Earlier in the year there were loads of large black slugs creeping across the reserve, now there seems to be lots of snails. Most of the snails I saw today are commonly known as banded snails, although as can be seen by the 3 fine examples I spotted on the screening outside the hide, they don’t all have bands on their shells.
The different shell patterns exhibited by these snails are a good example of natural selection, with different patterns being found in different habitats depending on how well camouflaged they are. For example, plain, unbanded yellow shells seem to be better camouflaged against new grass and leaves in the spring, shells with no bands or one band are more common in woodland, and shells with several bands are more common in grassland and hedgerows. Additionally, shells with more bands are more common in darker habitats as they absorb more heat allowing the snails to warm up quicker in these shaded conditions. This camouflage is particularly important to the snails when hungry song thrushes are looking for lunch!