Most locals know there are ptarmigan on the Kenai Peninsula. If you spend any time in the high country, you're bound to run into these birds at some point while tramping around. About this time of year, some ptarmigan will migrate down to the lowlands, showing up in odd places like Ski Hill Road or along the Soldotna airport fence. But a friend of mine, who I skied with through Crescent Lake recently, was unaware that there are three ptarmigan species on the Kenai despite the fact that he grew up here. And that got me thinking there might be a story here.
The Kenai Mountains are one of the few places in North America where all three ptarmigan species can be found living together. Willow and Rock Ptarmigan are circumpolar in their distributions, found throughout Alaska, and across Canada, Scandinavia and much of northern Eurasia. White-tailed ptarmigan, on the other hand, are restricted to North America, specifically southcentral and southeast Alaska, with discrete populations found in parts of the Rocky Mountains as far south as New Mexico.
Where all three species co-occur, they tend to separate themselves by habitats that occur at different elevations. White-tailed Ptarmigan prefer drier habitats at the highest elevations dominated by lichens, rock and dwarf shrubs, while Rock Ptarmigan are more common at slightly lower elevations in meadows with grasses, sedges and scattered woody shrubs. Willow Ptarmigan tend to nest in areas with dense, woody shrubs in the subalpine zone when in the mountains. Elsewhere in Alaska, it is common on the tundra. A strange fact about Willow Ptarmigan is that, unlike other game birds, the male sticks around to help raise its brood.
All three species are varying degrees of brown, white and black in the summer. This time of year, Willow Ptarmigan are white with a black tail, Rocks are similarly colored but smaller and with a black line from the bill through the eye, and the White-tailed is completely white and the smallest of the three species; in fact, it is the smallest member of the grouse family. In the winter, true to its name, Willow Ptarmigan (which, by the way, is our State Bird) eat mostly willow buds and twigs. Rock Ptarmigan eat mostly birch, and White-tailed tend to eat both willow and birch.
Both Willow and Rock Ptarmigan will migrate to lower elevations and southward in the winter, but White-tailed ptarmigan tough it out on their mountain peaks. I've always wanted to see the Willow Ptarmigan migration in Anaktuvuk Pass in the Brooks Range, an ecological phenomenon in which as many as 50,000 birds fly and walk through the pass in October and again in May.
Ptarmigan are well known for roosting under snow while being able to walk on top of it due to the feathers that grow around their toes in winter. Peter Kalifornsky told a Dena'ina story about how to choose the proper webbing for snowshoes based on the beak size of three birds. Mesh the size of a Raven's beak is for hill-sides; the Gray Jay's is for general use; and the Spruce Grouse's is for fluffy snow. Although the ptarmigan is part of this discussion among birds, it doesn't get to weigh in with its bill size, presumably because it already comes equipped with their own snowshoes. In fact, the scientific name for ptarmigan is lagopus, which is Greek for "foot of the hare", in deference to its ability to walk on snow like a Snowshoe Hare.
Dr. E. Otto Hohn, a University of Alberta physiologist, actually took the time to measure ptarmigan feet. Their claws are 30 percent longer in winter, but that contributes little additional surface area. The foot feathers, however, increase the weight bearing surface by 4 times, and reduces sinking of the foot in snow by 50 percent. These feathers presumably insulate the feet as well in the winter.
Are there any conservation concerns? As the climate warms, there is concern that ptarmigan habitat will shrink, particularly in areas like the Kenai where all three species are competing for space. Dr. Roman Dial and his colleagues have estimated that treeline has risen 50 meters in the past 50 years in the Kenai Mountains. This may not sound like a lot, but our ballpark estimate of alpine habitat lost on the peninsula is about 300,000 acres!
Additionally, as treeline rises, the distributions of these species essentially get compressed along the elevational gradient. One of the potential outcomes is genetic mixing. A Swedish study recently found that Willow and Rock Ptarmigan do hybridize, and the authors concluded that this will likely occur more frequently as the climate warms.
The White-tailed Ptarmigan is sort of a poster child for wildlife that will likely be affected by a rapidly changing climate. Unlike most wildlife which may migrate upward in elevation or northward in latitude in response to higher temperatures, White-tailed Ptarmigan simply run out of habitat, a situation analogous to polar bears on the northern extreme of the continent. White-tailed Ptarmigan populations in the Lower 48 are considered highly vulnerable to local extinction.
Fortunately, here on the Kenai, ptarmigan are still so common that hunters can shoot up to 10 per day during the hunting season. But we should start being more attentive to the status of their populations. The unintended loss of a species from the Kenai would be a loss indeed.
John Morton is the Supervisory Fish & Wildlife Biologist at the Kenai National Wildlife Refuge. For more detailed information about the refuge, you can check the refuge website at http://kenai.fws.gov or on Facebook at http://www.facebook.com/kenainationalwildliferefuge.
© 2017. All Rights Reserved. | Contact Us