|Head-started Blanding's turtles|
Blanding's turtle nests are protected with wire cages at several locations in Massachusetts. When the babies hatch in the fall they are sent to several institutions to be raised through the winter. By the following spring, they are large enough to improve their chance of survival, and are released back to the swamps where they were collected.
It isn't possible to determine the gender of baby turtles from the outside, but medical technology is now allowing us to look inside their bodies to determine whether they have testes or ovaries. These images are from a recent procedure we did to check the gender of ten head-started Blanding's turtles. The turtles will be released in a month or so.
The turtles are put under anesthesia, and a small incision is made in front of the hind leg to allow the scope to be introduced into the body cavity. The gonad is located along the front surface of the kidney.
In this image, the testicle is the light tan, smooth, elongated structure in the center of the image. It is only a few millimeters in size, but the scope magnifies it so that we can see it better.
We found that all of the babies were male! The gender of Blanding's turtles, like many turtle species, is determined by the incubation temperature of the egg. If the eggs in a nest were all at about the same temperature, all of the babies will be the same sex. For Blanding's, cooler temperatures produce males. So it is likely that the babies that we examined came from relatively cool nests. The biologists that study these turtles will be looking into this in more detail this summer. We are planning to check some more babies soon, and we are hoping to find some females.
We thank the many individuals and institutions that are working on this project in addition to the New England Aquarium: Zoo New England, Hyla Ecological, Oxbow Associates, Mass Wildlife, and U.S. Fish and Wildlife.