Snails are found in quite varied habitats, but the one thing in common is fairly stable humidity. We therefore find them in forests, but also rocks or fairly humid parks and gardens. However, some species have adapted to live in drier areas such as limestone lawns. This last type of habitat is in decline and benefits from protection measures such as those initiated by the Natura 2000 network. We can also encounter snails in the mountains such as Columella columella present up to 2900 meters in the Swiss Alps. In this article, we are interested in the most common forest and garden snails in France.
How many species of snails do we know?
In France, the diversity of snail species is remarkable. The League for the Protection of Birds (LPO) Île-de-France lists more than 400 species, but this includes snails and slugs which are closely related. The National Museum of Natural History lists 691 species of molluscs in France, including 33 species of bivalves, 251 freshwater snails and 407 land snails and slugs. A third of these species are endemic, meaning they are found nowhere else in the world, and 11% of them are threatened with extinction.
Do snails live in any forest or garden?
Snails are more common on limestone soils and those that live on acidic soils have more fragile shells. Indeed, you are certainly aware that snail shells are mainly made up of calcium carbonate, a compound abundant in limestone. These molluscs therefore need a significant amount of calcium to maintain and develop their shells. Limestone soils provide an ideal environment for snails.
Each species has carefully selected its habitat. But when we look more closely, we realize that we find more of them in limestone areas than in acidic areas. Thus, in a limestone forest, it is possible to identify 40 different species of snails while in an acidic forest (composed mainly of spruce trees for example), the number of species recorded falls to 10.
This number also varies depending on the average annual temperature. The warmer and more humid the climate, the greater the number of species.
Snails of the genus Cepeae
Among the species that you are most likely to encounter in your garden, provided you live in an area favorable to them, are Cepaea hortensis and Cepaea nemoralis.
However, these species are among the most common and observed snails due to their ability to occupy a wide variety of environments. You can therefore also encounter them in woods and meadows.
These snails are known for their globular, colorful shells which may have dark spiral bands. They vary greatly in color and pattern, which can make it difficult to identify and distinguish them from other closely related species. Cepaea hortensis and Cepaea nemoralis are distinguished by the color of the peristome (the edge of the shell opening) – light for the first and dark for the other. Needless to say, you have to be an expert to know who it is!
The forest snail (Cepaea sylvatica) lives in forests between 500 and 2,400 m altitude. Its shell is smaller than those of the two species already mentioned. This snail can be found in the Alps and the Jura, in France and Switzerland. It is also present in the upper Rhine valley as far as Karlsruhe and Worms. It was introduced into the gardens of Landsberg (Lech valley).
The shrub snail
The shrub snail or Arianta arbustorum is a species widely distributed in Europe. This snail is distinguished by its solid, spherical shell, the color of which varies from brown to yellowish green. It is also often decorated with darker bands or spots.
In terms of habitat, Arianta arbustorum shows a preference for moist and shady areas. It is found as much in deciduous and coniferous forests as in hedges, wet meadows and gardens. This species, adapted to life at altitude, can be found up to 2000 meters above sea level. It is active night and day, in humid weather, feeding on various plants, dead leaves and sometimes decomposing animal matter.
The little gray
The squirrel snail, scientifically named Helix aspersa, is one of the most common land snails.
It is found in various regions of the world, Europe, Africa, Asia, North and South America, as well as Australia and New Zealand. It feeds on a wide range of plants, including vegetables, flowers, fruits, and ornamentals. Its shell is rough and is distinguished by wide dark bands interrupted by fine yellowish stripes. The base has a clear bead.
It adapts to various environments but prefers humid and cool areas. In France, it is frequently found in parks and gardens, where it feeds in particular on nettles.
Helix pomatia is the largest species of snail living in mainland France. It has a large globular shell, thick and solid, creamy white to light brown in color and finely streaked.
This snail prefers habitats with high humidity and low temperatures. It likes soft soils to bury itself and hibernate or lay its eggs. It is found in open forests and bushes on calcareous substrates. It can live up to 2,100 meters above sea level in the Alps, but this remains uncommon. In southern England it is restricted to grassy or scrubby wastelands.
Helix pomatia is hermaphroditic. Its reproduction begins at the end of May in Central Europe. Eggs are laid in June and July, in groups of 40 to 65 eggs. It reaches maturity between two and five years old. Its life expectancy can reach 20 years, but many individuals die earlier due to summer drought and winter frost.
The species is listed in the IUCN Red List and enjoys some level of protection in Europe, even in places where it has been introduced, such as the United Kingdom. Commercial collection is thus regulated in several countries to regulate the harvest of populations living in freedom.
Are you allowed to collect snails anywhere, any way?
Outside of your garden, the “harvesting” and sale of Burgundy snails has been regulated in France since 1979. It is prohibited to collect these snails from April 1 to June 30, regardless of their size. The rest of the year, it is possible to collect them, provided that the shell has a diameter greater than or equal to 3 cm. The squirrel can be collected all year round provided that a hem is present on the edge of the shell: this is a criterion of maturity.
However, a prefectural decree may prohibit the collection of snails specifically for each department. It is therefore in your interest to find out what it is possible or not possible to do because the penalties range up to six months’ imprisonment and a fine of €9,000.