Effect of introduced Japanese Weasels (Mustela itatsi) on the nest height of Japanese Bush Warblers (Horornis diphone) on Miyake-jima Island, Japan

Japanese weasels (Mustela itatsi) artificially introduced to Miyake-jima Island, a peripheral island of Japan, in the early 1980s increased predation on bird nests. We investigated the breeding biology of Japanese Bush Warblers (Horornis diphone) before and after the weasel introduction. Nest height was higher after than before the introduction, while clutch size did not differ significantly between the periods. These results suggest that introduced carnivores affect not only nest predation but also the nest site selection of birds. Received 13 November 2012. Accepted 15 January. 2013. Key words: artificial introduction, carnivorous mammal, clutch size, nest height, nest predation, nest site selection.
Risk of nest predation affects the nest site selection and breeding biology of birds. For example, nest height from the ground increases with the risk of nest predation (Forstmeier and [...]