Document Type



The monthly distribution of live births were analyzed over a 26-year period, 1945-1970, for a rural Zapotec-speaking community in Oaxaca, Mexico. Monthly distributions of births deviated from that which would be expected by chance (p < 001). High monthly percentages of births coincided closely with the rainy season in the Oaxaca Valley, so that the number of births during the rainy season exceeded the expected, while the number of births during the dry season were less than expected (p < .(X) 1). Ethnographic observations for Zapotec communities suggest that the seasonal distribution of births may reflect the cultural pattern associated with the annual agricultural cycle.