Setting the scene
Brrrr. It’s a cold February day, with thirsty birds standing on a frozen bird bath and frogs trapped under ice on the pond. Yesterday we had a biting wind too. Cornwall’s position on the western fringes of Europe, beside the Atlantic Ocean and the Gulf Stream, usually gives us what is known as a maritime or oceanic climate: mild summers and mild winters. We are pretty far north on the globe, however, with the western tip of Cornwall at a similar latitude to much icier places, such as Krakow, Prague, and Winnipeg.
I live in an inland, quite high part of Cornwall (on a clear day you can see the sea to the distant north and south from the top of Kit Hill). For several mornings in the first half of January I woke up to a white world – one day snow, but mostly frost under a thick white mist – hazardous, but prettily sparkling when the sun breaks through. Now in February, it’s cold, hard ground and thick ice on the pond.
Ponds and ice
In January, I broke the ice on the ducks’ artificial pond in their enclosure, but not the thin, patterned ice on the wildlife pond, after reading this article: http://news.bbc.co.uk/earth/hi/earth_news/newsid_8451000/8451711.stm
It says, reassuringly, that research undertaken by Pond Conservation has found that pond wildlife can survive or even do well under a surface freeze. This is because oxygen remains trapped underwater, and plants underneath can still photosynthesise, increasing oxygen levels beneath the ice. However, a pond full of silt and dead leaves might need more oxygen, and a deep pond – or one covered in snow – would be too dark for photosynthesis to take place, so it’s worth brushing snow away. The findings provide another good reason to (ideally) have a pond with different depths, including shallow water.
Today, however, I found a large female frog, with wide, bulging sides showing that she was obviously almost ready to spawn, swimming around just under the surface of thick ice. I thought it best to pour a few jugs of warm water on the ice until I could clear some breathing space for the frogs. Best to be on the safe side. I think it will freeze over again tonight. Before the freeze, the frogs were splashing around, but were wisely hesitant to release the precious spawn with icy weather on the way, unlike the freely spawning frogs in the nearby woods in local valleys.
It is estimated that garden ponds now outnumber ‘wild’ ponds by six to one, and so until this changes, it is up to us garden pond owners to provide water for wildlife. This January, in cold parts of Britain where wetlands have frozen solid, wildlife gardeners have apparently been feeding normally shy birds including woodcock, snipe and grey wagtails that have appeared at bird feeders, and volunteers have been feeding bitterns with sprats. We shouldn’t disturb overwintering flocks of birds, though, as they need to conserve their energy when temperatures are low and food is scarce.
Water and food for mammals
In gardens, we can put out extra bowls of water for mammals as well as birds. Most mammals do not hibernate, and all mammals will need water, so do leave some out at ground level. Hedgehogs have been caught on trail camera in Cornwall during the cold weather, although ‘ours’ have left their food untouched and are (I hope) safely hibernating at present.
I have noticed tiny holes appearing in the frosty ground lately, indicating the presence of voles or wood mice. My trail camera revealed a wood mouse out and about, finding dropped pieces of bird food.
Water and food for birds
Bird baths, with their shallow water, freeze easily and ours needed to be refilled this morning, with warm water to thaw the ice. (Please don’t boil a kettle then slip over on the ice, pouring boiling water over yourself, as I did a few years ago on the way to the bird bath.) Another winter job is to clean nest boxes as well as keeping bird feeders clean too.
If we walk on frosty grass (to get to the bird bath in my case) it causes temporary damage, but let’s not worry about having a pristine lawn and instead focus on wildlife. Some species of birds – and small mammals – feed at ground level, and although our robins wait on the bird table and stare in at the kitchen window if their food runs out, they also perch close by when I’m tramping around the garden, hoping that I’ll disturb the ground and reveal live food.
The tits and house sparrows fly to fat balls suspended in mesh feeders and seed mixes in plastic tube feeders. Starlings can manage the gripping and dangling required for either of these, but the blackbirds forage at ground level. I have thrown some dried fruit and proprietary songbird food mix on the ground, but one blackbird has finally braved the bird table.
Competitive, scarlet-breasted robins and shy, grey-brown dunnocks use the bird table, as do large birds with large appetites, including collared doves and jackdaws. Blackbirds are still finding windfalls under the crab apple tree, whereas wrens can be kept alive in icy conditions by sprinkling grated cheese around garden edges. I thought I saw a hungry Kit Hill raven on the garden wall one morning, but perhaps it was just a really large crow ….
Toughing it out
As long as our garden wildlife is given the variety of water, food, shelter and space that it would have found in the varied countryside we had a century ago – prior to all those developments of the previous century’s that didn’t take wildlife conservation into account – it will be resilient. Native species have evolved to cope under ‘normal’ winter weather conditions which include frost, snow and ice. We wildlife gardeners can do our bit to reverse decades of anthropogenic damage by creating wildlife-friendly environments, our small gardens joining together to make the effect larger scale, to see our wildlife safely through to spring.