Willow Ptarmigan - Taxonomy and Systematics

Taxonomy and Systematics

The Willow Ptarmigan's scientific name, Lagopus lagopus is derived from Ancient Greek lagos (λαγως) "hare" + pous (πους) "foot", in reference to the bird's feathered feet which allow it to negotiate frozen ground (see also Snowshoe Hare).

Depending on the author, some 10-20 subspecies of the Willow Ptarmigan are recognized. Most differ little in appearance, though as noted above, L. l. scoticus is rather distinct. Some commonly-accepted subspecies are:

• L. l. lagopus – Scandinavian Willow Ptarmigan
• L. l. scoticus – Red Grouse
• L. l. alascensis – Alaskan Willow Ptarmigan
• L. l. variegatus – Trondheimsfjord Willow Ptarmigan

• Adult female in summer plumage, Trollheimen (Norway)

• Adult female in summer plumage, near Saranpaul in the northeast Urals (Beryozovsky District, Khanty-Mansi Autonomous Okrug, Russia)

• Adult male L. l. alascensis in autumn plumage, Lake Clark National Park (Alaska, USA)

• Adult female in winter plumage near Tromsø (Norway)

• Willow ptarmigan chicks, Denali National Park and Preserve (Alaska, USA)

• Adult male in summer plumage, Denali National Park and Preserve (Alaska, USA)

During the Pleistocene, the species widely occurred in continental Europe. Authors who recognize paleosubspecies have named the Pleistocene Willow Ptarmigan L. l. noaillensis (though the older name medius might be the correct one). These marginally different birds gradually changed from the earlier (Pliocene) Lagopus atavus into the present-day species. Pleistocene Willow Ptarmigan are recorded from diverse sites until the end of the Vistulian glaciation about 10,000 years ago, when the species, by then all but identical from the living birds, retreated northwards like its tundra habitat.