What's the difference between a seal and a sea lion?

The document distinguishes 'true seals' (Phocidae) from 'eared seals' (Otariidae), noting that sea lions have external ear flaps, rotatable hind flippers for walking on land, and loud vocalizations, whereas seals have ear holes, move by scooting on their bellies, and are generally quieter. It highlights the ecological role of pinnipeds as mid-level predators and prey for apex predators. The text identifies climate change, overfishing, entanglement in fishing gear, habitat loss, and pollution as primary threats to these species, specifically mentioning the risk to ice-dependent seals due to shrinking sea ice.

• True seals (family Phocidae) are distinguished from sea lions and fur seals (family Otariidae) by their lack of external ear flaps, having only "tiny holes for ears", and their inability to rotate hind flippers, which forces them to "inch and roll forward awkwardly on their bellies" on land.
• Sea lions are characterized by external ear flaps, the ability to "walk" on land using rotatable back flippers, and loud vocalizations including barking, roaring, and growling.
• Pinnipeds serve as mid-level predators that regulate populations of squid, fish, and crustaceans, while simultaneously serving as prey for apex predators such as polar bears, sharks, and orcas.
• Climate change is a primary threat to pinnipeds, particularly those dependent on sea ice, as the loss of ice reduces available areas for breeding, resting, and escaping predators.
• Other significant anthropogenic threats to pinniped populations include overfishing, which depletes prey stocks; entanglement in fishing gear; pollution from chemicals and plastics; and habitat loss caused by coastal development.

APA

WWF International (n.d.). What's the difference between a seal and a sea lion? https://www.worldwildlife.org/resources/facts/whats-the-difference-between-a-seal-and-a-sea-lion/

Chicago

WWF International. What's the difference between a seal and a sea lion? n.d. https://www.worldwildlife.org/resources/facts/whats-the-difference-between-a-seal-and-a-sea-lion/.

Wikipedia

{{cite report |author=WWF International |title=What's the difference between a seal and a sea lion? |url=https://www.worldwildlife.org/resources/facts/whats-the-difference-between-a-seal-and-a-sea-lion/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{wwfinternationalndwhats, author = {{WWF International}}, title = {{What's the difference between a seal and a sea lion?}}, institution = {WWF International}, url = {https://www.worldwildlife.org/resources/facts/whats-the-difference-between-a-seal-and-a-sea-lion/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }