Columbicola columbae

Geographic Range

Slender pigeon lice are host specific, being found on only four species of pigeons. The species of pigeons on which these lice are found are pale-backed pigeons , speckled pigeons , rock pigeons , and stock pigeons . The distribution of slender pigeon lice depends largely on the distribution of their hosts. Rock pigeons in particular have a wide geographic range that includes every continent of the world excluding Antarctica. Slender pigeon lice therefore may be found in any of these regions. Collectively, the hosts of slender pigeon lice are native to Europe, Africa, and parts of Asia, however pigeons have spread by human introduction to their current global distribution. Slender pigeon lice have followed their hosts, and are also considered introduced wherever pigeons are non-natives.

• Biogeographic Regions
• nearctic nearctic
  • introduced introduced
• palearctic palearctic
  • native native
• oriental oriental
  • introduced introduced
• ethiopian ethiopian
  • native native
• neotropical neotropical
  • introduced introduced
• australian australian
  • introduced introduced

• Other Geographic Terms
• cosmopolitan cosmopolitan

Habitat

Slender pigeon lice are primarily found in the feathers on the undersides and upper wings of pigeons. This is typical of flat-bodied lice such as Columbicola columbae , as opposed to rounder species that are traditionally found in other areas of a host, such as the head. For this reason, Columbicola columbae is rarely found on the bodies of pigeons.

Geographical habitats include any region a host pigeon would inhabit. Depending on the species of pigeon, hosts and their associated lice inhabit grasslands, shrublands, and deserts, as well as agricultural, urban and suburban areas.

• Habitat Regions
• temperate temperate
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• desert or dune desert or dune
• savanna or grassland savanna or grassland

• Other Habitat Features
• urban urban
• suburban suburban
• agricultural agricultural

Physical Description

Columbicola columbae resembles a typical louse, being wingless and dorso-ventrally flattened with eyes that are not well-developed (vestiges of eyes). However, it is long and slender with a more flattened appearance than many other louse species. Characteristic of this species is the presence of two blade-like hairs (setae) and thin antennae with five segments on the anterior portion of its head. They can normally grow to be from 2 to 3 mmm long and are black or brown in color. As a member of the suborder Ischnocera , Columbicola columbae also has an extension (known as the cylpeus) on the front or anterior portion of its head, which comes into contact with the hair or feathers of the host when the lice are feeding or at rest. This species exhibits no sexual dimorphism.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• sexes alike

Development

Columbicola columbae demonstrates hemimetabolous development, or gradual metamorphosis, which is characteristic of all Phthiraptera . Immature lice are termed nymphs, and Columbicola columbae , like all lice, proceeds through three nymphal instars, or stages between molts, to reach their final adult stage. As all species of lice are permanent ectoparasites of their hosts, slender pigeon lice have no free-living stages and would not live long if removed from their hosts.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

Little is known regarding specific mating systems of Columbicola columbae . Currently, this species is regarded as polygynandrous, and showing no mate fidelity. How these lice locate, select, or defend mates is poorly understood.

• Mating System
• polygynandrous (promiscuous) polygynandrous (promiscuous)

As permanent ectoparasites of their hosts, Columbicola columbae males and females mate on the host. This species exhibits a reversed mating position where the female is on top of the male with the male holding the female above him with his antennae. Males transfer sperm to females through an organ termed the aedeagus, which is located toward the back of the abdomen.

Female Columbicola columbae deposit and attach their eggs to the feathers on the underside of the host’s wing, usually trying to do so close to the pigeon’s body. This is presumably to provide warmth and a safer environment for the eggs. The eggs can typically be expected to hatch within 3 to 5 days if exposed to a steady temperature of around 98.6 degrees Fahrenheit (37 degrees Celsius). Females can potentially lay up to 9 eggs per day. Individuals of this species are sexually mature as soon as they reach the adult phase.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous

Little parental investment is involved in this species. Females lay eggs close to the bodies of pigeons, presumably in an effort to provide warmth and protection to the eggs.

• Parental Investment
• no parental involvement

Lifespan/Longevity

Columbicola columbae has an expected adult lifespan of about 4 to 7 weeks. Factors affecting lifespan are currently unknown.

Behavior

In order to evade the preening behaviors of their pigeon hosts, Columbicola columbae move between the feather barbs, using their legs and mandibles to attach themselves to the barbs. These lice are able to move between the feather barbs quite easily due to their slender, flattened body shape. Columbicola columbae do not have the capacity to disperse on their own, and therefore must rely on other organisms to transfer them to new hosts if needed. Physical contact between two pigeons is one method of transfer. The second method of transfer involves a hippoboscid pigeon fly pseudolynchia canariensis . Columbicola columbae will climb onto the highly motile fly to transfer from one host to another. However, this is risky for the lice as the flies aren't completely obligate to pigeons, which may result in the transfer of lice to an unsuitable host, and subsequent death.

• Key Behaviors
• parasite parasite
• motile motile
• sedentary sedentary
• solitary solitary

Home Range

Home range size for Columbicola columbae is unknown, however most lice hatch, live, and die while on one host pigeon.

Communication and Perception

This species has no significant forms of communication, but perceives its environment mainly through visual means by way of vestigial eyes, and arguably through tactile means.

• Perception Channels
• visual visual
• tactile tactile

Food Habits

Columbicola columbae feeds by chewing on the feathers of their pigeon hosts, particularly feeding on the downy part of the wing feathers. However, these lice also have the ability to move from the wings to the body to feed on the fluff of the basal parts of the feathers found there. The body structure known as a clypeus comes into contact with the feathers of the pigeon host when feeding. Columbicola columbae does not feed on blood.

Predation

This species has no known predators, although any predators of its pigeon hosts could be problematic for the resident lice.

Ecosystem Roles

Columbicola columbae is a louse that parasitizes four species of pigeons, pale-backed pigeons , speckled pigeons , rock pigeons , and stock pigeons . This species feeds on the feathers, but are not fatal to nor cause significant damage to their hosts. They are not known to vector or cause any diseases. Therefore, they do not cause any great losses in pigeon populations. This species has a bacterial endosymbiont in its gut belonging to the class Proteobacteria (gamma subdivision of the class) and may be a result of its feather diet.

• Ecosystem Impact
• parasite parasite

Economic Importance for Humans: Positive

Columbicola columbae is among the species of chewing lice frequently used by biologists and researchers looking to research the biology of interactions between parasites and their hosts, and possibly how these interactions change over time as the hosts and parasites co-evolve. In fact, such experiments with lice like Columbicola columbae have revealed a relatively strong correlation between the host specificity of a louse and its host’s body size. Experiments in which lice were transferred to hosts smaller than their normal hosts showed that the lice did not typically survive unless the host’s efficiency at grooming was somehow hindered. In the reverse situation in which lice were transferred to hosts larger than their own, they did not survive regardless of the hindering of the host’s grooming capabilities. This is significant because it leads one to hypothesize that lice are most likely to switch to a host whose body size resembles their own host’s body size. Therefore, lice such as Columbicola columbae can shed light on important aspects of the relationships between parasites and hosts, which humans can use for their advantage and possibly eradication.

Economic Importance for Humans: Negative

Columbicola columbae do not parasitize humans, and their pigeon hosts are not a significant food source for humans so they have virtually no negative impact on humans. Additionally, they are not known to vector or cause any diseases that could possibly infect humans.

Conservation Status

Presently, Columbicola columbae is not threatened or at risk of becoming endangered. Due to its reliance on host species, fluctuations in host populations can have a dramatic effect on populations of Columbicola columbae . Columba eversmanni is experiencing significant population declines of unknown origin. Hypothesized causes include overhunting, deforestation, or agriculture. As this species of pigeon becomes more scarce, the populations of the obligate parasitic lice feeding on them will inevitably suffer losses as well. Other populations of Columbicola columbae do not seem to be in any danger of decline, as rock pigeons Columba livia are one of the most widely distributed birds.

Additional Links

Encyclopedia of Life

Contributors

Andrea Kummer (author), University of Michigan-Ann Arbor, Heidi Liere (editor), University of Michigan-Ann Arbor, John Marino (editor), University of Michigan-Ann Arbor, Barry OConnor (editor), University of Michigan-Ann Arbor, Rachelle Sterling (editor), Special Projects.

References

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Bush, S., D. Clayton. 2006. Ecomorphology of parasite attachment: Experiments with feather lice. Journal of Parasitology , 1: 25-31.

Bush, S., D. Clayton. 2006. The role of body size in host specificity: Reciprocal transfer experiments with feather lice. Evolution , 10: 2158-2167.

Fukatsu, T., R. Koga, W. Smith, K. Tanaka, N. Nikoh, K. Sasaki-Fukatsu. 2007. Bacterial Endosymbiont of the Slender Pigeon Louse, Columbicola columbae, Allied to Endosymbionts of Grain Weevils and Tsetse Flies. Applied and Environmental Microbiology , 73: 6660-6668.

Keirans, J. 1975. A Review of the Phoretic Relationship Between Mallophaga (Phythiraptera: Insecta) and Hippoboscidae (Diptera: Insecta). Journal of Medical Entomology , 12: 71-76.

Martin, M. 1934. Life history and habits of the pigeon louse (Columbicola columbae [Linnaeus]). Canadian Entomologist , 66: 6-16.

Moyer, B., D. Clayton, D. Gardiner. 2002. Impact of feather molt on ectoparasites: looks can be deceiving. Oecologia , 131: 203-210.

Nelson, B., M. Murray. 1971. The Distribution of Mallophaga on the Domestic Pigeon (Columba Livia). International Journal for Parasitology , 1: 21-29.

Rakshpal, R. 1959. On the behaviour of pigeon louse, Columbicola columbae Linn. (Mallophaga). Parasitology , 49: 232-241.

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Schmidt, G., L. Roberts. 2009. Foundations of Parasitology . New York, NY: McGraw-Hill.