Identification. The Kiwai are a coastal people of southern New Guinea who live between the Pahoturi and Fly rivers and on the islands and river banks of the estuaries of the Fly and Bamu rivers. Almost all of what we know about these people comes from the work of Gunnar Landtman, who lived among the Kiwai of Kiwai Island in the Fly River Delta for two years from 1910 to 1912 and whose major descriptions were published in 1917 and 1927. This summary is based primarily on these descriptions.
Location. The Fly River Delta lies between 8° and 8° 15′ S and between 143° and 143°45′ E. The Fly River is approximately 80 kilometers wide at its mouth, and Kiwai Island, which is 60 kilometers long and 5 to 10 kilometers wide, is the largest of the islands in the delta. The islands of the Fly and Bamu deltas are extremely low and swampy as are the river banks and coastlines near the mouths of these rivers. In tidal areas, vegetation consists almost exclusively of mangroves and nipa palms, but further inland there are large freshwater swamps and dry savannas. The average annual rainfall at the mouth of the Fly River is about 200 centimeters, most of which falls during the northwest monsoon from December to April. During this period it rains almost every day, and the rain is often accompanied by violent thunderstorms and high winds.
Demography. In 1980 there were approximately 13,400 Kiwai. This figure includes 7,800 speakers of Southern Kiwai, 2,000 speakers of Wabuda, and 3,600 speakers of Bamu Kiwai. The population density of the area is about 2.5 persons per square kilometer. There are no reliable early population estimates for the Kiwai, and there is no reliable information on population growth or decline.
Linguistic Affiliation. Stefan Wurm has identified seven languages in the Kiwai (or Kiwaian) Language Family. The people who call themselves Kiwai, and who are the subject of this summary, speak the Southern Kiwai, Wabuda, and Bamu Kiwai languages. The other four languages of the Kiwai Family are Morigi, Kerewo, Arigibi, and Northeastern Kiwai. The Kiwai Family is part of the Trans-Fly Stock which, in turn, is part of the Trans-New Guinea Language Phylum. According to Wurm, however, the languages of the Kiwai Family are "aberrant members" of the Trans-New Guinea Stock, and the apparent relationship between the languages of the Kiwai Family and the other languages of the Trans-Fly Stock may be the result of relatively recent contact rather than genetic relationship. The languages of the Kiwai Family also show strong connections with the languages of the Upper Fly River area, particularly those of the Ok and Awin-Pa Families.