Ptarmigan Ptakeover!

4 comments

1. Could changing climate have allowed them to catch up – or get ahead – on their usual rate of reproduction success?

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   1. It is possible. A lot of unknowns likely since there is not much attention paid to events in the north. The scale there is vast.

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2. Something is missing here: what thing (s) normally exert downward pressure on this population?

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   1. I am not sure but ruffed grouse and hares are suppressed by chemicals in aspen buds. Something may be similar with ptarmigan.

      The pens attempt to mimic, in 20-meter squares, a curious fact about small Arctic mammals: Their populations change dramatically over time. Lemmings and voles both pulse and crash in three- to five-year cycles. In Utqiaġvik, a community 250 miles northwest of Toolik, Iñupiat Elders remember years so thick with lemmings that people had to actively avoid stepping on them. In other years, Team Vole barely sees a single animal.

      The pen with the multitude of voles simulates a boom year. Even at a glance, the tundra inside the pen was transformed: the sedges pruned, the moss trampled, the blueberries nibbled. Here and there along their runways, the voles have piled sedge clippings six or eight inches high; the conical heaps provide food and shelter through the winter. One runway dead-ends in a trampled oval, vole droppings mounded in the middle. The overall effect is a kind of ramshackle coherence. Look close enough, and the tundra suddenly appears built. And not just on a small scale: Scandinavian researchers have tracked Arctic mammals’ transformation of the landscape in satellite images.

      Maybe some clues here.

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