15/07/2015
Share 

British Tawny Owls evolve

e654d420-8b96-486e-90da-780c8094309e
British Tawny Owls appear to be developing white patches in their plumage, as well as increasingly calling during the day – are we seeing a new subspecies evolve? Photo: Steve Young (www.birdsonfilm.com).
British Tawny Owls appear to be developing white patches in their plumage, as well as increasingly calling during the day – are we seeing a new subspecies evolve? Photo: Steve Young (www.birdsonfilm.com).

 


A preliminary examination of museum Tawny Owl skins has produced evidence that we may have a new subspecies evolving in our midst.

Britain has been separated from Europe for about 8,500 years, enabling several unique endemic forms to evolve, including an endemic species, Scottish Crossbill. According to a recently published paper, this has also been enough time for Tawny Owl to begin a prolonged separation from its Continental cousins.

The species is virtually sedentary, rarely wandering more than five miles from its birthplace, and this seems to have enabled it to develop a plumage with prominent white patches among both rufous and grey morphs in Britain. Add to this the recently documented habit of regular daylight calling, known almost exclusively from Britain, and it looks like a unique form is evolving in real time.

The authors speculate that the white patches enable communication, particularly among rufous-morph birds, and this coloration appears to be increasing rapidly.

Reference
Martin, J R, and Mikkola, H. 2014. The changing face of Britain's Tawny OwlsBritish Wildlife 25: 391-399.

 

Content continues after advertisements