Archey's frog, Leiopelma archeyi, is an archaic, rare frog that is native to New Zealand, one of only three (or four) extant species belonging to the taxonomic family Leiopelmatidae. It is named after Sir Gilbert Archey (1890–1974), the former Director of the Auckland Institute. It is found only in the Coromandel Peninsula and near Te Kuiti in the North Island of New Zealand. This species, along with others in the family, have changed little over the past 200 million years, and thus represent "living fossils".
The species is fully terrestrial, living and reproducing under damp vegetation in native forests. Currently its distribution is confined to higher elevations at just two localities although just 15 years ago the species was abundant in a much wider distribution, down to sea level. Little is known about the natural history of this species. Although the species is sexually monomorphic, males are believed to be the primary care providers, and may prepare "nests" that they guard for the eggs, secreting antimicrobial peptides onto them, to ensure successful embryonic development. Clutch sizes vary between 4 and 15 eggs. Reproduction is fully terrestrial; tadpoles develop within gelatinous egg capsules, and upon hatching, tailed froglets crawl onto the male's back and are carried around for several weeks where they complete metamorphosis. Adult frogs do not give advertisement vocalisations, but may communicate by chemical signalling. However, frogs sometimes give startle calls when threatened by a predator.
An intensively monitored population in one Cormandel site declined by 88% from 1996 to 2001 but in many areas where frogs previously were common, none remain. Because populations are rapidly declining, and reproduction is infrequent, the species is at significant risk of imminent extinction.
As first shown by Bruce Waldman, the species appears to have an intrinsic low level of susceptibility to chytridiomycosis. However, frogs in the field show clinical signs, including blisters, that may be associated with other diseases. Pesticides such as 1080, sodium fluoroacetate, heavily used by the Department of Conservation (New Zealand) to control introduced mammalian pests, potentially could cause frogs to suffer from immunosuppression and thus make them vulnerable to disease. Hence, some environmental groups have voiced concern that continued use of this pesticide in the range of Archey's frog may cause them to go extinct in the wild.
A captive breeding programme was established at the University of Canterbury in 2002 to safeguard the species from disease, and frogs successfully bred. The programme was transferred to Auckland Zoo in 2005, where over half of the frogs, including juveniles bred at the Canterbury facility, died. Some of the remaining frogs produced offspring in December 2012, of which seven still survived as of February, 2013. After 8 years of failed attempts to get the frogs to breed at Auckland Zoo, zookeepers claimed "a massive and internationally important victory". Based on an Auckland Zoo press release that promoted their new public display of adult Archey's frogs, the Auckland Zoo breeding was widely but inaccurately reported as representing the first time the frogs had successfully reproduced in captivity. Auckland Zoo, Otago University, and James Cook University researchers attribute the mortality and reproductive failures at Auckland Zoo in part to metabolic bone disease, which they determined had not been a problem in the Canterbury facility.
- Bell (2004). Leiopelma archeyi. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Database entry includes a range map, a brief justification of why this species is critically endangered, and the criteria used
- "Leiopelma archeyi: Archey's Frog". AmphibiaWeb. http://www.amphibiaweb.org/cgi-bin/amphib_query?where-genus=Leiopelma&where-species=archeyi. Retrieved 13 June 2006.
- Bell BD, Carver S, Mitchell NJ, Pledger S (2004) The recent decline of a New Zealand endemic: How and why did populations of Archey’s frog Leiopelma archeyi crash over 1996–2001? Biol Conserv 120:189–199.
- Pesticides blamed for killing our rarest frogs. Sunday Star Times, 1 May 2005.
- Elimination of the amphibian chytrid fungus Batrachochytrium dendrobatidis by Archey’s frog Leiopelma archeyi. Aquatic Diseases of Organisms, 84: 9–15, 2009 doi:10.3354/dao02028.
- Waldman B (2011) Brief encounters with Archey's Frog. FrogLog 99:39-41.
- Pryor, Nicole (March 13, 2013). "1080 drop fears for frogs". Fairfax Newspapers. http://www.stuff.co.nz/science/8419477/1080-drop-fears-for-frogs. Retrieved March 13, 2013.
- Frog mission underway Independent Radio News, 31 July 2002.
- Waldman B (2011) Brief encounters with Archey's Frog. FrogLog 99:39-41
- Gibson, Eloise (28 March 2009). "Half of zoo frog colony dies". The New Zealand Herald. http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10563995. Retrieved 16 September 2011..
- Vaimoana Tapaleao (Feb 27, 2013). "Rare frogs thriving at zoo". The New Zealand Herald. http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10868019. Retrieved Feb 27, 2013.
- "Rare NZ native frog breeds at Auckland Zoo". Fairfax Newspapers. Feb 27, 2013. http://www.stuff.co.nz/science/8357975/Rare-frog-breeds-at-Auckland-Zoo. Retrieved Feb 27, 2013.
- "Big leap forward in breeding of rare frog". Auckland Zoo. Feb 27, 2013. http://www.aucklandzoo.co.nz/zoo-news/news/big-leap-forward-in-breeding-of-rare-frog.aspx. Retrieved Feb 27, 2013.
- Shaw SD, Bishop PJ, Harvey C, Berger L, Skerratt LF, Callon K, Watson M, Potter J, Jakob-Hoff R, Goold M, Kunzmann N, West P, Speare R (2012) Fluorosis as a probable factor in metabolic bone disease in captive New Zealand native frogs (Leiopelma sp.). Journal of Zoo and Wildlife Medicine: September 2012, 43:549-565.
- Rod Hitchmough, Leigh Bull and Pam Cromarty (compilers). New Zealand Threat Classification System lists - 2005. Wellington: Department of Conservation. ISBN 0-478-14128-9. Archived from the original on 20 April 2009. http://www.doc.govt.nz/publications/conservation/new-zealand-threat-classification-system-lists-2005/. Retrieved 2009-04-17.