Most probably a later addition to this myth, but there is a bemusing, historically stable, and well replicated correlation between stork breeding pairs and human births (1). On a per settlement level, this is commonly attributed to the number of chimneys as typical stork nesting places ≈ number of households ~ births. On a per area instead of a per city scale, I don’t know of any confounders that are quite as obvious; maybe industrialization as a confounder of the area of undisturbed wetlands as stork feeding grounds and an increase first of child mortality and later of sex ed. To be clear, I can’t exclude that medieval or early modern demografers already spotted at least the aforementioned city level correlation, as it’s strikingly clear and stable, but I highly doubt it’s the origin of the myth.
1: https://www.newscientist.com/article/mg26635482-600-the-uncanny-stork-baby-correlation-that-really-is-for-the-birds/
Most probably a later addition to this myth, but there is a bemusing, historically stable, and well replicated correlation between stork breeding pairs and human births (1). On a per settlement level, this is commonly attributed to the number of chimneys as typical stork nesting places ≈ number of households ~ births. On a per area instead of a per city scale, I don’t know of any confounders that are quite as obvious; maybe industrialization as a confounder of the area of undisturbed wetlands as stork feeding grounds and an increase first of child mortality and later of sex ed. To be clear, I can’t exclude that medieval or early modern demografers already spotted at least the aforementioned city level correlation, as it’s strikingly clear and stable, but I highly doubt it’s the origin of the myth. 1: https://www.newscientist.com/article/mg26635482-600-the-uncanny-stork-baby-correlation-that-really-is-for-the-birds/