Most turtle species lay all their eggs at one time in a small single hole. Depending on the species, those eggs won’t hatch for several more weeks to months. Once hatching does start, in a single clutch it can take several days to weeks for all of the eggs to hatch. If you are incubating the turtle eggs, or waiting for a clutch to naturally emerge from the ground, the range of time it can take for all the eggs to hatch can leave you questioning if all the eggs are even alive. There are a few ways to tell if a turtle egg is alive, however, due to the great variability in species incubation, you may not know with 100 percent accuracy if an egg is viable until it hatches.
Handle the egg gently when examining it. Turtle eggs, especially soft-shelled eggs are exceptionally fragile and over handling or rough handling can damage the egg and kill the embryo reports A.C. Highfield in “Practical Encyclopedia of Keeping and Breeding Tortoises and Freshwater Turtles.”
Take the egg into a dark room and hold a small flashlight to the underside of the egg. If the egg is fertile you will be able to see the turtle embryo.
Examine the egg again with a flashlight in a dark room one week after the first exam if you do not see the embryo. The development of turtle eggs is a slow process and you may not have been able to see the development yet.
Watch for color changes on the egg’s shell. When turtle eggs are first laid, the shell is a pink-white color. As the embryo develops, the shells becomes darker and lose the pink coloring. If the egg is not fertile or alive, then there will be no color changes to the egg.
Feel the egg. As the embryo develops, over time the egg texture will change and may feel harder or more rubbery to the touch. Eggs that are not alive or fertile will not have texture changes.