The Tiny yet Tenacious Merlin

The Merlin, or pidgeon hawk, Falco Columbarius, falco meaning falcon and columbarius meaning dove, is one of the smallest birds of prey to be found in the British isles, similar in size to the Kestrel. It is also one of the fastest and most agile, flying very low to the ground at high speeds jinking and banking as it chases after its prey.

Tiny but tenacious

Adult merlin are only 30 to 40cm long with a wingspan of 70 to 80cm and weigh just 150 to 300 grams, but despite their tiny size they are fierce and tenacious predators that will hunt down any small birds they can find, they will also catch mice, voles, insects such as beetles and even snatch dragonflies mid-flight!. Occasionally a Merlin will try to catch bigger prey like Grouse and Woodpigeons, they are nothing if not brave!

As with other birds of prey, such as the Peregrine, male Merlin are smaller than the female, hardly bigger than a Blackbird. They have blue/grey upperparts with black tips to the tail and wings, the female is a light brown above with streaks on her belly.

In the British isles the Merlin’s habitats are upland areas, heather moorland and blanket bogs, in winter our native birds are joined by migrants from Iceland and Scandinavia, and in very cold winters they will travel, alongside other upland birds of prey, like the Short-eared owl, down to lowland fields, estuaries and coastal areas.

speedy and manoeuvrable

Merlin rely upon their speed and manoeuvrability to capture prey in flight, but will occasionally stoop in a way similar to a Peregrine, they will sit on an elevated perch like a fence post or tree stump, and keep vigil for hours, they have even been recorded using sheep as look out posts!.

When prey is spotted it will make a high-speed attack, flying low from the perch to take its victim unawares, If its prey spots it a long chase may ensue. I’ve seen optimistic Merlin attempt to catch Swallows and despite their speed and agility their prey will often elude it during these high-speed chases. A pair of Merlin will sometimes tag-team a bird as well, cooperating to increase their chances of catching their dinner.

Breeding

Breeding season starts around April, with the male, called a tiercel, arriving first and setting up a territory, making short flights from perch to perch around the bounds of this area repeatedly calling with a chattering kind of call, before pairing up with a female. The female will lay a clutch of around 5 eggs in a shallow nest in grasses or heather, preferring areas with low vegetation and a wide field of view, they incubate the eggs for around a month, the young fledging a month later.

The male will feed the female and the chicks on the nest until they are old enough for them to leave, at which point both parents will hunt to feed the brood, they can both be very defensive of the nest at this time and will drive away intruders by diving and attacking them, screeching until they leave.

Disturbance during the nesting season is one of the main threats to their population in the British isles, along with competition from other birds of prey and habitat loss, but overall their numbers are increasing. On our fells and moors here in the Northwest they are doing very well, especially on the mix of Grouse moors and upland sheep pastures that dominate much of the landscape.

Dichlorodiphenyltrichloroethane

As with many other birds of prey the British Merlin population suffered a catastrophic hit in the 50s and 60s as a result of accumulations of DDT pesticides which stopped them from breeding successfully. DDT stands for Dichlorodiphenyltrichloroethane and is an insecticide still used in some parts of the world but banned in most of it including Europe and America, it is the insecticide Rachel Carson mentioned in her book ‘Silent Spring’ published in 1962.

Trace amounts are still found in samples taken from agricultural areas now, as in the 50s and 60s it was regarded as a miracle cure-all and used in ridiculously huge quantities, though one of the main reasons it was banned was not for ecological reasons but because it was suspected to cause breast cancer in humans.

Numbers of Merlin have recovered since, and with the excellent habitat management and restoration work that landowners, farmers, conservationists and keepers are currently carrying out here this diminutive but fierce bird of prey should have a very good future.

A B-H