The type locality of this species is in northern Papua New Guinea, but the exact location is not known. Otherwise the species is known with certainty only from Ivimka Camp, at 100m asl in the Lakekamu Basin, Gulf Province, Papua New Guinea (Richards and Oliver, 2006). Records from Darai Plateau, Southern Highlands Province, Papua New Guinea, and from Dark End Lumber, Gulf Province, Papua New Guinea refer to Litoria sauroni, whereas those from Huon Peninsula, Morobe Province, Papua New Guinea refer to L. dux, and those from the northwestern coastal mountains of Papua New Guinea refer to L. huntorum. Records from the Vogelkop Peninsula in Papua, Indonesia, could refer to one of these species, but most likely represent an undescribed species (S. Richards, pers. comm.). However, Litoria graminea almost certainly occurs more widely in eastern Papua New Guinea than is currently known.
Habitat and Ecology
This is an arboreal species, living entirely in the canopy of lowland and foothill rainforest. It needs high, closed-canopy, forest to survive, and is not found in degraded habitats. Its breeding requirements are unknown, though it possibly lays eggs in tree holes, and presumably breeds by larval development.
Although few specimens of this canopy-dwelling species exist in collections, it is probably abundant where it occurs, based on call records. It is hard to find, and so it has probably been under-sampled.
There is no information on current threats to this species, but it probably requires intact rainforest and so would suffer from forest clearance.
It is not known from any protected areas. Surveys are needed to determine its distribution, ecological requirements and conservation needs.
Richards and Oliver (2006) separated Litoria dux and L. sauroni from this species. The name Litoria graminea has been applied quite widely to canopy-dwelling treefrogs in New Guinea, but in some cases these refer to species that have not yet been described.
Richards, S. & Allison, A. 2008. Litoria graminea. In: IUCN 2014