The merlin is a predominantly ground nesting falcon and the UK’s smallest bird of prey. Preferring upland and moorland areas for breeding the bird may venture in to lowland regions during the winter when it is joined by migrating merlins from Iceland.
Adult male merlins have a slate grey head and upperparts, including the tail, which is banded near its end by a broad black strip. The tip of the tail is white. The body is small but proportionate and the head is also small and almost square. The neck is buff as are the cheeks and there is a white striped area above the eye. The throat is also white. The male’s underparts are a buff orange with black streaks and the undertail coverts are a creamy white. The sides of the breast and the leg feathers have a pale rusty brown hue. The eyes are dark brown and the bill is grey and hooked with a dark tip. The area on the bill from the nostrils to the base also known as the cere, is yellow and the legs are pale orange with black talons. Adult female merlins are up to 30% larger than the adult male and overall are much darker in colour being dark brown above with cream underparts, heavily streaked with brown. The upper tail is marked with up to four or five creamy bands and there are pale edges to the flight feathers. Facial markings, eye colour and bill are similar to the male. The female’s legs are yellow. Juveniles resemble the female in plumage and patternation although often slightly darker overall.
Close up of a Merlin
Merlin in flight
Both birds vocalise with the female’s call being somewhat deeper than the male and with more nasal overtones similar to a repeated, ‘kee – kee – kee’. The male issues a shorter and more staccato ‘ki – ki – ki’.
Catching its prey on the wing the merlin feeds mainly on small birds but will take flying insects.
During the breeding season and throughout the summer merlins tend to restrict themselves to the open country of higher ground or uplands and moorlands in Scotland, Wales and northern England. During this period if ground nesting they are very elusive and difficult to spot. Merlins often perch overlooking their hunting grounds and are more likely to be seen starting their attack from a perched position as opposed to chancing upon a victim during normal flight. In the winter they move down to both coastal and lowland areas although seldom straying more than a hundred miles from their breeding grounds.
Small, compact and fast flying, the merlin has an average straight-line speed of around 50 kilometres per hour. It rarely dives in order to catch its prey preferring to travel very low to the ground using constant wingbeats with few glides but is also adept at fast turns and climbs.
Merlin in flight
Nests are usually ground scrapes in heather although old disused crows’ nests in trees are occasionally utilised instead. One brood is produced annually between April and June and consists of 3 – 6 smooth, pale buff coloured eggs with brown markings. Incubation lasts from twenty eight to thirty two days with fledging taking place between twenty five to thirty two days after hatching.
Nest and eggs of a Merlin
The average life expectancy for merlins is a maximum of ten years.
Eleonora’s falcons are polymorphic. That is to say they have two different plumage patterns and colours which are apparent within the single species. They are also monotypic indicating that there are no sub-species.
Frequently known as simply a peregrine, this magnificent bird, whilst not the fastest in level flight, can achieve incredible speeds in excess of 300 kilometres an hour when diving on to its prey, making it the fastest of any bird or animal in the world.