IMPACT OF RURAL-URBAN MIGRATION ON FERTILITY - A POPULATION ECOLOGY ANALYSIS IN THE KOMBIO, PAPUA-NEW-GUINEA

The Anjangmui dialect group of the Kombio in Papua New Guinea has expe rienced a rapid increase in rural-urban migration since European conta ct commenced in the 1930s. Population ecology analyses of birth and mi gration histories for 240 Anjangmui women showed a higher total marita l fertility rate in the cohort born in 1940-59 than that born in 1920- 39. A decline in the age at menarche for nutritional :reasons, and red uction in the birth interval for behavioural reasons, may explain the fertility difference between cohorts. Comparison of age-specific marit al fertility rates between migrants in urban areas and non-migrants in rural areas revealed higher rates among migrants in the 15-19 and 20- 24 year age groups, but lower rates in the 25-29 year or older age gro ups; the total marital fertility rate for migrants was lower than that for non-migrants. The differences may be attributable to the differen t influences of birth control practices on fertility reduction between the migrants in urban areas and non-migrants in rural areas. It is su ggested that rural-urban migration in the Anjangmui during the post-co ntact period has had the effect of reducing fertility in the populatio n as a whole.