The New Zealand Placostylus (Placostylus bivaricosus) is preyed on by Eurasian Blackbirds, which is causing the decline of this species. Other causes for the decline include habitat clearing and modification, predation and habitat disturbance by other exotic fauna species and possibly herbicide and pesticide use. There is no evidence that this has caused a local extinction of these species (NSW National Parks and Wildlife Service 2001, Threatened Species Scientific Committee).