Western house martinThe western house martin (Delichon urbicum), sometimes called the common house martin, northern house martin or, particularly in Europe, just house martin, is a migratory passerine bird of the swallow family which breeds in Europe, north Africa and across the Palearctic; and winters in sub-Saharan Africa and tropical Asia. It feeds on insects which are caught in flight, and it migrates to climates where flying insects are plentiful. It has a blue head and upperparts, white rump and pure white underparts, and is found in both open country and near human habitation.
Tree swallowThe tree swallow (Tachycineta bicolor) is a migratory bird of the family Hirundinidae. Found in the Americas, the tree swallow was first described in 1807 by French ornithologist Louis Vieillot as Hirundo bicolor. It has since been moved to its current genus, Tachycineta, within which its phylogenetic placement is debated. The tree swallow has glossy blue-green , with the exception of the blackish wings and tail, and white . The bill is black, the eyes dark brown, and the legs and feet pale brown.
Barn swallowThe barn swallow (Hirundo rustica) is the most widespread species of swallow in the world. It appears to have the largest natural distribution of any of the world's passerines, ranging over 251 million square kilometres globally. It is a distinctive passerine bird with blue upperparts and a long, deeply forked tail. It is found in Europe, Asia, Africa and the Americas. In Anglophone Europe it is just called the swallow; in northern Europe it is the only common species called a "swallow" rather than a "martin".
River martinThe river martins form a distinctive subfamily Pseudochelidoninae within the swallow and martin bird family Hirundinidae. The two species are the African river martin Pseudochelidon eurystomina, found in the Congo and Gabon, and the white-eyed river martin Pseudochelidon sirintarae, known only from one site in Thailand. These are medium-sized, largely black swallows that have a light buoyant flight and feed on insects caught in the air. They appear to be more terrestrial than other swallows, frequently walking rather than perching, and the white-eyed may be crepuscular.
Bird nestA bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest of the American robin or Eurasian blackbird, or the elaborately woven hanging nest of the Montezuma oropendola or the village weaver—that is too restrictive a definition.
Brown-throated martinThe brown-throated martin or brown-throated sand martin (Riparia paludicola) is a small passerine bird in the swallow family. It was first formally described as Hirundo paludicola by French ornithologist Louis Vieillot in 1817 in his Nouveau Dictionnaire d'Histoire Naturelle. It was formerly regarded as conspecific with the grey-throated martin (R. chinensis) under the name "plain martin". It has a wide range in Africa. It is a partially migratory species, with some populations making seasonal movements.
African river martinThe African river martin (Pseudochelidon eurystomina) is a passerine bird, one of two members of the river martin subfamily of the swallow family, Hirundinidae. When discovered, it was not initially recognised as a swallow, and its structural differences from most of its relatives, including its stout bill and robust legs and feet, have led to its current placement in a separate subfamily shared only with the Asian white-eyed river martin. The African river martin is a large swallow, mainly black with a blue-green gloss to the head and a greener tint to the back and wings.
Bird vocalizationBird vocalization includes both bird calls and bird songs. In non-technical use, bird songs are the bird sounds that are melodious to the human ear. In ornithology and birding, songs (relatively complex vocalizations) are distinguished by function from calls (relatively simple vocalizations). The distinction between songs and calls is based upon complexity, length, and context. Songs are longer and more complex and are associated with territory and courtship and mating, while calls tend to serve such functions as alarms or keeping members of a flock in contact.
Violet-green swallowThe violet-green swallow (Tachycineta thalassina) is a small North American passerine bird in the swallow family. These aerial insectivores are distributed along the west coast from Alaska to Mexico, extending as far east as Montana and Texas. With an appearance very similar to the tree swallow, these individuals can be identified by the white rump side-patches that appear to separate their green back and purple tail. Violet-green swallows are secondary cavity nesters, found in a number of habitats including deciduous and coniferous forest.
Bird migrationBird migration is the regular seasonal movement, often north and south, along a flyway, between breeding and wintering grounds. Many species of bird migrate. Migration carries high costs in predation and mortality, including from hunting by humans, and is driven primarily by the availability of food. It occurs mainly in the northern hemisphere, where birds are funnelled onto specific routes by natural barriers such as the Mediterranean Sea or the Caribbean Sea.