A bird louse is any

chewing louse The Mallophaga are a possibly paraphyletic section of lice Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been re ...

(small, biting insects) of order

Phthiraptera Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been recognized as an order, infraorder, or a parvorder, as a result of ...

which parasitizes warm-blooded animals, especially

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s. Bird lice may feed on feathers,

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different de ...

, or

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

. They have no wings, and their biting mouth parts distinguish them from true lice, which suck blood."Bird louse" on Encyclopædia Britannica. Almost all domestic birds are hosts for at least one species of bird louse. Chickens and other poultry are attacked by many kinds of bird lice. Bird lice usually do not cause much harm to a bird unless it is unusually infested as in the case of birds with damaged bills which cannot preen themselves properly. A blood-consuming louse that infests Galápagos Hawks i
more numerous on hawks without territories
possibly because those individuals spend more time looking for food and less time preening than hawks with territories. In such cases, their irritation may cause the bird to damage itself by scratching. In extreme cases, the infestation may even interfere with egg production and the fattening of poultry. Unlike true lice, bird lice do not carry infectious diseases. Having

coevolved In biology, coevolution occurs when two or more species reciprocally affect each other's evolution through the process of natural selection. The term sometimes is used for two traits in the same species affecting each other's evolution, as well ...

with their specific host(s),

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

relationships among bird lice are sometimes of use when trying to determine phylogenetic relationships among birds.Cohen, Baker, Belchschmidt, Dittmann, Furness, Gerwin, Helbig, de Korte, Marshall, Palma, Peter, Ramli, Siebold, Willcox, Wilson and Zink (1997).
Enigmatic phylogeny of skuas.
' Proc. Biol. Sci. 264(1379): 181–190. Earlier all chewing lice were considered to form the paraphyletic order

Mallophaga The Mallophaga are a possibly paraphyletic section of lice Louse ( : lice) is the common name for any member of the clade Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera has variously been re ...

while the sucking lice were thought to form the order

Anoplura Sucking lice (Anoplura, formerly known as Siphunculata) have around 500 species and represent the smaller of the two traditional superfamilies of lice. As opposed to the paraphyletic chewing lice, which are now divided among three suborders, ...

. Recent reclassification (Clay, 1970) has combined these orders into the order Phthiraptera. The bird lice belong to two suborders,

Amblycera The Amblycera are a large clade of chewing lice, parasitic on both birds and mammals. The Amblycera are considered the most primitive clade of lice. Description These insects are very much like the familiar advanced sucking lice, except t ...

and Ischnocera, although some members of these suborders do not parasitize birds and are therefore not bird lice.Gillot, C. ''Entomology'' 2nd Ed. (1995) Springer, , . Accessed o
Google Books
on 9 Apr 2010.{{rp, 2010–202 The families which parasitize birds are: * Suborder Amblycera ** Family

Menoponidae Menoponidae is a monophyletic family of lice in the superfamily of chewing lice, Amblycera, often referred to as the chicken body louse family. They are ectoparasites of a wide range of birds including chickens, which makes them important to ...

- birds, especially poultry. ** Family

Laemobothriidae The Laemobothriidae are a family of a larger group Amblycera of the chewing lice. Most commonly they are ectoparasites of birds. The genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil ...

- water birds and hawks. ** Family Ricinidae - hummingbirds and

passerine A passerine () is any bird of the order Passeriformes (; from Latin 'sparrow' and '-shaped'), which includes more than half of all bird species. Sometimes known as perching birds, passerines are distinguished from other orders of birds by th ...

s. * Suborder Ischnocera ** Family

Philopteridae The Philopteridae are a family of Ischnocera, chewing lice mostly parasitic on birds. The taxonomy and systematics of the group are in need of revision; the Philopteridae are almost certainly paraphyletic. Genera Some notable species are also l ...

- birds, especially poultry.

Footnotes

References

"Bird louse"

Encyclopædia Britannica The (Latin for "British Encyclopædia") is a general knowledge English-language encyclopaedia. It is published by Encyclopædia Britannica, Inc.; the company has existed since the 18th century, although it has changed ownership various t ...

Online 2010. Retrieved 9 April 2010.] Lice Parasites of birds