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!

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.

Slimed

Any time we get a bit of rain, we get a sudden irruption of Garden Snails (Cornu aspersum) on the walls of the house. They slither their way around, looking for plant material to nibble — and for other snails to mate with, presumably! They can be a problem in a garden (or agricultural field) if their numbers grow high enough, but that hasn't been an issue here yet. That might be because we have a number of Song Thrushes in the neighborhood, and they're well-known gourmands of snails. We do find slime trails regularly across the paving stones near the driveway, but whether the snails or their cousins the slugs have made them, we're not sure.

Like most land snails, the Garden Snail is a hermaphrodite, producing both male and female gametes. They fire love darts at each other during the mating process, though we haven't seen any evidence of those. These "darts" are covered with mucus that appears to help prime the recipient's female sex organs to receive the donor's sperm. They mate for hours (!!) then produce up to 80 tiny, pearly-white eggs, which they lay into sheltered areas such as cracks in the soil.

The Garden Snail (dubbed the "Brown Snail" in parts of the New World) is native to Europe, from the British Isles south to the Mediterranean, as well as northern Africa and east to Asia Minor; it has been widely introduced (intentionally and otherwise) to much of the rest of the world. While sometimes considered a pest, as it is primarily a herbivore, it is also consumed by a variety of birds, mammals (including humans), reptiles, amphibians and insects. In other words, it definitely has a place in our wildlife garden.