The falcon family (Falconidae) includes about 60 different species, distributed almost worldwide. The merlins have been classified into ten or eleven subspecies with a Holarctic circumpolar distribution in boreal and subarctic areas. The merlin subspecies which can be seen on the Faroe Islands, both as a breeding bird and as a migratory bird, is called Falco columbarius subaesalon in Latin, and it also breeds in Iceland and Scotland. In particular it is the long wings of the birds of this subspecies that distinguishes them from the aesalon subspecies which breeds in northern Scandinavia and onwards into Siberia.
Appearance:
The merlin is the smallest of the European species of falcon. Its length is between 25 and 30 cm, and it has a wingspan of 50 to 60 cm. The male and female merlins are very different. The male has a greyish blue back and is rusty brown underneath with distinctive lateral stripes. The back of the female is dark brown and the underside is a pale yellowish brown with distinctive dark brown lateral stripes. The juveniles look like the females until early spring the following year, when they start moulting for the adult plumage, and the greyish blue feathers break through on the backs of the young males. The average weight of the females is 210 g, which means that they are slightly larger and heavier than the males which weigh 50 g less on average.
Distribution and migration:
Today between 25 and 50 merlin pairs breed on the Faroe Islands. The population is now increasing after a steep decline in the middle of the last century. One of the reasons for their current increase is probably the relatively mild winters when many starlings and sparrows do well and thereby provide a good basic diet for the merlins. It is not known for certain, but it is presumed that at least part of the Faroese population consists of non-migratory birds. The Icelandic population totals between 1000 and 2000 pairs, most of which are migratory birds. Many of them pass the Faroe Islands in both spring and autumn when they are on their way to their winter habitats in Ireland, Scotland, England and northern France. This means that some of the merlins staying on the Faroe Islands in winter are probably Icelandic. Only the northernmost merlins are migratory birds, and this is for the simple reason that the small birds, which are their prey, migrate to the south in the autumn, thereby forcing the merlins to follow.
Food:
The merlin mostly hunts in open areas where its tactics are high-speed surprise attacks. Most birds are caught on the ground or close to the ground. What makes the merlin the perfect hunter is its sight in particular, as its retina has approximately 1 million visual cells per mm2. In comparison, humans only have around 100,000 per mm2. On the Faroe Islands the prey is often species such as starlings, sparrows, meadow pipits, rock pipits and wheatears, but also waders such as golden plovers and snipes feature on the menu. It is astonishing that the merlin can take a bird as large as the golden plover which weighs about the same as the merlin itself.
Breeding biology:
The merlins select a territory of a certain size depending on the availability of food in the area. In a large area in Iceland the territories of the merlins are around 35 km2. The merlin prefers to breed on inaccessible steep mountainsides, but it does not build its own nest. If it can find an old crow’s or raven’s nest in a suitable location, it will happily take it over. But it can also lay its eggs directly on the bare rock ledge without any sort of nest. The merlins usually start laying their eggs in May, and they often lay four eggs, although nests with between three and six eggs also have been seen. The eggs are approximately 40 mm long and relatively round. They are reddish brown with closely spaced darker dots. The brooding time is approximately four weeks, and the chicks are fledged in just under four weeks.
When the eggs have hatched only the male hunts, and often he also plucks his prey in a particular spot close to the nest with the chicks before handing it over to the female. The female tears the prey into suitable chunks before feeding it to the chicks.
Miscellaneous:
The Faroese name for merlin is smyril and this name is often seen in everyday life on the Faroe Islands. A shipping company is called Smyril Line, and the large ferry to Suðuroy is called “Smyril”.
The merlin is also included in the “Fuglakvæðið” (“Bird Poem”) which has 229 stanzas and was written by Nólsoyar Páll (Páll of Nólsoy) in the early 19th century. A saying, which is still used today, when for example a group of children are playing together well, and a troublemaker suddenly intrudes and destroys the peace and quiet, goes: “Now the smyril came into the flock of starlings”.
