Striped

White-lipped Snail (Cepaea hortensis)

While wandering around the garden last week, I discovered this handsome White-lipped Snail (Cepaea hortensis) hanging from the leaf of a Common Nettle (Urtica dioica) plant near the fire pit. The pale "lip" of its shell – the edge closest to where its foot emerges – quickly distinguishes it from the Dark-lipped Snail (Cepaea nemoralis) which featured on the blog several years ago. As with that closely related species, these snails can vary remarkably from one individual to the next. Some, like the one above, are marked with up to five bands of colour while others, like the one below, are a single solid shade, typically pinkish or yellow. Considerable research done on this genus of snails suggests that the wide variety of markings may serve two purposes: camouflage and temperature control. By blending in with their surroundings, and not looking like every other snail a potential predator might come across, snails with different markings might avoid being eaten. And snails with lighter coloured shells heat up less quickly than do snails with darker shells, which may explain why those in more open areas tend to be paler.

White-lipped Snails are widespread across the UK, and indeed across much of central and western Europe; they're also found along the coast of northeastern North America. Their habitats range from grasslands and gardens to dunes, clifftops and woodland, and they're known to reach altitudes of more than 2000 metres (6500 feet) in the Alps. Favourite foods include Common Nettle, Common Ragwort and Common Hogweed, so they're going to find plenty to munch in our garden!

Slugger

Green Cellar Slug (Limacus maculatus)

When I went out into a gently misting evening last weekend, I spied this 3-inch (7.5 cm) long slug making its way up the wall beside the garage door. Its overall speckled pattern caught my eye. Back inside, I checked our copy of Slugs of Britain and Ireland (yep, we're nerds). Intriguingly, the only one that looked right showed a map with no occurence anywhere near East Anglia. This immediately interested Mike, who went out to retrieve it for a closer look. In the light of the kitchen, we confirmed its identity: it's a Green Cellar Slug (Limacus maculatus), also known as Irish Yellow Slug. Though initially known only from Ireland, this species is rapidly expanding its range, and is now common and widespread across much of Great Britain. It is thought to have been a relatively recent introduction from southeastern Europe; its native range stretches from western Russia through Romania and Bulgaria to Turkey. The heavy blotching on its mantle and tail, the coarseness of its tubercules (the small, closely-packed protuberances covering its body) and its blue-grey tentacles (its eyestalks and feelers) help to identify it. It feeds on algae, mould and lichens, (particularly those on walls) as well as on decaying plant material, and is regularly found in compost bins. Like all slugs, it prefers moist areas, such as under stones and logs; however, it also regularly occurs in buildings. It can be found at any time of the year, so undoubtedly – now that we know where it lives and how to identify it – we'll be seeing it again.

Slow

Dark-lipped Snail (Cepaea nemoralis)

While weeding one of the flowerbeds yesterday, Mike spotted this little mollusc curled up in its house among the mosses. It's a Dark-lipped Snail (Cepaea nemoralis), one of the most widespread and best-known snails in western Europe. That dark lip around the opening in its shell gives it one of its common names. I say "one" because it has a remarkable number of common names: Grove Snail, Banded Snail, Brown-lipped Snail and Lemon Snail among them. Some of that variety comes from the polymorphism the snail exhibits. It comes in a wide array of colours, from very pale yellow through orange and pink to very dark brown, and can be patterned with bands (like this one) and/or one to five stripes that follow the shell's spiral. Scientists think the variety of colours is the result of several intersecting selection pressures. The snails are found in a wide range of habits from woodland and gardens (where darker snails are common) to dunes and grassland (where paler ones are). Some birds (particularly Song Thrushes), mammals, and even some other invertebrates will happily gobble up any snail they find, so looking like the surroundings – and not like every other snail, so that predators can't form a consistent search image – can help a snail to avoid being eaten. These little molluscs are plant eaters, but prefer dead and decaying material, particularly that of nettles and buttercups, so are seldom a problem in the garden. They'll certainly find plenty to eat here! They grow to a reasonably large size, reaching up to 25 mm (about an inch) across. Though reasonably common across most of the UK, they don't quite reach northern Scotland.