The BR (Bayerischer Rundfunk) produced a movie about Vipera berus in Bavaria. It is in German language, but the documentary is well worth seeing even if you might not get every word (I had some problems with the very Bavarian parts as well ). The footage includes beautiful and rare pictures of adders giving birth, during ritual fights, as well as juveniles luring their prey by moving their tails (!).
It is online for 6 more days, so hurry up:
http://www.br.de/mediathek/video/video/ ... n-100.html
Cheers,
Laura