators from these ecosystems is often considered the best solution.
2- In some ecosystems, however, it can generate a greater threat for endemic prey, through what is called the "mesopredator release". This process predicts that, once superpredators are suppressed, a burst of mesopredators may follow that leads their shared prey to extinction.
3- This process is studied through a mathematical model describing a three species system (prey-mesopredator-superpredator). Analysis of the model, with and without control of meso- and superpredators, shows that this process does indeed exist and can drive shared prey to rapid extinction.
4- This work emphasises that, although counter-intuitive, eradication of introduced superpredators, such as feral domestic cats, is not always the best solution to protect endemic prey when introduced mesopredators, such as rats, are also present.