Effectiveness of coypu control in small Italian wetland areas.

摘要

Introduced coypu (Myocastor coypus) [nutria] damage crops and natural vegetation and undermine riverbanks. Coypu was controlled using cage traps to protect vegetation in 3 wetlands in the park of the rivers Po and Orba in northwestern Italy. A field experiment was conducted in a natural reserve in Valenza (NRV), Italy, from 1998 to 2000, to control coypu. The park wardens in NRV were involved in approximately 18 man-days of work annually and the cost was 1518 Euros ($1867) per year. From 2001, a control programme was conducted in 3 areas. Removal densities (0.06-1.3 animal/ha) suggested that 2 trapping periods conducted annually were adequate to slow down coypu population increase. The recovery of yellow waterlily (Nuphar lutea) in 3 plots and the colonization of new ponds by vegetation indicated that coypu were maintained at a level sustainable for vegetation development..