WILDLIFE – THE MERLIN

The UK’s smallest bird of prey, this compact, dashing falcon has a relatively square-cut tail and rather broad-based pointed wings, shorter than those of other falcons. Its wingbeat tends to be rapid with occasional glides, wings held close to the body. Male merlins are blue-grey above, with a grey head and orangey-cream underparts that are streaked in black. Females are mainly grey-brown, with dark streaking underneath. Merlins have blunt tails and compact, broad-based wings that are pointed at the tip. Juvenile merlins look similar to adult females but have darker brown upper parts, grey-brown eyes, and greenish legs and feet.

The Merlin is the smallest European falcon.

Females are significantly larger than males and this size difference brings an advantage in that a breeding pair can prey on a broader range of species than if both male and females were the same size . Their diet consists of small birds, such as Meadow Pipits and Skylarks. Prey is caught by surprise attack from a low gliding flight close to the ground, by persistence pursuit or from a vertical dive.

Merlins breed between May and June. They are solitary nesters and typically monogamous and produce one brood per season. If clutches are lost, they will often lay a replacement. Usually, merlins nest in trees in the old stick nests of corvid, but will also use cavities in trees, and cliff ledges. However, in the UK most merlins nest on the ground, which is unique to the UK population, although since the 1970s they have started to nest in conifer trees. The female builds the nest which is a shallow scrape in the ground lined with twigs, heather, and other plant matter.

In North America merlins used to be known as ‘pigeon hawks’, not because they prey on pigeons, but because in flight they look somewhat pigeon-like. Their species name, columbarius, is also a reference to pigeons.

Merlins lay 3-6 white or pale buff eggs marked with reddish-brown spots which are incubated for 28-32 days mainly by the female. She also defends the nest, while the male brings her food. Chicks are covered in brown and white down and are fed by both parents. They fledge at 28-32 days but if hatched on the ground will leave the nest earlier at about 18-20 days and hide in nearby undergrowth away from predators. At this stage they can catch insects but rely on their parents for food for another 5 weeks. Female merlins reach sexual maturity at a year, and males at 2 years.

In winter, the UK population increases as most of the Icelandic breeding birds migrate to our warmer climate. Merlins can be seen in the UK all year round. In breeding season they can be found in the uplands of Scotland, Wales, and northern England on moorland but also in conifer plantations. In winter they are joined by birds from Northern Europe and move to lowland areas as far as south-west England. Look out for them in reed beds, boggy areas, salt marshes, farmland, and heathland.

The oldest known Merlin was a male and at least 11 years, 11 months old.

Due to their small size, Merlins are susceptible to predation from other birds of prey and corvids and as a result are often seen dive bombing larger birds in an attempt to drive them away from their nesting areas. Although recovering from a population crash in the late 20th century, it is on the Red List. It is a Schedule 1 listed species on The Wildlife and Countryside Act.