Klaus Malling Olsen (KMO) is a free lance ornithologist, born in Copenhagen, Denmark in 1955. KMO has a special interest in identification of WP birds, and has since the 1970s travelled extensively, partly as tour guide. He is the author of the widely acclaimed "triology" Terns, Skuas and Gulls, of which both the book on Terns and Gulls were acknowledged as "Bird Book of the Year" by
 the British magazine Birdwatch. The extensive texts, made from years of studies in the entire Northern Hemisphere,  are accompagnied by plates by the young Swedish bird artist Hans Larsson. Other works includes the official Danish birdlist, the editing of a special Danish version of  Beaman & Madge "Handbook in bird identification" and the translation of the Collins guide (the field birder´s bible) into Danish.

 KMO have served as a member of the Danish Rarities Committee for a total of 14 years, and is on the editorial board of Dutch Birding. He has led bird identification lectures and workshops for more than 30 years, having an extense knowledge of bird feather details and jizz - all of which are combined in the lectures in Israel, a country he has visited 11 times. 

Apart from his passion for the family Laridae (Gulls and Terns), his other favourites include raptor identification and the birds of the Indian subcontinent.