Thursday 8 July 2010

Mating Molluscs

The mating snails amongst my vegetable seedlings present me with an ecological and ethical dilemma. When I was a kid, I loved snails. I would don my cagoule and scour my parents’ garden for them in the rain, following their slime trails on the grass and collecting as many as possible into an old icecream tub. I would study my catch, marvelling at the different patterns and colours of their shells. I would gently stroke their tentacles and watch, intrigued, as they retracted back into their moist bodies. I would laugh as they blew bubbles and race them against each other, before releasing them back into the garden.

My love for snails began to wane when I started growing vegetables. At first, unable to bring myself to kill them, I would collect them from my allotment and take them to a public park several miles away. But, the sheer number of snails I found started to make the whole process a bit ridiculous and so, sadly, I realised that if I wanted to ever eat any of the vegetables that I so carefully nurtured from seed, I would have to wage war on the molluscs. So, I started to kill them. Not with slug pellets, which are lethal to so many non-target animals, but with a quick blow from a trowel.

Now though, I was witnessing something very intimate, which I’d never taken the time to notice before. It was the perfect weather for snail love-making – a warm, wet, summer evening and the two snails, both hemaphrodites, had reared up and were entwined in an embrace. I hovered over them, trowel in hand, but they seemed oblivious to my presence. This particular pair were probably responsible for the fact that, out of three packets of seeds, I have only a single carrot plant left; the fact that I have never managed to grow a summer squash to maturity; that my lettuces are more holey than Honiton Lace; and the fact that every sunflower I have ever tried to grow has been cut down before its time by a rasping radula. If I allow them to continue reproducing, their ranks will be swollen by more vegetable-decimating invertebrates. And yet, and yet, I cannot bring myself to bash them, whilst they are so absorbed in what must be one of the most important moments of their lives.

Feeling like a voyeur, I peer a little closer. The two snails are joined by their partially everted genitalia and a calcified ‘love dart’, which is thought to increase the male's chance of siring offspring. My decision made, I pick up the courting pair and take them away from my pots of seedlings, to dump them next to a lane at the back of my garden. It is a token gesture. There is no doubt in my mind that they will quickly find their way back, to each lay their hundred or so eggs amongst my much-loved plants. Then, in two weeks, their progeny will, I'm sure, emerge to grow fat on mangetout and rhubarb that is meant for my plate and I will have to call an end to this temporary ceasefire. At least the song thrushes are on my side.

Now you do it
One of the most bizarre courtships of the animal world could be going on in your back yard. Surprisingly little is known about the mating rituals of the garden snail, one of our most common and familliar of animals. To witness this unusual event, you will probably need to search with a torch on a warm, wet night. Your vegetable patch is a good place to start looking...