The Australian Freshwater Turtle Catalogue. Edition

Transcription

1 1 The concept, text, lay-out and all images contained in this publication are by Gunther Schmida and protected by copyright. The Australian Freshwater Turtle Catalogue This preview shows only the first eight pages in actual size, all other pages are much reduced, each image shown in this preview representing a full screen page in the finished volume. This also contains the common and scientific names, author and year of description, places of origin ( or ancestry, if captive bred), and actual shell size of the turtles in the images. (This is important, as juveniles often look different from adults.) Edition 1-17 Broad-shelled Turtle Chelodina (Macrochelodina) expansa 2 day old hatchling Change pages by using the up or down keys on the keyboard. Tablet users just need to scroll the pages.

2 Gunther Schmida The Australian Freshwater Turtle Catalogue 2 Krefft s Turtle Emydura macquarii krefftii 25 cm - Qld.

3 Concept, lay-out, text and photography Gunther Schmida 3 Saw-shelled Turtle Wollumbinia latisternum - adult female - 25 cm - SE Qld.

4 Photographic assistants: Terry Adams, Glynn & Kieran Aland, Dr. Gavin Bedford, Gavin Brown, Dr. Danny Brown, John Cann, Greg Miles, Jason Sulda, Gary Stephenson and Dave Wilson 4 Northern Long-necked Turtle Chelodina (Macrochelodina) oblonga (Macrochelodina rugosa) 12 cm -Darwin - NT

5 The Australian Freshwater Turtle Pictorial Over 900 different species of reptiles have been recorded in Australia, and about 30 of these are described species of freshwater turtles (Cann 2008) - mostly referred to as tortoises in older Australian literature, a name that is now only used for land dwelling species. Although Australia is considered to be the driest inhabitable continent of our planet, there are no native tortoises here, only aquatic turtles of the family Chelidae (Also called Cheluidae in some literature), and the only species of the family Carettochelydidae, the Pig-nosed Turtle. All species of the Chelidae are endemic - only occurring in Australia - and when they feel threatened, they protect their heads by bending the neck sideways under the shell, hence they are also called side-necked freshwater turtles. There are two basic groups. Long- or snake-necked and short-necked species. Some of the latter are often referred to as snapping turtles or snappers, because they may bite when handled. All have a body enclosed in a bony shell covered with horny shields. Depending on the species, the shells of adults can measure from 12 to 49 cm in length and can be flat or highly domed. Although they spend most of their life immersed in water, they have powerful legs with webbed feet, the toes ending in long sharp claws. Unlike other reptiles, turtles do not have teeth, but rather horny cutting edges on their jaws. The jaws are very powerful in some species, which can crush the shells of molluscs or crustaceans with ease. Hatchlings and juveniles of all species are essentially carnivorous, feeding on aquatic insects and their larvae, shrimp, small fish and tadpoles; adults take larger prey, and some species will also eat plant matter. They are excellent swimmers, but can also move reasonably well on land, and are sometimes seen wandering on or near roads, most often during the breeding season when they leave the water to deposit their eggs in burrows on land, sometimes well away from, and above the flood zone. Many get run over by vehicles during this time, sometimes deliberately. Most species can be observed in the wild when they bask in the sun on logs or rocks to regulate their temperature. More side-necked species are likely to be described in future. Unlike the other Australian turtles, the pig-nosed turtle retracts its head as far as possible straight back into the shell, not sideways, and the shell is covered by leathery skin instead of shields. All limbs are flipper-like similar to those of sea turtles. This is the largest of all Australian freshwater turtles, growing to over 60 cm in length. It only occurs in some rivers in the top end of the Northern Territory and also in New Guinea. It is the most aquatic of all Australian freshwater turtles and like marine turtles, only leaves the water to nest. Oblong Turtle Chelodina (Macrodiremys) colliei (Macrodiremys oblonga) 20 cm - Perth - WA 5

6 6 An exposed fossilized shell of a turtle, embedded in limestone at the Riversleigh fossil site in north-west Queensland. Turtles seem to have a much better relationship with humans than most other reptiles. Although some large Australian freshwater turtles can inflict painful bites if handled carelessly, they are considered to be harmless and not feared or even despised by the general public as many snakes are, or even some lizards and crocodiles. Also, there is no denying that baby turtles look cute and appeal to many people for that reason. Before European settlement, turtles were a valuable food resource for the first people on the Australian continent, and this holds true even today. In the last 50 odd years they have also become quite popular as pets of the urban population and huge numbers were taken from the wild and sold in pet shops for that purpose for some time. This usually involved the plundering of nests and incubation of eggs in controlled conditions. The cute hatchings were sold as penny turtles, and with barely any information about their successful keeping available at the time, most perished within short periods. Thankfully all reptiles have been protected by law for almost 40 years, but equally important is the protection of their habitats, which still leaves much to be desired. The protection of wild stocks has led to captive breeding programs of many species, and much better husbandry techniques for keeping them as pets. Some species are wide ranging and also commonly encountered, others only occur in particular habitats and are rarely seen. One species, the Western Swamp Turtle, was on the brink of extinction, but predator-proof fencing of the habitat and captive breeding helped to avert its demise. Apart from their natural predators, all turtles are also threatened by human activities such as habitat destruction, pollution, or capture in carelessly set fish traps, to name a few, as well as the introduced feral populations of foxes and pigs. Even the ever further spreading, and also introduced poisonous cane toad, may have an adverse impact on turtle populations in northern Australia. This Pictorial introduces almost all Australian turtles in a way that they are rarely seen in the wild or even in captivity. In the element they prefer to live in, and rarely leave, fresh water. As few natural turtle habitats are suitable to photograph them in the wild, most images shown here were taken in specially designed tanks, with sets recreated as close as possible to their real habitats.

7 Painted Turtle Emydura subglubosa subglubosa Krefft, All species are shown in alphabetical order by their current scientific names as listed in Cogger Reptiles & Amphibians of Australia, Wherever changes are recent, the older names are shown in brackets. The name of the author (describer) and the year of description of the first known specimen are also given. Both data may at times be given in ( ), indicating that the species was originally placed in a different genus by the author. Taxonomy (naming of species), often reflects the opinions of researchers and with ongoing studies and better understanding of species relationships, name changes are sometimes necessary. Also many species were described several times during the time of new discoveries. These other names are called synonyms ( Check reference volumes in this series for more details.) Also given are the approximate size of the turtles pictured and their origins, if known. If captive bred, the origin of the ancestry.

8 Pig-nosed Turtle Carettochelys insculpta Family: Carettochelydidae 8 20 cm - Daly River - NT - captive bred

9 Pig-nosed Turtle Carettochelys insculpta Habitat - Daly River - NT 9 Alligator Rivers Daly River 10 NT Although sometimes also called Pitted-shelled or Fly River Turtle, the name Pig-nosed Turtle seems far more appropriate.

10 Pig-nosed Turtle Carettochelys insculpta Ramsay, Adult female on a sand bank - Photographed at Greg Miles breeding facility near Darwin - NT This species only leaves the water to nest.

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23 Specimens courtesy of: Terry Adams Dr. Gavin Bedford Gavin Brown Grant Husband Kieran Aland Dr. Danny Brown John Cann Tania Carter & Neil Charles Brian McLean Jason Sulda Greg Miles Gary Stephenson 206 Broad-shelled Turtle Macrochelodina expansa 10 day old hatchling - captive bred

24 239 Thank you for taking the time to view this condensed preview of The Australian Turtle Catalogue - 1 If you like it, find it useful, and wish to support its continuing expansion and updates, you can do so by purchasing the FULL SIZE pdf version for a fee of only $ Just return to previous window and click BUY NOW button, then follow the links. 207 Northern Snake-necked Turtle Chelodina oblonga - Darwin - NT