''Columbicola extinctus'', also known as the passenger pigeon chewing louse, is an

extant Extant or Least-concern species, least concern is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Exta ...

species of phtilopterid

louse Louse (: lice) is the common name for any member of the infraorder Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera was previously recognized as an order (biology), order, until a 2021 genetic stud ...

. It was once believed to have become

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

with its only known host, the

passenger pigeon The passenger pigeon or wild pigeon (''Ectopistes migratorius'') is an bird extinction, extinct species of Columbidae, pigeon that was endemic to North America. Its common name is derived from the French word ''passager'', meaning "passing by" ...

(''Ectopistes migratorius''), prior to its rediscovery living on

band-tailed pigeon The band-tailed pigeon (''Patagioenas fasciata'') is a pigeon native to the Americas, and the largest pigeon native to North America. They are a native species throughout the Southwestern United States and Mexico, extending south to Peru. Taxo ...

s (''Patagioenas fasciata'').

Taxonomy

The generic name ''Columbicola'' comes from the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

words ''columba'', "dove," and ''-cola'', "inhabitant," in reference to the genus's primary hosts. ''Columbicola extinctus'' was originally described by Richard O. Malcomson in 1937. It was originally believed to have only lived on the passenger pigeon, which had been extinct for 23 years by the time of its discovery. Malcomson believed that ''Columbicola extinctus'' had become extinct with its host and gave it the specific name ''extinctus'' to mark this fact. However, by 1999 ''Columbicola extinctus'' had been rediscovered living on the band-tailed pigeon, which is the passenger pigeon's closest living relative.

Description

Like other members of the genus ''Columbicola'', the insect is a long, slender louse that shows marked

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

in the antennae, as the male's are much longer than those of the female in the third segment. It is between long overall. The male's head is between long and broadens to form a slight shoulder at the anterior plate. The female's head is slightly larger at . The thorax has two very long

seta In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae, ...

e on each side.

Distribution

While the precise

range Range may refer to: Geography * Range (geographic), a chain of hills or mountains; a somewhat linear, complex mountainous or hilly area (cordillera, sierra) ** Mountain range, a group of mountains bordered by lowlands * Range, a term used to i ...

of ''Columbicola extinctus'' is not known, it is only known to live on one extant host, the band-tailed pigeon, and has been found on individuals across its range. The band-tailed pigeon lives along the Pacific coast of North America from southern

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

to northern

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

. It is also found in the southern

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

and

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

south down the center of the continent through Central America and into South America. While its second known host, the passenger pigeon, was extant, the louse could also be found in eastern North America from southern Canada south to the Gulf Coast and northern Florida; due to the passenger pigeon's extinction, the louse is now

extirpated Local extinction, also extirpation, is the termination of a species (or other taxon) in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinctions. Local extinctions mark a chan ...

from this side of the continent.

Ecology

''Columbicola extinctus'' feeds on the feathers and skin debris of their host. Their elongated shape allow them to conceal themselves between feather shafts and therefore avoid dislodgement while its host is

preening Preening is a found in birds that involves the use of the beak to position feathers, interlock feather that have become separated, clean plumage, and keep ectoparasites in check. Feathers contribute significantly to a bird's insulation, waterp ...

or in flight. They spend their entire life on a host pigeon, and can only be transferred from one pigeon to another when the pigeons come in contact. These lice lay their eggs in parts of the body inaccessible to preening, such as the interior of feather shafts. ''Columbicola extinctus'' is an

exopterygote The Exopterygota (Ancient Greek ''ἔξω'' (éxō, "outside") + ''πτερόν'' (pterón, "wing") + Neo-Latin ''-ota'' ("having")), also known as Hemimetabola, are a superorder of insects of the subclass Pterygota in the infraclass Neoptera, ...

and is born as a miniature version of the adult that is known as

nymph A nymph (; ; sometimes spelled nymphe) is a minor female nature deity in ancient Greek folklore. Distinct from other Greek goddesses, nymphs are generally regarded as personifications of nature; they are typically tied to a specific place, land ...

. The nymphs molt three times before reaching the final adult form, usually within a month of hatching.

References

Cited texts

* * {{Taxonbar, from=Q16980889 Lice Parasites of birds Insects of North America Insects described in 1937