By Stephen Moss
Naturalist and Snow Watch producer
Increased garden feeding means more birds will survive the cold
The cold weather is not all bad news for Britain's birds, but some species will struggle to survive when the snow melts.
As the Big Freeze of 2010 continues its hold on the UK, reports are coming in to the
Snow Watch website,
from all over the country, of birds in unusual places or doing unusual things.
We've had hundreds of reports of unexpected visitors to gardens - with
top of the list of new arrivals.
These winter thrushes arrived in the UK from Scandinavia back in the October, and having spent the autumn feeding on berries along hedgerows, they usually forage in muddy fields during the winter months. But with snow lying almost everywhere, they have headed en masse into our gardens.
The British Trust for Ornithology's
survey has reported a huge increase in both species, which have joined the more familiar tits, finches, robins and blackbirds.
Rare birds may have been hit so hard that they face annihilation as British breeders
Many people are also noticing a rise in aggressive behaviour around their bird feeders - with so many more birds competing for food, it's hardly surprising that fights are breaking out.
is that many more of these birds will survive this cold spell compared to previous 'big freezes', simply because of the huge rise in numbers of people feeding garden birds.
Out in the wider countryside, though, things are looking much less rosy. Many birds are foraging by the sides of gritted roads, hoping to find seeds or other morsels of food.
Unfortunately as they get thinner and weaker, they simply don't have the energy to fly out of the way when a vehicle goes past, and are being hit and killed.
Water birds on the thin side are in trouble in the cold
Waterbirds, too, are in big trouble - at least the thin ones are. Plump birds such as ducks, geese and swans can cope pretty well with ice and snow.
But herons, bitterns, kingfishers, water rails and snipe are struggling - which paradoxically makes them much easier to see as they venture out into the open to find food.
For some birds, the only sensible strategy is to flee to the south or west in the hope of finding milder weather and food.
remain in East Anglia, while
a recent colonist, have headed to the coast, or across the channel to western France.
Winners and losers
Some birds do benefit from a cold spell: predators and scavengers - tawny owls, kestrels, buzzards and crows - all thrive in harsh weather, as there are weak birds and small mammals to prey on, and plenty of dead ones to eat.
Expect some novel visitors as the cold weather continues
So once the snow and ice have finally melted, what are
the prospects for Britain's birds?
This spring we'll find out just how they have fared, and it's very likely that populations of vulnerable species such as the wren, long-tailed tit, goldcrest, kingfisher and grey heron will be well down on normal.
The good news, especially for smaller birds (which only live a year or two anyway) is that within two or three years their numbers should return to normal.
But rare birds, such as the bittern and
may have been hit so hard that they face annihilation as British breeders - as almost happened in 1963, when only a dozen pairs of Dartford warblers survived to breed.
One way we'll be able to assess the fortunes of our common birds is through the largest Citizen Science project in the UK: the RSPB's
Big Garden Birdwatch,
in which more than half a million people take part each year.
Scheduled for the weekend of 30-31 January, it will give us a chance to take a closer look at the birds in our garden as we count them; and give the RSPB's scientists the opportunity to get an early snapshot of how our birds have fared in the winter of 2010 - one of the top five coldest winters in the last hundred years.
Stephen Moss is a TV producer based at the BBC Natural History Unit in Bristol, and author of 'Birds and Weather'.
'Snow Watch' is on BBC Two on Wednesday 13th January from 8-9 pm
Find out more.