While we were watching she was attacked by a sparrowhawk. She fled across the lake, squeaking loudly and flying very low just above the water. She wasn't able to outfly the sparrowhawk and had to dive into the water to cause it to overshoot. It was a near escape but she immediately flew back to the perch by the hide to get her breath back. Within a few minutes she was back fishing for sticklebacks.
The photos above are all of the same bird on the same day and you can see the variation in colour, particularly of the green/blue on the head and back, depending on the intensity and angle of the light. The photo below is of a young male taken last month with the sun directly behind me and so full on the bird.
In fact the kingfisher's feathers contain no blue or green pigment. Their colour is produced by a phenomenon known as semi-iridescence - you can read more about it here and here.
The kingfisher is Alcedo atthis, alcedo from the Greek ἀλκυών meaning halcyon, a bird of ancient legend which was said to nest on the sea in midwinter, thereby calming the waters.
Thomas Bewick, in A History of British Birds (1832), described it as a "splendid little bird of rather clumsy shape, the head being large in proportion to the body, and the legs and feet very small".
The UK population is about 5000 pairs in summer. Numbers fluctuate depending on the weather and fall significantly after a cold winter.
The kingfisher often announces its arrival with a shrill piping call which you can hear here. Listen to the BBC Radio 4 Tweet of the Day on kingfisher here.