The Common kingfisher is amongst the most colorful birds and has beautiful brilliant plumage, though, despite its extraordinary colors, sometimes it is difficult to see when it is in dappled shade, and its colors are also not very obvious in flight. Furthermore, its shy nature means that it is not often seen. Its upperparts are bright blue and its underparts a rich chestnut-red. Male and female are generally similar but the females have a bill with a red base, whereas males have one that is completely black. Juveniles are similar in appearance but have duller, greener plumage.
The Common kingfisher occurs throughout Europe and in Asia as far to the east as Japan, and south of the Sahara in Africa. Common kingfishers live year round in the south, while northern populations fly south in winter away from the freezing water. They are found in wetlands and on the shores streams, ponds and lakes. They have been known to seek prey from brackish waters, especially in winter when bodies of water are generally frozen.
As with all kingfishers, the Common kingfisher is very territorial, mainly because each day is has to eat about 60% of its body weight. They even defend their territory against their mates and offspring. Individuals are solitary for most of the year, roosting in heavy cover beside their favorite hunting spot. When another kingfisher comes into its territory, the birds will both sit on a perch at some distance from one another and perform territorial displays, usually the display of beaks and plumage. Fights occasionally occur, one bird grabbing the other one’s beak and trying to hold their opponent under water. Their flight is very fast, causing their wings to seem like a blue haze. These birds communicate vocally and are well known for a long, trilling call like a repetition of the sound “chee”. During mating, a male whistles loudly to a female and will chase her through and above the trees. When diving for prey, their eyes are covered by a membrane and they rely on touch alone to know when they should snap their jaws shut.
There birds are serially monogamous and seek a new mate every year. They nest on their own. The female is given food by the male before copulation, usually a fish. 2-3 clutches of eggs are laid yearly, in April, and another by July, with sometimes, a third in early October. Nests are on sandy banks along streams. Sometimes they use a hole in a wall or a rotten tree stump, or a termite mound, where they dig a tunnel and at the end create a nest chamber. Both male and female work to excavate 50 to 90 cm long burrow, taking turns. 6 to 7 white eggs are laid and incubation lasts around 19 to 21 days, done by both parents. Usually, the female does the brooding at night and both male and female do it during the day. Young are given food by both their parents and they fledge at about 23-24 days, sometimes more. Four days later they make their first dive. Very soon they become independent and leave the territory where they were born.
The Common kingfisher in most parts of its range, is indeed common, but it is under threat from river pollution, disturbances and human developments. It is also vulnerable to bouts of severe winter weather, as it is unable to feed when bodies of water freeze over.
According to IUCN’s Red List, the global population of the Common kingfisher is around 700,000-1,399,999 mature individuals. Estimates for national populations include: in China, about 10,000-100,000 breeding pairs and 50-10,000 individuals on migration; in Taiwan, 10,000-100,000 breeding pairs; in Korea, 100-10,000 breeding pairs, with 50-1,000 individuals on migration; in Japan, 10,000-100,000 breeding pairs with 50-1,000 individuals on migration, and in Russia, 100-100,000 breeding pairs with 50-10,000 individuals on migration. The European population is estimated at 97,500-167,000 pairs, which equates to 195,000-334,000 mature individuals. Overall, currently Common kingfishers are classified as Least Concern (LC) on the IUCN Red List.
Common kingfishers serve as a good indicator of the health of an ecosystem. As they feed on small aquatic animals, toxins in the water affect them severely. A strong kingfisher population therefore usually means a healthy habitat. Common kingfishers are also important predators throughout their range of small fish from freshwater habitats, thus controlling their populations.