Whales — Ocean Giants
WHALES are MAMMALS that evolved from land ancestors and returned to the SEA about 50 million years ago. Their closest land relatives today are HIPPOS. Whales breathe air (need to surface), give birth to live young, nurse with milk, and have warm blood. They include the largest animals ever to live: BLUE WHALES can reach 100 feet (30 meters) and 200 tons — bigger than any dinosaur.
Two main groups. TOOTHED WHALES (orcas, dolphins, sperm whales): hunt with teeth; use ECHOLOCATION (sound bouncing off prey). BALEEN WHALES (blue, humpback, gray): no teeth — instead, comb-like baleen plates filter tiny krill and small fish from huge mouthfuls of water. Some baleen whales eat 4 tons of krill PER DAY. Many whales sing complex songs (especially humpbacks); songs can travel hundreds of miles in deep ocean.
How is a BLUE WHALE able to grow so enormously big — even bigger than dinosaurs?
Whaling and recovery. Industrial whaling in the 19th-20th centuries nearly drove many whale species extinct. The blue whale population dropped to ~5,000 from ~250,000. Whaling moratorium in 1986 by the IWC. Some species (humpback) are recovering well. Others (right whales) remain critically endangered. Modern threats: ship strikes, fishing gear entanglement, ocean noise (from ships), pollution, and warming waters affecting prey availability.
Whale Sounds
Search for "humpback whale song" online. Listen to the haunting calls. Whales communicate across miles of ocean. Some songs change yearly across populations — culture spreading through whale communities.
Whales are some of Earth's most magnificent animals. They link us to ocean depths most humans never see. Protecting them protects entire ocean ecosystems.
Want to keep learning?
Sign up for free to access the full curriculum — all subjects, all ages.
Start Learning Free