The demographic structure of the migrant groups of fishermen living in Puri, India, is studied. Data on age, sex, birth place, endogamy, consanguinity, and reproductive histories of 1409 couples and a census of 690 households are utilized. The results suggest the existence of three breeding units within the complex, in different stages of settlement as local populations. Random genetic drift has not yet assumed any significant role in any of these populations. Childhood mortality rates are high; 22% in the Vadabalija of Penticotta, 32% in the Vadabalija of Vadapeta and 35% in the Jalary.
In almost all the components of population structure and demographic variables studied, sympatric populations with similar recent migratory histories show greater similarity than the ethnically similar groups.