Toporkov Island in the Commander Islands archipelago is inhabited not only by tufted puffins – the brightly colored birds with orange beaks that give the island its name – but also by pigeon guillemots. These relatives of the murre share the same nesting grounds but exhibit distinct physical characteristics and behaviors.
During the breeding season, pigeon guillemots develop solid black plumage marked by prominent white wing patches, accompanied by bright red beaks and feet. In the winter months, their appearance transitions to a pale ash-gray coloration.
The geological structure of Toporkov Island provides optimal nesting conditions for the species. While tufted puffins excavate burrows in the soil, pigeon guillemots utilize deep crevices in the rocks and the empty spaces beneath large boulders. These narrow stone corridors offer protection for their typical clutches of one to two eggs against predatory gulls and harsh weather conditions.
The species communicates using a distinct, high-pitched whistling sound. This piercing vocalization is highly recognizable and carries clearly over the ambient noise of the surrounding bird colonies.
Toporkov is the third-largest of the four islands in the Commander archipelago. The landmass is roughly circular, measuring slightly less than one kilometer in diameter with a surface area of approximately 0.21 square kilometers, excluding the adjacent rocky shoals.
As a designated section of the Commander Islands National Park, the island serves as a major avian breeding site. The total bird population on the island is estimated at 50,000 individuals, consisting primarily of tufted puffins, gulls, and cormorants.