Biology for beginners

We're just back from our beloved Dunraven Bay; a favourite holiday spot for us, where we always have adventures. We've been so many times now that I can track the growing up of my children by simply recalling what we got up to when we were there in previous years. I remember the buggy-on-the-sand struggles, the sandy nappy changes, the one-toe-in-the-sea-and-that-was-enough paddles. My children would dig in the sand, and play with shells and pebbles along with their toy cars and figures. They loved to waddle in the sand-pool shallows, and they would use their buckets for all kinds of busy fetching and carrying. A little more sophisticated this year, their activities included intrepid body-boarding in the icy cold sea, ambitious sand-fort and moat building, confident and nimble rock rambling, fastidious fossil hunting, film-making with Action Man, and proper rock-pooling - with an identification book and everything.

Using our tattered Spotter's Guide to the Seashore took me back to the biology field-trips of my undergraduate years. Is there anything more satisfying than finding which particular sea-lavender or limpet you've just found by flicking through the pages of such a book, checking the particular shape, colour or markings on leaf or shell? No? Well, I know not everyone gets a buzz from it - but I really do. While I hoped I was passing on my enthusiasm for ecology to the children, I also knew I needed to hold back a little. I didn't, for example, push them to count and record the number of bladders on seaweed samples in ten different rock-pools, or mark out 50cm quadrats for them to study biodiversity up and down the shoreline with the Usborne pocket book in hand. Those joys must surely wait another year or two.

Indeed the best biological thing we learned about the seashore habitat didn't come from a book at all. Paddling in the sea, as the tide was coming in, we spotted a hermit crab tumbling in with the waves. As the water retreated, the crab emerged from its whelk shell and resisted being pulled back into the sea with its characteristic sideways walk. This was amazing enough - Daisy named it Swirly because of the captivating way it let itself tumble and swirl with the incoming water, and we watched it repeat its trick over and over. Imagine then how exciting it was to discover at least fifteen more hermit crabs - all equidistant from each other (about 2m apart) - doing exactly the same thing as Swirly, like they were on parade or something. We ran up and down the beach waving and jumping at each other every time we found one; the shells punctuated the smooth sand like a row of fullstops; it was incredibly cool. For my own interest, I've been searching the internet to see if there have been any studies on this kind of tidal behaviour of hermit crabs (sad, I know) - but for my children, it will simply be the magical discovery of the crabs on parade that they'll remember. They need biology for beginners for now - so I can leave its formalisation to the hermit crabs because, it seems, they're absolutely brilliant at it.