1 Rouble Rose-colored gull

Issued as part of Russia's ongoing Red Book series — a program launched in 1993 to commemorate species listed in the Russian Federation's endangered species register — this rouble corresponds to the Rosy Tern (Rhodostethia rosea), a small arctic gull whose breeding range is so restricted and poorly documented that its total world population remained uncertain well into the 2000s. The species was first scientifically described from a specimen collected during William Edward Parry's 1821–23 Arctic expedition, and for decades naturalists debated whether confirmed breeding colonies even existed.