Garden bird survey aims to solve goldfinch mystery

While many of our familiar songbird species are in decline, one avian character in particular has been spotted increasingly frequently in UK gardens - the goldfinch.

Now, the British Trust for Ornithology wants volunteers to help work out what has boosted the bird's numbers.

The organisation wants to know what goldfinches feed on in our gardens.

The aim is to work out whether supplementary feeding is helping the birds to thrive.

The increase in the UK goldfinch population has been dramatic. According to the BTO, it increased by about 80% between 2002 and 2012.

Ups and downs

• British songbirds increasing in population include: blue tit; great tit; coal tit; long tailed tit; chaffinch; great spotted woodpecker; wren; collared dove; wood pigeon; robin; blackcap and chiffchaff.

• Species in decline include: hawfinch, lesser spotted woodpecker, greenfinch, bullfinch, skylark, yellowhammer, linnet, corn bunting, song thrush, meadow pipit and dunnock.

Source: RSPB

And while there are many factors and landscape changes that affect the habitat and food available to Britain's birds, the supplementary food that people put in their gardens may be having a significant impact.

Researchers want volunteers to help record what goldfinches are feeding on in UK gardens

A recent study, also led by the BTO, found that garden food - especially fats and sunflower hearts - had caused European blackcaps to shift their winter migration route north to the UK. The birds were apparently taking advantage of the abundant food available in British gardens.

Clare Simm, the Goldfinch Feeding Survey organiser, said it was "vital to understand what resources birds are using in our gardens, in order to help them when times are hard".

Grahame Madge from the RSPB said: "There's no doubt that goldfinches are adapting to the availability of garden bird feeders, as surveys show they are more frequent garden visitors now than they were 20 years ago.

"Goldfinches are reliant on seeds and it's extremely welcome to see such a charming bird doing so well, at a time when the numbers of other seed-eating birds, such as the corn bunting, are continuing to plummet."