Ptarmigan
Although the ptarmigan population naturally fluctuates up and down, the total population has declined sharply throughout Fennoscandia, including here on the Varanger Peninsula.
But what is the actual cause of this decline?
And can we do anything to stabilize the population?
Much of the decline in the ptarmigan population can be traced back to climate change.
The ptarmigan is part of a complex food web with species that are affected by climate change in various ways.
Many predators feed on ptarmigan, and research suggests that changes in the populations of these predators affect the ptarmigan.
On the following pages, you can read about what changes in climate and the populations of the different animals in the figure to the right mean for the ptarmigan population.
Click here to see how changes in various factors may
affect the ptarmigan population in the future. Photo: Valeri Belov
Changes in climate can affect ptarmigans directly
Extreme Weather
In the first few weeks after hatching, young ptarmigan chicks are thinly feathered and vulnerable to cold and rain.
Wet down feathers insulate poorly, and if it rains a lot over extended periods, the chicks risk freezing to death.
Shorter winters
The timing of when ptarmigans change to their white winter plumage is mainly controlled by the length of the day, not temperature.
This means that when the snow arrives later in the fall - and disappears earlier in the spring - the ptarmigan remains white even though the ground is bare of snow. This makes it an easy target for predators.
Wet winters lead to more reindeer dying on the pasture.
More reindeer carcasses mean more food for generalists: red foxes, crows, and other animals that eat what they can easily find. They therefore manage well and increase in number.
As a result, the ptarmigan becomes more vulnerable to attacks from these predators.
Photo: Ground ice: Jan Erik Knutsen, dead reindeer: Rolf A. Ims, ptarmigan chick: Marita Anti Strømeng, and red fox: Geir Vie.
Fewer small rodents survive the wet, unstable winters.
This leads to years with large populations of small rodents such as lemmings and voles becoming less common on the tundra.
Therefore, small rodent specialists instead eat ptarmigan eggs and chicks to satisfy their hunger.
Small rodent specialists are predators that primarily feed on small rodents.
Examples of small rodent specialists: stoat, lesat weasel, arctic fox, rough-legged buzzard, and snowy owl.
Photo: Ground ice: Jan Erik Knutsen, dead lemming: Rolf A. Ims, ptarmigan chick: Marita Anti Strømeng, and wood lemming: coat.no
The gyrfalcon is a ptarmigan specialist, meaning it primarily feeds on ptarmigans. It is therefore dependent on the ptarmigan, and its population follows fluctuations in the ptarmigan population, as illustrated above.
If the ptarmigan population declines, the gyrfalcon could be severely affected. It has few alternatives for food, and if the ptarmigan population becomes too small, the gyrfalcon is at risk of extinction. The gyrfalcon is therefore listed as vulnerable (VU) on the Norwegian Red List.
Although each individual gyrfalcon eats many ptarmigans, its population is small relative to the ptarmigan population and does not seem to significantly affect the total number of ptarmigans.
The relationship between the gyrfalcon and the ptarmigan is something we are researching, and in a few years, we hopefully can say something about both how many ptarmigans there need to be to maintain a viable gyrfalcon population and what effect the gyrfalcon has on the ptarmigan population.
How we do research on Willow ptarmigan
In collaboration with FeFo and local hunters, we take trips along fixed routes every autumn, where a pointing dog is used to locate willow ptarmigan broods.
The registrations provide an estimate of the number of ptarmigans and how many chicks they have produced each year.
Photo: Marita Anti Strømeng
We record the amount of ptarmigan droppings at fixed locations to gain insight into how many ptarmigans are present in the mountains each year. Photo: John-André Henden
In this box, there is a sound recorder that is used to record the calls of ptarmigan cocks in the spring.
The recordings are used to register both the number of willow ptarmigans and rock ptarmigans. Photo: Jan Erik Knutsen
We count nests and chicks of gyrfalcons, golden eagles, rough-legged buzzards, and ravens to monitor the populations of predators that can take both willow ptarmigan and rock ptarmigan.
In the winter, we set out bait and install wildlife cameras to register the predators that show up.
Here, one of our wildlife cameras has captured a golden eagle that has settled right in the middle of the food supply.
Rock ptarmigan
There is little knowledge about the rock ptarmigan in mainland Norway, and Varanger is actually the only place where monitoring of rock ptarmigan is conducted.
The method using pointing dogs is rarely used on rock ptarmigan. The rock ptarmigan lives in habitats where it is difficult to use dogs, and it behaves differently towards the dogs than the willow ptarmigan does.
Therefore, we have some slightly different methods for monitoring the population of rock ptarmigan than for willow ptarmigan.
Rock ptarmigan broods are searched for each autumn without the use of dogs. The registrations in each nest are used to calculate the number of chicks per hen that year.
Photo: Geir Vie
Listening boxes are used to record rock ptarmigan in the
same way as for willow ptarmigan.
Photo: Jan Erik Knutsen
What is the ptarmigan research used for?
Management
Knowledge about what causes changes in the ptarmigan population makes it possible to give recommendations to local authorities on how to increase the population – such as by hunting predators that take ptarmigan.
The calculations we make of the number of rock and willow ptarmigans on the Varanger Peninsula can be used for the management of the populations – for example, for quotas on ptarmigan hunting.
Hunting Quotas
Although the number of predators has a significantly greater impact on the ptarmigan population than the number of ptarmigans shot during hunting, the annual quotas on ptarmigan are also an important measure to prevent the total pressure on the population from becoming too great.
Photo: Alfred Ørjebu