The annual birth cycle in rural Egypt peaks in December and has two distinguishable minima in June and September. This pattern bears a striking inverse resemblance to the seasonal movements of employment and wages. Infant and child mortality and marriage also display stable, though different seasonal patterns. The paper explores whether the correlation between labor demand, mortality events and fertility reflect some causal behavioral relationship. It is shown that the probability of a birth is lower in months with high opportunity cost of time. Direct replacement is a significant phenomenon in rural Egypt and it occurs fairly quickly.