Changes in the landsnail fauna of Great Island, Three Kings Islands, northern New Zealand

Abstract

Thirty‐three species of landsnail were recorded during surveys of Great Island in 1996–99. Twelve of these species were endemic to Great Island, and another 17 were restricted to the Three Kings group. One previously recorded species, Cytora kiama Climo, 1973, is regarded here as a junior synonym of Cytora solitaria (Powell, 1935). For more than 300 years up to 1946, sequential anthropic disturbances severely restricted distributions and diminished populations of many landsnail species on Great Island. Some original landsnail species probably became extinct during this period. Conversely, it is possible that some present‐day landsnails originated from accidental anthropic translocations from other islands in the Three Kings group and mainland Northland. Since feral goats (Capra hircus) were eradicated from the island in 1946, many formerly rare landsnail species have become widespread and abundant, primarily in response to vegetation changes.