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Why do Arctic fox and snowy owl populations decline when lemmings are scarce?
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Polar ecosystem
Southern limit of Arctic tundra and approximate line of demarcation between Low and High Arctic.
In the Arctic tundra, the populations of predators such as Arctic foxes and snowy owls are closely linked to the availability of lemmings, which serve as a primary food source. Because the Arctic environment has a limited number of species, these predators experience significant population oscillations that follow the rise and fall of their prey.1
When lemming populations decline, these predators respond in different ways:
- Arctic Fox: Their populations drop significantly when lemmings are scarce, as they rely heavily on these rodents for sustenance.1
- Snowy Owl: Rather than experiencing a direct population decline in the region, snowy owls often migrate to the coniferous forest belt to find more abundant food sources.1
While Arctic foxes are opportunistic feeders that may also hunt birds or follow polar bears to scavenge remains, their overall numbers remain tethered to the cyclical abundance of lemmings.12