The Black-throated Loon (Gavia arctica) is the signature bird of Sweden's clear forest lakes, a large and striking waterbird measuring 58–73 cm long with a wingspan of 110–130 cm and a weight of 1.3–3.4 kg. In summer plumage it has a black head with a velvety grey nape, black-and-white barred patches on the neck, and a black back marked with clean, square white spots; in winter the upperside turns grey-black and the underside white, with a sharp border running along the side of the neck. Its straight, strong bill is held horizontally in flight and at rest, which distinguishes it from the smaller Red-throated Loon.
The species breeds on clear lakes across northern and central Sweden, concentrated in the forest country of Norrland and Svealand, with a population of 5,000–7,000 pairs; it arrives in April and leaves in September–October to winter along Western European coasts and in the Baltic. It favours clear, nutrient-poor lakes with good fish stocks, since it needs clean water to see and pursue prey underwater — diving to depths of 3–10 metres for perch, roach, smelt and other small fish — and it also requires a long stretch of open water to take off, its heavy body demanding a long running start. The nest is placed right at the water's edge on an islet or shore, since the bird is clumsy on land and needs to slip straight into the water; a pair lays two eggs, incubated for 28–30 days. Its long, drawn-out, eerily melancholic call — rendered "aa-oo-loo-ii" — together with resonant, cackling "klo-klo-klo" series, carries far across still forest lakes and is one of the most evocative sounds of the northern wilderness, though the species is highly sensitive to disturbance and a distance of at least 150 metres should be kept from breeding pairs.
Read about this species in Swedish →