In medieval falconry the kestrel was reserved for the knave, reflecting its lowly status.
Country kestrels feed almost exclusively on small rodents (particularly voles), but those living in towns will take sparrows instead.
Though rodents may be the principal diet, they will also take a wide variety of other prey, including lizards, earthworms, large insects and even bats.
Vole numbers affect kestrel numbers: in good vole years more young kestrels are fledged.
Kestrels have remarkably keen eyesight even in extremely poor light, allowing them to hunt almost until dark.
Kestrels hunt from static perches and by hovering: the latter is far more productive, but uses lots of energy, which is why they hunt mainly from perches during the winter.
Hovering gives the kestrel its country name of windhover.
Kestrels aren’t as big as they look. An adult weighs on average a mere 220gm, less than half the weight of a red-legged partridge.
Our kestrel is one of a large group of similar species, found throughout much of the world, but it has the largest range, breeding through much of Europe, Africa and Asia.
Kestrels are Britain’s most widely distributed bird of prey, breeding throughout the mainland and on many offshore islands.
Kestrels rarely breed on Shetland: the most recent record was in 1905.
Their absence from Shetland may be explained by the absence of voles there.
Until recently kestrels were also our most numerous bird of prey, but the buzzard has taken over the No 1 slot.
Breeding kestrels like to use old crows’ nests, but they will also use holes in trees, nest boxes and cliff ledges.
Most kestrel nest failures occur during incubation; if eggs hatch, then it is most likely that some of the young will fledge.
Though not a colonial species, in years when there is an abundance of voles they will sometimes nest within a few metres of each other.
The lesser kestrel, which breeds in southern and eastern Europe, is a strictly colonial nester, often found in large colonies.
The world’s rarest species of kestrel lives on Mauritius, where it has come perilously close to extinction. There were just eight birds left in the wild 30 years ago, but the number is now close to 1,000.
Kestrels have been seen to rob sparrowhawks and both barn and short-eared owls of their prey.
The major cause of death among young kestrels is starvation: only 30-40% survive their first year.
The film Kes, about a young working-class boy training a kestrel, was made in 1969 but is still regarded as a classic.