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Archive for June 19, 2017

Snapping Turtles Laying Eggs

6-19-17 snapping turtle laying eggs2 309In June,  mature female Snapping Turtles leave their ponds in search of a sandy spot in which to lay their eggs. (Capable of storing viable sperm for up to three years, female snappers do not necessarily mate every year prior to laying eggs.) Once this prehistoric-looking reptile locates a suitable location she slowly scoops one footful of earth at a time up and to the rear of her, alternating her left and right hind feet. If the soil is dry and tightly packed, she will urinate on it in order to facilitate digging.

Hole made, she proceeds to slowly lift her body and release ping pong ball-sized, -colored and -shaped eggs, usually one at a time, but occasionally two, into the hole beneath her. Down she comes for a minute or two of rest, and then up she rises again to release another egg. She does this anywhere from 20 to 40 times, a process that can take up to several hours, depending on the number of eggs she lays. Then her large, clawed hind feet slowly begin to scrape the two piles of soil she removed back into the hole, one foot at a time, until the eggs are covered, at which point she tamps the soil down with her plastron, or bottom shell. She then returns to the water, leaving the eggs and hatchlings to fend for themselves.

It is hard to accept that after all the effort that has been put into this act, studies have shown that 90 percent or more of turtle nests are raided by the likes of raccoons, skunks and crows. For those nests that are not discovered by predators, the sex of the turtle that emerges from each egg is determined by the temperature it attained during a specific part of its development. Eggs maintained during this period at 68°F produce only females; eggs maintained at 70-72°F produce both male and female turtles, and those incubated at 73-75°F produce only males. The eggs hatch in September, with many of the Snapping Turtles emerging then, but in the northern part of their range, young Snapping Turtles sometimes overwinter in their nest and emerge in the spring. (Thanks to Chiho Kaneko and Jeffrey Hamelman for photo op.)

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