Hybrid between Black grouse and Willow ptarmigan (Yrurus tetrix x lagopus lagopus) illustrated by the von Wright brothers.… https://www.rawpixel.com/image/325969/free-illustration-image-von-wright-brothers-grouse-vintageFree Image from public domain licenseHybrid between Black grouse and Willow ptarmigan (Yrurus tetrix x lagopus lagopus) illustrated by the von Wright brothers.… https://www.rawpixel.com/image/326328/premium-illustration-psd-america-ancient-animalView license