Tuesday, August 20, 2013

WINC Becomes a Turtle Nursery

All sorts of animals are admitted to WINC over the summer—large and small, adult and infant, mammal, bird, and reptile. Among the wide variety of animals cared for at WINC, one of the most abundant is—surprisingly—turtle eggs. We currently have in our incubators over 100 eggs from snappers and painted turtles. Some were recovered from turtles that were deceased upon arrival, but some were laid at the Wildlife In Need Center! One such case is that of a snapping turtle with an interesting story.
WINC is currently caring for a female snapping turtle, which came to us in June after being hit by a car. When she arrived at WINC staff palpated her and discovered she had eggs! Her injuries were serious, but before we put her through surgery to repair her shell, we wanted her to lay her eggs.  After an appointment with our vet we realized she was close to lying because on her radiograph we saw that the first eggs were working their way out. She was given a room to herself with a pool and a large pan of dirt for her to lay her eggs in. After days of waiting, she had still not laid. 
Radiograph showing the 40 eggs the female Snapping Turtle was carrying.
Eventually, Staff had to induce lying by administering a shot of oxytocin into the muscle of the turtle to start the lying process. It was hoped she would make her way to the pan of dirt to lay her eggs, but she had different plans. The turtle floated in the water to lay her eggs while staff member Mandy Feavel had to standby to collect them all as she laid them. In total, there were 40 eggs. They are now reaching the end of their 6-8 week incubation period and are expected to hatch sometime in August.
Even more snapping turtle eggs were recovered by a female who was deceased upon arrival. She had been struck by a car, but staff and interns were able to pull out her eggs—all 63 of them! Over 100 Snapping Turtle eggs join several buckets of Painted Turtle eggs, which are all being incubated in the ICU.
A total of 63 Snapping Turtle eggs from one female.
 One bucket of painted turtle eggs has just hatched on August 6th and the rest are expected soon! The newborn turtles will be monitored for a few days while they finishing absorbing their yolk sac, then they will be released. Baby turtles are independent of their mother upon hatching, so they can be released as soon as possible.
Painted Turtle hatching.
Upon hatching, baby turtles look almost exactly like adults. Besides the obvious size difference, they are also born with two morphological features which distinguish them from full grown turtles. First, most young oviparous (egg-laying) species are born with a caruncle, or egg tooth, which aids in hatching. This is a small, hard point on the tip of their “snout” used to pip the egg shell. The caruncle will be shed within a few weeks. Turtles can also be born with part of the yolk sac still attached to their umbilicus. The yolk sac is mostly absorbed in the egg, but sometimes hatching occurs before this process is finished. The yolk sac should be absorbed in about 3 days.
Snapping Turtle Hatchling saying "Hello" to the world for the first time.
The incubation process is very important for the survival of the baby turtles.  An incubator keeps the eggs at a controlled temperature for long periods of time. Reptile Medicine and Surgery by Mader states three requirements for a good incubator: they should be well-insulated, heat should be evenly dispersed, and the heat should be controlled with a reliable thermostat. They also need to be kept in a moist dirt substrate to allow oxygen flow, moisture, and an even temperature. Many factors affect the health and viability of the developing turtles, so it is important they are undisturbed and kept in constant ideal conditions.

In the wild, eggs can take anywhere from 9 to 15 weeks to hatch, depending on temperature. Higher temperatures cause faster development and therefore earlier hatching. Since our eggs are incubated at a constant warm temperature, we expect a gestation period of about 8-10 weeks. The hatching process is not quick; it can take 24 to 48 hours! Once the first turtles of a clutch hatch, the rest should be expected within a few days. If incubation goes well, we will have over 100 turtles hatching within the next few weeks—how exciting!

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