Leiopelma hochstetteri

Hochstetter's frog

Leiopelma hochstetteri
(Fitzinger, 1861)

Hochstetter's frog (Pukeamaru). <a href="https://www.instagram.com/samanimalman/">© Samuel Purdie</a>
Image attribution
Hochstetter's frog (Pukeamaru). © Samuel Purdie
Herpetofaunal category
NZ Frogs
Species complex
Conservation Status
At Risk - Declining
Common names
Hochstetter's frog

Length: SVL: Males up to 38mm; Females up to 47mm

Weight: unknown

Description

The Hochstetter’s frog is New Zealand's most widespread, and commonly encountered native frog species. Whilst still in decline they have fared much better than their close relatives (the Hamilton's and Archey's frogs), and still occupy a significant proportion of their former range. This may be attributed to their much more aquatic nature; being almost exclusively associated with small forested catchments or seepages.

In general Hochstetter's frogs match the mossy and clay-like tones of their environment, with their dorsal (upper) surface ranging in colouration from greenish-brown to reddish-brown with dark markings and numerous warts. The ventral (lower) surface is yellow-brown. There is no visible tympanum (external hearing structure).

Hochstetter’s frogs are similar in appearance to our other native frog species but can be differentiated by their much squatter build, and the presence of webbing (although only partial) on their feet. Hochstetter’s frog also exhibits a greater degree of sexual dimorphism than the other Leiopelma species, with the males being significantly smaller and exhibiting much broader forelimbs than females.  

Life expectancy

Up to 30 years.

Distribution

Fossils records indicate that Hochstetter’s frog was originally found over most of the North Island, however, as a result of habitat destruction and modification it is now restricted to the northern North Island from Waipu in the north through to the Central Plateau, including some of the larger offshore islands (e.g. Great Barrier).

Distribution maps are simplified, predicted distributions based on a combination of known distribution data, historical distribution data, suitability of habitat, and known biogeographic patterns. In some cases, the potential distribution of a species may be very unlikely. However, due to the cryptic nature of some of New Zealand's herpetofauna, it should not be ruled out entirely. Only significant historical records outside the known range of each species are used. 

Ecology and habitat

Hochstetter’s frog are a semi-aquatic species, inhabiting shaded creek edges in forested areas up to altitudes of 800m. They are nocturnal, sheltering during the day in wet crevices or under logs and stones, usually close to stony streams or rocky seepages.

Social structure

Largely unknown. Hochstetter’s frog use chemical signals to mark territory.

Breeding biology

Hochstetter’s frog reach breeding age at around three years. During mating the male grasps the female around the waist and fertilises eggs as she is laying them. Approximately 20 eggs are laid each breeding season with tadpoles developing inside the egg. Unlike the other three Leiopelma species froglets hatch with well-developed hind legs, continuing their development in water without parental care.

Diet

Hochstetter’s frog are carnivorous feeding on a variety of invertebrates such as spiders and mites.

Disease

Amphibian chytrid fungus and Ranavirus pose a major threat to Hochstetter’s frog.

Conservation strategy

Hochstetter’s frog is listed on the IUCN list as ‘vulnerable’.

DOC have purchased substantial areas of land with suitable habitat for populations of Hochstetter’s frog.

References

Auckland City Council (2016). Hochstetter's frog. Retrieved October 15, 2016 from http://www.aucklandcouncil.govt.nz/EN/environmentwaste/coastalmarine/Documents/hochstetterfrogfactsheet.pdf

Easton, L. (2018). Taxonomy and genetic management of New Zealand's Leiopelma frogs (Doctoral dissertation, University of Otago).

Easton, L. J., Rawlence, N. J., Worthy, T. H., Tennyson, A. J., Scofield, R. P., Easton, C. J., ... & Bishop, P. J. (2018). Testing species limits of New Zealand’s leiopelmatid frogs through morphometric analyses. Zoological Journal of the Linnean Society183(2), 431-444.

Fouquet, A., Green, D. M., Waldman, B., Bowsher, J. H., McBride, K. P., & Gemmell, N. J. (2010). Phylogeography of Leiopelma hochstetteri reveals strong genetic structure and suggests new conservation priorities. Conservation Genetics11(3), 907-919.

Gill, B., & Whitaker, T. (2007). New Zealand frogs and reptiles. Auckland: David Bateman Publishing Ltd.

Green, D. M., & Tessier, C. (1990). Distribution and abundance of Hochstetter's frog, Leiopelma hochstetteri. Journal of the Royal Society of New Zealand20(3), 261-268.

Hitchmough, R.A., Anderson, P., Barr, B., Monks, J., Lettink, M., Reardon, J., Tocher, M., & Whitaker, T. (2012). Conservation status of New Zealand reptiles, in New Zealand Threat Classification Series 2. DOC: Wellington.

Jewell, T. (2011). A photographic guide to reptiles and amphibians of New Zealand. Auckland: New Holland Publishing.

van Winkel, D., Baling, M. & Hitchmough, R. (2018). Reptiles and Amphibians of New Zealand: A field guide. Auckland: Auckland University Press, 376 pp.

Worthy, T. H. (1987). Palaeoecological information concerning members of the frog genus Leiopelma: Leiopelmatidae in New Zealand. Journal of the Royal Society of New Zealand17(4), 409-420.