Jenny Dixon

Wharfedale Naturalists Society

LAST week saw a change of duvet for us – as the first frosts began to nip. Out in the garden preparations were also going on: coal tits hurrying to cache seed from the feeder, jays and squirrels collecting fallen acorns to bury around the neighbourhood, and blackbirds and redwings from N Europe checking pyracantha, berberis and cotoneaster berries for ripeness.

Many mammals eat a lot and hope to get through the lean times with little or no activity. My visiting badgers will still be out and about but not so often and not so far afield. In the UK we have a few species that truly hibernate – hedgehogs, bats and dormice. A couple of weeks ago we had a sad reminder of how serious this business is. Under the bird feeders lay a small hedgehog, tightly rolled up and very dead. A late birth and not enough time to put on the insulating fat that would see it safely through till Spring, it had succumbed to our first frost. Hedgehogs need to reach a critical weight, about 450gms; they then keep their metabolism just ticking over till warmth returns. Raising levels again takes a lot of energy so a winter with warm interludes is bad news for hedgehogs.

How about the cold-blooded? We’ve probably all come across frogs hidden among leaf litter or in the mud at the bottom of a garden pond, perfectly safe as long as they don’t get frozen solid. And reptiles? Well, information suddenly poured in.

My stepson, Chris, who lives on a smallholding in the Snowdonia National Park had a shock recently. In his polytunnel he encountered a grass snake basking in the warmth. Grass snakes can grow to 1.5metres long and this was a whopper. Quite harmless and rather shy, the snake made a quick exit. Chris turned to fill his watering can from a convenient butt only to find a smaller version swimming around apparently unable to get out. He assisted it. Then a couple of weeks ago he opened one of his compost bins – a wonderfully ripe collection of kitchen and garden waste and stable sweepings, only to find a collection of young snakes, clearly having hatched in the incubator/heap and not ready to leave. Each was about 4/5inches long with the typical black and yellow “collar”. Later excavation of the heap revealed the empty leathery egg cases.

Snakes hibernate through winter and need to keep frost free. No doubt they’ve found the perfect spot. A new compost heap has been started nearby as a further refuge!