Birds
European Robin
Erithacus rubecula · also called robin, robin redbreast
The European robin is Britain’s best-loved bird — a tame, round, orange-fronted presence at the edge of the flowerbed. It is also a surprisingly aggressive one, and a star of one of the strangest lines of research in biology: how a bird can see magnetic north.
Overview
Erithacus rubecula ranges across Europe into western Siberia and northwest Africa. It is a small chat, brown with an orange-red face and breast in both sexes, feeding on worms and insects with berries in winter. British birds are largely resident; northern ones migrate.
A year-round fighter
Robins hold individual territories through the winter, which is why their thin, wistful song carries across bare December gardens. The red breast is a threat display, and a robin will attack a tuft of red feathers; territorial fights sometimes kill.
The magnetic sense
Robins are a leading model for magnetoreception. They appear to sense the Earth’s field through a light-driven chemical reaction in the eye involving cryptochrome proteins — a mechanism so delicate that faint radio-frequency noise switches it off.
Tame, and festive
British robins follow gardeners for turned-up worms, a habit borrowed from shadowing wild boar. Their Christmas-card fame comes from Victorian postmen, who wore red and were nicknamed “robins.”
Status
The European robin is Least Concern and stable to increasing, bouncing back quickly from hard winters. The unrelated American robin is a thrush that merely shares the name.
European Robin: common questions
How does a robin sense magnetic north?
The leading explanation is a light-dependent chemical compass in the eye. Molecules called cryptochromes in the retina absorb blue light and form a pair of radicals whose behaviour is subtly influenced by the direction of the surrounding magnetic field, and the bird is thought to perceive this as a pattern overlaid on its vision. Evidence for the model in robins is strong — the compass only works in certain wavelengths of light, it needs a brief adjustment period in the dark, and, tellingly, it is knocked out by extremely weak radio-frequency electromagnetic noise of the kind that should not affect a simple magnetic particle. Robins use the compass, alongside the stars and landmarks, to orient during their night-time migration.
Why are robins so tame in Britain but not elsewhere?
The favoured idea is that British robins have generalised a natural behaviour. In undisturbed woodland, robins follow large animals such as wild boar and deer that root up the soil, waiting to grab the worms and grubs exposed. In Britain, centuries of gardening and a long tradition of not persecuting robins seem to have let them transfer that behaviour to people, so a robin will perch a metre from a spade. On much of the European continent, where small birds were long trapped and shot for food, robins stayed shy and keep to the cover of woods, behaving as their ancestors did.
Are male and female robins different?
Not to look at. Both sexes have the same orange-red breast and face and the same brown back, and there is no reliable way to tell them apart in the field. This is unusual; in most songbirds the male is brighter. In robins, both sexes defend territories and both sing, so both benefit from carrying the signal. The one visible difference in the life cycle is the juvenile, which is heavily spotted and mottled gold and brown with no red at all, gaining the breast only when it moults into adult plumage in its first autumn.
Is the European robin related to the American robin?
No. The American robin is a thrush, in the same genus as the blackbird, and it is a much larger bird. Early English colonists in North America named it after the bird they missed from home simply because it also has a reddish breast. The European robin is a small member of the chat group, related to nightingales and redstarts. Australia and other regions have their own unrelated red-breasted birds also called robins, all named for the same superficial resemblance. The shared name reflects homesick naming, not kinship.