By Victoria Gill
Science reporter, BBC News
4 November 2015
Ornithologists are asking the public to help survey garden goldfinches, in an effort to work out if feeding is driving up the birds' population
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.
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.