Why turtles travel in nesting season

Posted
Thursday June 21, 2012

A female painted turtle was the focus of much curiosity and exploration among a group of preschoolers that I spent time with recently. She had climbed out of a river, crawled through the shoreline buffer of silver maples and clambered across a lawn in search of a sunny spot to lay her eggs.

This is a vulnerable time for turtles, as they leave the rivers and ponds where they spend most of their life, following an irresistible urge to produce the next generation of their kind. But it is also the time when we have the best chance for a close encounter with this common but normally skittish reptile.

The children had many questions and declarations during their close encounter.

"It's a snapper!" one boy exclaimed.

I explained that it was opening its mouth in attempts to startle us, but that the red and yellow stripes on its face, plus its smooth shell and small size, made it a harmless painted turtle.

One of the girls asked, "Why is he here?"

I answered that "he" was probably a "she" and showed them how to determine the gender of a turtle.

Often the plastron (lower shell) of the female is flatter than the male's. However, an unmistakable sign is that the male has long front claws used for clinging to the female's shell during mating. His tail is also thicker and longer, with the anal opening beyond the rear margin of the shell. The opening on the female's thin, short tail is under the edge of the shell.

I also suspected the turtle was a female because she was on land. From May through July, females may travel up to a half a mile from the water to find a suitable place to dig her nest and deposit five to 10 eggs. These eggs are oblong, about 1.5 inches long by 0.75 inches wide. The leathery shell is white or may have a yellow tint.

The eggs will be warmed by the sun throughout the summer. The temperature of the nest influences the sex of the hatchlings. Females are formed if the temperature is very high or low, and males develop when the temperature is more moderate. Because the eggs at the bottom of the nest may be a different temperature than those at the top, a single nest can produce both male and female young. The young may emerge in mid-August to late September, but some may overwinter in the nest and come out the following May.

Turtle nests are nearly impossible to see, because the female covers them so the ground looks as though she was never there. Predators such as skunks, raccoons and foxes use their sense of smell to find the nests though and frequently dig up and consume the eggs within 48 hours. It is estimated that 50 to 90 percent of nests are destroyed this way.

Egg predation is only one of the challenges that turtles face. During their journey on land the adults are also vulnerable to predators. Their webbed feet make them adept at swimming but awkward out of the water. Because ideal nest characteristics include loose, sandy soil in a sunny spot, females often pick sites along roadsides, gravel banks, or other disturbed areas where human activity occurs. This is the time of year when turtles are seen along the road or even crossing a street. Unfortunately, many of them don't survive these migrations, as they are hit by cars.

The most interesting question that the children asked about our visitor was, "What should we do with her?"

They clearly wanted to help. I explained that the best way to help turtles (or other wild animals) is to put them back where they are found. She was on a mission and needed to complete her task. The only exception is a turtle in the middle of the road, when she can safely be moved in the same direction she was traveling.

The best way we all can help turtles is to be observant and slow down when driving to avoid hitting them. With our caution and respect and a lot of luck, these creatures can live to be more than 30 years old. Good luck to those mommas on a mission!



What: 'Up close with snakes and turtles' -- search for reptiles with naturalist Réné Wendell

Where: Bartholomew's Cobble, Wheatogue Road, Sheffield

When: July 7, 10 a.m.

Admission: $4, or a family for $15

Information: (413) 229-8600, www.thetrustees.org


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