Garden birds: Are there fewer this year?
The RSPB says this winter more people than ever are getting in touch about the lack of birds in gardens. So are they disappearing?
For those living in towns and cities, they are one of the highlights of winter. The annual arrival of hungry birds looking for food is something to look forward to as the chill sets in.
Blue tits, chaffinches and house sparrows are among those usually spotted in urban gardens at this time of year.
But the RSPB says it is being inundated with letters and emails from concerned people who say they are seeing a lot fewer garden birds this year. So are they right?
Garden use in winter is related to two main things when it comes to birds - weather and food availability, says the British Trust for Ornithology (BTO).
Birds you should see in gardens
- Great tit
- House sparrow
If it's cold, small birds burn off more energy reserves keeping warm and need to take on board more food to keep them going. Usually by this stage of the winter, seed and fruit crops are running low in the countryside so birds have to use suburban gardens to get enough to eat.
But as it has been unseasonably mild of late across much of the country, the birds have not been under so much pressure to find more food, says Mike Toms, head of garden ecology at the BTO. Bumper fruit crops also mean there is more to go round.
So some species haven't been visiting gardens in their usual numbers, says the BTO, which surveys and documents bird numbers in UK on a weekly basis throughout the year. Numbers of redwing and fieldfare in gardens are lower this month, compared to last January - also siskins and lesser redpolls. They, however, don't normally peak in gardens until late winter, so there is still time to see them coming in greater numbers, it adds.
The RSPB says usually at this time of year the food birds eat is covered by frost and snow, but this year there are still berries and insects available in the countryside.
"The birds are out and about finding good supplies of natural food," says the RSPB's Abbi Jinks. "Berries, seed heads and insects are all very plentiful in mild weather, so birds are able to feed in the wilder countryside without turning to our gardens for help."
It is conducting its annual Big Garden Birdwatch this weekend, which should help establish figures. It estimates that more than half a million people will be taking part in the wildlife survey, which it says is the world's biggest.
But on the flip side, it's hard to establish if numbers in the countryside are higher than usual this winter as birds don't need to be around people if their wild food supply is plentiful, says Jinks.
The UK has five million breeding pairs of blackbirds
Others have noticed the decrease in many bird species in town and city gardens this year. Matt Merritt from Bird Watching Magazine agrees that the weather is the main reason.
"It plays a huge part in what birds you see," he says. "Bird numbers can decline for other reasons, but it's not usually something that becomes so obvious so quickly. Over periods of 10 or 15 years you might see a difference in numbers when a decline is down to things other than weather."
The dip in numbers in urban gardens this year could also be more obvious because the past two winters have been so cold, say bird experts. In 2010 we had the coldest December documented for the UK since nationwide records began 100 years ago, according to the Met Office. This resulted in birds you rarely spot in urban areas being forced to use gardens for food.
"I was getting woodcocks in my garden, which is very unusual," says Stuart White, who is a birdwatching guide in Norfolk. "The birds were starving so many more than usual were forced to come into urban areas to find food.
"Some people probably think the amount of birds they have seen over the last two years in their garden is normal, but it's not.
"This year it has been unseasonably mild. There was also a bumper crop of fruit last autumn, it was literally dripping off bushes in the countryside. This will have kept a lot more birds there than usual."
February can be the harshest month of the year and a time when birds should be getting well fed to get in shape for the breeding season.
Good energy supplies now give them the best chance of producing healthy young.
But experts say a lack of certain garden birds this year is not necessarily something to worry about.
The BTO says its weekly recording of bird numbers has shown there is a general pattern of garden use for each species. It may fluctuate over the weeks and months, but the average is what is important. So people should not worry if they are seeing fewer birds in their garden, it does not necessarily mean populations are decreasing.
Also, some species are arriving as normal.
"In terms of general garden species like thrushes and finches, numbers are not that different from what we would normally expect," says Toms. "People might have noticed, however, that the birds are not eating as much bird food because of the milder conditions."
The prolonged abundance of food supplies in the countryside also has advantages. It means birds have had a good chance to get in shape ahead of the breeding season.
The RSPB is still asking urban bird lovers to be vigilant.
"The weather could still turn cold in February," says Jinks. "So it's really important to keep an eye on your garden at this time and keep at least a small supply of food in your feeders so they know they can return when the weather turns colder. Keep a fresh supply of water out there too."