In 2014 I published a study on human birth seasonality and childhood disease in Proceedings of the Royal Society Biological Sciences as co-first author with Kevin Bakker. Using data from countries throughout the Northern Hemisphere, we found pronounced seasonal fluctuations in human birth rates. We demonstrated that the timing of the seasonal birth pulse varies from place-to-place. Regions further from the equator have a birth pulse that occurs early in the year, while places closer to the equator have a birth pulse that occurs later. We showed that birth seasonality is important for the study of childhood infections, because large seasonal influxes of infants into a population can interact with the transmission of diseases such as measles and polio to either exacerbate or dampen the size of epidemics.
Here is our manuscript:
Martinez-Bakker, Bakker, King, and Rohani (2014). Human Birth Seasonality: Latitudinal Gradient and Interplay with Childhood Disease Dynamics. Proceedings of the Royal Society B: Biological Sciences, 281. PDF. Supporting Information. Altmetrics for this publication.
This work garnered some media attention. Below are select news releases.
Why Northerners are Born Earlier in the Year than Southerners in The Business Insider.
When are Moms Most Likely to Make Babies? video by DNews
Here are also some more general interviews about why susceptible recruitment (via births) matters for childhood disease dynamics:
Unvaccinated Infants Work as ‘Kindling’ to Fuel Epidemics in Michigan News.
Unvaccinated Infants Fueling Disease Epidemics in Fox News