Conservation-induced extinction

Conservation-induced extinction is where efforts to save endangered species lead to the extinction of other species. This mostly threatens the parasite and pathogen species that are highly host-specific to critically endangered hosts. When the last individuals of a host species are captured for the purpose of captive breeding and reintroduction programs, they typically undergo anti-parasitic treatments to increase survival and reproductive success. This practice may unintentionally result in the extinction of the species antagonistic to the target species, such as certain parasites. It has been proposed that the parasites should be reintroduced to the endangered population. A few cases of conservation-induced extinction have occurred in parasitic lice.

Examples Extinct species Host species Notes Colpocephalum californiciDunn RR 2009. Coextinction: anecdotes, models, and speculation. In Holocene Extinctions (ed. S.T. Turvey), pp. 167–180. Oxford University Press, Oxford, UK. (California condor louse) California condor The parasite most probably became extinct when the last individuals of its only host species were captured for a captive-breeding program; all parasites found were deliberately killed in an attempt to assist the host's survival. Felicola isidoroiPérez, J.M.; Sánchez, I. & Palma, R.L. (2013). The dilemma of conserving parasites: the case of Felicola (Lorisicola) isidoroi (Phthiraptera: Trichodectidae) and its host, the endangered Iberian lynx (Lynx pardinus). Insect Conservation and Diversity 6: 680–686. (Iberian lynx louse) Iberian lynx As with Colpocephalum californici, likely became extinct when the last individuals of its host species were taken into captivity and deloused to assist survival. Linognathus petasmatus Scimitar-horned oryx The host specificity of this parasite is uncertain. Either it was specific to the scimitar-horned oryx and became extinct during captive breeding of the host, or – alternatively – it may be specific to the addax and possibly still surviving in the wild. Rallicola guami Guam rail The only known host species of this parasite exists exclusively in captivity and kept under veterinary control. Little information about the fate of the parasite, likely extinct.Emerson, K. C. (1957, August 4). Pror. ent. soc. Wash., vol. 59, no. -1, August, 1957 185 soc. 2: ... Biodiversity Library. Accessed at https://www.biodiversitylibrary.org/partpdf/63868 Rallicola pilgrimiBuckley TR, Palma RL, Johns PM, Gleeson DM, Heath ACG, Hitchmough RA, Stringer IAN 2012. The conservation status of small or less well known groups of New Zealand terrestrial invertebrates. New Zealand Entomologist 35: 137–143. Little spotted kiwi The parasite most probably became extinct when the last individuals of its only host species were captured and, after routine veterinary antiparasitic treatments, re-introduced into predator-free islands.

Erroneous example The trichodectid louse of the black-footed ferret has been mentioned in the literature several timesGompper ME, Williams ES 1998. Parasite conservation and the black-footed ferret recovery program. Conservation Biology 12: 730–732. as a parasite that became extinct during the captive breeding program of the host. However, this parasite most probably never existed as a separate species from Neotrichodectes minutus.

Species threatened by conservation-induced extinction Stephanocircus domrowi, the goblin flea, is a critically endangered insect endemic to the Australian state of Victoria.Kwak, M.L., 2018. Australia’s vanishing fleas (Insecta: Siphonaptera): a case study in methods for the assessment and conservation of threatened flea species. Journal of Insect Conservation, pp.1-6. It is host specific, and lives only with the co-endangered Leadbeater's possum.Dunnet, G.M. and Mardon, D.K., 1974. A monograph of Australian fleas (Siphonaptera). Australian Journal of Zoology Supplementary Series, 22(30), pp.1-273. Most conservation efforts of the possum include cleaning its body of parasites to increase chances of survival for the host. Combined with the small size of possum population in the wild, the flea is now a critically endangered species. There has been proposals for its conservation, but none have been carried out.

Conservation-induced extinction

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