A passerine is any bird of the order Passeriformes which includes more than half of all bird species. Sometimes known as perching birds, passerines generally have an anisodactyl arrangement of their toes, which facilitates perching.
Near passerines and higher land-bird assemblage are terms of traditional, pre-cladistic taxonomy that have often been given to tree-dwelling birds or those most often believed to be related to the true passerines owing to morphological and ecological similarities; the group corresponds to some extent with the Anomalogonatae of Alfred Henry Garrod.
The Pelecaniformes are an order of medium-sized and large waterbirds found worldwide. As traditionally—but erroneously—defined, they encompass all birds that have feet with all four toes webbed. Hence, they were formerly also known by such names as totipalmates or steganopodes. Most have a bare throat patch, and the nostrils have evolved into dysfunctional slits, forcing them to breathe through their mouths. They also have a pectinate nail on their longest toe. This is shaped like a comb and is used to brush out and separate their feathers. They feed on fish, squid, or similar marine life. Nesting is colonial, but individual birds are monogamous. The young are altricial, hatching from the egg helpless and naked in most. They lack a brood patch.
The Tyranni (suboscines) are a suborder of passerine birds that includes more than 1,000 species, the large majority of which are South American. It is named after the type genus Tyrannus. These have a different anatomy of the syrinx musculature than the oscines, hence the common name of suboscines.
Neognathae is an infraclass of birds, called neognaths, within the class Aves of the clade Archosauria. Neognathae includes the majority of living birds; the exceptions being the tinamous and the flightless ratites, which belong instead to the sister taxon Palaeognathae. There are nearly 10,000 living species of neognaths.
Neoaves is a clade that consists of all modern birds with the exception of Palaeognathae and Galloanserae. Almost 95% of the roughly 10,000 known species of extant birds belong to the Neoaves.
Mirandornithes is a clade that consists of flamingos and grebes. Many scholars use the term Phoenicopterimorphae for the superorder containing flamingoes and grebes.
Aequornithes, or core water birds, are defined as "the least inclusive clade containing Gaviidae and Phalacrocoracidae".
The order Falconiformes is represented by the extant family Falconidae and a handful of enigmatic Paleogene species. Traditionally, the other bird of prey families Cathartidae, Sagittariidae (secretarybird), Pandionidae (ospreys), Accipitridae (hawks) were classified in Falconiformes. A variety of comparative genome analysis published since 2008, however, found that falcons are part of a clade of birds called Australaves, which also includes seriemas, parrots and passerines. Within Australaves falcons are more closely related to the parrot-passerine clade (Psittacopasserae), which together they form the clade Eufalconimorphae. The hawks and vultures occupy a basal branch in the clade Afroaves in their own clade Accipitrimorphae, closer to owls and woodpeckers.
Cariamiformes is an order of primarily flightless birds that has existed for over 60 million years. The group includes the family Cariamidae (seriemas) and the extinct families Phorusrhacidae, Bathornithidae, Idiornithidae and Ameghinornithidae. Though traditionally considered a suborder within Gruiformes, both morphological and genetic studies show that it belongs to a separate group of birds, Australaves, whose other living members are Falconidae, Psittaciformes and Passeriformes.
Eufalconimorphae is a proposed clade of birds, consisting of passerines, parrots, falcons, caracaras, and forest falcons. It has whole-genome DNA support. Eufalconimorphae birds are characterized by their strong and hooked beaks, sharp talons, and powerful wings. They have excellent eyesight, which allows them to spot their prey from great distances. The Eufalconimorphae is noted to produce aerodynamic force during the upstroke of flight to help create a vertical flight pattern.
Strisores, sometimes called nightbirds, is a clade of birds that includes the living families and orders Caprimulgidae, Nyctibiidae (potoos), Steatornithidae (oilbirds), Podargidae (frogmouths), Apodiformes, as well as the Aegotheliformes (owlet-nightjars) whose distinctness was only recently realized. The Apodiformes and the Aegotheliformes form the Daedalornithes.
Australaves is a recently defined clade of birds, consisting of the Eufalconimorphae as well as the Cariamiformes. They appear to be the sister group of Afroaves. As in the case of Afroaves, the most basal clades have predatory extant members, suggesting this was the ancestral lifestyle; however, some researchers like Darren Naish are skeptical of this assessment, since some extinct representatives such as the herbivorous Strigogyps led other lifestyles. Basal parrots and falcons are at any rate vaguely crow-like and probably omnivorous.
Telluraves is a recently defined clade of birds defined by their arboreality. Based on most recent genetic studies, the clade unites a variety of bird groups, including the australavians as well as the afroavians. They appear to be the sister group of the Ardeae.
Columbea is a clade suggested by genome analysis that contains Columbiformes, Pteroclidae (sandgrouse), Mesitornithidae (mesites) and Mirandornithes. Until their recent placement as the sister taxon to Passerea, in the last decade various genetic analysis found them to be in the obsolete clade Metaves.
Eurypygimorphae or Phaethontimorphae is a clade of birds that contains the orders Phaethontiformes (tropicbirds) and Eurypygiformes recovered by genome analysis. The relationship was first identified in 2013 based on their nuclear genes. Historically these birds were placed at different parts of the tree, with tropicbirds in Pelecaniformes and the kagu and sunbittern in Gruiformes. Some genetic analyses have placed the eurypygimorph taxa in the controversial and obsolete clade Metaves, with uncertain placement within that group. More recent molecular studies support their grouping together in Eurypygimorphae, which is usually recovered as the sister taxon to Aequornithes within Ardeae.
Phaethoquornithes is a clade of birds that contains Eurypygimorphae and Aequornithes, which was first recovered by genome analysis in 2014. Members of Eurypygimorphae were originally classified in the obsolete group Metaves, and Aequornithes were classified as the sister taxon to Musophagiformes or Gruiformes.
Columbimorphae is a clade discovered by genome analysis that includes birds of the orders Columbiformes, Pterocliformes (sandgrouse), and Mesitornithiformes (mesites). Previous analyses had also recovered this grouping, although the exact relationships differed. Some studies indicated a sister relationship between sandgrouse and pigeons while other studies favored a sister grouping of mesites and sandgrouse instead.
Columbaves is a clade that contains Columbimorphae and Otidimorphae discovered by genomic analysis by Prum et al. (2015). This conflicts with the Columbea and Otidae hypotheses which Mirandornithes are the sister taxon to Columbimorphae and Cypselomorphae the sister taxon to Otidimorphae, respectively, found by Jarvis et al. (2014). Neither hypothesis supports the two subdivisions of Metaves and Coronoaves as previous studies had found.
Pelecanimorphae is a clade of aequornithean birds that comprises the orders Ciconiiformes, Suliformes and Pelecaniformes. In the past the name has been used as a homonym for Pelecaniformes.
