* Wide Range: Lemmings live in a vast area across the Arctic, including parts of Norway, Sweden, Finland, Russia, Greenland, Canada, and Alaska. Their populations fluctuate dramatically.
* Difficult to Count: Lemmings are small and live in dense, often inaccessible environments. It's extremely difficult to conduct accurate counts.
* Population Cycles: Lemmings have natural boom-and-bust cycles. Their populations can increase rapidly, leading to overgrazing and then a dramatic decline.
Instead of a specific number, scientists study lemming populations through:
* Population Indices: Researchers use various methods like trapping or counting burrows to get an idea of the relative abundance of lemmings in different areas.
* Predator Studies: Observing the populations of predators that rely on lemmings (like arctic foxes, owls, and weasels) can provide clues about lemming numbers.
The bottom line: While we can't give an exact number, we know that lemming populations fluctuate significantly and are a key part of the Arctic ecosystem.