Alison E. Mitchell, |Executive Director at njconservation.org, emailed a post (they don't seem to be available online) about the Moon and wildlife. It got me thinking, since I post about all the Full Moons on another blog of mine, and tonight is a Full Moon.
It is often said that Full Moons affect humans, but the evidence is weak. It does affect things that affect humans. The gravitational field of the Moon is the dominant factor controlling terrestrial tides, contributing approximately twice the tidal force of the Sun due to its relative proximity to Earth. This profound geophysical cycle is hypothesized to drive corresponding circalunar rhythms in various biological organisms.
Wildlife, especially marine wildlife, is affected by the Moon. A direct correlation is observed between the lunar cycle and the reproductive success of certain coastal species. Specifically, the syzygy tides (occurring during Full and New Moons, resulting in maximum tidal range) facilitate the mass spawning event of Limulus polyphemus (horseshoe crabs) on beaches. This predictable influx of eggs is a critical nutritional resource for migratory avifauna, such as the endangered Calidris canutus rufa (red knot), enabling their protracted flight to Arctic breeding grounds.
Furthermore, celestial navigation is a documented behavioral pattern in marine life. Sea turtle hatchlings and nesting females utilize the luminance gradient provided by the Moon's reflection on the ocean surface to orient their movements toward the sea.
In benthic organisms, circalunar periodicity is evident in bivalves. Studies on Crassostrea gigas (oysters) have revealed a correlation between valve opening/closing behavior and the lunar phase, with maximal closure observed during the full moon. This phenomenon is likely an adaptive response linked to lunar-driven alterations in hydrodynamics and seston availability.
Moving onto land, the Moon's light intensity modulates the behavior and inter-species interaction of nocturnal fauna. Increased moonlight can enhance the foraging efficiency of certain predators while simultaneously elevating the detection risk for smaller prey species. For instance, the white plumage of Tyto alba (barn owls) is theorized to increase crypsis against the illuminated sky, affording a hunting advantage.
With us humans, the co-evolutionary history between life and the lunar cycle extends to circadian rhythms that are primarily guided by photoperiod (sunlight). Recent research published in Science Advances identified a statistically significant correlation between the length of the human menstrual cycle and the 29.5-day lunar phase cycle. These findings underscore the deep-seated biological integration with Earth's natural cycles. Ongoing research continues to elucidate the complex mechanisms linking lunar periodicities to animal physiology and behavior.
Then again, you can also just look up at the Moon when it is full, new, or in any phase and wonder at the wonder of it all.
To learn more about how you can help preserve New Jersey’s natural resources,
visit the New Jersey Conservation Foundation at www.njconservation.org
