Kingfishers cough up pellets made of indigestible fish bones and scales etc. Here the pellet is in mid air to her left, just over the branch she is sitting on.
The colours are quite amazing and vary with the light - sometimes more blue , sometimes more green. This one in bright early morning sunlight has a greenish colour.
Compare the colour with this adult female - taken previously with the same camera from the same viewpoint but in different light.
Kingfishers are not common birds - there are only around 5000 pairs in the UK - but they are found on rivers, lakes and streams across most of lowland Great Britain.
The population can plummet in harsh winters but recovers quickly when conditions improve. Overall it is stable.
Listen to the BBC Radio 4 Tweet of the Day on kingfishers here. Read more about kingfishers on the BTO site here.