How our wildlife copes with the Big Freeze
As the Big Freeze takes hold - the worst winter I can remember since 1979 - . This is NOT, as you might think, simply from the cold, but because of the snow and ice, which covers up their food supplies.
For finding food is the key at this time of year - with only eight hours of daylight, garden birds like the blue tit and robin must east up to 40% of their body weight EVERY SINGLE DAY, just to survive.
That's about 4g for the blue tit and 7g for the robin - which may not sound like much, but is an awful lot of seeds to find for such small birds. That's why feeding your garden birds is so crucial in these freezing conditions - it really will make the difference between life and death for many of them.
Our wildlife has all sorts of strategies to avoid the problems caused by the Big Freeze:
Hibernation: hedgehogs, dormice, bats and many insects have simply gone to sleep, and won't wake up until the spring. In some ways the freeze is good for them - it avoids them emerging too early, as happens on mild winter days in 'normal' winters.
Strength in numbers: birds form larger flocks than usual - it helps them seek out the best places to feed, and also enables to them to huddle together at night to keep warm; so your nestbox may now be home to up to a dozen wrens!
Seeking a new home: many species will radically alter their habits during cold weather - so look out in your gardens for unexpected visitors, including waterbirds such as moorhen, water rail, and snipe, which struggle more than most to find food.
Moving away: have you noticed that many familiar birds have simply disappeared from your area? Lapwings and redwings are especially sensitive to cold weather, and head south and west at the first sign of snow. High altitude birds move down to sea level; while many waterbirds such as the kingfisher head towards the coast, seeking ice-free water where they can feed. And many of our garden birds have already hopped across the Channel to seek warmer climes.
Moving here: these birds are replaced by birds from farther north and east, such as ducks, geese and swans from mainland Europe; these also head south and west, and end up here in the UK, especially on our south-coast estuaries.
And last, but not least, staying put: predators and scavengers, such as raptors, owls and crows, will simply stay where they are and wait for other creatures to weaken or die - easy pickings for them...
In summary, here are this winters likely losers and winners...
LOSERS
Garden birds, especially ground feeders such as the dunnock and thrushes, whose normal food supply is covered with snow.
Small birds which don't normally visit bird tables, such as the stonechat and treecreeper.
Waterbirds, especially smaller, sedentary ones such as the moorhen and kingfisher.
Small mammals: like small birds, voles, shrews and mice lose heat very easily, and need to feed constantly.
WINNERS
Scavengers, such as gulls, crows and buzzards; and of course foxes - there's plenty of dead stuff out there for them to eat (though if it gets covered by snow or frozen this can still cause them problems).
Predators: birds such as the peregrine can easily pick off weakened prey; while foxes take advantage of frozen lakes and ponds to grab roosting ducks.
Birdwatchers! Especially if you live in the south and west, where there may be plenty of new arrivals to look out for - so keep your eyes peeled...
Please tell us about your experiences of our wildlife in the Big Freeze
Stephen Moss is a series producer at the ´óÏó´«Ã½ Natural History Unit, with a special interest in British wildlife. He is author of the book Birds and Weather (Hamlyn, 1995).
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