UNUSUAL FROG

Hauraki Plains Gazette, Volume 54, Issue 32536, 14 February 1945, Page 3

UNUSUAL FROG

HABITAT ON PENINSULA NEW ZEALAND SPECIES INFORMATION FROM MUSEUM The appearance, after recent wet weather, of frogs in the streets of Thames, led to inquiries about whether these were the Coromandel tree frogs. The Auckland War Memorial Museum, however, has advised that the frogs in the streets are not likely to be the Coromandel frog, but more Likely the ordinary naturalised Australian tree frog, hyla aurea. Why the latter is called a tree frog is not known, for it has never been known to be anywhere but in pools or long grass. The Coromandel frog' is not a tree

frog, but a ground creature which lives under logs on the hilltops, and has a most interesting feature in that it has become quite independent of water for its breeding. Dr. Gilbert Archey, director of the museum, lias made a special study of the Coromandel frog, and in a paper which he wrote on it he mentions that frogs are abundant in meadovs, swamps and streams in all parts of New Zealand, but it is not generally known that the subdued cacophony cf croaks, creaks and dull metallic clunks which announces the spring and swells to a steady diapason through summer, is the performance of an Australian vocalist. Acclimatisation Introduction The Auckland Acclimatisation Society introduced the first Australian green frogs into New Zealand in 1867. In a letter in 1916, Mr R. D. Dansey wrote to the Hon. G. M. Thomson as follows: “I well remember the uneasiness and consternation in the native village upon some native excitedly reporting his having seen a peculiar ngarara (reptile) in a pond near the lake, and describing that it had fingers and toes and swam like a human being. Dread was expressed at the idea of swallowing young ones while drinking water, that they might grow inside* to gnaw away at their stomachs. Others described the bringing into the district of such reptiles as the doing of some evil-minded European to wipe out the natives and secure their lands.” The native frog may be described as uncommon in both of the senses in which the word is used. It is hardly rare; but it has a very restricted distribution and an unusual habitat for a frog; it is one of the most primitive of all frogs in its structure, but has, at the same time, an extremely specialised and unusual life history. Natives Alarmed The supposed presence of frogs in 1 New Zealand was reported as far back as 183 S, when Polack wrote rather unconvincingly of their baromet- • ric croak on the approach of rain * (actually they have a faint squeak). ’ It is to be feared that Polack wrote i of what might have been, not what he 1 actually observed. 1 But, in 1852, when gold was first 1 discovered at Coromandel, the miners, 1 on displacing boulders from a stream 1 bank, unearthed a small frog which ’ they preserved. Dr. Thomson subsequently obtained it and showed it to 1 many natives, including keenly obser- '■ vant and intelligent old men, none of 1 whom had ever seen the animal be- < fore, nor could they give any name to 1 it. They remarked that it must be ] the atua, the spirit or god of the gold, 1 which had appeared on the earth; ( many of them shrunk back from it in 1 horror and some of them were inclined to draw unfavourable omens from its discovery at such a particular time. ' 1

In due course the species was scientifically described under the name of liopelma hochstetteri. Chance discoveries at different places indicated that its range extended along the whole length of the Coromandel gold peninsula and eastward to Opotiki; but beyond ‘this little was learned about it for 60 years either by settlers or students. The streams within its range were diligently searched, but frogs were seldom found and it was generally thought that the species was rare. Moreover, no one had seen its eggs or tadpoles, and indeed, nothing was known of its breeding habits. Investigation Made

In 1921 Dr. Archey followed up the independent observations and discoveries of Coromandel residents in both the habitat and life history of the frog. Specimens were required for the Canterbury Museum, and inquiry brought several letters, including one from Mr J. D. Regan, who stated he

had seen the eggs, with young frogs swimming in them like fish. A trip to Coromandel followed, and a search, first under the guidance of Mr F. C. Horne, who had frequently seen the frogs, and later with Mr Regan and his friend, Mr Stewart O’Neil, who had both seen the eggs, soon made it clear that the frogs did not inhabit streams at all but lived under logs and rocks in the crest of the Tokatea ridge. The habitat of the frogs, lacking, as it does, surface water in which other frogs breed, clearly demanded a modified life history to meet the unusual conditions, and further search • soon confirmed Mr Regan’s original observations. Here and there under the logs, frogs were found sitting over clusters of eggs, 12 eggs in two groups of six in one cluster, and six eggs of two groups of three in another, each group being covered by a membrane enclosing a transparent gelatinous or semi-fluid mass. Each egg within the mass had its own spherical gelatinous capsule containing a fluid in which the yoke (i.e., the heavily yolked egg itself) was suspended. The modified life history is an adaptation to special climatic conditions. The mountain ridges lack surface water, but they are not dry or arid. On the contrary, they are perpetually mist-driven, and it is the constant humid atmosphere which has enabled the native frogs to attain independence of i>ools and streams for their breeding.