Tuatara: Volume 9, Issue 3, January 1962
What Frogs Were These? *
What Frogs Were These? *
Polack's (1838) reference to the presence of ‘toads and frogs’ in New Zealand ‘with their barometrical croak! croak! abound in the swamps’, is somewhat mystifying and difficult of interpretation in view of the fact that the indigenous species, belonging to the genus Leiopelma, were not reported till 1853 (Thomson). But, as some of Polack's observations, at first regarded as fanciful, have since been proved correct, this statement cannot be dismissed too lightly. As the indigenous species, Leiopelma, are believed to be silent, they could not have called forth Polack's comment. Accordingly, we must look beyond New Zealand for the authors of the croaks. Some foreign species may have been accidentally or deliberately introduced at a very early date. In a country with few natural enemies the frogs may have increased for a time and then for some unknown reason vanished, for no other observers refer to the croaking of frogs. This suggestion is almost as weak as Polack's statement. Alternatively, Polack may have heard the croaking of frogs or toads in some other land of his travels and when compiling his work forgetfully ascribed them to New Zealand.
As neither agriculture nor university students were flourishing during Polack's sojourn in New Zealand it is obvious that frogs would not have been willfully introduced as subjects for dissection! Alternatively, frogs may have been introduced as a source of page 129 supplementing the food supply. Of all nationals visiting the country as whalers or explorers in the early days the French are famous for their special appetite for a ‘froggy delicacy’ and so the finger of suspicion points at them. It is quite possible that some of the early French voyagers attempted introducing the edible European frog, Rana esculenta or R. temporaria, or perhaps some Australian species and liberated them with a joyful vive la grenouille! in much the same way as Captain Cook transported and liberated pigs in the hope that they would increase and multiply to provide food for future visits — the effects of the latter liberations we know well!
The earliest authentic record of an attempt to introduce the European Brown Frog, Rana temporaria, was made in 1864 (Thomson, p. 182). Thirty specimens were brought to Canterbury from Great Britain, but none appear to have survived. Their disappearance was attributed to a swan! Attempts to introduce the Common Toad were made in 1867, but evidently this was also unsuccessful.
Polack's statement must remain a mystery.
* See Tuatara 9 (2), p. 86.