River kingfisher: a small coloured arrow

The river kingfisher (Alcedo atthis) is one of the most colourful species of the Portuguese avifauna. The blue colouration of its back and wings and its orange belly make its appearance unmistakable. Its beauty makes this a preferred species among nature photographers in Portugal. But photographing such a small bird is not always easy.

This bird is often spotted perched on small poles and/or dry branches by the water, where it hunts. The river kingfisher can be seen throughout mainland Portugal, is abundant in coastal regions and flatlands and is seldom seen at altitudes above 1000 meters.

Alcedo atthis spreads throughout North Africa and Europe, except Iceland and the Scandinavian Peninsula. Eastern European populations are migratory and tend to spend the winter on the Iberian Peninsula, France and the West African coast, unlike Western European populations that are sedentary or have unsettling behaviours.

A large territory for such a small bird

Despite being only 18 centimetres long, the river kingfisher can cover a territory of up to one and a half kilometres of river. Known to be a solitary and very territorial bird, it strives to protect its spacious terrain seeking abundant food, safety and quality in its nesting site.

When fighting over territory, fights can be deadly. High-speed aerial chases, beak fights, and attempts to drown their opponents characterise the river kingfisher fights.

A pause in hostilities

The mating season of the kingfisher starts in April and ends at the end of July. During this period, hostilities between the sexes are limited. In order to mate, the male tends to offer a fresh fish to the female. A detail worth mentioning is the care how the male turns the fish head towards the female beak.

When fellow birds occupy contiguous territories, temporary territorial unification may occur. This bird’s nest is dug by both, usually near the bank of a river and usually in earth barriers or bank slopes. The nests consist of a tunnel of about 60 to 90 centimetres leading to a chamber where the eggs will be. Building a nest can take 14 days of the couple’s time.

River kingfishers strive to place the nest high enough to avoid occasional flooding. The excavation also includes the right sloping to prevent the eggs from rolling out of the nest.

Eggs are hatched three weeks after being laid. After birth, chicks remain in the nest for 3 to 4 weeks. During this period, both relatives hunt to feed their chicks and may take 50 to 70 fish everyday to the nest. As they do not ingest them, river kingfishers usually accumulate large amounts of fish bones in their nests.

Their litters produce about four eggs at a time and often raise three litters during the mating period. Given its prolific reproduction, the Red Book of Vertebrates of Portugal classified this species as Least Concern species regarding the risk of extinction.

Nevertheless, threats to river kingfishers have been growing as result of increase in water pollution and eventual contamination and reduction of their food resources. Tourism, hunting and sport fishing have also contributed to the disturbance of nesting and feeding areas for river kingfishers.

A cute little hunter

Despite its beauty, the river kingfisher is an excellent hunter. It can dive and return to its landing with a fish in its beak in two seconds. This bird dives at a speed of up to 40km/h. Its very precise aiming capacity allows this bird to catch fish more than half a meter deep, despite the translucent protective membrane covering its eyes underwater.

The river kingfisher feeds on small freshwater fish, aquatic insects, amphibians small crustaceans and freshwater crayfish, in particular.

Did you know that…

•  The River Kingfisher is nicknamed in over 25 different ways. Its designation varies from region to region: ditch-kite, lurking tides, little nun, river judge, river crosser, fish stinger,  small-river robin, and king-of-the-sea, are some examples.
•  We can identify the gender of the river kingfisher by the colour of its beak. The beak of males is mostly black, while females have an orange colour underside the beak. Nevertheless, the sexual dimorphism of the species is small, and the physical differences between males and females are considered very small.
•  During the hunting process, the river kingfisher dives and carries a fish in its beak to a landing site. Upon landing, this species usually knocks the fish against a surface to stun it.
• Unlike most birds, river kingfishers are somehow quiet and discreet during the spring.