Some kinds of river fish, such as the salmon family, spend much of their lives in the sea but migrate up rivers to breed. Birds that feed and breed in freshwater wetlands include ducks and geese, wading birds like sandpipers and plovers, gulls and terns, herons, cranes, fish eagles, and a huge number of smaller birds like kingfishers, weavers, warblers and finches. Wetland birds have adapted to life in or near water in many ways. Some ducks dabble in the mud for worms and crustacea with their heads under water, others dive deep to feed on algae growing on the lake bed. Waders have long bills for probing the mud for small worms and molluscs.
Herons stand motionless by the water's edge and stab a passing fish with their dagger-like beak.
The African fish eagle dives from its perch and catches fish with its sharp talons. The waterbuck is a shaggy antelope with oily fur that feeds around wetlands in Africa. Every where you find water, you will find life. The smallest puddle and water-filled tree hollow has its complement of plants and animals. There are even animals that have adapted to life in underground cave lakes where no light penetrates.