The common kingfisher (Alcedo atthis), also known as the Eurasian kingfisher and river kingfisher, is a small kingfisher with seven subspecies recognized within its wide distribution across Eurasia and North Africa. It is resident in much of its range, but migrates from areas where rivers freeze in winter.

This sparrow-sized bird has the typical short-tailed, large-headed kingfisher profile; it has blue upperparts, orange underparts and a long bill. It feeds mainly on fish, caught by diving, and has special visual adaptations to enable it to see prey under water. The glossy white eggs are laid in a nest at the end of a burrow in a riverbank.

Taxonomy

The common kingfisher was first described by Carl Linnaeus in the 10th edition of his Systema Naturae in 1758 as Gracula atthis. The modern binomial name derives from the Latin ', 'kingfisher' (from Greek , '), and Atthis, a beautiful young woman of Lesbos, and favourite of Sappho.

The genus Alcedo comprises seven small kingfishers that all eat fish as part of their diet. The common kingfisher's closest relative is the cerulean kingfisher that has white underparts and is found in parts of Indonesia.

  • A. a. ispida <small>Linnaeus, 1758</small>. Breeds from Ireland, Spain and southern Norway to Romania and western Russia and winters south to Iraq and southern Portugal.
  • A. a. atthis. Breeds from northwestern Africa and southern Italy east to Afghanistan, Kashmir region, northern Xinjiang, and Siberia; it is a winter visitor south to Israel, northeastern Sudan, Yemen, Oman and Pakistan. Compared to A. a. ispida, it has a greener crown, paler underparts and is slightly larger.
  • A. a. bengalensis <small>Gmelin, 1788</small>. Breeds in southern and eastern Asia from India to Indonesia, China, Korea, Japan and eastern Mongolia; winters south to Indonesia and the Philippines. It is smaller and brighter than the European races.
  • A. a. taprobana <small>Kleinschmidt, 1894</small>. Resident breeder in Sri Lanka and southern India. Its upperparts are bright blue, not green-blue; it is the same size as A. a. bengalensis.
  • A. a. floresiana <small>Sharpe, 1892</small>. Resident breeder from Bali to Timor. Like A. a. taprobana, but the blues are darker and the ear-patch is rufous with a few blue feathers.
  • A. a. hispidoides <small>Lesson, 1837</small>. Resident breeder from Sulawesi to New Guinea and the islands of the western Pacific Ocean. Plumage colours are deeper than in A. a. floresiana, the blue on the hind neck and rump is purple-tinged and the ear-patch is blue.
  • A. a. solomonensis <small>Rothschild and Hartert, 1905</small>. Resident breeder in the Solomon Islands east to San Cristobal. The largest southeast Asian subspecies, it has a blue ear-patch and is more purple-tinged than A. a. hispidoides, with which it interbreeds.

Habitat and distribution

The common kingfisher is widely distributed over Europe, Asia, and North Africa, mainly south of 60°N. It is a common breeding species over much of its vast Eurasian range, but in North Africa it is mainly a winter visitor, although it is a scarce breeding resident in coastal Morocco and Tunisia. In temperate regions, this kingfisher inhabits clear, slow-flowing streams and rivers, and lakes with well-vegetated banks. It frequents scrubs and bushes with overhanging branches close to shallow open water in which it hunts. In winter it is more coastal, often feeding in estuaries or harbours and along rocky seashores. Tropical populations are found by slow-flowing rivers, in mangrove creeks and in swamps like in Bangladesh. Measures to improve water flow can disrupt this habitat, and in particular, the replacement of natural banks by artificial confinement greatly reduces the populations of fish, amphibians and aquatic reptiles, and waterside birds are lost. It can tolerate a certain degree of urbanisation, provided the water remains clean.

This species is resident in areas where the climate is mild year-round, but must migrate after breeding from regions with prolonged freezing conditions in winter. Most birds winter within the southern parts of the breeding range, but smaller numbers cross the Mediterranean into Africa or travel over the mountains of Malaysia into Southeast Asia. Kingfishers migrate mainly at night, and some Siberian breeders must travel at least between the breeding sites and the wintering areas. The oldest bird on record was 21 years.

Other causes of death are cats, rats, collisions with vehicles and windows, and human disturbance of nesting birds, including riverbank works with heavy machinery. Since kingfishers are high up in the food chain, they are vulnerable to build-up of chemicals, and river pollution by industrial and agricultural products excludes the birds from many stretches of otherwise suitable rivers that would be habitats. Minnows, sticklebacks, small roach and trout are typical prey. About 60% of food items are fish, but this kingfisher also catches aquatic insects such as dragonfly larvae and water beetles, and, in winter, crustaceans including freshwater shrimps. In Central Europe, however, fish represented 99.9% of the diet (data from rivers, streams, and reservoirs from years 1999 to 2013). One study found that food provisioning rate increased with brood size, from 1498 g (505 fishes for four nestlings) to 2968 g (894 fishes for eight nestlings). During the fledging period each chick consumed on average 334 g of fish, which resulted in an estimated daily food intake of 37% of the chick's body mass (average over the entire nestling period). The average daily energy intake was 73.5 kJ per chick (i.e., 1837 kJ per 25 days of the fledging period).

A challenge for any diving bird is the change in refraction between air and water. The eyes of many birds have two foveae (the fovea is the area of the retina with the greatest density of light receptors),

Each cone cell of a bird's retina contains an oil droplet that may contain carotenoid pigments. These droplets enhance color vision and reduce glare. Aquatic kingfishers have high numbers of red pigments in their oil droplets; the reason red droplets predominate is not understood, but the droplets may help with the glare or the dispersion of light from particulate matter in the water.

Further reading

  • Photos, audio and video of common kingfisher from Cornell Lab of Ornithology's Macaulay Library
  • Ageing and sexing (PDF; 5.3 MB) by Javier Blasco-Zumeta & Gerd-Michael Heinze