The rock ptarmigan is a circumpolar chicken-like bird found in Alaska, Sweden, Iceland, Greenland, Canada, and Russia. It is commonly found in the Arctic circle or around the North pole. In may also be found further south in Japan. It measures up to 12 to 16 inches and weighs 450-650 grams. It belongs to the grouse family.
Rock ptarmigan inhabit elevated, rocky slopes, open tundra, and edges of forests. Females and chicks like to stay hidden away in the bushes. Males prefer to stay in open barren areas. This helps them keep watch for predators and other ptarmigans.
Fully grown-up ptarmigans feed on flowers, berries, leaves, buds, twigs and other vegetations. However, insects are the major source of food for ptarmigan.
Rock ptarmigan is a popular game bird in Canada’s two most easterly provinces Labrador and Newfoundland. It is an important source of food in Iceland. But because of strict hunting restrictions during the off-season, rock ptarmigans are still in large numbers in the wild.
Rock ptarmigans molt at least twice a year and change the colors of their plumage when they do so. During the summer, they sport a spotted brown color, though males delay the shedding of their white plumage compared to females. They do so to be easily spotted by the females in the brown surroundings of the tundra. But this helps the predators to spot them.
It’s very difficult to spot the females even from close distances in the summer months. When they are incubating the eggs in the nest, the plumage color is so much similar to the brown surrounding that it is not possible to sport them.
In the winter, both male and female rock ptarmigans don a pure white coat, shedding their brown summer plumage. Males have a distinct red comb near their eyes.
Eggs & incubation
Females lay 3 – 10 eggs and incubate them for nearly 3 weeks. The male leaves the female, eggs, and nest sometime during the incubation while the female completes the raising of the chicks alone. The chicks get fledging or the feathers in about 10 – 12 days.
Male, female plumage
Females have brown-grayish plumage while males have a grey back and white bellies. Males have ornamental red comb near their eyes that they can expose or retract at will. Both male and female have a black line near the eyes that acts like sunglasses and reduce solar radiation
They have a short, dark bill, square-shaped, short tail, and thick body. Their legs and feet are covered with feathers that help them walk on the snow and maintain body heat in the winter.
Though rock ptarmigan can fly, they spend most of their time on the ground occasionally flying short distances, mostly to find food.
Their natural enemies are arctic foxes, arctic skuas, ermines, golden eagles, glaucous gulls, and snowy owls.
In the US, they are called snow chickens, in Japan thunderbirds, in Gaelic croakers, and Greek hare feet.
Mating & breeding
Rock ptarmigan’s mating season takes place in the spring and males delay molting of their white winter feathers so females can easily identify them in the brown background of the tundra.
During the breeding season, males exhibit territorial claims by leaping into the air, flapping their wings and producing loud croaking calls. During the courtship, males circle females with the red comb over the eyes exposed and tails widespread.
Due to their plumage camouflage, females are virtually invisible during the mating season. They can be detected only from a very close distance.
Chicks have dense feathers when they hatch out of the eggs. Six to 12 hours after hatching, they leave the nest.
Within 10 to 12 days of their birth, rock ptarmigans grow adult plumage. They learn to fly soon afterward. They start to live independently by 3 months and reproduce at 6 months. Rock ptarmigans typically survive for 2 to 4 years.
Except for breeding and migration seasons, they stay together in flocks and number a few dozen at a time. However, their flocks are segregated by sexes.
The worldwide population of rock ptarmigans is believed to be more than 8 million. Rock ptarmigans are protected throughout Japan and Toyama Prefecture has adopted them as the official bird of the province.