🐋 Whales & Dolphins

What you’ll learn

1. Mammals of the SeaUnderstand that whales and dolphins are mammals, not fish.Cetaceans are fully aquatic mammals. Like all mammals they breathe air with lungs, are warm-blooded, give live birth, nurse their young with milk, and have some hair. They evolved from land animals and returned to the sea.
2. From Land to SeaTrace cetacean evolution from land-dwelling mammals.Cetaceans descend from hoofed land mammals that lived around 50 million years ago. Fossils show a gradual shift from walking on land to swimming, with hind limbs shrinking and the body becoming streamlined. Their closest living relatives are even-toed ungulates like the hippopotamus.
3. Baleen vs. Toothed WhalesCompare the two cetacean feeding strategies.Baleen whales have plates of keratin that filter small prey like krill and small fish from huge gulps of water. Toothed whales have teeth and echolocate to hunt individual prey such as fish and squid. The two groups diverged long ago and feed in very different ways.
4. The Blue Whale, Largest of AllAppreciate the scale and biology of the blue whale.The blue whale is the largest animal known to have ever existed, reaching about 30 meters long and over 150 tonnes. It feeds almost entirely on krill, has a heart the size of a small car, and was driven to the brink by whaling before gaining protection.
5. The Song of the HumpbackExplore humpback communication and behavior.Humpback whales are famous for long, structured songs sung by males, especially in breeding areas. They are also acrobatic, breaching and slapping the water, and use cooperative bubble-net feeding. Their long flippers and knobbly heads make them easy to recognize.
6. Dolphins: Intelligence and SocietyExamine dolphin cognition and social life.Dolphins are highly social, intelligent toothed whales. They live in groups called pods, cooperate to hunt, use signature whistles like names, and have shown self-recognition and tool use. The bottlenose dolphin is the best-studied species.
7. Echolocation: Seeing with SoundUnderstand how toothed whales hunt with sound.Toothed whales emit clicks and interpret the returning echoes to build a picture of their surroundings and prey. Sound is produced in nasal structures, focused through a fatty melon, and received through the lower jaw. This biological sonar works where light cannot.
8. Orcas: The Ocean's Top PredatorLearn about orca biology, society, and culture.The orca, or killer whale, is the largest member of the dolphin family and an apex ocean predator. Orcas live in stable matriarchal family groups, hunt cooperatively, and show distinct cultures with specialized diets and dialects among different populations.
9. Migration, Whaling, and ConservationUnderstand whale migration, the whaling era, and modern threats.Many whales migrate thousands of kilometers between feeding and breeding grounds. Industrial whaling devastated populations until international protection, notably a commercial moratorium. Today whales face bycatch, ship strikes, ocean noise, plastic, and climate change.

Questions this course answers

Grounded in trusted sources

• NOAA Fisheries (fisheries.noaa.gov)
• Smithsonian National Museum of Natural History — Ocean
• IUCN Red List of Threatened Species
• International Whaling Commission (iwc.int)
• Smithsonian Institution Ocean Portal

Every Wunder lesson is built from real, reputable sources — never invented.

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