A survey of land molluscs of the South Haven Peninsula carried out by C. Diver and C. Oldham in the 1930s was used as a basis for resurveying in 1999, albeit with different methodology. Significant changes have occurred, with a net increase in species diversity and in distributions of many species. Some of these changes are associated with parallel habitat changes both natural and anthropogenic. Only a few reflect national trends; others appear to track local changes with some time lag. Some species have not yet reached new areas of apparently suitable habitat.
South Haven Peninsula.