Feel Like Learning Something New?

This comes from Sea Otter Savvy, which writes:

Sea otters and river otters may both be mustelids (weasels) with big appetites, but these cousins live very different lives. Sea otters are marine mammals who can live their entire lives in the ocean and their diet is specific to marine invertebrates (animals without backbones), while river otters move between fresh, saltwater, and terrestrial habitats—and have a far more varied diet.

New research from Megan Isadore and Terence Carroll of the River Otter Ecology Project, just published in the IUCN Otter Specialist Group Bulletin, reveals a surprising twist in river otter diet: predation on Brown Pelicans at Abbotts Lagoon in Point Reyes National Seashore.

From 2018–2023, researchers documented this novel predator-prey relationship, with 73 pelican carcasses recorded during 19 surveys in 2023. Despite the surprising number, pelicans didn’t seem to shift their use of the lagoon in response. The study raises intriguing ecological questions—like how these carcasses might act as nutrient subsidies for local scavengers, and what long-term effects this could have on local ecosystems.

This research highlights the dynamic role river otters are playing as a recovering predator species—and reminds us that even familiar animals can surprise us.

📚 Citation: Carroll & Isadore (2025). IUCN Otter Spec. Group Bull. 42 (2): 71–84