This species is known only from the type locality, the north-east slope of Mount Dayman, and from the eastern slope of Mount Simpson 40km further south, in Milne Bay Province, in extreme eastern Papua New Guinea. Its true range is probably small but is likely to include Mount Suckling to the north of Mount Dayman, although it is unlikely to extend further north than this. The type locality is at 1,370m asl, and this species has been recorded from 1,300-1,500m asl on the eastern slope of Mount Simpson.
Habitat and Ecology
This species is generally found along small streams (approximately 2-5m wide) in primary forest. On the eastern slope of Mount Simpson it has been observed to be tolerant of habitat disturbance and in places it lives along village streams largely devoid of trees. If it is similar to other species in the genus, it lays eggs in streams where the larvae also develop.
It is known to be very common in areas of suitable habitat on Mount Simpson.
It is unlikely at present that there are any major threats to this species, even though it is not known to what degree habitat destruction has taken place within its range. It is tolerant of the degree of disturbance that is characteristic of the area at present.
Given the declines of torrent-dwelling hylids in Australia, the population status of this species requires close monitoring.
Stephen Richards, Richard Zweifel, Fred Kraus 2004. Nyctimystes persimilis. In: IUCN 2014