The green linnet, alias the greenfinch, deserves such lavish praise; the male, in his green array, has bright-yellow wing-bars and tail-fringes. With a bill heavier and stronger than a chaffinch’s, he can tackle most nuts and seeds. Females are duller, browner, with less-conspicuous markings on wings and tail.
This bird of woodland fringes has taken to living close to us, so much so that it’s unusual to find one far from dwellings or farms. A sociable creature, it joins winter flocks of chaffinches, sparrows and buntings, as they roam the countryside, mopping up left-over grain on stubble fields.
A keen patron of bird-tables, the greenfinch thrives on muesli, stale bread, and peanuts. Although not shy of people, it can be a sensitive soul, becoming stressed if captured. Ringers must deploy their best bed-side manner when handling them. As with sociable birds generally, greenfinches have a wide vocabulary of wheezy, chest-infection-sounding calls. The song is a mixture of warbles and a loud shriek resembling a sharp intake of breath. Wordsworth was a bit over-the-top about his hero’s performance: “hail to three, far above the rest in joy of voice and pinion”, etc. The song is distinctive and evocative, but the greenfinch is no nightingale. Poets make poor ornithologists.
This little seed-eater still holds dominion, as it did in Wordsworth’s day. According to the organisers of BirdWatch Ireland’s Garden Bird Survey, it’s one of the 10 most widely distributed species in built-up areas. However, its future is uncertain.
Greenfinches prospered up to the mid-1990s. Then, according to the British Trust for Ornithology, the species “suffered a rapid and severe decline from the mid-2000s”. In the late 1960s, observers were able to find, and monitor, 500 greenfinch nests in Britain and Ireland each year. By the mid-2000s, they were tracking fewer than 50. The decline seemed to peak in 2006, by which time the UK greenfinch population had fallen from 4.3m to 2.8m individuals. Pairs seemed to be nesting later. By 2008, the collapse had spread to Scandinavia and Finland.
The reduction in numbers may have been less-severe in Ireland. In 2006, BirdWatch started to receive reports of dead birds, victims of a mysterious disease. The Garden Bird Survey here found that greenfinch numbers fell by 8% between 2004 and 2011. The bird’s fortunes have fluctuated since.
Post-mortem examinations revealed that the dead birds had suffered from trichomonosis. This is caused by a parasite that attacks the upper digestive tract. The throat swells, the bird can’t swallow, and becomes lethargic. With its feathers fluffed-up, it begins drooling saliva and dies of starvation. Fewer than a hundred nestlings were ringed in Britain and Ireland in 2013. In 2017, the total was 61. The current edition of Lifecycle magazine asks ringers and nest-recorders to focus attention on this species, which we took for granted.
Other finch species, sparrows, pigeons and birds of prey are also vulnerable to this infectious disease. However, it presents no threat to people. Nor do dogs and cats suffer from it. The parasite can’t survive out of water. Cleanliness is crucial; bird-tables and feeders should be disinfected and cleaned regularly.
Monitoring priorities: Greenfinch, Lifecycle, autumn 2018.