Differences in the sites of activity of coexisting species of land mollusc

Nocturnal observations of the activity of land molluscs at four locations (three open and rocky, one wooded), show that there are substantial differences in the sites of activity of some species living in the same place. Vertical and horizontal rock faces, bare soil, living and dead vegetation, tree trunks and fallen logs all have characteristic species. The sites of activity of snails are related to shell shape, with the tallest preferring hard vertical surfaces and the most flattened, bare soil. Such differences help, in a limited way, to account for the diversity of species found in some habitats.