Phases of the moon: tortoise style

How do you measure the cycle of the moon? If you’re a werewolf, chances are you just howl and transform once the cycle reaches the familiar full moon stage. If you’re a prepared werewolf, you most likely own a calendar that has the cycles labeled on the appropriate dates. But for those werewolves who existed before wall and phone calendars, there was another way. Just like the indigenous peoples of North America, they would use the tortoise.

Since we know werewolves aren’t real (spoiler alert), you may be thinking that reading the phases of the moon via tortoise is just another Halloween-holiday hoax. I’m here to tell you it’s not. To understand how the tortoise was used, we’ll need to look at how the moon cycles. First you need to know that back in those days, the moon was used to keep track of seasonal changes (which is still true today, but chances are most of us have let that skill slip away over the generations). According to some Native American teachings, the moon goes through 13 phases within a year (remember this number) and there are 28 days between each full moon (another number to remember). Depending on the tribe and what was happening in the world (seasonally speaking), such as when harvest would begin, leaves changing, where certain birds were in their migration, etc., indigenous peoples would know what phase the moon was in.

Okay, so how does this relate back to a tortoise? If you look at the top of a tortoise’s shell (also known as the carapace) you’ll see what are called scutes: bony external plates made of keratin (you know, the same stuff that makes up your fingernails). Hopefully you remembered those numbers from earlier. Remember the 13 phases the moon goes through in a year? Guess how many of those larger scutes you’ll find on every tortoise’s shell: 13! If you count the smaller scutes that circle the shell, you’ll discover 28, just like the 28 days between full moons.

Spooky coincidence, right? The coolest part about this is, just like we tell ghost stories during Halloween, each tribe would tell the corresponding story at the beginning of each new phase of the moon, and because seasons, plants and animals’ migration and growth pattern can vary regionally, each tribe had their own individual stories that have been passed down from generation to generation. So next time you see a North American tortoise, try to count the scutes on the top of its shell and remember that just like your trick-or-treat bag is full of candy, a tortoise’s shell is full of generations of stories that connect us to the world around us and the moon above.

Happy Halloween!
Deidre O.
Keeper III, Ambassador Animals