Abstract

Cats and rodents are the most widely introduced and damaging mammals to island biota. Most islands are invaded by more than one of these species. These multiple invasions can lead to complex interactions among the invaders, modifying both predator-prey and competitive interactions among all players. The outcomes of these interactions and their mode of regulation are important for understanding impacts on island biota, and the appropriate form island conservation actions such as pest eradication should take. In this talk I outline mathematical models and empirical studies of both predator-prey interactions between cats and rats, and competitive interactions among multiple rat species, and place these within a community ecology context of direct and indirect effects. Empirical work is drawn from fieldwork undertaken on French tropical islands of the Indian and Pacific Oceans.