K is for Kingfisher

KINGFISHER (ALCEDO ATTHIS)

The kingfisher is undoubtedly one of Britain’s most beautiful birds. Though usually seen as a metallic blue flash as it whizzes away, this is enough to bring joy to a riverside walk.

The kingfisher’s glimmering plumage is unrivalled amongst British birds.  The contrasting glittering, deep blue-green upperside, orange chest and smart white dashes make this living jewel.  The silvery-turqouise back provides the distinctive gleam from behind. The secret to the kingfisher’s glowing colours is the way their  feather structure reflects light, known as ‘structural colour’, creating their metallic sheen. Without this effect, they would simply be dark brown¹!
Males and females can be told apart by their beak colour. Females have an orange lower jaw, whilst the male’s is completely black.

The kingfisher is fairly common on rivers, streams and lakes, though is rarely seen by most people. Its habit of perching in waterside trees obscures it from the banks and it is more easily seen from the water .  During my time in Worcester with the rowing club, I used to see several kingfishers with each practice, yet I only saw one from the banks.

Appearances aside, the kingfisher certainly lives up to its name with its predatory skill.  They hunt from a perch on a branch or stem(sometimes even a fisherman’s rod!), or sometimes by hovering, over the water.  Seeing into water presents challenges, but the kingfisher overcomes these with eyes which polarize light to neutralise the reflection of the surface, and the mental ability to calculate refraction effect (the bending of light through the water)¹.  Once focussed, the bird dives in like a harpoon up to 25cm deep, locates and grabs its quarry by touch, bobs to the surface and pushes off with its wings back to the perch all in a split second (See this stunning  slow-motion BBC footage of a kingfisher strike).  The kingfisher then bashes its prey against the perch to stun it into submission before swallowing it whole. Their main prey is, of course, small fish though shellfish such as small crustaceans, water beetles and insect larvae are also on the menu ².

Unsurprisingly for such a beautiful bird, the kingfisher has a history of human admiration.
The Ancient Greek Moon Goddess, Alcyone was believed to protect sailors from storms and to be responsible for the yearly resurrection of Zeus. When Zeus defied her power and killed her husband Ceyx at sea with a lightning bolt, Alcyone plunged into the water and the couple were turned into kingfishers. It is from their names that the scientific genus name ‘Alcedo’ derives³.

Alcyone could still control the sea in her feathered form. This gave us the poetic expression ‘Halcyon days’, applying to the real phenomenon of the calming of the Mediterranean sea during midwinter, when it was believed that the kingfisher bred on a floating nest made of fish bones³.

The kingfisher’s real nest is less romantic, but still an incredible feat. Like their relatives, the woodpeckers, kingfishers dig out a nest hole.  They choose a spot of soft exposed river bank, and then fly at it and literally ram it with their beak! Once they have created a hollow, the pair excavates a tunnel about 60–90 cm (24–36 in) long ending in a nest chamber, inclined upwards to protect the nest from rising water levels⁴.
 For such a beautiful bird, the nest is rather sordid, being lined with fish bones and pellets of other indigestible, hard parts of prey engorged by the adults and young ⁴(So at least the Greeks were partly right!). The offspring poo out into the chamber, creating a harsh smell which may deter predators.

Kingfishers are very fecund, producing 2-3 broods a year⁴. To support these families they must maintain a fishing territory, and fights are aggressive to the point of drowning one another!

In Britain, kingfishers were hunted by the Victorians to for ornamental stuffed birds and feather hat decorations, and later water pollution from industrial and agricultural waste caused further declines.  Fortunately, improved water quality means kingfishers are now recovering. Their greatest natural threat is freezing winters, when many migrate to saltier estuaries and coasts.

So next time you walk along a British river, look for this living jewel, perhaps even watch it fishing, and be grateful that this Goddess on the river is rising again.

References

1-BBC Nature (No date). Common Kingfisher. Available from: http://www.bbc.co.uk/nature/life/Common_Kingfisher

 2-Hilary Fry, Kathie Fry and  Alan Harris. (1999) Kingfishers, Bee-eaters and Rollers. London: Christopher Helm. Cited by Wikipedia (2013). Common Kingfisher. Available from: http://en.wikipedia.org/wiki/Common_Kingfisher

3- Fransesca Greenoak. (1979) All the Birds of the Air. A. Brown and Sons.

4-Jeannine Miesle and Avianweb. (No date) Common Kingfisher. Available from: http://www.avianweb.com/commonkingfishers.html