This list's taxonomic treatment (designation and sequence of orders, families and species) and nomenclature (common and scientific names) follow the conventions of The Clements Checklist of Birds of the World, 2022 edition. The family accounts at the beginning of each heading reflect this taxonomy, as do the species counts found in each family account.
The following tag has been used to highlight accidental species.
(A) Accidental - a species that rarely or accidentally occurs in Rivers State
Anatidae includes the ducks and most duck-like waterfowl, such as geese and swans. These birds are adapted to an aquatic existence with webbed feet, flattened bills, and feathers that are excellent at shedding water due to an oily coating.
Phasianidae consists of the pheasants and their allies. These are terrestrial species, variable in size but generally plump, with broad, relatively short wings. Many species are gamebirds or have been domesticated as a food source for humans.
Grebes are small to medium-large freshwater diving birds. They have lobed toes and are excellent swimmers and divers. However, they have their feet placed far back on the body, making them quite ungainly on land.
The turacos, plantain eaters and go-away-birds make up the bird family Musophagidae. They are medium-sized arboreal birds. The turacos and plantain eaters are brightly coloured, usually in blue, green or purple. The go-away birds are mostly grey and white.
The family Cuculidae includes cuckoos, roadrunners, coucals and anis. These birds are of variable size with slender bodies, long tails, and strong legs.
Nightjars are medium-sized nocturnal birds that usually nest on the ground. They have long wings, short legs and very short bills. Most have small feet, of little use for walking, and long pointed wings. Their soft plumage is camouflaged to resemble bark or leaves.
Swifts are small birds which spend the majority of their lives flying. These birds have very short legs and never settle voluntarily on the ground, perching instead only on vertical surfaces. Many swifts have long swept-back wings which resemble a crescent or boomerang.
Rallidae is a large family of small to medium-sized birds which includes the rails, crakes, coots and gallinules. The most typical family members occupy dense vegetation in damp environments near lakes, swamps or rivers. In general they are shy and secretive birds, making them difficult to observe. Most species have strong legs and long toes which are well adapted to soft uneven surfaces. They tend to have short, rounded wings and to be weak fliers.
The thick-knees and stone-curlews are a group of largely tropical waders in the family Burhinidae. They are medium to large waders with strong black or yellow-black bills, large yellow eyes, and cryptic plumage. Despite being classed as waders, most species have a preference for arid or semi-arid habitats.
Recurvirostridae is a family of large wading birds, which includes the avocets and stilts. The avocets have long legs and long up-curved bills. The stilts have extremely long legs and long, thin, straight bills.
The family Charadriidae includes the plovers, dotterels and lapwings. They are small to medium-sized birds with compact bodies, short, thick necks and long, usually pointed, wings. They are found in open country worldwide, mostly in habitats near water.
The jacanas are a group of tropical waders in the family Jacanidae. They are found throughout the tropics. They are identifiable by their huge feet and claws which enable them to walk on floating vegetation in the shallow lakes that are their preferred habitat.
Scolopacidae is a large diverse family of small to medium-sized shorebirds including the sandpipers, curlews, godwits, shanks, tattlers, woodcocks, snipes, dowitchers, and phalaropes. The majority of these species eat small invertebrates picked out of the mud or soil. Variation in length of legs and bills enables multiple species to feed in the same habitat, particularly on the coast, without direct competition for food.
The buttonquails are small, drab, running birds which resemble the true quails. The female is the brighter of the sexes and initiates courtship. The male incubates the eggs and tends the young.
Glareolidae is a family of wading birds comprising the pratincoles, which have short legs, long pointed wings and long forked tails, and the coursers, which have long legs, short wings and long, pointed bills which curve downwards.
Laridae is a family of medium to large seabirds, the gulls, terns, and skimmers. Gulls are typically grey or white, often with black markings on the head or wings. They have stout, longish bills and webbed feet. Terns are a group of generally medium to large seabirds typically with grey or white plumage, often with black markings on the head. Most terns hunt fish by diving but some pick insects off the surface of fresh water. Terns are generally long-lived birds, with several species known to live in excess of 30 years. Skimmers are a small family of tropical tern-like birds. They have an elongated lower mandible which they use to feed by flying low over the water surface and skimming the water for small fish.
The procellariids are the main group of medium-sized "true petrels", characterised by united nostrils with medium septum and a long outer functional primary.
Storks are large, long-legged, long-necked, wading birds with long, stout bills. Storks are mute, but bill-clattering is an important mode of communication at the nest. Their nests can be large and may be reused for many years. Many species are migratory.
Darters are often called "snake-birds" because of their long thin neck, which gives a snake-like appearance when they swim with their bodies submerged. The males have black and dark-brown plumage, an erectile crest on the nape and a larger bill than the female. The females have much paler plumage especially on the neck and underparts. The darters have completely webbed feet and their legs are short and set far back on the body. Their plumage is somewhat permeable, like that of cormorants, and they spread their wings to dry after diving.
Phalacrocoracidae is a family of medium to large coastal, fish-eating seabirds that includes cormorants and shags. Plumage colouration varies, with the majority having mainly dark plumage, some species being black-and-white and a few being colourful.
Pelicans are large water birds with a distinctive pouch under their beak. As with other members of the order Pelecaniformes, they have webbed feet with four toes.
The hammerkop is a medium-sized bird with a long shaggy crest. The shape of its head with a curved bill and crest at the back is reminiscent of a hammer, hence its name. Its plumage is drab-brown all over.
The family Ardeidae contains the herons, egrets, and bitterns. Herons and egrets are medium to large wading birds with long necks and legs. Bitterns tend to be shorter necked and more secretive. Members of Ardeidae fly with their necks retracted, unlike other long-necked birds such as storks, ibises, and spoonbills.
Threskiornithidae is a family of large terrestrial and wading birds which includes the ibises and spoonbills. They have long, broad wings with 11 primary and about 20 secondary feathers. They are strong fliers and despite their size and weight, very capable soarers.
Accipitridae is a family of birds of prey which includes hawks, eagles, kites, harriers, and Old World vultures. These birds have powerful hooked beaks for tearing flesh from their prey, strong legs, powerful talons, and keen eyesight.
The typical owls are small to large solitary nocturnal birds of prey. They have large forward-facing eyes and ears, a hawk-like beak and a conspicuous circle of feathers around each eye called a facial disk.
The family Trogonidae includes trogons and quetzals. Found in tropical woodlands worldwide, they feed on insects and fruit, and their broad bills and weak legs reflect their diet and arboreal habits. Although their flight is fast, they are reluctant to fly any distance. Trogons have soft, often colourful, feathers with distinctive male and female plumage.
The woodhoopoes are related to the kingfishers, rollers and hoopoes. They most resemble the hoopoes with their long curved bills, used to probe for insects, and short rounded wings. However, they differ in that they have metallic plumage, often blue, green or purple, and lack an erectile crest.
Hornbills are a group of birds whose bill is shaped like a cow's horn, but without a twist, sometimes with a casque on the upper mandible. Frequently, the bill is brightly colored.
The bee-eaters are a group of near passerine birds in the family Meropidae. Most species are found in Africa but others occur in southern Europe, Madagascar, Australia and New Guinea. They are characterised by richly coloured plumage, slender bodies and usually elongated central tail feathers. All are colourful and have long downturned bills and pointed wings, which give them a swallow-like appearance when seen from afar.
Rollers resemble crows in size and build, but are more closely related to the kingfishers and bee-eaters. They share the colourful appearance of those groups with blues and browns predominating. The two inner front toes are connected, but the outer toe is not.
The barbets are plump birds, with short necks and large heads. They get their name from the bristles which fringe their heavy bills. Most species are brightly coloured.
Honeyguides are among the few birds that feed on wax. They are named for the greater honeyguide which leads traditional honey-hunters to bees' nests and, after the hunters have harvested the honey, feeds on the remaining contents of the hive.
Woodpeckers are small to medium-sized birds with chisel-like beaks, short legs, stiff tails, and long tongues used for capturing insects. Some species have feet with two toes pointing forward and two backward, while several species have only three toes. Many woodpeckers have the habit of tapping noisily on tree trunks with their beaks.
Characteristic features of parrots include a strong curved bill, an upright stance, strong legs, and clawed zygodactyl feet. Many parrots are vividly coloured, and some are multi-coloured. In size they range from 8 cm (3.1 in) to 1 m (3.3 ft) in length. Old World parrots are found from Africa east across south and southeast Asia and Oceania to Australia and New Zealand.
Parrots are small to large birds with a characteristic curved beak. Their upper mandibles have slight mobility in the joint with the skull and they have a generally erect stance. All parrots are zygodactyl, having the four toes on each foot placed two at the front and two to the back.
The cuckooshrikes are small to medium-sized passerine birds. They are predominantly greyish with white and black, although some species are brightly colored.
The wattle-eyes, or puffback flycatchers, are small stout passerine birds of the African tropics. They get their name from the brightly coloured fleshy eye decorations found in most species in this group.
The helmetshrikes are similar in build to the shrikes, but tend to be colourful species with distinctive crests or other head ornaments, such as wattles, from which they get their name.
Bushshrikes are similar in habits to shrikes, hunting insects and other small prey from a perch on a bush. Although similar in build to the shrikes, these tend to be either colourful species or largely black; some species are quite secretive.
The drongos are mostly black or dark grey in colour, sometimes with metallic tints. They have long forked tails, and some species have elaborate tail decorations. They have short legs and sit very upright when perched, like a shrike. They flycatch or take prey from the ground.
Shrikes are passerine birds known for their habit of catching other birds and small animals and impaling the uneaten portions of their bodies on thorns. A shrike's beak is hooked, like that of a typical bird of prey.
The family Corvidae includes crows, ravens, jays, choughs, magpies, treepies, nutcrackers, and ground jays. Corvids are above average in size among the Passeriformes, and some of the larger species show high levels of intelligence.
Most of the species of this small family are found in Africa, though a few inhabit tropical Asia. They are not closely related to other birds called "flycatchers".
The Cisticolidae are warblers found mainly in warmer southern regions of the Old World. They are generally very small birds of drab brown or grey appearance found in open country such as grassland or scrub.
The reed-warblers or acrocephalid warblers are a family of oscine passerine birds, in the superfamily Sylvioidea. The species in this family are usually rather large " warblers". Most are rather plain olivaceous brown above with much yellow to beige below. They are usually found in open woodland, reedbeds, or tall grass.
The family Hirundinidae is adapted to aerial feeding. They have a slender streamlined body, long pointed wings and a short bill with a wide gape. The feet are adapted to perching rather than walking, and the front toes are partially joined at the base.
Bulbuls are medium-sized songbirds. Some are colourful with yellow, red or orange vents, cheeks, throats or supercilia, but most are drab, with uniform olive-brown to black plumage. Some species have distinct crests.
Leaf warblers are a family of small insectivorous birds found mostly in Eurasia and ranging into Wallacea and Africa. The species are of various sizes, often green-plumaged above and yellow below, or more subdued with greyish-green to greyish-brown colours.
The members of this family are found throughout Africa, Asia, and Polynesia. Their taxonomy is in flux, and some authorities place genus Erythrocerus in another family.[4]
The family Sylviidae is a group of small insectivorous passerine birds. They mainly occur as breeding species, as the common name implies, in Europe, Asia and, to a lesser extent, Africa. Most are of generally undistinguished appearance, but many have distinctive songs.
The white-eyes are small and mostly undistinguished, their plumage above being generally some dull colour like greenish-olive, but some species have a white or bright yellow throat, breast or lower parts, and several have buff flanks. As their name suggests, many species have a white ring around each eye.
These small to medium-sized songbirds have soft fluffy plumage but are otherwise rather diverse. Members of the genus Illadopsis are found in forests, but some other genera are birds of scrublands
Starlings are small to medium-sized passerine birds. They are medium-sized passerines with strong feet. Their flight is strong and direct and they are very gregarious. Their preferred habitat is fairly open country, and they eat insects and fruit. Plumage is typically dark with a metallic sheen.
The thrushes are a group of passerine birds that occur mainly but not exclusively in the Old World. They are plump, soft plumaged, small to medium-sized insectivores or sometimes omnivores, often feeding on the ground. Many have attractive songs.
Old World flycatchers are a large group of small passerine birds native to the Old World. They are mainly small arboreal insectivores. The appearance of these birds is highly varied, but they mostly have weak songs and harsh calls.
The sunbirds and spiderhunters are very small passerine birds which feed largely on nectar, although they will also take insects, especially when feeding young. Flight is fast and direct on their short wings. Most species can take nectar by hovering like a hummingbird, but usually perch to feed.
Weavers are a group of small passerine birds related to the finches. These are seed-eating birds with rounded conical bills, most of which breed in sub-Saharan Africa, with fewer species in tropical Asia. Weavers get their name from the large woven nests many species make. They are gregarious birds which often breed colonially.
The estrildid finches can be classified as the family Estrildidae (waxbills, munias, and allies), or as a subfamily within the family Passeridae, which strictly defined comprises the Old World sparrows. They are gregarious and often colonial seed eaters with short thick but pointed bills. They are all similar in structure and habits, but have wide variation in plumage colors and patterns.
The indigobirds are finch-like species which usually have black or indigo predominating in their plumage. All are brood parasites, which lay their eggs in the nests of estrildid finches.
Old World sparrows are small passerine birds. In general, sparrows tend to be small, plump, brown or grey birds with short tails and short powerful beaks. Sparrows are seed eaters, but they also consume small insects.
Motacillidae is a family of small passerine birds with medium to long tails. They include the wagtails, longclaws and pipits. They are slender, ground feeding insectivores of open country.
Finches are seed-eating passerine birds, that are small to moderately large and have a strong beak, usually conical and in some species very large. All have twelve tail feathers and nine primaries. These birds have a bouncing flight with alternating bouts of flapping and gliding on closed wings, and most sing well.