This summer is the very first during which my garden has become a happy hunting ground for lots of snails.
Slugs, the unshelled cousins of my snails, used to be commonplace in my garden despite my every effort to keep their population under strict control. But snails were virtually unknown … until this year. Now I have large snails, small snails and in-between-sized snails in considerable numbers, with quite a variety of shell patterns, although the basic colour is usually a shade of brown, ranging from dark chestnut brown to something quite close to orange. The question is … where have they all come from, all of a sudden? Nothing appears from nowhere in the natural world, so these mollusc invaders have arrived from somewhere by some means that I don’t understand. Has some terrorist group launched an airborne attack on garden vegetable crops by spraying areas of the country with millions of baby snails? Have these families of snails spent years making painfully slow progress up the verges of the A1 and M6/M74 arterial road routes from the south to Scotland? Have they crept down the side of the A9 from the north of Scotland to reach the central belt? Or is their sudden appearance a warning of the dire consequences of voting ‘yes’ or ‘no’ in September’s referendum … and, if so, which is the wrong way to vote?
And the honest answer is that I have been unable to find out whence or why they have come. Some sources blame the increase in the snail population on climate change, otherwise known as global warming, while other sources take a directly contrary view, claiming that climate change is reducing the number of snails and limiting the areas where they can thrive.
What I can tell, gentle reader, is that there are many tens of thousands of types of molluscs … snails, slugs and their kin … with estimates of the number of species ranging from 60,000 to perhaps as many as 200,000. Most of them have shells, making them what I would commonly call ‘snails’ although I really should call them ‘gastropod molluscs.’ Many species of snails live in salt water while other species live in fresh water or on land; and, while an aquarist friend seeks to encourage freshwater snails to live in his aquariums … or ‘aquaria’ for those with a classical education … where they work as cleaners, I am concerned with the land-living versions which I regard as unwelcome residents in my garden.
Snails are hermaphrodites, meaning that they are both male and female. However, it still takes two to tango, after which both will be fertile and will lay rather a lot of eggs. The most widespread type in Scotland is the common garden snail whose pukka scientific name is Cornu aspersa. As one might expect, this is the mollusc that feeds on a wide variety of vegetables and ornamental garden plants, eating holes in the leaves, the stems and the flowers. And yes, being very accomplished … if rather slow … climbers, they can readily reach those parts of plants that other molluscs can’t reach. To be fair, they do sometimes help the hard-pressed gardener by doing some tidying up, eating dead and rotting vegetation, small animal droppings and dead slugs, some adding a cannibalistic variation to their diet by eating their own dead kind. But the average gardener doesn’t have much trouble with dead snails.
Their slime trails are the give-away to their presence; and it is this sticky mucus which helps them move over rough surfaces and gives them the ability to climb and even to ‘walk’ upside-down. Among the slowest-moving creatures in the world, they are most active at night … especially damp nights … and live for a number of years, hibernating through the winter. Ah, that’s the news I really wanted to hear … that most of those which survive this summer will be back next year to join their babies. Oh joy! Oh rapture! Oh ****!