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Turtles & Tortoises     Some 20 species make their home in Ecuador, which is actually few considering the ideal warm habitats the country can offer them. Especially surprising is the fact that the Amazon hosts so few species. Most living there are the more primitive side-necked turtles (primitive meaning here more ancient specie). The coast boasts of a few species as well and among marine species, the Green Sea Turtle is quite abundant around the Galapagos islands. Speaking of Galapagos, there you find the most famous of them all which is of course the Giant Tortoise, which is dealt with on its own page.   Yellow-foot Tortoise, locally called Motelo, is a terrestrial tortoise found in the Amazon. It would be a terrific choice for being the ancestor of the Galapagos Tortoise as it is quite similar in behavior and shape although much smaller (but animals are known to grow to giant sizes on islands in the absence of predators and other limitations found in the home habitat). But the only problem is that it is not found on the coast and it is very unlikely that once in the past it crossed the Andes and hitched a ride on a vegetation raft heading to the far away isles. This photo was taken in the rainforest and shows the tortoises in its defensive stance with the head tucked in and furthermore shielded by the feet.   This pre-historic looking beast with a triangular shaped head and a long proboscis extending from its snout (a fine adaptation for breathing while submerged) is a sideneck turtle called Matamata. It is an aquatic turtle found living on the bottom of smaller rivers, oxbow lakes and ponds of the Amazon. It is a very aggressive turtle so watch your fingers while handling it. Always (and that goes for any turtles) grab it from behind and keep your hands away from its mouth's range. Their usual prey however are fish which they catch by stealth and a special technique where they very rapidly (movement can't be seen with naked eye) stretch ahead their neck and at same time open their wide mouth which creates an in-rush of water and fish.      Charapa is a large aquatic specie which can grow up to one meter and is found along Amazonian rivers. Those two turtles were photographed while basking in the sun on the Yasuni river in the far eastern rainforest part of the country (another good river to see them is Tiputini). They commonly sit on logs sticking out of the water and dive into the water once approached too closely. Often you will see butterflies sitting on their heads. They suck up fluids around the turtles' eyes and this also seems to benefit the turtles as they do not seem at least bothered by this activity. Charapas are also known as Arrau Sideneck Turtles, Arran Turtles, South American River Turtle or True Amazon Turtle, so do take your pick. This turtle is prized for its delicious meat and their nutritious eggs. That led to some local extinction already and they are now endangered. Conservation efforts are undertaken now to protect them.     Turtles like some other tretapods (animals with four feet) returned back to sea after a fish ancestor crawled out of it some 440 million years ago. Evidence shows that marine turtles exist for some 110 million years and presently there are seven marine species roaming the oceans. The most common specie in Ecuador, especially in Galapagos waters is the Pacific Green Sea Turtle. In that protected marine environment it can encountered in all major diving sites.        The Pacific Green Sea Turtle spends all its life in tropical marine waters (with the exception of females coming ashore for nesting purposes) and feed mostly on marine vegetation. For that life style adaptations took place over time and present marine species have a more flattened shell to avoid water resistance and modified respiration for longer underwater stay. Most importantly their feet evolved into flippers with the front ones used for propulsion and the hind ones for steering and braking.   Female Sea Turtles become fertile in their late twenties and are known to return to the nesting site from where they themselves hatched in order to lay their own eggs. They come only on land at night and lay up to 200 eggs in various nests and leave then again to return in a few years. Once the young hatch they are on their own and that time is the most perilous for the helpless and still soft-shelled young as birds, mammals and reptiles prey on them. It is a race to the sea with the ones reaching it being in more relative safety. That's the reason many eggs are laid to assure survival of a few. Once that early time of their life is mastered and they reach adulthood, they have relatively few enemies. Sharks, especially the tiger sharks, hunt them but the most danger is again by humans. Man's activities puts them all on the endangered species list and protective laws are instituted in some countries. Clearing all those hurdles Green Sea Turtle may live a long life reaching ages up to 100 years.    In Galapagos quite a few sand beaches exist for nesting purposes and tracks lead to the sites which are always located above the tide mark. Baby turtle working its way out of the sand.

Natural History This ancient group of animals make up the order of Testudines (also sometimes denoted as Chelonia)and date back more than 230 million years. That is well before the rise of the dinosaurs and they are still being around after their reptilian relative's mighty fall and extinction. The first testudines could not draw their heads into the shell and this adaptation occurred later. Today there are two major living sub-orders, the more primitive (meaning in the evolutionary context more ancient) Pleurodira, which can already hide their head by bending their necks sideways. Some 70 species belong to them. The other sub-order Cryptodira include all the other turtles and tortoises which pull their head right into the shell bending their neck in an S-shape fashion. Ecologically this group of animals radiated successfully into many niches. You have the land dwelling tortoises which are mostly grazers. The freshwater species heir neckare mostly carnivores and some even returned to the seas. Altogether 250 species in 12 families exist worldwide living in temperate and tropical regions.      Evolutionary Thought It is said that sea turtles use the magnetic field of the earth for navigation. That makes sense as they are known to roam the wide oceans but always return to the site of their hatching. A magnetic imprint at birth lets thus the female and male return to the beach of their births. But how do they deal with the ongoing deviations of the wandering magnetic pole and in the extreme with the reversals of magnetic pole from north to south and back again which happens quite often but irregularly over geological time?      Ecuadorian  Species   Name Scientific Location   Giant Tortoise (Galapagos) Geochelone elephantopus Galapagos  (terrestrial) Yellow-footed Tortoise (Motelo) Geochelone denticulata Amazon (terrestrial) Matamata Chelus fimbriatus Amazon (aquatic) Yellow-Spotted River Turtle Podocnemis unifilis Amazon (aquatic) Chelydra acutirostris(Charapa) Podocnemis expansa Amazon (aquatic) Common Snapping Turtle (Mordedora) Chelydra serpentina Coast (aquatic) White-lipped Mud Turtle (Taparrabo) Kinosternon leucostomum Coast (aquatic) Green Sea Turtle Chelonia mydas Pacific (marine) Hawksbill Sea Turtle (Carey) Eretmochelys imbricata Pacific (marine) Leatherback Sea Turtle Dermochelys coriacea Pacific (marine)        Biologically Speaking Their most distinctive feature and which sets them apart from other larger animals is that hard shell which protects their body. This shell is made up of several bony plates covered with a horny shield. The ribs and backbone of the animal are attached to the inside of the shell to give it added strength (therefore it is impossible for them to crawl out of their own shell). Terrestrial turtles, commonly named tortoises have a dome shaped shell whereas aquatic and marine turtles have a more flattened shell, which does not hinder it swimming or diving in the water. In case of danger all turtles retract their feet, tail and head into the carapace, which is the upper or dorsal part of the shell. The lower or ventral half (which however in some species is soft) is called the plastron and protects it from underneath. As they are already around for so very long they surly arrived at a successful solution.        Turtle Vocabulary   Terrestrial:  living primarily on land and feeding mostly on vegetation, those species are also commonly called tortoises, wherelse the other ones are named turtles. Aquatic:  species living in a freshwater water environment like lakes, rivers and swamps. Marine:  spending their entire lives in oceans and coming only on land to deposit eggs.