How to Tell the Age of Turtles

The record for the longest-lived turtle is held by one that belonged to thee royal family of the Pacific island nation of Tonga. This turtle lived from 1777 to 1965—an incredible 188 years! Turtles are known for their long lifespan and often live for 50, 75 or even 100 years, depending on the species. But how do you tell the age of turtles when there isn’t any record of when they were born? Well, you can’t tell precisely, but there are ways to reliably estimate the age of turtles. Many turtles have hard shells that form lines on the scutes (scales) of the shell like the growth rings of a tree. Tree rings are an accurate measure of a tree’s age. Turtle scute lines aren’t as precise but you can use them in combination with other information to tell the age of turtles fairly closely. Read on to learn how to tell the age of turtles.

Things You'll Need

  • Turtle
  • Information on the species of your turtle
  • Scale
  • Measuring tape
  • Any information available about the turtle’s history
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Instructions

    • 1

      Identify the turtle’s species. Turtle species vary in their lifespan and this information helps you know how long it took your turtle to mature and how long it might have lived already. Also, it needs to be a turtle species that is hard-shelled. Soft-shelled species don’t form the tell-tale lines. You can use the link below to go to an extensive library of information about many turtle species.

    • 2

      Look closely at one of the scutes. These are the scale-like sections that make up a turtle’s shell. You will see a pattern of lines that formed as the turtle grew and added layers to its shell. Count the lines. This number will be your starting point to estimate the turtle’s age once other information is taken into account.

    • 3

      Weigh the turtle and measure its shell using a measuring tape. Compare your results with a description for this turtle species. If the turtle is small (and especially if there are few rings) it’s a young turtle. Most turtles mature in six years or so, so you can probably guess a young turtle’s age within a year.

    • 4

      Examine the shell for damage and wear if the turtle is big enough to be an adult. A shell that has few scrapes or chips indicates a turtle that is likely to be younger than the number of scute lines indicates. Turtles who have a good food supply and environment or who have been in captivity a long time will grow faster and form more lines. On the other hand, a turtle whose shell is heavily marked may be older than the scute lines indicate.

    • 5

      Put all this together with any information you can gather about the turtle’s past and make an estimate of its age. You won’t be able to say for sure, but you will be able to make a reliable guess within five years for so—perhaps 10 years if it’s a really old turtle.