whales

Whales are large marine mammals belonging to the order Cetacea, living in oceans worldwide. They are divided into baleen whales (Mysticeti), which filter small prey with baleen plates, and toothed whales (Odontoceti), which hunt using teeth. Whales evolved from terrestrial artiodactyls and share ancestry with hippos; their ancestors first adapted to an aquatic life around 50 million years ago.

Physically, whales have streamlined bodies, paddle-like fins, and tail flukes for propulsion, with nostrils on top of the head forming blowholes for breathing at the surface. Baleen whales feed by taking in seawater and prey and pushing water out through baleen plates, while toothed whales use echolocation and teeth to locate and capture prey.

Many species migrate seasonally, travelling thousands of kilometers between feeding and breeding areas; some live in stable social groups, while others are more solitary. Reproduction varies by species, but gestation typically lasts about a year, and calves remain dependent on their mothers for many months or years.

Human interactions have profoundly affected whale populations. A global moratorium on commercial whaling was adopted in 1986 by the International Whaling Commission, and some indigenous communities continue subsistence hunts under exemptions. Whales face ongoing threats from bycatch, ship strikes, habitat pollution, and climate change; conservation status ranges from vulnerable to endangered among species.