Toxicological Trivia from January 11, 2010: The Kingfisher "Alcedo atthis," also called "flying jewels", has been named Bird of the Year 2009 in Germany to call attention to the future of aquatic ecosystems, because:
a) Its colors make it a particularly beautiful bird;
b) It is considered a kind of thermometer to measure the health of the water (and pollution);
c) Another reason.

Correct Answer b. The assertion (a) also it is correct but not why it was nominated. Read more in previous article in Spanish: … We also need to Alcedo atthis
Own image of Kingfisher in Rosario