More humans may not be born during the full moon, but apparently more cows are.
Despite common lore, most researchers have remained unconvinced that the moon influences human births, but a new study by a group of Tokyo researchers shows that it does influence the birth of cows.
Associate Professor Tomohiro Yonezawa of the Graduate School of Agriculture and Life Sciences said that the results in human studies may have varied due to factors such as nutrition, social environment, and genetic background.
"However, cows may provide a good model for teasing apart the lunar effect from other factors that also influence birth," he explained.
Over a three-year period between September 2011 and August 2013, Yonezawa and his colleagues analyzed the birth timing of 428 genetically similar Holstein cows that had all been reared in uniform conditions on a dairy farm in Hokkaido, Japan.
The study showed that the birth rate was statistically higher during the near full and full moon; approximately 70 calves were birthed during the full moon, while only 30 to 50 were birthed when the moon was waning.
However, Yonezawa believes the study needs to be replicated with more cows.
"Before we can draw any strong conclusions, we have to verify our results with a larger sample size," Yonezawa said.
And just because more cows give birth during the full moon doesn't necessarily mean more humans do.
"Our findings do not immediately hold true for human births and we still don't know why the number of calves delivered increases around the full moon," Yonezawa said.
"However, we are excited to do further research because the findings should eventually lead to discoveries that can be generalised to human births."