By Charlotte Owen
There are six million chaffinch territories in the UK, which sounds like enough to qualify as our commonest breeding bird – but the chaffinch is pipped to the post by the secretive yet innumerable wren, which occupies at least two million more. The chaffinch can claim the title of commonest finch, and the male could easily vie for most colourful too. As is often the way, the female chaffinch is a bird of subtle beauty designed to blend in with the natural tones of her woodland surroundings. Her only indulgence is a splash of vibrant white forming double go-faster stripes on each wing, with matching trim along the tail.
Not to be outdone, the male sports these stripes too but it’s his sunset orange chest that really catches the eye. His colours are slightly muted now that winter is coming and he won’t look his best until spring, when the tips on his brownish head feathers will wear away to reveal the slate-grey plumage beneath and the chaffinch truly gains his crown. For now, he’s dressing down and relaxing in the company of other males, earning himself the title of bachelor bird.
The chaffinch’s scientific name means ‘unmarried sparrow’ and this arose from early observations of winter flocks made up almost entirely of male chaffinches. These flocks are the result of a phenomenon known as differential migration. While most of our resident chaffinches stay put for the winter, they are joined by birds migrating from Norway, Finland and Sweden. Their arrival can double the chaffinch population (and they may finally outnumber the wrens) but these large winter flocks are usually skewed to one sex or the other, with males and females travelling separately towards different destinations. Outside the breeding season, male chaffinches are dominant over females and it turns out that females migrate further west than males to avoid having to compete with them for scarce winter food. Seeds are their main food source and their powerful bills can crush the toughest of husks. While the large winter flocks are busy gleaning the fields in the countryside, smaller groups will often visit gardens for easy pickings under bird feeders.