Carbon and nitrogen isotopic characterization for Papua New Guinea foods

Stable carbon and nitrogen isotope ratios of the animal and plant food of the Gidra, who inhabit lowland Papua New Guinea and subsist mainly on hunting, gathering and horticulture, were measured to characterize the nutritional input of carbon and nitrogen of the Gidra. All the staple plant foods of the Gidra, such as sago and tuberous crops, were classified as C3 plants from their ¹³C/¹²C ratios (δ¹³C). The δ¹³C of the terrestrial mammals varied to a considerable extent (—11 to —26.5 per mil); the highest value was observed for a species of wallaby inhabiting savanna grassland while two other species of wallabies inhabiting woodland were —25.3 and —22.8 per mil. The δ¹³C of the aquatic animals was distinctive between marine (—17.0 to —7.1 per mil) and freshwater (—34.6 to —24.0 per mil) groups. The δ¹⁵N of the fishes and reptiles were generally higher than terrestrial animals. Major foods of the Gidra were isotopically divided into 5 groups: C3 plant, C3 plant feeder, C4 plant feeder, marine animal and freshwater animal.

Key words:

• Papua New Guinea
• food
• carbon
• nitrogen
• stable isotope analysis
• isotopic characterization

Notes

Present address: Environmental Chemistry Division, National Institute for Environmental Studies, Onogawa 16–2, Tsukuba‐shi, Ibaraki 305, Japan.