The RSPB's 2008 Big Garden Birdwatch results show the average number of birds seen in each garden in Wales has declined by two per cent since last year, however five species of finch, which spend the winter in Wales, have increased.

The chaffinch has crept up to number three in the Welsh rankings and the greenfinch has made its way into the top 10.

For the first time in the survey's 29-year history, the striking siskin makes it into the top 20, being seen in four times as many Welsh gardens as in 2007.

Scarcer finch species such as brambling, moving from 53 to 34 in the rankings, and redpoll, seen in almost twice as many gardens this year as last, have been much more numerous that usual.

The RSPB's Director, Wales, Dr Tim Stowe, said: "It's definitely been a good winter for finches!

"Many of them are here because of food supplies.

"The increase in bramblings reflects the scarcity of beech seed known as 'mast' in northern Europe and Scandinavia – if the mast crop is poor in these countries, we see more of them here in our gardens.

"Along with siskin increases, numbers of redpolls seen in gardens have skyrocketed.

"Again this is probably due to supply of food; both birds feed on conifers and deciduous seeds, so the figures suggest that tree seed supplies have been poor this year and they've been forced into gardens to find food."

Participants in Big Garden Birdwatch also noted an increase in song thrushes, with numbers up by almost 50 per cent in Wales, compared to last year.

This is probably thanks to last year's warm, wet summer, which made it easier for them to find snails, slugs and earthworms to feed their young.

However, a decline of almost two thirds in song thrush numbers over the past 30 years indicates that there is a long way to go before the declines of the past are reversed.

As predicted, numbers of blue tits dropped significantly – from an average of 4 birds per garden, to 3.5 – nudging this colourful and popular garden bird from third place down to fourth in the Welsh rankings. This decline probably results from of the extremely wet breeding season in 2007.

In addition, blue tits have begun laying eggs earlier and earlier over the last 40 years, which means they are increasingly out-of-sync with the appearance of caterpillars, a key food source.

Over the weekend of January 26 and 27, almost 22,000 people in Wales were among 400,000 across the UK that counted the birds in their gardens as part of the RSPB's annual Big Garden Birdwatch.

The house sparrow retained its top spot with an average of 5.1 per garden in Wales, significantly higher than the UK average of 3.6 per garden.