A rhythmic dance: how lunar cycles influence reproductive behavior in vertebrates

This review explores how lunar-controlled rhythms influence vertebrate reproduction, bridging the gap between historical folklore and modern science. For centuries, cultural beliefs have connected the moon’s phases to fertility and natural cycles. Recent chronobiological studies have uncovered more specific connections, identifying complex lunar rhythms in many aquatic species that combine daily and tidal cues to regulate behaviors like spawning and migration. While circalunar and circasemilunar clocks are known to regulate reproduction in numerous invertebrates and vertebrates, the most exciting discoveries lie ahead. In the meantime, this review aims to synthesize current scientific literature to examine how lunar rhythms specifically influence reproductive behavior in vertebrates. Analyzing studies across fish, amphibians, reptiles, birds, and mammals (including humans), this review highlights how lunar phases have discernible effects on several reproductive aspects, including courtship, ovulation, semen quality, conception, embryonic development, and parturition timing. In conclusion, the growing scientific interest in lunar influence on animal reproduction underscores its potential significance in animal biology. Further interdisciplinary research is necessary to elucidate the underlying physiological mechanisms and explore their practical applications.