Turtles!
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He turned and spread all four flippers and launched himself off the branch.
On landing at the bottom in a pile of soft, dead leaves, he shook himself off, walked back to the bottom of the tree and with a sigh started to climb.
About an hour later, he again reached the very high branch, walked along, turned, spread his flippers and flung himself off the branch. Again, he landed on the bottom, shook himself off, went to the bottom of the tree, sighed and started climbing.
Watching these proceedings from the end of the branch were two little birds.
Mummy bird turned to Daddy bird and said, "Don't you think it's time we told him he was adopted?"
Turtle housing
The ideal situation for your pet is to duplicate its natural environment as closely as possible. Turtles can grow very large when cared for properly and given plenty of space to swim. A large heated aquarium, provided with a deep swimming area and rock or shelf where the turtle can get completely out of the water provides suitable indoor quarters. Some baby turtles are best reared in very shallow water, allowing them to feed in slightly deeper water. In warm climates or during the summer, turtles can be kept outdoors in ponds or plastic pools with islands fashioned from rocks or floating basking material such as logs or cork boards. With smaller turtles be sure to cover the pool with screening to prevent the entry of birds, cats, dogs, etc. NEVER put turtles (or tortoises) outside in a glass aquarium as the glass heats up too fast, making the water extremely hot. The pool or pond should also be partially shaded. (A board placed over a portion of the pool will allow needed shade. The setup should be completely dismantled and scrubbed thoroughly from time to time to Prevent growth of microorganisms that can cause illnesses. A calcium block made from plaster of paris or one purchased from a pet store should be placed in the water.Care of Turtles
Correct temperature for turtles
A heat source must be provided, whether an aquarium heater or the light itself. Submersible heaters are available which allow more shallow water than regular aquarium heaters require. Temperature should be maintained at 75-85°F. An overhead light for warmth during the day should be installed above the basking area. It should be turned off at night to simulate normal daytime/nighttime conditions in nature.Turtles need natural sunlight
This is essential to the well being of the average water turtle in order to properly utilize calcium and to properly assimilate the food as well as for curing sundry minor scratches or skin ailments. Sunlight filtered through the glass is deprived of its value; sunlight must reach the turtle unfiltered. When placing a turtle in the sun, be sure a shaded area is available to escape the heat, which can kill it quickly. Also watch to see that the water does not become too hot from the sun. UVA/UVB bulbs are good sun substitutes used in conjunction with direct sunlight. They require a fluorescent fixture for installation, and do not give off warmth for basking purposes. If preferred to this lighting arrangement a Mercury vapor bulb may be used that fulfills all requirements.Turtle feeding
Most turtles must be fed directly in the water; otherwise they cannot swallow. Turtles eat a variety of chopped lean raw meats and occasional greens. A few turtles like banana as a treat. Beef, fish, smelt and fresh shellfish, earthworms, tubifex worms and brine shrimp (for babies) should comprise their diet. Calcium, bone meal and liquid or powdered vitamins should be added to their food to supplement their diet. Small turtles should be fed every day and larger ones at least three times a week. Always remove excess food when the turtle shows no further interest in it. Some turtle keepers prefer to feed their pets in a separate container for easier tank cleaning, but some turtles will not feed when removed for their tank for feeding. Great advances have been made in the last few years with high quality prepared foods, many turtles take readily to these as part of a varied diet.Turtle diseases
Most turtle ailments land and aquatic—are a result of improper diet and lack of natural sunlight. All sick turtles should be isolated from other turtles, and newly acquired turtles (or tortoises) should be isolated for at least three months and watched for disease symptoms before placing them in with others. Fungus appears as white or gray spots, lumps or flakes on the shell and fleshy parts. Adding 1/4-cup plain table salt to each five gallons of water is a good preventative. Fungus remedies sold for tropical fish can be used in the water. Shell fungus can be painted lightly with 5% iodine, allowing it to dry before putting the turtle back into the water. This procedure should be repeated daily. Very clean water and natural sunlight are needed to facilitate healing, which can take up to a year.A soft shell and swollen eyes are due to improper diet and lack of natural sunlight. Make sure vitamins and bone meal are added to the diet and that the turtle is placed in unfiltered sunlight for several hours each day (a shaded area must be provided when placing the turtle in the sun). Immediately consult a veterinarian experienced in treating turtles and he can recommend the proper treatment. Call another keeper, your Humane Society, or a local club for a referral. If you are online, go to Locating a Veterinarian to find a reptile medicine specialist near you. You can also network to find a vet near you that works with turtles.
Turtles are highly susceptible to respiratory ailments caused by drafts, abrupt temperature changes and improper diet. Symptoms include gasping and runny or bubbly noses. The turtle should be kept warmer than normal and quiet to hasten recovery. If the condition does not improve in short order, consult a veterinarian. Time is always critical in reptile and amphibian illnesses because, by the time the affliction has manifested itself, it has reached a possibly fatal stage.
Flesh injuries resulting from bites, scratches, or cuts can be treated with a variety of antibiotic ointments and/or creams which your veterinarian can recommend. Water soluble antibiotic ointments such as nolvasan ointment or silver sulfadiazine are best as they do not impede healing like oil based creams do. NOTE: Anytime a turtle or tortoise is injured, it MUST be brought into the house immediately to prevent flies from laying eggs on the wound; maggots will result. Basking rocks should be checked for sharpness and replaced if too sharp or abrasive. Remember that water turtles must surface occasionally and can brush the rocks.
Turtles for sale
In 1975 an attempt to curtail the incidence of turtle-associated Salmonella infections in the United States Federal regulations now restrict the sale of turtles less than four inches and their eggs. Turtle farms that are producing millions of baby turtles each year can only sell their harvest directly to customers overseas or to other exporters in the United States.There are exceptions within PHSA (42 U.S.C.271) which, states
(1) The sale, holding for sale and distribution of live turtles and viable eggs for bona fide scientific, educational, or exhibition purposes, other than use as pets.
(2) The sale, holding for sale, and distribution of live turtles and viable turtle eggs not in connection with a business.
(3) The sale, holding for sale, and distribution of live turtles and turtles eggs intended for export only, provided that the outside of the shipping package is conspicuously labeled ìfor export only.?
(4) Marine turtles excluded from this regulation under provisions of paragraph (a) of this section and eggs of such turtles.
Turtles sold are purchased from multipliable bonafide breeders who provide us with educational and scientific data of their harvest. This information, along with care instruction is sent with each turtle order. Therefore, some areas have allowed pet stores to sell turtles under 4 inches once a sign is posted (educational purpose only) and proper care information is provided.
All turtles under 4 inches are sold for scientific, educational, or export purposes only.
Galapagos Turtles
The Galapagos tortoise (or Galapagos giant tortoise), is the largest living tortoise, native to seven islands of the Galapagos archipelago. Fully grown adults can weigh over 300 kilograms (661 lb) and measure 1.2 meters (4 ft) long. They are long-lived with a life expectancy in the wild estimated to be 100-150 years. Populations fell dramatically because of hunting and the introduction of predators and grazers by humans since the seventeenth century. Now only ten subspecies of the original twelve exist in the wild. However, conservation efforts since the establishment of the Galapagos National Park and the Charles Darwin Foundation have met with success, and hundreds of captive-bred juveniles have been released back onto their home islands. They have become one of the most symbolic animals of the fauna of the Galapagos Islands.Galapagos Turtles Anatomy and morphology
Galapagos Turtles Shell
The tortoises have very large shells (carapace) made of bone. The bony plates of the shell are integral to the skeleton, fused with the ribs in a rigid protective structure.Naturalist Charles Darwin, remarked "These animals grow to an immense size, several so large that it required six or eight men to lift them from the ground." This is due to the phenomenon of island gigantism whereby in the absence of natural predation, the largest tortoises had a survival advantage and no disadvantage in fleeing or fending off predators.
When threatened, it can withdraw its head, neck and forelimbs into its shell for protection, presenting a protected shield to a would-be predator. The legs have hard scales that also provide armour when withdrawn. Tortoises keep a characteristic scute pattern on their shell throughout life. These have annual growth bands but are not useful for aging as the outer layers are worn off. There is little variation in the dull-brown colour of the shell or scales. Physical features (including shape of the shell) relate to the habitat of each of the subspecies. These differences were noted by Captain Porter even before Charles Darwin. Larger islands with more wet highlands such as Santa Cruz and the Alcedo Volcano on Isabela have lush vegetation near the ground. Tortoises here tend to have 'dome-back' shells. These animals have restricted upward head movement due to shorter necks, and also have shorter limbs. These are the heaviest and largest of the subspecies.
Smaller, drier islands such as Española and Pinta are inhabited by tortoises with 'saddleback' shells comprising a flatter carapace which is elevated above the neck and flared above the hind feet. Along with longer neck and limbs, this allows them to browse taller vegetation. On these drier islands the Galapagos Opuntia cactus (a major source of their fluids) has evolved a taller, tree-like form. This is evidence of an evolutionary arms race between progressively taller tortoises and correspondingly taller cacti. Saddlebacks are smaller in size than domebacks. They tend to have a yellowish color on lower mandible and throat. At one extreme, the Sierra Negra volcano population that inhabits southern Isabela Island has a very flattened "tabletop" shell. However, there is no saddleback/domeback dualism; tortoises can also be of 'intermediate' type with characteristics of both.
Sexual dimorphism is more apparent in the 'intermediate' and saddleback populations since males have more angled and higher front openings. Males also have a longer tail and a shorter and concave undershell and which has thickened knobs at the back edge, which facilitates mating. Male are larger than females: adult males weigh in at 272-317 kg; females 136-181 kg.
Galapagos Turtles Range and distribution
The Galapagos tortoise is unique to the Galapagos Islands, a group of thirteen major islands and many smaller islets, all of volcanic origin lying west of Ecuador in South America.Galapagos Turtles Ecology and behavior
The tortoises are slow-moving reptiles with an average long-distance walking speed of 0.3 km/h (0.18 mph). Although feeding giant tortoises browse with no apparent direction, when moving to water-holes or nesting grounds, they can move at a surprising speed for their size. Marked individuals have been reported to have traveled 13 km in two days.On the wetter islands, the tortoises migrate down gentle mountain slopes after the wet season to feed on the grass-covered plains. In the dry season they climb back up to feed on grasses of the mountain meadows. On these islands, the tortoises appear to be gregarious, often found in large 'herds'.
Being cold-blooded, the tortoises bask for two hours after dawn, absorbing the energy through their shells, then becoming active for 8-9 hours a day. They may sleep for about sixteen hours in a mud wallow partially or submerged in rain-formed pools (sometimes dew ponds formed by garua-moisture dripping off trees). This may be both a thermoregulatory response and a protection from parasites such as mosquitoes and ticks. Some rest in a 'pallet'- a snug depression in soft ground or dense brush- which probably helps to conserve heat and may aid digestion. On the Alcedo Volcano, repeated use of the same sites by the large resident population has resulted in the formation of small sandy pits.
Darwin observed that: "The inhabitants believe that these animals are absolutely deaf; certainly they do not overhear a person walking close behind them. I was always amused, when overtaking one of these great monsters as it was quietly pacing along, to see how suddenly, the instant I passed, it would draw in its head and legs, and uttering a deep hiss fall to the ground with a heavy sound, as if struck dead." The tortoises can vocalise in aggressive encounters, whilst righting themselves if turned upside down and, in males, during mating. The latter is described as "rhythmic groans".
Galapagos Turtles Diet
The tortoises are herbivorous animals with a diet comprising cactus, grasses, leaves, vines, and fruit. Fresh young grass is a favorite food of the tortoises, and others are the 'poison apple' (Hippomane mancinella) (toxic to humans), the endemic guava (Psidium galapageium), the water fern (Azolla microphylla), and the bromeliad (Tillandsia insularis). Tortoises eat a large quantity of food when it is available at the expense of incomplete digestion.By acquiring most of their moisture from the dew and sap in vegetation (particularly the Opuntia cactus), tortoises can go for long periods without actually drinking. They can also survive for over a year being forcefully deprived of all liquids, by breaking down their body fat to produce water.
Galapagos Turtles Mutualism
Tortoises have a classic example of a mutualistic symbiotic relationship with some species of Galapagos finch. The finch hops in front of the tortoise to show that it is ready and the tortoise then raises itself up high on its legs and stretches out its neck so that the bird can pick off ticks that are hidden in the folds of the skin (especially on the rear legs, cloacal opening, neck, and skin between plastron and carapace), thus freeing the tortoise from harmful parasites and providing the finch with an easy meal. Other birds, including Galapagos Hawk and flycatchers, use tortoises as observation posts from which to sight their prey.Galapagos Turtles Reproduction
Mating occurs at any time of the year, although it does have seasonal peaks between January and August. When two mature males meet in the mating season they will face each other, rise up on their legs and stretch up their necks with their mouths open to assess dominance. Occasionally, head-biting occurs, but usually the shorter 'loser' tortoise will back off, leaving the other to mate with the female. In groups of tortoises from mixed island populations, saddleback males have an advantage over domebacks. Frustrated non-dominant males have been observed attempting to mate with other males and boulders.The male sniffs the air when seeking a female, bellows loudly, and bobs his head. The male then rams the female with the front of his shell and bites her exposed legs until she withdraws them, immobilizing her. Copulation can last several hours with roaring vocalisations from the males. Their concave shell base allows males to mount the females from behind. It brings its tail which houses the penis into the female's cloaca.
After mating (June-December), the females journey up to several kilometres to reach nesting areas of dry, sandy ground (often near the coast). Nest digging can last from hours to days and is elaborate and exhausting. It is carried out blindly using only the hind legs to dig a 30 cm deep hole, into which she lays up to sixteen hard-shelled eggs the size of tennis balls. The female makes a muddy plug for the nest hole out of soil mixed with urine and leaves the eggs to incubate. In rocky areas, the eggs are deposited randomly into cracks.
The young emerge from the nest after 120 to 140 days gestation later (December-April) and may weigh only 80 grams (2.8 oz) and measure 6 centimetres (2.4 in). Temperature plays a role in the sex of the hatchling: if the nest temperature is lower, more males will hatch; if it is high, more females will hatch. When the young tortoises emerge from their shells, they must dig their way to the surface, which can take up to a month. All have domed carapaces, and subspecies are indistinguishable. Galapagos Hawk used to be the only native predator of the tortoise hatchlings, as Darwin remarked: "The young tortoises, as soon as they are hatched, fall prey in great numbers to buzzards".
Sex can be determined only when the tortoise is 15 years old, and sexual maturity is reached at 20 to 25 years old. The tortoises grow slowly for about 40 years until they reach their full size. Reproductive prime is considered to be from the ages of 60-90.
Galapagos Turtles Etymology and taxonomic history
The shape of the carapace of some subspecies of the tortoises is said to have reminded the early Spanish explorers of a kind of saddle they called a "galápago," and for these saddle-shaped tortoises they named the archipelago. Up to 250,000 tortoises inhabited the islands when they were discovered. Today only about 15,000 are left.The inhabitants...state that they can distinguish the tortoise from different islands; and that they differ not only in size, but in other characters. Captain Porter has described those from Charles and from the nearest island to it, namely Hood Island, as having their shells in front thick and turned up like a Spanish saddle, whilst the tortoises from James Island are rounder, blacker, and have a better taste when cooked.---Charles Darwin 1845.
There were probably twelve subspecies of Geochelone nigra in the Galapagos Islands, although some recognise up to 15 subspecies. Now only 11 subspecies remain, five on Isabela Island, and the other six on Santiago, Santa Cruz, San Cristóbal, Pinzón, Española and Pinta. Of these, the Pinta Island subspecies is extinct in the wild and is represented by a single individual. In the past, zoos took animals without knowing their island of origin. Production of fertile offspring from various pairings of tortoises largely confirmed that they are subspecies and not different species.
All the subspecies of giant tortoise evolved in Galapagos from a common ancestor that arrived from the mainland, floating on the ocean currents (the tortoises can drift for long periods of time as they are buoyant and can stretch head upwards to breathe). Only a single pregnant female or breeding pair needed to arrive in this way, and then survive, for Galapagos to be colonised. The closest living relative of the Galapagos giant tortoises is Geochelone chilensis, a small tortoise found in Chile. The split between G. chilensis and the Galapagos lineage probably occurred 6-12 million years ago based on mitochondrial DNA analysis, before the origin of the oldest extant Galapagos island.
Espanola and San Cristobal, the oldest islands, were colonized first; this was followed by several migration events to and between other islands via local currents. The four named southern subspecies on the largest island, Isabela, are possibly not distinct genetic units, whereas a genetically distinct northernmost Isabela subspecies is probably the result of a separate colonization. Unexpectedly, the lone survivor of the abingdoni subspecies from Pinta Island ("Lonesome George") is very closely related to tortoises from San Cristobal and Espanola, the islands farthest from the island of Pinta. This informed breeding attempts more successful in the future as breeding had been attempted with Isabela Island populations
It is thought that the saddle-backed type carapace evolved independently several times as a reaction to dry environments, although extinction of crucial populations by human activities confounds whether domed versus saddleback carapaces of different populations are mono- or polyphyletic.
Pending further discussion the more conservative subspecies arrangement is retained here. Population details for each subspecies are summarised below.
Only one known purebred individual is alive ("Lonesome George"), and is currently maintained at the Charles Darwin Research Station. This population was severely depleted by whalers and fishermen, and the introduction of goats in 1958 resulted in massive destruction of vegetation. Tortoise droppings, probably not more than a few years old, were found in the island in 1981, so there is a possibility that a second individual of this subspecies still exists, though this appears
increasingly unlikely. Recent reports of a clutch of eggs in Lonesome George's enclosure have garnered excitement that the lineage may continue. Extinct in the wild, hybrid eggs have been laid and at least one hybrid adult is also known
Heavily exploited and completely eliminated over much of its original range. Trampling of nests by feral donkeys, and the predation of young by feral dogs decimated populations, but the breeding program had led to successful releases.
Large numbers of tortoises were removed from the island in the early nineteenth century by whaling vessels, and introduced goats reduced the coastal lowlands to deserts, restricting the remaining tortoises to the interior. The sex ratio is strongly imbalanced in favour of the males and most nests and young are destroyed by feral pigs. Some nests are now protected by lava corals and since 1970 eggs have been transported to the Charles Darwin Research Station for hatching and rearing. Release programs have been successful.
Although relatively undisturbed by whalers, fairly large numbers of tortoises were removed by expeditions in the latter half of the nineteenth century and early twentieth. After the introduction of black rats some time before 1900, there was no natural breeding. Since 1965, eggs have been transported to the Charles Darwin Research Station for hatching and rearing.
Formerly abundant but heavily exploited by visiting ships and a penal colony in the twentieth century. Darwin saw them in 1835, and noted that tortoises comprised the main food item in the Floreana colony; "two days hunting will find food for the other five in the week." Although he commented on how the numbers had been obviously reduced from those in years past ("not many years since the Ship's company of a Frigate brought down to the Beach in one day more then 200"), he did mention Vice Governor Lawson's prediction that "there is yet sufficient for 20 years." Indeed there is a well-documented record of heavy collecting in the years leading up to Darwin's visit, but then just three years later, a visiting ship could find no tortoises and in 1846, another visitor declared them extinct. Descriptions of the Floreana race are based on skeletal material from individuals who fell down into lava tubes and died. However in 2008, research into mitochondrial DNA in museum specimens of the Floreana race by Dr Caccone of Yale University suggested that a population from Floreana may have been transposed to Isabela. Theoretically, a breeding programme could be established to 'resurrect' the pure Floreana race from the hybrid subpopulation. Using marker-assisted selection for a captive breeding population, it is estimated that the project would last a century. Extinct, hybrid subpopulation exists on Isabela
This population was very heavily exploited by whalers in the nineteenth century and collapsed around 1850. 13 adults were found in the early 1970s and held at the Charles Darwin Research Station as a breeding colony. The 2 males and 11 females were initially brought to the Darwin Station. Fortuitously, a third male was discovered at the San Diego Zoo and joined the others in a captive breeding program. These 13 tortoises have given rise to over 1000 tortoises now released into their home island. Mating had not occurred naturally for some time because the individuals were so scattered that they did not meet.
Depleted by heavy exploitation for oil at least until the 1930s. Reproductive success severely hampered for many years by the presence of feral dogs and pigs, but breeding programs are steady. MtDNA evidence shows that there are actually three genetically distinct populations on Santa Cruz island. 3000 Volcán Wolf Tortoise G. n. becki Rothschild, 1901 Northern Isabela (Albermarle) Island: northern and western slopes of Volcano Wolf Reproduction is successful 2000.
Iguana Cove Tortoise G. n. vicina Günther, 1875 Eastern Isabela Island: Cerro Azul A typical dome-shelled tortoise. Range overlaps with G. n. guentheri. This population was depleted by seamen in the last two centuries and by extensive slaughter in the late 1950s and 60's by employees of cattle companies based at Iguana Cove.
Sierra Negra Tortoise G. n. guntheri Baur, 1889 Isabela Island: Volcano Sierra Negra, one group in the east and another over the western and southwestern slopes. Severely depleted by settlement and exploitation for tortoise oil which continued until the 1950s. The wild reproduction is successful in the east but in the western-southwestern area pigs, dogs, rats and cats are present as predators. It is one of the most threatened of the existing subspecies, and 20 adults were taken into captivity for a breeding program in 1998 following the threat of a volcanic eruption from the nearby Cerro Azul volcano.
Volcán Darwin Tortoise G. n. microphyes Günther, 1875 Isabela Island: southern and western slopes of Volcano Darwin Heavily exploited in the nineteenth century by whaling vessels, but wild reproduction is successful. 1000.
Volcán Alcedo TortoiseG. n. vandenburghi DeSola, 1930 Central Isabela Island: caldera and southern slopes of Volcano Alcedo The largest population in the archipelago, wild reproduction successful. 5000.
Known from only one male specimen found (and killed) by members of the 1906 San Francisco Academy of Sciences expedition. There was a discovery of putative tortoise droppings in 1964. However, no other tortoises or even remains have been found on Fernandina and it is entirely possible that that one lone male was a stray or a release. Fernandina is the most pristine of the islands and any tortoise population would not be likely to have become extinct at the hands of introduced animals. If G. n. phantastica was, indeed, a real subspecies, then it is the only one to become extinct by natural means.
Santa Fe Island Tortoise Possible existence
Santa Fe Island Tortoise Santa Fe Island (purportedly) There are only 2 records of whalers removing tortoises, and there are two eye-witness accounts of locals removing tortoises in 1876 and 1890. These accounts, however, were given 15 and 30 years after the incident. Expeditions found old bones but no shell fragments, the most durable part of a tortoise skeleton, casting strong doubt on the validity of this subspecies. Doubtful existence.This putative subspecies is known from only one specimen. Tracks were seen on Rabida in 1897 and a single individual was removed by the Academy of Sciences in 1906. No logs from whaling or sealing vessels make any mention of collecting at Rabida. Rabida has a good anchorage and near which is found a corral in which tortoises, perhaps from other islands, were temporarily held. The type specimen of G. n. wallacei, the individual from which the race was named, actually has an unknown provenance: it was assigned to Rabida because it resembled the one removed in 1906. Doubtful existence.
Galapagos Turtles Notable specimens
Lonesome George is the only known living specimen of the Pinta Island Tortoise.Lonesome George, the last surviving Pinta Tortoise
Harriet was the second oldest tortoise ever authenticated with an estimated age of 175 years at the time of her death in 2006 in Australia Zoo.
Galapagos Turtles Human disturbance
In the seventeenth century, pirates started to use the Galapagos islands as a base for resupply, restocking on food, water and repairing vessels before attacking Spanish colonies on the South American mainland. The tortoises were collected and stored live on board ships where they could survive for at least a year without food or water, providing valuable fresh meat, whilst their diluted urine and water stored in their neck bags could also be used as drinking water. Of the meat, Darwin wrote: "the breast-plate roasted (as the Gauchos do 'carne con cuero'), with the flesh on it, is very good; and the young tortoises make excellent soup; but otherwise the meat to my taste is indifferent."In the nineteenth century, whaling ships and fur-sealers collected tortoises for food and many more were killed for high grade 'turtle oil' from the late 1800s onward. Darwin described this process thus: "beautifully clear oil is prepared from the fat. When a tortoise is caught, the man makes a slit in the skin near its tail, so as to see inside its body, whether the fat under the dorsal plate is thick. If it is not, the animal is liberated and it is said to recover soon from this strange operation." A total of over 15,000 tortoises is recorded in the logs of 105 whaling ships between 1811 and 1844. As hunters found it easiest to collect the tortoises living round the coastal zones, the least decimated populations tended to be those in the highlands.
Population decline accelerated with the early settlement of the islands, when they were hunted for meat, their habitat was cleared for agriculture and alien mammal species were introduced. Feral pigs, dogs, cats and black rats are effective predators of eggs and young tortoises, whilst goats, donkeys and cattle compete for grazing. In the twentieth century, increasing human settlement and urbanisation and collection of tortoises for zoo and museum specimens depleted numbers even more.
Galapagos Turtles Conservation
The Galapagos giant tortoise is now strictly protected. Geochelone nigra is listed on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora. Appendix I listing requires that trade in the taxon and its products is subject to strict regulation by ratifying states and international trade for primarily commercial purposes is prohibited.In 1936 the Ecuadorian government listed the giant tortoise as a protected species. A period of inaction followed until 1959, when it declared all uninhabited areas in the Galapagos to be a National Park and established the Charles Darwin Foundation. In 1970 it was made illegal to capture or remove many species from the islands, including tortoises and their eggs. To halt the trade altogether, it became illegal to export the tortoises from Ecuador, captive or wild, continental or insular in provenance. United States Public Law 91-135 (1969) automatically prohibited the importation of Galapagos tortoises into the U.S.A. as their export was declared illegal. A 1971 decree made it illegal to damage, remove, alter or disturb any organism, rock or other natural object in the National Park. Today, all tour groups must be guided and are asked to stay on the paths to avoid disruption of all flora and fauna.
Young tortoises are raised in a programme by the Charles Darwin Research Station in order to bolster the numbers of the extant subspecies. Eggs are collected from places on the islands where they are threatened and when the tortoises hatch they are kept in captivity until they have reached a size that ensures a good chance of survival and are returned to their original ranges. The Galapagos National Park Service systematically culls feral predators and competitors where necessary such as the complete eradication of goats from Pinta.
The conservation project begun in the 1970s successfully brought 10 of the 11 endangered subspecies up to guarded population levels. The most incredible recovery was that of the Española Tortoise, whose breeding stock comprised 2 males and 11 females brought to the Darwin Station.
Fortuitously, a third male was discovered at the San Diego Zoo and joined the others in a captive breeding program. These 13 tortoises gave rise to over 1000 tortoises now released into their home island. In all, 2500 individuals of all breeds have been reintroduced to the islands.
However, persecution still continues on a much smaller scale; more than 120 tortoises have been killed by poachers since 1990 and they have been taken hostage as political leverage by local fishermen.
Green Sea turtle
Chelonia mydas, commonly known as the green sea turtle is a large sea turtle belonging to the family Cheloniidae. It is the only species in the genus Chelonia. The range of the species extends throughout tropical and subtropical seas around the world, with two distinct populations in the Atlantic and Pacific Oceans. Their common name derives from the green fat underneath their shell.The green turtle is the quintessential sea turtle, possessing a dorsoventrally-flattened body covered by a large, teardrop-shaped carapace and a pair of large, paddle-like flippers. Despite the turtle's common name, it is lightly-colored all around while its carapace's hues range from olive-brown to black in Eastern Pacific green turtles. The turtle is actually named for the greenish coloration of its fat and flesh. Unlike other members of its family such as the hawksbill and loggerhead turtles, Chelonia mydas is mostly herbivorous. The adults are commonly found in shallow lagoons, feeding mostly on various species of seagrass.
Like other sea turtles, green turtles are known to migrate long distances between their feeding grounds and the beaches they hatched from. Many islands worldwide have been called Turtle Islands primarily for the large amounts of green turtles that nest on their beaches each year. Female turtles dredge themselves onto beaches and lay eggs in nests that they dig during the night. After a period of time, hatchlings emerge from the nests and head for the water. Those that survive grow to maturity and live to a maximum of eighty years.
As a species recognized as endangered by the IUCN and CITES, Chelonia mydas is protected from exploitation in most countries worldwide. It is illegal to collect, harm or kill individual turtles. In addition, many countries have implemented various laws and ordinances to protect individual turtles and turtle nesting areas within their jurisdiction. However, the turtles' populations are still in danger because of several human practices. In some countries, the turtles are still hunted for their flesh and their eggs are collected from nests and eaten as a delicacy. Pollution indirectly harms the turtle populations both on the population and the individual scale. Many turtles die as a result of being caught in fishermen's nets and drowning. Finally, habitat loss due to human development is a major reason for the loss of green turtle nesting beaches.
Pond Turtles
Clemmys is a genus of turtle, consisting of one North American species, the spotted turtle (C. guttata),"Clemmys guangxiensis" is a composite taxon described from specimens of Mauremys mutica and the natural hybrid "Mauremys" × iversoni (Parham et al. 2001).
Until recently, the genus Clemmys consisted of four species (Bog Turtle, Spotted Turtle, Western Pond Turtle, and the Wood Turtle). Recent genetic analyses have revealed that the Spotted Turtle is distinct from the other three species[1] . The Bog Turtle and the Wood Turtle were moved to the genus Glyptemys, while the Western Pond Turtle has been re-named Actinemys. This makes the Spotted Turtle the sole member of the genus Clemmys.
The Emydidae are the largest and most diverse family of Testudines.
The family Emydidae includes more than 40 species in 12 genera. Members are distributed throughout North America, northern South America, Europe, northwestern Africa, and Asia. Emydids are primarily freshwater species, though some species inhabit brackish waters (Malaclemmys terrapin) or are terrestrial (Terrapene, except T. coahuila).
Pond Turtles Anatomy
Sizes are variable and range from only 11 centimetres (4.3 in) (Clemmys) to nearly 60 centimetres (24 in) (Kachuga) in carapace length. Coloration is also quite variable. The family does not have a distinguishing suit of superficial characters, although they all have well-developed limbs with webbed feet. In most species, the carapace is low-arching, but some have a higher dome. The plastron is hinged and movable in some, while fixed in others. There are few distinctive skeletal features, but there is a lack of contact between the squamosal and parietal bones in the skull, and the the frontal bone forms part of the orbit.Turtles
Turtles are reptiles of the order Testudines (all living turtles belong to the crown group Chelonia), most of whose body is shielded by a special bony or cartilagenous shell developed from their ribs. The order of Testudines includes both extant (living) and extinct species, the earliest turtles being known from the early Triassic Period, making turtles one of the oldest reptile groups, and a much more ancient group than the lizards and snakes.About 300 species are alive today. Some species of turtles are highly endangered.
Turtle, tortoise, or terrapin?
In British English it is normal to describe these reptiles as turtles, terrapins, or tortoises depending on whether they live in the sea, in fresh water, or on land, respectively. Thus the green sea turtle, Chelonia mydas, is considered a turtle; the red-eared slider, Trachemys scripta elegans, a terrapin; and the eastern box turtle, Terrapene carolina carolina, a tortoise.In American English it is common to refer to all freshwater chelonians as turtles. Ocean-going species are sea turtles, and members of the family Testudinidae, such as the gopher tortoise (Gopherus polyphemus), are considered tortoises. "Terrapin" is reserved for the diamondback terrapin (Malaclemys terrapin), a North American species whose name is derived from the Algonquian word for this animal, though the average speaker would simply refer to it as a turtle.
There are no fully-terrestrial forms in Australia; therefore, speakers of Australian English tend to use turtle for marine species and tortoise for freshwater species. This confusing nomenclature is changing as recent publications have used turtle for both marine and freshwater species.
The word chelonian, an umbrella term covering turtles, tortoises, and terrapins, is increasingly popular among scientists, conservationists, hobbyists and veternarians working with these animals. It is based on the Greek word, chelone, meaning tortoise, and is used, for example, by the Chelonian Research Foundation.
Geoffroys side-necked turtle (Phrynops geoffroanus) lives in tropical pools and lakes in South America
Turtle Evolution
The first turtles are believed to have existed in the Mesozoic, around 200 million years ago. Their exact ancestry is disputed. It was believed that they are the only surviving branch of the ancient clade Anapsida, which includes groups such as procolophonoids, millerettids, protorothyrids and pareiasaurs. All anapsid skulls lack a temporal opening, while all other extant amniotes have temporal openings (although in mammals the hole has become the zygomatic arch). Most anapsids became extinct in the late Permian period, except procolophonoids and possibly the precursors of the testudines (turtles).However, it was recently suggested that the anapsid-like turtle skull may be due to reversion rather than to anapsid descent. More recent phylogenetic studies with this in mind placed turtles firmly within diapsids, slightly closer to Squamata than to Archosauria. All molecular studies have strongly upheld this new phylogeny, though some place turtles closer to archosauria. Re-analysis of prior phylogenies suggests that they classified turtles as anapsids both because they assumed this classification (most of them studying what sort of anapsid turtles are) and because they did not sample fossil and extant taxa broadly enough for constructing the cladogram. Future analyses may show the turtles to be relatives of the placodonts.
The earliest known modern turtle is proganochelys, though this species already had many advanced turtle traits, and thus probably had many millions of years of preceding "turtle" evolution and species in its ancestry. It did lack the ability to pull its head into its shell (and it had a long neck), and had a long, spiked tail ending in a club, implying an ancestry occupying a similar niche to the ankylosaurs (though, presumably, only through parallel evolution).
Turtle Physical Description
Turtles vary widely in size, although marine turtles tend to be relatively big animals. The largest chelonian is a marine turtle, the great leatherback sea turtle, which can reach a shell length of 200 cm (80 in) and can reach a weight of over 900 kg (2,000 lb, or 1 short ton). Freshwater turtles are smaller, with the largest species being the Asian softshell turtle Pelochelys cantorii, which has been reported to measure up to 200 cm or 80 inches (Das, 1991). This dwarfs even the better-known alligator snapping turtle, the largest chelonian in North America, which attains a shell length of up to 80 cm (31.5 in) and a weight of about 76 kg (170 lb). Giant tortoises of the genera Geochelone, Meiolania, and others were relatively widely distributed around the world into prehistoric times, and are known to have existed in North and South America, Australia, and Africa. They became extinct at the same time as the appearance of Man, and it is assumed that humans hunted them for food. The only surviving giant tortoises are on the Seychelles and Gal'pagos Islands and can grow to over 130 cm (50 in) in length, and weigh about 300 kg (670 lb).The largest ever chelonian was Archelon ischyros, a Late Cretaceous sea turtle known to have been up to 4.6 m (15 ft) long.
The smallest turtle is the speckled padloper tortoise of South Africa. It measures no more than 8 cm (3 in) in length and weighs about 140 g (5 oz). Two other species of small turtles are the American mud turtles and musk turtles that live in an area that ranges from Canada to South America. The shell length of many species in this group is less than 13 cm (5 in) in length.
Turtle Neck folding
Turtles are broken down into two groups, according to how they evolved a solution to the problem of withdrawing their neck into their shell (something the ancestral Proganochelys could not do): the Cryptodira, which can draw their neck in while folding it under their spine; and the Pleurodira, which have to fold their neck to the side.Turtle Shell
The upper shell of the turtle is called the carapace. The lower shell that incases the belly is called the plastron. The carapace and plastron are joined together on the turtle's sides by bony structures called bridges. The inner layer of a turtle's shell is made up of about 60 bones that includes portions of the backbone and the ribs, meaning the turtle cannot crawl out of its shell. In most turtles, the outer layer of the shell is covered by horny scales called scutes that are part of its outer skin, or epidermis. Scutes are made up of a fibrous protein called keratin that also makes up the scales of other reptiles. These scutes overlap the seams between the shell bones and add strength to the shell. Some turtles do not have horny scutes. For example, the leatherback sea turtle and the soft-shelled turtles have shells covered with leathery skin instead.The shape of the shell gives helpful clues to how the turtle lives. Most tortoises have a large dome-shaped shell that makes it difficult for predators to crush the shell between their jaws. One of the few exceptions is the African pancake tortoise which has a flat, flexible shell that allows it to hide in rock crevices. Most aquatic turtles have flat, streamlined shells which aid in swimming and diving. American snapping turtles and musk turtles have small, cross-shaped plastrons that give them more efficient leg movement for walking along the bottom of ponds and streams.
Tortoises have rather heavy shells in contrast to aquatic and soft-shelled turtles which have lighter shells that help them avoid sinking in water and swim faster and more agilely. These lighter shells have large spaces called fontanelles between the shell bones. The shell of a leatherback turtle is extremely light because they lack scutes and contain many fontanelles.
The color of a turtle's shell may vary. Shells are commonly coloured brown, black, or olive green. In some species, shells may have red, orange, yellow, or grey markings and these markings are often spots, lines, or irregular blotches. One of the most colorful turtles is the eastern painted turtle which includes a yellow plastron and a black or olive shell with red markings around the rim.
Turtle Skin and Moulting
As mentioned above, the outer layer of the shell is part of the skin, each scute (or plate) on the shell corresponding to a single modified scale. The remainder of the skin is composed of skin with much smaller scales, similar to the skin of other reptiles. Turtles and terrapins do not moult their skins all in one go, as snakes do, but continuously, in small pieces. When kept in aquaria, small sheets of dead skin can be seen in the water (often appearing to be a thin piece of plastic), having been sloughed off, often when the animal deliberately rubs itself against a piece of wood or stone. Tortoises also shed skin, but a lot of dead skin is allowed to accumulate into thick knobs and plates that provide protection to parts of the body outside the shell.The scutes on the shell are never moulted, and as they accumulate over time, the shell becomes thicker. By counting the rings formed by the stack of smaller, older scutes on top of the larger, newer ones, it is possible to estimate the age of a turtle, if you know how many scutes are produced in a year. This method is not very accurate, partly because growth rate is not constant, but also because some of the scutes eventually fall away from the shell.
Turtle Head
Most turtles and tortoises have eyes placed on the upper sides of their heads. Species of turtles that spend most of their life on land have their eyes looking down at objects in front of them. Some aquatic turtles, such as snapping turtles and soft-shelled turtles, have eyes closer to the top of the head. These species of turtles can hide from predators in shallow water where they lie entirely submerged except for their eyes and nostrils. Sea turtles possess glands near their eyes that produce salty tears that rids their body of excess salt taken in from the water they drink.Turtles are thought to have exceptional night vision due to the unusually large amount of rod cells in their retinas. Normal daytime vision is marginal at best due to their color-blindness and poor visual acuity. In addition to daytime vision problems, turtles have very poor pursuit movement abilities, which is most likely due to the fact that pursuit movement abilities are normally reserved for predators that hunt quick moving prey.
Turtles use their jaws to cut and chew food. Instead of teeth, the upper and lower jaws of the turtle are covered by horny ridges. Carnivorous turtles usually have knife-sharp ridges for slicing through their prey. Herbivourous turtles have serrated edged ridges that help them cut through tough plants. Turtles use their tongues to swallow food, but they can't, unlike most reptiles, stick out their tongues to catch food.
Turtle Limbs
Terrestrial tortoises have short, sturdy feet. Tortoises are famous for moving slowly, in part because of their heavy shell but also because of the relatively inefficient sprawling gait that they have, with the legs being bent, as with lizards rather than being straight and directly under the body, as is the case with mammals.The amphibious turtles normally have limbs similar to those of tortoises except that the feet are webbed and often have long claws. These turtles swim using all four feet in a way similar to the dog paddle, with the feet on the left and right side of the body alternately providing thrust. Large turtles tend to swim less than smaller ones, and the very big species, such as aligator snapping turtles, hardly swim at all, preferring to simply walk along the bottom of the river or lake. As well as webbed feet, turtles also have very long claws, used to help them clamber onto riverbanks and floating logs, upon which they like to bask. Male turtles tend to have particularly long claws, and these appear to be used to stimulate the female while mating. While most turtles have webbed feet, a few turtles, such as the pig-nose turtles, have true flippers, with the digits being fused into paddles and the claws being relatively small. These species swim in the same way as sea turtles (see below).
Sea turtles are entirely aquatic and instead of feet they have flippers. Sea turtles "fly" through the water, using the an up-and-down motion of the front flippers to generate thrust; the back feet are not used for propulsion but may be used as rudders for steering. Compared with freshwater turtles, sea turtles have very limited mobility on land, and apart from the dash from the nest to the sea as hatchlings, male sea turtles normally never leave the sea. Females must come back onto land to lay eggs. They move very slowly and laboriously, dragging themselves forwards with their flippers. The back flippers are used to dig the burrow and then fill it back with sand once the eggs have been deposited.
