Time for another animal spotlight, and this week we’re revisiting our feathered friends, with an episode on the Arctic bird, the ptarmigan. This bird’s most striking feature is it’s fluffiness, but it is a master of survival in the harsh climate of it’s northern home. Here we’ll be looking at how it survives, from it’s blood to it’s colour, to it’s love of thunderstorms. Enjoy!
Staying cosy in winter
The rock ptarmigan is a bird of the grouse family, found from as far south as Japan and Scotland to across the high Arctic. Unlike most Arctic birds who migrate south to warmer climes over winter, ptarmigans stay in the region year round. This means they have to cope with incredibly cold and harsh winter weather, with temperatures plummeting to -40°C (-40F) and beyond. They are very limited in their ability to store fat, so need to eat regularly to maintain enough energy to stay warm, with their fat reserves only lasting them 2 days if they cannot feed. A subpopulation in the Arctic island of Svalbard have evolved to carry slightly more fat, enough to last them 10 days, but regular feeding is still important. All this means that, unlike many other animals that live in the Arctic year round, ptarmigans can’t hibernate.
The other way they keep cosy during this period is through their feathers. Feathers are made of keratin, the same material found both in hair and in reptilian scales. When fluffed up, these feathers act like a thick fur coat, trapping air to keep the bird warm. Ptarmigans have extended this feathery coat to cover their feet too, and their scientific name Lagopus comes from the ancient Greek for ‘hare foot’ due to their fluffiness. The English name ‘ptarmigan’, comes from Scots Gaelic tàrmachan, meaning croaker, thanks to the sound it makes.
Even with a little fur on their feet, the lack of fat in this part of their body could put ptarmigans at a real risk of frostbite. To cope with this they have evolved a mechanism called countercurrent heat exchange, which means they can manage standing barefoot on the ice. Countercurrent heat exchange works by the vessels of fresh blood going into the foot, and vessels of used blood leaving the foot, running side by side. The heat from the fresh blood coming in warms up the cold, used blood going out instead of being lost to the ground (see picture below).
Ptarmigans are mainly herbivores, eating buds of aspen, birch and willows, as well as berries, leaves and seeds. Chicks will sometimes also eat insects and snails. Males are distinct because of a red semicircle above their eye, known as a comb. This comb gets bigger during the breeding season, and studies have shown that the bigger the comb, the more testosterone the bird has, and the more aggressively he will fight other males. Turns out for ptarmigans size does matter…
These birds are a food source to other species in the north, including owls, eagles, lynx and foxes. To protect themselves, they change colour throughout the year, being a mottled brown in summer to blend in with vegetation, and changing to a pure white in winter to hide in the snow.
Rock ptarmigans, perhaps the best known ptarmigans, are one of a few ptarmigan species. There is also the willow ptarmigan who lives a little further south, as far as Ireland, and is not found above the treeline. It is also a bit larger than the stocky rock ptarmigan. White-tailed ptarmigans are the smallest, and a bit more grey in colour, found above the treeline mainly in western Canada and Alaska. Finally, the red grouse in Scotland used to be thought of as a separate species, and was distinct due to it’s red colour, though it has now been demoted to a subspecies.
The various ptarmigans have become cultural symbols in many areas. Willow ptarmigans are the state birds of Alaska, red grouse are the well known symbol of The Famous Grouse whiskey in Scotland, and the rock ptarmigan is the official bird of the Nunavut territory in northern Canada. Known as raichō (雷鳥), meaning thunderbird, in Japan, the rock ptarmigan is also the official bird of Gifu, Nagano, and Toyama Prefectures. It is said this name of thunderbird comes from their behaviour, being most active early in the morning, late in the evening, and during stormy weather in order to avoid predators.
Whilst worldwide ptarmigan numbers are not considered worrisome by the IUCN, the international organization who monitors the health of wildlife populations, some local areas have seen a decline. Ptarmigans were a popular part of Icelandic cuisine, yet due to declines in number, their hunting was banned in 2003-2004. Since 2005 some hunting has been allowed but it is incredibly restricted. In Japan too, ptarmigans are a protected species.
Ptarmigans are truly hardy creatures. They are one of the few species who remain in the Arctic year-round, and don’t even have the luxury of hibernation to get them through this tough period, as they need to keep active and feeding to survive. This makes them essential for predators like lynx and Arctic foxes who would struggle to survive the Arctic winter without them as a vital source of food. Through their thunderbird behaviour, their camouflage plumage and their ability to weather the storms of winter, they are an excellent example of how in the Arctic even cute and fluffy critters must be experts of survival.
For more info:
Information on ptarmigans along with research and conservation work going on in Japan here
How birds stay warm here
Title Image: Daisuke Tashiro/CC BY-SA 2.0