Notes on Habitat.
Archey (1922, 70) has described the habitat of L. archeyi: it lives and breeds on “damp, mist-swept hill tops moist enough all the year round for frogs to live there in comfort” without access to surface water. Mr. A. Richardson states (in litt.) that at the summit peg on the Thames-Tapu-Whitianga road it is active at night and may be seen climbing trees. The eggs (Archey ibid.) develop directly on land, the larva being intracapsular and at no time passing through a tadpole stage.
The absence of webs from the toes in the adult and the direct development may be regarded as adaptations to the absence of surface water in the habitat.
Turning to L. hochstetteri, one finds it, throughout its range, living in water at the edge of streams or in swampy areas. The adult is normally found sitting immersed in water except for the eyes and nostrils, and swims feebly with alternate leg strokes. It has been found only in streams surrounded by forest, or in swampy ground with plenty of protecting swamp-plants, possibly because, as in Ascaphus (Noble and Putnam, 1931, 97) the high temperatures of exposed lowland stream beds are not tolerated. It does not appear in streams lacking half-submerged stones, or moss and liverworts, providing recesses in which the adults may find concealment.
The half-webbing of the toes in the adult may be regarded as being related to this close dependence on surface water.
Although L. hochstetteri has not been observed at night in the field, it almost certainly feeds nocturnally away from the stream-beds. Partly-digested food, including the shell of a small, flat-spired gasteropod and portion of an arthropod appendage, probably of the terrestrial genus Parorchestia, comprised the stomach-contents of a
freshly-killed specimen, both food organisms inhabiting leaf-mould bordering on the stream-bed. This specimen was collected at 2·30 p.m., at which time the stomach contents were at a fairly advanced stage of digestion, as if the food had been taken during the previous night. Vivarium specimens will feed only at dusk, when living crane-flies (Tipulidae) and blue-bottles (Calliphora quadrimaculata) proffered by hand are accepted.