Wanderlust World Wanderlust World Both belong to the Mustelidae family, but river otters and weasels lead very different lives.
| Trait | River Otter | Weasel |
|---|---|---|
| Size | 10–30 lb (4.5–13.5 kg) | 0.5–4 lb (0.2–1.8 kg) |
| Habitat | Semi‑aquatic: rivers, lakes, wetlands | Terrestrial: forests, grasslands, deserts |
| Diet | Fish, frogs, crayfish, aquatic invertebrates | Small rodents, rabbits, birds, eggs |
| Social Structure | Live in family groups (“romps”) | Solitary, territorial |
Otters are adapted for swimming with webbed feet, dense fur, and streamlined bodies; weasels are elongated, agile hunters on land. Despite shared ancestry, their ecological niches barely overlap.