Incredible Footage Documents Wolverine Digging for “Fish-cicles” In Frozen River
by Stephen Sautner, Wildlife Conservation Society
June 12, 2023
The Wildlife Conservation Society released footage of a wolverine (Gulo gulo) foraging for fish frozen in a perennial spring along a river in the Alaskan Arctic. It is the first-known observation of a wolverine eating fish – usual prey includes everything from snowshoe hares to caribou to voles. The researchers described their results in the journal Ecology.
The footage, gathered though a collaborative effort between WCS and the BBC, shows the wolverine clawing through thick ice and eventually extracting Arctic grayling and Dolly Varden char that had presumably died from lack of oxygen. Perennial springs traditionally provide refuge for fish in far northern rivers that would otherwise freeze solid, but they sometimes become oxygen-depleted and cause mass mortality events.
The wolverine, nicknamed Nimbus, was equipped with a GPS collar and being tracked by WCS scientists as part of study on how these rarely seen predators use permafrost. Nimbus was observed clawing and gnawing, and then excavating fish one-by-one. The researchers observed other scavengers – arctic fox, red fox, and ravens – close behind, cleaning up.
The observation was made along the Shaviovik River in the Brooks Mountain Range near the Arctic National Wildlife Refuge.
Read the Ecology paper: https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.4097