Yertle The Amazonian Turtle

The Yellow-Spotted Amazonian River turtle or Podocnemis unifilis is one big turtle.  With females weighing 5.3-11.6 kg and their carapaces (hard upper shell of the turtle) reaching sizes of 52 cm long by 45 cm wide (males about half that weight and size), the Yellow-Spotted Amazonian Turtle is one of the largest species of turtle alive today.  Hence its name, the turtle is native to the Amazon River basin and can be found in the Amazon and Orinoco rivers in Venezuela, eastern Columbia, northeastern Peru, eastern Ecuador, the Guianas, northern Bolivia, and Brazil.  To achieve their large size, they feed on fruits, weeds, fish, and small invertebrates making them omnivores.  They spend the majority of their time in large rivers, backwaters, lagoons, and flooded forests.  Coming on land only to bask in the sun, reproduce, and lay their eggs.  This turtle can be easily identified by its large size and the yellow spots on their brown/gray head.  These yellow spots do fade as the females age, but are present on males throughout their lifespan.  These turtles can live up to 20 years on average in captivity, but some think as long as 70 years old in the wild as long as they can avoid the biggest threat to their continued existence which I will address later.

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The Yellow-Spotted Amazonian Turtle http://lavishlifeofhenry.blogspot.com

Pleurodira and Cryptodira are the two living suborders of turtles today.  Turtles are divided into these suborders depending on how they retract their heads into their shells.  Cryptodira meaning the turtle withdraws its head vertically into its shell, and Pleurodira meaning the head is withdrawn horizontally.  The differences in head retraction come from differences in the turtles’ anatomy of the cervical vertebrae.  Turtles falling into the Pleurodira suborder possess narrow cross-section and spool shaped centra (solid central part of the vertebra).  Because centra are shaped like this, it allows the Yellow-spotted turtle to withdraw its head by folding it sideways into its shell.

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Pleurodira vs. Cryptodira Neck Movement    http://borbl426-526.blogspot.com

The Yellow-Spotted Amazonian turtles’ mating season varies with location, but the courting ritual and the rest of the process remains unchanged.  During mating season, females will congregate on a beach to bask and wait for males.  The male turtles, like other Pleurodira turtles, court the females by biting at their feet and tails.  Approximately two weeks after a mate is selected, the female turtle will lay 15-20 eggs in a shallow hole dug in the sand.  The female will then cover the eggs in sand, pat the loose sand down, and finally return to the water.  Roughly two months later the eggs will hatch, and the baby Yellow-Spotted turtles will make their way to the water.

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Yellow-Spotted Amazonian turtle nest and eggs. http://www.gettyimages.fr/photots

Due to their large size, the turtle nests and the juveniles are preyed upon most often.  The Yellow-Spotted Amazonian turtle is preyed upon by birds, snakes, large fish, frogs, and other mammals.  However, the greatest threat to these turtles is the Yekuana Indians (a native indigenous people) who have hunted the turtles and their eggs for food.  Recently, the Yekuana Indians have begun to hunt the turtle in a more sustainable way, leaving their eggs alone and only taking the largest turtles for food.  The Yellow-Spotted Amazonian turtle also faced threats from the pet trade in the 1960s.  The Yellow-Spotted turtles’ coloration provided a contrast to the more commonly sold Red-eared Slider turtle and was highly sought after.  It was not until 1970 that the species was protected under the Endangered Species Act, resulting in more rules and regulations regarding the collecting and transporting of these animals.  Finally, rises in global temperatures have affected the Yellow-Spotted turtles numbers in the wild.  Because the sex of the egg is temperature dependent, a small increase or decrease in temperature can drastically alter the numbers of females and males in a population.

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Yellow-Footed tortoise captured by the Yekuana Indians. http://www.arkive.org/south-american-yellow-footed-tortoise

Due to multiple threats against the Yellow-Spotted Amazonian turtle, it is listed as Vulnerable on the IUCN Red List of Threatened Species.  As the pet trade becomes more regulated and with the new conservation efforts of the Yekuana Indians, hopefully the Yellow-Spotted turtle will continue to survive in the Amazon.  If you are looking to see this amazing turtle without a long trek, I highly recommend going to the reptile house at the Lincoln Park Zoo to see one of these amazing turtles in person.

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Photograph of a Yellow-Spotted Amazonian turtle taken by myself at the Lincoln Park Zoo.                      http://www.lpzooo.org
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