All footage is produced and owned by Kas Koenraads and Arnold van den Burg or permitted to use from the legacy of photographer and owner Eddy Kuis, unless specified otherwise below.

Mark Zekhuis (Saxifraga) – photo: Eurasian otter spraint

Mark Zekhuis (Saxifraga) – photo: pine marten looking outside from tree cavity

Mark Zekhuis (Saxifraga) – photo: pine marten hanging on tree stem, just before entering tree cavity

Rick Middelbos – photo: European adder sunbathing in curled position

Rick Middelbos – video: European adder swallowing frog as prey

Scottish Owl Centre – photos Snowy owl in snow habitat & Pharaoh eagle-owl

Niels de Nijs – photos Rock ptarmigan & Little auck

Joachim Menzel – photo Glaucous gull