Whales

Whales are fully aquatic mammals that breathe air through blowholes on the top of their heads. Their bodies have evolved remarkable adaptations for life in the ocean: streamlined forms, flippers evolved from forelimbs, and a horizontal tail fluke that provides powerful propulsion. A thick layer of blubber provides insulation in cold waters and serves as an energy reserve during migrations and fasting periods. Whales are warm-blooded, give birth to live young, and nurse their calves with milk — all distinctly mammalian characteristics retained from their land-dwelling ancestors.

Whale communication is among the most sophisticated in the animal kingdom. Humpback whales produce complex songs that can last for hours and travel thousands of kilometres through the ocean. These songs evolve over time, with new phrases spreading through populations like cultural trends. Sperm whales communicate using patterns of clicks called codas, with different family groups having distinct dialects. Blue whales produce the loudest sounds of any animal — low-frequency calls that can travel across entire ocean basins. Scientists believe whale communication plays roles in mate attraction, social bonding and navigation.

Many whale species undertake some of the longest migrations of any animal on Earth. Humpback whales travel up to 25,000 kilometres annually between their tropical breeding grounds and polar feeding areas. Grey whales migrate along the Pacific coast of North America, covering up to 20,000 kilometres each way. These migrations are driven by the seasonal availability of food — whales feed intensively in productive polar waters during summer, then fast during winter while breeding in warmer tropical seas. Climate change is disrupting these ancient migration patterns as prey distributions shift.

Commercial whaling in the 20th century brought many whale species to the brink of extinction. Blue whale populations were reduced by over 99% before international protections were introduced. While the International Whaling Commission moratorium on commercial whaling in 1986 allowed some populations to begin recovering, many species remain endangered. Today, whales face threats from ship strikes, entanglement in fishing gear, underwater noise pollution, plastic ingestion and climate change. Protecting whale populations requires international cooperation and addressing the full range of human impacts on the marine environment.