Thousands of people in Cornwall are expected to take part in the Big Garden Bird Watch
A new survey hopes to discover if one of the coldest December's ever has had a big impact on Cornwall's bird population.
Thousands of people in the county are expected to take part in the RSPB's Big Garden Bird Watch.
The wildlife charity believes that the extremely low temperatures will mean that gardens have already been occupied by higher numbers of birds than normal.
The event takes place on Saturday 29 and Sunday 30 January 2011.
The cold winter could lead to some unusual sightings
Dr Mark Avery, the RSPB Conservation Director said: "The really cold weather began quite early in December, and this would have when been natural food sources became scarce.
"Birds that wouldn't usually be found in gardens had to adapt their behaviour and look closer to home in our gardens.
"By now, these birds could have been making the most of our hospitality for over a month, meaning even more unusual sightings this weekend."
The RSPB's local spokesman Tony Whitehead said: "We've had a flock of up to twelve brambling with us since the snows.
"This colourful finch from the far north and east has only visited us once before, in the winter of 2008/9 so this is quite exceptional."
The charity hopes that as well as providing useful data to study trends and spot any worrying declines, the survey will act as a reminder that garden birds still need our help for a few weeks yet.
The RSPB is advising people to continue putting out supplementary food and water, to attract all kinds of species.
Find out more about
The Big Garden Bird Watch