Predation of a Rare Arboreal Land Snail Euhadra brandtii sapporo by Introduced Common Raccoon Procyon lotor

摘要

Introduced species are one of the primary threats to biological diversity. Their invasion often yields serious negative impacts on endemic biota through competition for resources, habitat alterations, parasitism, disease, and predation (Wonham, 2006;Hunter & Gibbs, 2007). Predation by introduced animals has been a major cause of the decline of land snails. In the Southeast Pacific region, the exotic carnivorous land snail Euglandina rosea exterminated 56 of the 61endemic arboreal land snails after its introduction in a biological control program targeting the giant African snail, Achatina fulica (Coote & Loeve, 2003). In the Bonin Islands, Japan, the introduced rat Rattus rattus severely preys upon native land snail species, which have extensivelyradiated throughout a unique evolutionary history (Chiba, 2009). Platydemus manokwari, a flatworm originating from New Guinea Island, has spread to many regions in the world, killing native land snails and thereby being listed among the world's100 worstinvasive alien species (Lowe et al" 2000).