Fish: Aquatic animal that usually has gills for breathing. Gulls, pelicans, and cormorants eat fish. Piscivory.

Fruit: The sweet and fleshy part of a plant that contains seeds. Fruits are eaten by birds such as mousebirds and parrots. Frugivory.

Insect: A type of small invertebrate animal with six legs and a hard exoskeleton. Swallows and flycatchers eat insects. Insectivory.

Invertebrate: Animal that lacks a backbone or vertebral column, such as crustaceans, molluscs and worms. Insects are also invertebrates, but have their own category due to their importance to many bird species. Robins and warblers eat invertebrates.

Meat: The flesh or body parts of vertebrate animals, including mammals, amphibians, reptiles, other birds or their eggs, carrion, etc. Eagles and vultures eat meat as part of their diet. Carnivory.

Plant: A living organism that uses photosynthesis to produce its own food. Many birds, like dabbling ducks, eat plants. Herbivory.

Seed: Reproductive portion of a plant not surrounded by a fleshy fruit, such as on grasses. Sparrows and finches eat seeds. Granivory.

Extremely Small: Birds ranging from a Penduline-tit (~8cm) to a Pytilia (~13cm).

Small: Between the size of a Sparrow (~14cm) and a Robin-chat (~20cm).

Medium: Ranging from a Thrush (~21cm) to a Spurfowl (~42cm).

Large: Birds between the size of a Coot (~43cm) and a Spur-winged Goose (~100cm).

Extremely Large: Birds larger than a Spur-winged Goose (~100cm), for example a Crane (~120cm), or Common Ostrich (~200cm).

Hunting: Using sharp claws or talons on the feet for catching, hunting or holding onto prey or carcasses. Birds of prey like eagles, falcons and vultures have talons.

Perching: Using the feet to grip onto something for support. Sparrows and finches use their feet for perching.

Swimming: Having the toes connected by a web of skin, efficient for swimming and, in some species' cases, wading. Many water birds, such as ducks and geese, have webbed feet.

Walking: Moving on foot on the ground. For example, cranes, spurfowls and many waders use their feet for walking.

Aerial: Living mostly on the wing, in the air. Some aerial birds include martins, swallows and swifts.

Agriculture: An area used for growing crops. Many birds, such as larks and pipits, live in agricultural areas.

Arid: An area that is very dry and characterised by little to no rain, which includes desert or semi-desert such as the Kalahari or Karoo. Birds such as the Kalahari Scrub Robin, Sociable Weaver and Ostrich live in arid or desert areas.

Bushveld: The bushveld is a type of vegetation found in the subtropics and tropics, consisting of trees, shrubs, and grasses.

Coastal: Area situated near or on the coast, such as beaches, rocky shorelines, and shallow coastal waters. Gulls and terns live in or near coastal areas.

Forest: A dense area of trees and undergrowth. Birds such as trogons, turacos, bush-shrikes and woodpeckers live in forests.

Fynbos: An endemic type of vegetation found mostly in the Western Cape of South Africa, consisting of proteas, ericas and restios. Birds such as rockjumpers and sugarbirds live in fynbos.

Garden: An area used for growing flowers, vegetables, or other plants. Bulbuls and thrushes live in or visit gardens.

Grassland: An area covered with grass. Birds such as larks and francolins live in grassland habitats.

Marine: The saltwater ocean environment. Albatrosses and penguins live in marine habitats.

Wetland: An area permanently or ephemerally saturated with water, such as a swamp, lake or marsh. Ducks, herons, and ibises live in wetland habitats.