Diving birds must pursue and catch their prey while under water. They do this by propelling themselves by their feet. Special built-in “goggles” (nictitating membranes) enable them to see whilst under water. They have non-waterproof feathers that decreases buoyancy, while some species even swallow rocks before foraging to further decrease their buoyancy. They must dry their feathers while on land and do this by stretching out their wings. Because they are efficient foragers they are able to live in most regions on earth, including marine and freshwater environments.

• To have a long neck and hook-tipped bill.
• Short, stout legs that are used in swimming underwater.
• Non-waterproof feathers that decrease your buoyancy in the water.
• An oil gland that is used to help shed water while on land.
• A membrane that protects the eye underwater (nictitating membrane).
• An efficient lung capacity that enables prolonged dive time.

The body shape of diving birds is hydrodynamic, streamlined so that it can be propelled easily through the water. They have long necks with hook-tipped bills. Their legs are used to swim underwater and are thus short, stout and strong, with webbed feet. Their tails are long with hard, almost spiky feather shafts. Black and white are the main plumage colours in these birds, with patterns including pied and full black.

Diving birds have an extensive range including polar, temperate and equatorial regions of the earth. Many species are wholly marine, while others travel between marine, estuarine and freshwater environments. Marine species live on rocky headlands and islands, entering the water to forage. “Terrestrial” species can be found around inland water systems, where they roost communally in trees. Diving birds enter the water to forage, however, must leave the water to dry their apparently non-waterproof feathers

Diving birds eat fish (piscivores). They must pursue their prey underwater. From the air, or floating on the surface of the water the birds must dive under the water and swim in search of prey. While swimming they use only their legs for propulsion. Most diving birds have nictitating membranes that protect the eyes while underwater, acting like built in goggles. Diving birds have been used as examples of an animal that uses ‘optimal foraging’, that is they search for prey where other members of their species (conspecifics) are hunting.

Marine species of diving birds may suffer predation from a number of sources. These may include sea eagles and skuas, as well as leopard seals, sharks and killer whales. The “terrestrial” species of diving birds can suffer predation from any form of land predator, in particularly foxes and feral cats.

Diving birds are colonial breeders, and can be found in communities consisting of more than one thousand birds. The females lay from 1 to 5 eggs, which can be incubated by both parents. The nests consist of vegetative debris, and can be formed as mounds on the ground or as platforms in trees. After hatching, the chicks are fed on a liquid diet, then receive predigested food as they get older. The hatchlings have a distinctive “reptilian” appearance. The juveniles reach maturity after approximately a year. Diving birds breed annually, but the timing of breeding is subject to seasonal variation.

Diving birds are communal birds and are usually found with birds of the same species (conspecifics). However, during nesting they may associate with a number of different species. Many species of diving birds nest on the fringes of ibis or heron colonies, while others may share their habitat with marine mammals (eg. fur seals).

Diving birds can be found living in close proximity to human habitats. As a result they are subject to a number of detrimental effects. These may include pollution (eg. plastic and storm water run-off) and predation by feral animals. Diving birds live and breed in areas that are desirable to humans (eg. beaches), and as a result they can suffer habitat destruction and displacement. The ability of diving birds to catch fish has also been utilised by humans (eg. Asians), who make the pet birds regurgitate their catch!