Palaeoecological information concerning members of the frog genus Leiopelma: Leiopelmatidae in New Zealand

The endemic New Zealand frog framily Leiopelmatidae has three living species, all with very restricted distributions, and three extinct species, whose former natural history is unknown. The subfossil distributions of the extant Leiopelma hochstetteri Fitzinger 1861, and L. hamiltoni McCulloch 1919, show that until the late Holocene these species ranged from Punakaiki, on the west coast of the South Island, to Waitomo in the North Island. The morphological characters of the frogs, and the characteristics of the subfossil sites, suggest that the presumably extinct L. waitomoensis Worthy 1987 was a strongly hopping, stream or streamside frog, whereas L. markhami Worthy 1987, a slightly smaller extinct species, was primarily a walking, terrestrial frog. The formerly widespread species of Leiopelma, (L. markhami, L. waitomoensis, L. hochstetterz, and L. hamiltom all tended to become larger in southern populations. Size appears to be negatively correlated with temperature. The distribution of body sizes among adults of the extant Maud Island population of L. hamiltoni is similar to that of the extinct population of the same species previously living at Karamea, northwest Nelson. The disappearance of the extinct species, and the decline in range of the surviving species, date to the last millenium and is probably correlated with the arrival of the kiore, Rattus exulans, in New Zealand.