title: "Komodo dragon" content: Komodo dragons also occasionally attack humans. Mating begins between May and August, and the eggs are laid in September. About 20 eggs are deposited in abandoned megapode nests or in a self-dug nesting hole. The eggs are incubated for seven to eight months, hatching in April, when insects are most plentiful. Young Komodo dragons are vulnerable and therefore dwell in trees, safe from predators and cannibalistic adults. They take 8 to 9 years to mature, and are estimated to live up to 30 years. Komodo dragons were first recorded by Western scientists in 1910. Their large size and fearsome reputation


title: "Komodo dragon" content: make them popular zoo exhibits. In the wild, their range has contracted due to human activities, and they are listed as vulnerable by the IUCN. They are protected under Indonesian law, and a national park, Komodo National Park, was founded to aid protection efforts. Komodo dragons were first documented by Europeans in 1910, when rumors of a "land crocodile" reached Lieutenant van Steyn van Hensbroek of the Dutch colonial administration. Widespread notoriety came after 1912, when Peter Ouwens, the director of the Zoological Museum at Bogor, Java, published a paper on the topic after receiving a photo and a skin


title: "Komodo dragon" content: from the lieutenant, as well as two other specimens from a collector. The first two live Komodo dragons to arrive in Europe were exhibited in the Reptile House at London Zoo when it opened in 1927. Joan Beauchamp Procter made some of the earliest observations of these animals in captivity and she demonstrated the behaviour of one of these animals at a Scientific Meeting of the Zoological Society of London in 1928. The Komodo dragon was the driving factor for an expedition to Komodo Island by W. Douglas Burden in 1926. After returning with 12 preserved specimens and 2 live


title: "Komodo dragon" content: ones, this expedition provided the inspiration for the 1933 movie "King Kong". It was also Burden who coined the common name "Komodo dragon." Three of his specimens were stuffed and are still on display in the American Museum of Natural History. The Dutch, realizing the limited number of individuals in the wild, outlawed sport hunting and heavily limited the number of individuals taken for scientific study. Collecting expeditions ground to a halt with the occurrence of World War II, not resuming until the 1950s and 1960s, when studies examined the Komodo dragon's feeding behavior, reproduction, and body temperature. At around


title: "Komodo dragon" content: this time, an expedition was planned in which a long-term study of the Komodo dragon would be undertaken. This task was given to the Auffenberg family, who stayed on Komodo Island for 11 months in 1969. During their stay, Walter Auffenberg and his assistant Putra Sastrawan captured and tagged more than 50 Komodo dragons. The research from the Auffenberg expedition would prove to be enormously influential in raising Komodo dragons in captivity. Research after that of the Auffenberg family has shed more light on the nature of the Komodo dragon, with biologists such as Claudio Ciofi continuing to study the


title: "Komodo dragon" content: creatures. The Komodo dragon is also known as the Komodo monitor or the Komodo Island monitor in scientific literature, although this is not very common. To the natives of Komodo Island, it is referred to as "ora", "buaya darat" (land crocodile), or "biawak raksasa" (giant monitor). The evolutionary development of the Komodo dragon started with the genus "Varanus", which originated in Asia about 40 million years ago and migrated to Australia, where it evolved into giant forms (the largest of all being the recently extinct "Megalania"), helped by the absence of competing placental carnivorans. Around 15 million years ago, a


title: "Komodo dragon" content: collision between Australia and Southeast Asia allowed these larger varanids to move back into what is now the Indonesian archipelago, extending their range as far east as the island of Timor. The Komodo dragon was believed to have differentiated from its Australian ancestors 4 million years ago. However, recent fossil evidence from Queensland suggests the Komodo dragon actually evolved in Australia before spreading to Indonesia. Dramatic lowering of sea level during the last glacial period uncovered extensive stretches of continental shelf that the Komodo dragon colonised, becoming isolated in their present island range as sea levels rose afterwards. Extinct Pliocene


title: "Komodo dragon" content: species of similar size to the modern Komodo dragon, such as "Varanus sivalensis", have been found in Eurasia as well, indicating that they fared well even in environments containing competition such as mammalian carnivores until the climate change and extinction events that marked the beginning of the Pleistocene. In the wild, an adult Komodo dragon usually weighs around , although captive specimens often weigh more. According to "Guinness World Records", an average adult male will weigh and measure , while an average female will weigh and measure . The largest verified wild specimen was long and weighed , including undigested


title: "Komodo dragon" content: food. The Komodo dragon has a tail as long as its body, as well as about 60 frequently replaced, serrated teeth that can measure up to in length. Its saliva is frequently blood-tinged, because its teeth are almost completely covered by gingival tissue that is naturally lacerated during feeding. It also has a long, yellow, deeply forked tongue. Komodo dragon skin is reinforced by armoured scales, which contain tiny bones called osteoderms that function as a sort of natural chain-mail. This rugged hide makes Komodo dragon skin a poor source of leather. As with other varanids, Komodo dragons have only


title: "Komodo dragon" content: a single ear bone, the stapes, for transferring vibrations from the tympanic membrane to the cochlea. This arrangement means they are likely restricted to sounds in the 400 to 2,000 hertz range, compared to humans who hear between 20 and 20,000 hertz. It was formerly thought to be deaf when a study reported no agitation in wild Komodo dragons in response to whispers, raised voices, or shouts. This was disputed when London Zoological Garden employee Joan Proctor trained a captive specimen to come out to feed at the sound of her voice, even when she could not be seen. The


title: "Komodo dragon" content: Komodo dragon can see objects as far away as , but because its retinas only contain cones, it is thought to have poor night vision. It can distinguish colours, but has poor visual discrimination of stationary objects. The Komodo dragon uses its tongue to detect, taste, and smell stimuli, as with many other reptiles, with the vomeronasal sense using the Jacobson's organ, rather than using the nostrils. With the help of a favorable wind and its habit of swinging its head from side to side as it walks, a Komodo dragon may be able to detect carrion from away. It


title: "Komodo dragon" content: only has a few taste buds in the back of its throat. Its scales, some of which are reinforced with bone, have sensory plaques connected to nerves to facilitate its sense of touch. The scales around the ears, lips, chin, and soles of the feet may have three or more sensory plaques. The Komodo dragon prefers hot and dry places, and typically lives in dry, open grassland, savanna, and tropical forest at low elevations. As an ectotherm, it is most active in the day, although it exhibits some nocturnal activity. Komodo dragons are solitary, coming together only to breed and


title: "Komodo dragon" content: eat. They are capable of running rapidly in brief sprints up to , diving up to , and climbing trees proficiently when young through use of their strong claws. To catch out-of-reach prey, the Komodo dragon may stand on its hind legs and use its tail as a support. As it matures, its claws are used primarily as weapons, as its great size makes climbing impractical. For shelter, the Komodo dragon digs holes that can measure from wide with its powerful forelimbs and claws. Because of its large size and habit of sleeping in these burrows, it is able to


title: "Komodo dragon" content: conserve body heat throughout the night and minimise its basking period the morning after. The Komodo dragon hunts in the afternoon, but stays in the shade during the hottest part of the day. These special resting places, usually located on ridges with cool sea breezes, are marked with droppings and are cleared of vegetation. They serve as strategic locations from which to ambush deer. Komodo dragons are carnivores. Although they have been considered as eating mostly carrion, they will frequently ambush live prey with a stealthy approach. When suitable prey arrives near a dragon's ambush site, it will suddenly charge


title: "Komodo dragon" content: at the animal at high speeds and go for the underside or the throat. Komodo dragons make no attempt to deliberately allow the prey to escape with fatal injuries, but try to kill prey outright using a combination of lacerating damage and blood loss. They have been recorded as killing wild pigs within seconds, and observations of Komodo dragons tracking prey for long distances are likely misinterpreted cases of prey escaping an attack before succumbing to infection. Komodo dragons have been observed knocking down large pigs and deer with their strong tails. It is able to locate carcasses using its


title: "Komodo dragon" content: keen sense of smell, which can locate a dead or dying animal from a range of up to . Komodo dragons eat by tearing large chunks of flesh and swallowing them whole while holding the carcass down with their forelegs. For smaller prey up to the size of a goat, their loosely articulated jaws, flexible skulls, and expandable stomachs allow them to swallow prey whole. The vegetable contents of the stomach and intestines are typically avoided. Copious amounts of red saliva the Komodo dragons produce help to lubricate the food, but swallowing is still a long process (15–20 minutes to


title: "Komodo dragon" content: swallow a goat). A Komodo dragon may attempt to speed up the process by ramming the carcass against a tree to force it down its throat, sometimes ramming so forcefully, the tree is knocked down. A small tube under the tongue that connects to the lungs allows it to breathe while swallowing. After eating up to 80% of its body weight in one meal, it drags itself to a sunny location to speed digestion, as the food could rot and poison the dragon if left undigested for too long. Because of their slow metabolism, large dragons can survive on as


title: "Komodo dragon" content: few as 12 meals a year. After digestion, the Komodo dragon regurgitates a mass of horns, hair, and teeth known as the gastric pellet, which is covered in malodorous mucus. After regurgitating the gastric pellet, it rubs its face in the dirt or on bushes to get rid of the mucus, suggesting it does not relish the scent of its own excretions. The largest animals eat first, while the smaller ones follow a hierarchy. The largest male asserts his dominance and the smaller males show their submission by use of body language and rumbling hisses. Dragons of equal size may


title: "Komodo dragon" content: resort to "wrestling". Losers usually retreat, though they have been known to be killed and eaten by victors. The Komodo dragon's diet is wide-ranging, and includes invertebrates, other reptiles (including smaller Komodo dragons), birds, bird eggs, small mammals, monkeys, wild boar, goats, deer, horses, and water buffalo. Young Komodos will eat insects, eggs, geckos, and small mammals, while adults prefer to hunt large mammals. Occasionally, they attack and bite humans. Sometimes they consume human corpses, digging up bodies from shallow graves. This habit of raiding graves caused the villagers of Komodo to move their graves from sandy to clay ground


title: "Komodo dragon" content: and pile rocks on top of them to deter the lizards. The Komodo dragon may have evolved to feed on the extinct dwarf elephant "Stegodon" that once lived on Flores, according to evolutionary biologist Jared Diamond. The Komodo dragon drinks by sucking water into its mouth via buccal pumping (a process also used for respiration), lifting its head, and letting the water run down its throat. Although previous studies proposed that Komodo dragon saliva contains a variety of highly septic bacteria that would help to bring down prey, research in 2013 suggested that the bacteria in the mouths of Komodo


title: "Komodo dragon" content: dragons are ordinary and similar to those found in other carnivores. They actually have surprisingly good mouth hygiene. As Bryan Fry put it: "After they are done feeding, they will spend 10 to 15 minutes lip-licking and rubbing their head in the leaves to clean their mouth... Unlike people have been led to believe, they do not have chunks of rotting flesh from their meals on their teeth, cultivating bacteria." Nor do Komodo dragons wait for prey to die and track it at a distance, as vipers do; observations of them hunting deer, boar and in some cases buffalo reveal


title: "Komodo dragon" content: that they kill prey in less than half an hour, using their dentition to cause shock and trauma. The observation of prey dying of sepsis would then be explained by the natural instinct of water buffalos, who are not native to the islands where the Komodo dragon lives, to run into water after escaping an attack. The warm, faeces-filled water would then cause the infections. The study used samples from 16 captive dragons (10 adults and six neonates) from three US zoos. Researchers have isolated a powerful antibacterial peptide from the blood plasma of Komodo dragons, VK25. Based on their


title: "Komodo dragon" content: analysis of this peptide, they have synthesized a short peptide dubbed DRGN-1 and tested it against multidrug-resistant (MDR) pathogens. Preliminary results of these tests show that DRGN-1 is effective in killing drug-resistant bacterial strains and even some fungi. It has the added observed benefit of significantly promoting wound healing in both uninfected and mixed biofilm infected wounds. In late 2005, researchers at the University of Melbourne speculated the perentie ("Varanus giganteus"), other species of monitors, and agamids may be somewhat venomous. The team believes the immediate effects of bites from these lizards were caused by mild envenomation. Bites on human


title: "Komodo dragon" content: digits by a lace monitor ("V. varius"), a Komodo dragon, and a spotted tree monitor ("V. scalaris") all produced similar effects: rapid swelling, localised disruption of blood clotting, and shooting pain up to the elbow, with some symptoms lasting for several hours. In 2009, the same researchers published further evidence demonstrating Komodo dragons possess a venomous bite. MRI scans of a preserved skull showed the presence of two glands in the lower jaw. The researchers extracted one of these glands from the head of a terminally ill dragon in the Singapore Zoological Gardens, and found it secreted several different toxic


title: "Komodo dragon" content: proteins. The known functions of these proteins include inhibition of blood clotting, lowering of blood pressure, muscle paralysis, and the induction of hypothermia, leading to shock and loss of consciousness in envenomated prey. As a result of the discovery, the previous theory that bacteria were responsible for the deaths of Komodo victims was disputed. Other scientists have stated that this allegation of venom glands "has had the effect of underestimating the variety of complex roles played by oral secretions in the biology of reptiles, produced a very narrow view of oral secretions and resulted in misinterpretation of reptilian evolution". According


title: "Komodo dragon" content: to these scientists "reptilian oral secretions contribute to many biological roles other than to quickly dispatch prey". These researchers concluded that, "Calling all in this clade venomous implies an overall potential danger that does not exist, misleads in the assessment of medical risks, and confuses the biological assessment of squamate biochemical systems". Evolutionary biologist Schwenk says that even if the lizards have venom-like proteins in their mouths they may be using them for a different function, and he doubts venom is necessary to explain the effect of a Komodo dragon bite, arguing that shock and blood loss are the primary


title: "Komodo dragon" content: factors. Mating occurs between May and August, with the eggs laid in September. During this period, males fight over females and territory by grappling with one another upon their hind legs, with the loser eventually being pinned to the ground. These males may vomit or defecate when preparing for the fight. The winner of the fight will then flick his long tongue at the female to gain information about her receptivity. Females are antagonistic and resist with their claws and teeth during the early phases of courtship. Therefore, the male must fully restrain the female during coitus to avoid being


title: "Komodo dragon" content: hurt. Other courtship displays include males rubbing their chins on the female, hard scratches to the back, and licking. Copulation occurs when the male inserts one of his hemipenes into the female's cloaca. Komodo dragons may be monogamous and form "pair bonds", a rare behavior for lizards. Female Komodos lay their eggs from August to September and may use several types of locality; in one study, 60% laid their eggs in the nests of orange-footed scrubfowl (a moundbuilder or megapode), 20% on ground level and 20% in hilly areas. The females make many camouflage nests/holes to prevent other dragons from


title: "Komodo dragon" content: eating the eggs. Clutches contain an average of 20 eggs, which have an incubation period of 7–8 months. Hatching is an exhausting effort for the neonates, which break out of their eggshells with an egg tooth that falls off before long. After cutting themselves out, the hatchlings may lie in their eggshells for hours before starting to dig out of the nest. They are born quite defenseless and are vulnerable to predation. Sixteen youngsters from a single nest were on average 46.5 cm long and weighed 105.1 grams. Young Komodo dragons spend much of their first few years in trees,


title: "Komodo dragon" content: where they are relatively safe from predators, including cannibalistic adults, as juvenile dragons make up 10% of their diets. The habit of cannibalism may be advantageous in sustaining the large size of adults, as medium-sized prey on the islands is rare. When the young approach a kill, they roll around in faecal matter and rest in the intestines of eviscerated animals to deter these hungry adults. Komodo dragons take approximately 8 to 9 years to mature, and may live for up to 30 years. A Komodo dragon at London Zoo named Sungai laid a clutch of eggs in late 2005


title: "Komodo dragon" content: after being separated from male company for more than two years. Scientists initially assumed she had been able to store sperm from her earlier encounter with a male, an adaptation known as superfecundation. On 20 December 2006, it was reported that Flora, a captive Komodo dragon living in the Chester Zoo in England, was the second known Komodo dragon to have laid unfertilised eggs: she laid 11 eggs, and seven of them hatched, all of them male. Scientists at Liverpool University in England performed genetic tests on three eggs that collapsed after being moved to an incubator, and verified Flora


title: "Komodo dragon" content: had never been in physical contact with a male dragon. After Flora's eggs' condition had been discovered, testing showed Sungai's eggs were also produced without outside fertilization. On 31 January 2008, the Sedgwick County Zoo in Wichita, Kansas, became the first zoo in the Americas to document parthenogenesis in Komodo dragons. The zoo has two adult female Komodo dragons, one of which laid about 17 eggs on 19–20 May 2007. Only two eggs were incubated and hatched due to space issues; the first hatched on 31 January 2008, while the second hatched on 1 February. Both hatchlings were males. Komodo


title: "Komodo dragon" content: dragons have the ZW chromosomal sex-determination system, as opposed to the mammalian XY system. Male progeny prove Flora's unfertilised eggs were haploid (n) and doubled their chromosomes later to become diploid (2n) (by being fertilised by a polar body, or by chromosome duplication without cell division), rather than by her laying diploid eggs by one of the meiosis reduction-divisions in her ovaries failing. When a female Komodo dragon (with ZW sex chromosomes) reproduces in this manner, she provides her progeny with only one chromosome from each of her pairs of chromosomes, including only one of her two sex chromosomes. This


title: "Komodo dragon" content: single set of chromosomes is duplicated in the egg, which develops parthenogenetically. Eggs receiving a Z chromosome become ZZ (male); those receiving a W chromosome become WW and fail to develop, meaning that only males are produced by parthenogenesis in this species. It has been hypothesised that this reproductive adaptation allows a single female to enter an isolated ecological niche (such as an island) and by parthenogenesis produce male offspring, thereby establishing a sexually reproducing population (via reproduction with her offspring that can result in both male and female young). Despite the advantages of such an adaptation, zoos are cautioned


title: "Komodo dragon" content: that parthenogenesis may be detrimental to genetic diversity. Attacks on humans are rare, but this species has been responsible for several human fatalities, in both the wild and captivity. According to a data from Komodo National Park, within 38 years in a period between 1974 and 2012, there were 24 reported attacks on humans, 5 of them deadly. Most of the victims are local villagers living around the national park. Reports of attacks include: The Komodo dragon is a vulnerable species and is on the IUCN Red List. The Komodo National Park was founded in 1980 to protect Komodo dragon


title: "Komodo dragon" content: populations on islands including Komodo, Rinca, and Padar. Later, the Wae Wuul and Wolo Tado Reserves were opened on Flores to aid with Komodo dragon conservation. Komodo dragons avoid encounters with humans. Juveniles are very shy and will flee quickly into a hideout if a human comes closer than about . Older animals will also retreat from humans from a shorter distance away. If cornered, they will react aggressively by gaping their mouth, hissing, and swinging their tail. If they are disturbed further, they may start an attack and bite. Although there are anecdotes of unprovoked Komodo dragons attacking or


title: "Komodo dragon" content: preying on humans, most of these reports are either not reputable or caused by defensive bites. Only a very few cases are truly the result of unprovoked attacks by abnormal individuals, which lost their fear towards humans. Volcanic activity, earthquakes, loss of habitat, fire, loss of prey due to poaching, tourism, and illegal poaching of the dragons themselves have all contributed to the vulnerable status of the Komodo dragon. Under Appendix I of CITES (the Convention on International Trade in Endangered Species), commercial trade of skins or specimens is illegal. In 2013, total population in the wild was assessed as


title: "Komodo dragon" content: 3,222 individuals, declining to 3,092 in 2014 and 3,014 in 2015. Populations remained relatively stable on the bigger islands (Komodo and Rinca), but decreased on smaller island such as Nusa Kode and Gili Motang, likely due to diminishing prey availability. On Padar, a former population of the Komodo dragon became extinct, of which the last individuals were seen in 1975. It is widely assumed that the Komodo dragon died out on Padar after a strong decline of the populations of large ungulate prey, for which poaching was most likely responsible. Komodo dragons have long been great zoo attractions, where their


title: "Komodo dragon" content: size and reputation make them popular exhibits. They are, however, rare in zoos because they are susceptible to infection and parasitic disease if captured from the wild, and do not readily reproduce. As of May 2009, there were 13 European, 2 African, 35 North American, 1 Singaporean, and 2 Australian institutions that kept Komodo dragons. The first Komodo dragons were displayed at London Zoo in 1927. A Komodo dragon was exhibited in 1934 at the National Zoo in Washington, D.C., but it lived for only two years. More attempts to exhibit Komodo dragons were made, but the lifespan of these


title: "Komodo dragon" content: animals was very short, averaging five years in the National Zoological Park. Studies done by Walter Auffenberg, which were documented in his book "The Behavioral Ecology of the Komodo Monitor", eventually allowed for more successful managing and reproducing of the dragons in captivity. A variety of behaviors have been observed from captive specimens. Most individuals are relatively tame within a short time, and are capable of recognising individual humans and discriminating between familiar keepers. Komodo dragons have also been observed to engage in play with a variety of objects, including shovels, cans, plastic rings, and shoes. This behavior does not


title: "Komodo dragon" content: seem to be "food-motivated predatory behavior". Even seemingly docile dragons may become unpredictably aggressive, especially when the animal's territory is invaded by someone unfamiliar. In June 2001, a Komodo dragon seriously injured Phil Bronstein, the then husband of actress Sharon Stone, when he entered its enclosure at the Los Angeles Zoo after being invited in by its keeper. Bronstein was bitten on his bare foot, as the keeper had told him to take off his white shoes and socks, which the keeper stated could potentially excite the Komodo dragon as they were the same colour as the white rats the


title: "Komodo dragon" content: zoo fed the dragon. Although he escaped, Bronstein needed to have several tendons in his foot reattached surgically. Komodo dragon The Komodo dragon ("Varanus komodoensis"), also known as the Komodo monitor, is a species of lizard found in the Indonesian islands of Komodo, Rinca, Flores, Gili Motang, and Padar. A member of the monitor lizard family Varanidae, it is the largest living species of lizard, growing to a maximum length of in rare cases and weighing up to approximately . Their unusually large size has been attributed to island gigantism, since no other carnivorous animals fill the niche on the


title: Kayak content: Kayak A kayak is a small, narrow watercraft which is propelled by means of a double-bladed paddle. The word kayak originates from the Greenlandic word "qajaq" (). The traditional kayak has a covered deck and one or more cockpits, each seating one paddler. The cockpit is sometimes covered by a spray deck that prevents the entry of water from waves or spray, differentiating the craft from a canoe. The spray deck makes it possible for suitably skilled kayakers to roll the kayak: that is, to capsize and right it without it filling with water or ejecting the paddler. ] Some


title: Kayak content: modern boats vary considerably from a traditional design but still claim the title "kayak", for instance in eliminating the cockpit by seating the paddler on top of the boat ("sit-on-top" kayaks); having inflated air chambers surrounding the boat; replacing the single hull by twin hulls, and replacing paddles with other human-powered propulsion methods, such as foot-powered rotational propellers and "flippers". Kayaks are also being sailed, as well as propelled by means of small electric motors, and even by outboard gas engines. The kayak was first used by the indigenous Aleut, Inuit, Yupik and possibly Ainu hunters in subarctic regions of


title: Kayak content: the world. Kayaks (Inuktitut: "qajaq" (ᖃᔭᖅ ), Yup'ik: "qayaq" (from "qai-" "surface; top"), Aleut: "Iqyax") were originally developed by the Inuit, Yup'ik, and Aleut. They used the boats to hunt on inland lakes, rivers and coastal waters of the Arctic Ocean, North Atlantic, Bering Sea and North Pacific oceans. These first kayaks were constructed from stitched seal or other animal skins stretched over a wood or whalebone-skeleton frame. (Western Alaskan Natives used wood whereas the eastern Inuit used whalebone due to the treeless landscape). Kayaks are believed to be at least 4,000 years old. The oldest existing kayaks are exhibited


title: Kayak content: in the North America department of the State Museum of Ethnology in Munich, with the oldest dating from 1577. Native people made many types of boat for different purposes. The Aleut baidarka was made in double or triple cockpit designs, for hunting and transporting passengers or goods. An umiak is a large open sea canoe, ranging from , made with seal skins and wood. It is considered a kayak although it was originally paddled with single-bladed paddles, and typically had more than one paddler. Native builders designed and built their boats based on their own experience and that of the


title: Kayak content: generations before them, passed on through oral tradition. The word "kayak" means "man's boat" or "hunter's boat", and native kayaks were a personal craft, each built by the man who used it—with assistance from his wife, who sewed the skins—and closely fitting his size for maximum maneuverability. The paddler wore a tuilik, a garment that was stretched over the rim of the kayak coaming, and sealed with drawstrings at the coaming, wrists, and hood edges. This enabled the "eskimo roll" and rescue to become the preferred methods of recovery after capsizing, especially as few Inuit could swim; their waters are


title: Kayak content: too cold for a swimmer to survive for long. Instead of a "tuilik", most traditional kayakers today use a spray deck made of waterproof synthetic material stretchy enough to fit tightly around the cockpit rim and body of the kayaker, and which can be released rapidly from the cockpit to permit easy exit. Inuit kayak builders had specific measurements for their boats. The length was typically three times the span of his outstretched arms. The width at the cockpit was the width of the builder's hips plus two fists (and sometimes less). The typical depth was his fist plus the


title: Kayak content: outstretched thumb (hitch hiker). Thus typical dimensions were about long by wide by deep. This measurement system confounded early European explorers who tried to duplicate the kayak, because each kayak was a little different. Traditional kayaks encompass three types: "Baidarkas", from the Bering sea & Aleutian islands, the oldest design, whose rounded shape and numerous chines give them an almost Blimp-like appearance; "West Greenland" kayaks, with fewer chines and a more angular shape, with gunwales rising to a point at the bow and stern; and "East Greenland" kayaks that appear similar to the West Greenland style, but often fit more


title: Kayak content: snugly to the paddler and possess a steeper angle between gunwale and stem, which lends maneuverability. Most of the Aleut people in the Aleutian Islands eastward to Greenland Inuit relied on the kayak for hunting a variety of prey—primarily seals, though whales and caribou were important in some areas. Skin-on-frame kayaks are still being used for hunting by Inuit people in Greenland, because the smooth and flexible skin glides silently through the waves. In other parts of the world home builders are continuing the tradition of skin on frame kayaks, usually with modern skins of canvas or synthetic fabric, such


title: Kayak content: as sc. ballistic nylon. Contemporary traditional-style kayaks trace their origins primarily to the native boats of Alaska, northern Canada, and Southwest Greenland. Wooden kayaks and fabric kayaks on wooden frames dominated the market up until the 1950s, when fiberglass boats were first introduced in the US, and inflatable rubberized fabric boats were first introduced in Europe. Rotomolded plastic kayaks first appeared in 1973, and most kayaks today are made from roto-molded polyethylene resins. The development of plastic and rubberized inflatable kayaks arguably initiated the development of freestyle kayaking as we see it today, since these boats could be made smaller,


title: Kayak content: stronger and more resilient than fiberglass boats. Typically, kayak design is largely a matter of trade-offs: directional stability ("tracking") vs maneuverability; stability vs speed; and primary vs secondary stability. Multihull kayaks face a different set of trade-offs. The paddler's body shape and size is an integral part of the structure, and will also affect the trade-offs made. If the displacement of a kayak is not enough to support the passenger(s) and gear, it will sink. If the displacement is excessive, the kayak will float too high, catch the wind and waves uncomfortably, and handle poorly; it will probably also be


title: Kayak content: bigger and heavier and than it needs to be. Being excessively big will create more drag, and the kayak will move more slowly and take more effort. Rolling is easier in lower-displacement kayaks. On the other hand, a higher deck will keep the paddler(s) dryer and make self-rescue and coming through surf easier. Many paddlers who use a sit-in kayak feel more secure in a kayak with a weight capacity substantially more than their own weight. Maximum volume in a sit-in kayak is helped by a wide hull with high sides. But paddling ease is helped by lower sides where


title: Kayak content: the paddler sits and a narrower width. Most manufacturers make kayaks for paddlers weighing , with some kayaks for paddlers down to . Kayaks made for paddlers under 100 pounds are almost all very beamy and intended for beginners. There seem to be no anthropometry stats of kayakers, who may not be representative of the general population. In the American civilian population of the early 1960s, about 0.7% of men and 9% of women weighed under ; 20% of men and 7% of women weighed over . In the same population in the late sixties, the average weight of both


title: Kayak content: male and female children crossed at age thirteen. In the early 2000s, it was a year or two earlier, and the mean weight of adults was over heavier. Also in the early 2000s, the mean weight of men was , and the mean weight of women was . As a general rule, a longer kayak is faster: it has a higher hull speed. It can also be narrower for a given displacement, reducing the drag, and it will generally track (follow a straight line) better than a shorter kayak. On the other hand, it is less manuverable. Very long kayaks


title: Kayak content: are less robust, and may be harder to store and transport. Some recreational kayak makers try to maximize hull volume (weight capacity) for a given length as shorter kayaks are easier to transport and store. Kayaks that are built to cover longer distances such as touring and sea kayaks are longer, generally . With touring kayaks the keel is generally more defined (helping the kayaker track in a straight line). Whitewater kayaks, which generally depend upon river current for their forward motion, are short, to maximize maneuverability. These kayaks rarely exceed in length, and "play boats" may be only long.


title: Kayak content: Recreational kayak designers try to provide more stability at the price of reduced speed, and compromise between tracking and maneuverability, ranging from . Length alone does not fully predict a kayak's maneuverability: a second design element is "rocker", i.e. its lengthwise curvature. A heavily "rockered" boat curves more, shortening its effective waterline. For example, an kayak with no rocker is in the water from end to end. In contrast, the bow and stern of a rockered boat are out of the water, shortening its lengthwise waterline to only . Rocker is generally most evident at the ends, and in moderation


title: Kayak content: improves handling. Similarly, although a rockered whitewater boat may only be a few feet shorter than a typical recreational kayak, its waterline is far shorter and its maneuverability far greater. When surfing, a heavily rockered boat is less likely to lock into the wave as the bow and stern are still above water. A boat with less rocker cuts into the wave and makes it harder to turn while surfing. The overall width of a kayak's cross section is its "beam". A wide hull is more stable, and packs more displacement into a shorter length. A narrow hull has less


title: Kayak content: drag and is generally easier to paddle; in waves it will ride more easily and stay dryer. A narrower kayak makes a somewhat shorter paddle appropriate and a shorter paddle puts less strain on the shoulder joints. Some paddlers are comfortable with a sit-in kayak so narrow that their legs extend fairly straight out. Others want sufficient width to permit crossing their legs inside the kayak. "Primary" (sometimes called "initial") stability describes how much a boat tips, or rocks back and forth, when displaced from level by paddler weight shifts. "Secondary" stability describes how stable a kayak feels when put


title: Kayak content: on edge or when waves are passing under the hull perpendicular to the length of the boat. For kayak rolling, "tertiary" stability, or the stability of an upside-down kayak, is also important (lower tertiary stability makes rolling up easier). Primary stability is often a big concern to a beginner, while secondary stability matters both to beginners and experienced travelers. By example, a wide, flat-bottomed kayak will have high primary stability and feel very stable on flat water. However, when a steep wave breaks on such a boat, it can be easily overturned because the flat bottom is no longer level.


title: Kayak content: By contrast, a kayak with a narrower, more rounded hull with more hull flare can be edged or leaned into waves and (in the hands of a skilled kayaker) provides a safer, more comfortable response on stormy seas. Kayaks with only moderate primary, but excellent secondary stability are, in general, considered more seaworthy, especially in challenging conditions. The shape of the cross section affects stability, maneuverability, and drag. Hull shapes are categorized by roundness/flatness, and by the presence and angle of chines. This cross–section may vary along the length of the boat. A chine typically increases secondary stability by effectively


title: Kayak content: widening the beam of the boat when it heels (tips). A V-shaped hull tends to travel straight (track) well, but makes turning harder. V-shaped hulls also have the greatest secondary stability. Conversely, flat-bottomed hulls are easy to turn, but harder to direct in a constant direction. A round-bottomed boat has minimal wetter area, and thus minimizes drag; however, it may be so unstable that it will not remain upright when floating empty, and needs continual effort to keep it upright. In a skin-on-frame kayak, chine placement may be constrained by the need to avoid the bones of the pelvis. Sea


title: Kayak content: kayaks, designed for open water and rough conditions, are generally narrower at and have more secondary stability than recreational kayaks, which are wider , have a flatter hull shape, and more primary stability. The body of the paddler must also be taken into account. A paddler with a low center of gravity will find all boats more stable; for a paddler with a high center of gravity, all boats will feel tippier. On average, women and children have a lower COG than men. Unisex kayaks are built for men. A paddler with narrow shoulders will also want a narrower kayak.


title: Kayak content: Newcomers will often want a craft with high primary stability (see above). The southern method is a wider kayak. The northern method is a removable pair of outriggers, lashed across the stern deck. Such an outrigger pair is often homemade of a small plank and found floats such as empty bottles or plastic ducks. Outriggers are also made commercially, especially for fishing kayaks and sailing. If the floats are set so that they are both in the water, they give primary stability, but produce more drag. If they are set so that they are both out of the water when


title: Kayak content: the kayak is balanced, they give secondary stability. Some kayak hulls are categorized according to the shape from bow to stern Common shapes include: Traditional-style and some modern types of kayaks (e.g. sit-on-top) require that paddler be seated with their legs stretched in front of them, in a right angle, in a position called the "L" kayaking position. Other kayaks offer a different sitting position, in which the paddler's legs are not stretched out in front of them, and the thigh brace bears more on the inside than the top of the thighs (see diagram). A kayakker must be able


title: Kayak content: to move the hull of their kayak by moving their lower body, and brace themselves against the hull (mostly with the feet) on each stroke. Most kayaks therefore have footrests and a backrest. Some kayaks fit snugly on the hips; others rely more on thigh braces. Mass-produced kayaks generally have adjustable bracing points. Many paddlers also customize their kayaks by putting in shims of closed-cell foam, or more elaborate structure, to make it fit more tightly. Paddling puts substantial force through the legs, alternately with each stroke. The knees should therefore not be hyperextended. Separately, if the kneecap is in


title: Kayak content: contact with the boat, this will cause pain and may injure the knee. Insufficient foot space will cause painful cramping and inefficient paddling. The paddler should generally be in a comfortable position. Attempting to lift and carry a kayak by oneself or improperly is a significant cause of kayaking injuries. Good lifting technique, sharing loads, and not using needlessly large and heavy kayaks prevents injuries. Today almost all kayaks are commercial products intended for sale rather than for the builder's personal use. Fiberglass hulls are stiffer than polyethylene hulls, but they are more prone to damage from impact, including cracking.


title: Kayak content: Most modern kayaks have steep V sections at the bow and stern, and a shallow V amidships. Fiberglass kayaks need to be "laid-up" in a mold by hand, so are usually more expensive than polyethylene kayaks, which are rotationally molded in a machine. Plastic kayaks are rotationally molded ('rotomolded') from a various grades and types of polyethylene resins ranging from soft to hard. Such kayaks are particularly resistant to impact. Wooden hulls don't necessarily require significant skill and handiwork, depending on how they are made. Kayaks made from thin strips of wood sheathed in fiberglass have proven successful, especially as


title: Kayak content: the price of epoxy resin has decreased in recent years. A plywood, stitch and glue (S&G) doesn't need fiberglass sheathing though some builders do. Three main types are popular, especially for the home builder: Stitch & Glue, Strip-Built, and hybrids which have a stitch & glue hull and a strip-built deck. Stitch & Glue designs typically use modern, marine-grade plywood — eighth-inch, or up to quarter-inch, thick. After cutting out the required pieces of hull and deck (kits often have these pre-cut), a series of small holes are drilled along the edges. Copper wire is then used to "stitch" the


title: Kayak content: pieces together through the holes. After the pieces are temporarily stitched together, they are glued with epoxy and the seams reinforced with fiberglass. When the epoxy dries, the copper stitches are removed. Sometimes the entire boat is then covered in fiberglass for additional strength and waterproofing though this adds greatly to the weight and is unnecessary. Construction is fairly straightforward, but because plywood does not bend to form compound curves, design choices are limited. This is a good choice for the first-time kayak builder as the labor and skills required (especially for kit versions) is considerably less than for strip-built


title: Kayak content: boats which can take 3 times as long to build. Strip-built designs are similar in shape to rigid fiberglass kayaks but are generally both lighter and tougher. Like their fiberglass counterparts the shape and size of the boat determines performance and optimal uses. The hull and deck are built with thin strips of lightweight wood, often cedar, pine or Redwood. The strips are edge-glued together around a form, stapled or clamped in place, and allowed to dry. Structural strength comes from a layer of fiberglass cloth and epoxy resin, layered inside and outside the hull. Strip–built kayaks are sold commercially


title: Kayak content: by a few companies, priced USD 4,000 and up. An experienced woodworker can build one for about USD 400 in 200 hours, though the exact cost and time depend on the builder's skill, the materials and the size and design. As a second kayak project, or for the serious builder with some woodworking expertise, a strip–built boat can be an impressive piece of work. Kits with pre-cut and milled wood strips are commercially available. Skin on frame boats are more traditional in design, materials, and construction. They were traditionally made of driftwood, pegged or lashed together, and stretched seal skin,


title: Kayak content: as those were the most readily available materials in the Arctic regions. Today, seal skin is usually replaced with canvas or nylon cloth covered with paint, polyurethane, or a hypalon rubber coating and a wooden or aluminum frame. Modern skin-on-frame kayaks often possess greater impact resistance than their fiberglass counterparts, but are less durable against abrasion or sharp objects. They are often the lightest kayaks. A special type of skin-on-frame kayak is the folding kayak. It has a collapsible frame, of wood, aluminum or plastic, or a combination thereof, and a skin of water-resistant and durable fabric. Many types have


title: Kayak content: air sponsons built into the hull, making the kayak float even if flooded. Modern kayaks differ greatly from native kayaks in every aspect—from initial form through conception, design, manufacturing and usage. Modern kayaks are designed with computer-aided design (CAD) software, often in combination with CAD customized for naval design. Modern kayaks serve diverse purposes, ranging from slow and easy touring on placid water, to racing and complex maneuvering in fast-moving whitewater, to fishing and long-distance ocean excursions. Modern forms, materials and construction techniques make it possible to effectively serve these needs while continuing to leverage the insights of the original


title: Kayak content: Arctic inventors. Kayaks are long—, short—, wide—, or as narrow as the paddler's hips. They may attach one or two stabilizing hulls (outriggers), have twin hulls like catamarans, inflate or fold. They move via paddles, pedals that turn propellers or underwater flippers, under sail, or motor. They're made of wood/canvas, wood, carbon fiber, fiberglass, Kevlar, polyethylene, polyester, rubberized fabric, neoprene, nitrylon, polyvinyl chloride (PVC), polyurethane, and aluminum. They may sport rudders, fins, bulkheads, seats, eyelets, foot braces and cargo hatches. They accommodate 1-3 or more paddlers/riders. Modern kayaks have evolved into specialized types that may be broadly categorized according to


title: Kayak content: their application as "sea or touring kayaks", "whitewater" (or "river") "kayaks", "surf kayaks", "racing kayaks", "fishing kayaks," and "recreational" kayaks. The broader kayak categories today are 'Sit-In', which is inspired mainly by traditional kayak forms, 'Sit-On-Top' (SOT), which evolved from paddle boards that were outfitted with footrests and a backrest, 'Hybrid', which are essentially canoes featuring a narrower beam and a reduced free board enabling the paddler to propel them from the middle of the boat, using a double blade paddle (i.e. 'kayak paddle'), and twin hull kayaks offering each of the paddler's legs a narrow hull of its own.


title: Kayak content: In recent decades, kayaks design have proliferated to a point where the only broadly accepted denominator for them is their being designed mainly for paddling using a kayak paddle featuring two blades i.e. 'kayak paddle'. However, even this inclusive definition is being challenged by other means of human powered propulsion, such as foot activated pedal drives combined with rotating or sideways moving propellers, electric motors, and even outboard motors. Recreational kayaks are designed for the casual paddler interested in fishing, photography, or a peaceful paddle on a lake, flatwater stream or protected salt water away from strong ocean waves. These


title: Kayak content: boats presently make up the largest segment of kayak sales. Compared to other kayaks, recreational kayaks have a larger cockpit for easier entry and exit and a wider beam () for more stability. They are generally less than in length and have limited cargo capacity. Less expensive materials like polyethylene and fewer options keep these boats relatively inexpensive. Most canoe/kayak clubs offer introductory instruction in recreational boats. They do not perform as well in the sea. The recreational kayak is usually a type of touring kayak. "Sea kayaks" are typically designed for travel by one, two or even three paddlers


title: Kayak content: on open water and in many cases trade maneuverability for seaworthiness, stability, and cargo capacity. Sea-kayak sub-types include "skin-on-frame" kayaks with traditionally constructed frames, open-deck "sit-on-top" kayaks, and recreational kayaks. The sea kayak, though descended directly from traditional types, is implemented in a variety of materials. Sea kayaks typically have a longer waterline, and provisions for below-deck storage of cargo. Sea kayaks may also have rudders or skegs (fixed rudder) and upturned bow or stern profiles for wave shedding. Modern sea kayaks usually have two or more internal bulkheads. Some models can accommodate two or sometimes three paddlers. Sealed-hull (unsinkable)


title: Kayak content: craft were developed for leisure use, as derivatives of surfboards (e.g. paddle or wave skis), or for surf conditions. Variants include planing surf craft, touring kayaks, and sea marathon kayaks. Increasingly, manufacturers build leisure 'sit-on-top' variants of extreme sports craft, typically using polyethylene to ensure strength and affordability, often with a skeg for directional stability. Water that enters the cockpit drains out through scupper holes—tubes that run from the cockpit to the bottom of the hull. Sit-on-top kayaks come in 1-4 paddler configurations. Sit-on-top kayaks are particularly popular for fishing and SCUBA diving, since participants need to easily enter and


title: Kayak content: exit the water, change seating positions, and access hatches and storage wells. Ordinarily the seat of a sit-on-top is slightly above water level, so the center of gravity for the paddler is higher than in a traditional kayak. To compensate for the higher center of gravity, sit-on-tops are often wider and slower than a traditional kayak of the same length. Contrary to popular belief, the sit-on-top kayak hull is not self bailing, since water penetrating it does not drain out automatically, as it does in bigger boats equipped with self bailing systems. Furthermore, the sit-on-top hull cannot be molded in


title: Kayak content: a way that would assure water tightness, and water may get in through various holes in its hull, usually around hatches and deck accessories. If the sit-on-top kayak is loaded to a point where such perforations are covered with water, or if the water paddled is rough enough that such perforations often go under water, the sit-on-top hull may fill with water without the paddler noticing it in time. Specialty surf boats typically have flat bottoms, and hard edges, similar to surf boards. The design of a surf kayak promotes the use of an ocean surf wave (moving wave) as


title: Kayak content: opposed to a river or feature wave (moving water). They are typically made from rotomolded plastic, or fiberglass. Surf kayaking comes in two main varieties, High Performance (HP) and International Class (IC). HP boats tend to have a lot of nose rocker, little to no tail rocker, flat hulls, sharp rails and up to four fins set up as either a three fin thruster or a quad fin. This enables them to move at high speed and maneuver dynamically. IC boats have to be at least long and until a recent rule change had to have a convex hull; now


title: Kayak content: flat and slightly concave hulls are also allowed, although fins are not. Surfing on international boats tends to be smoother and more flowing, and they are thought of as kayaking's "long boarding". Surf boats come in a variety of materials ranging from tough but heavy plastics to super light, super stiff but fragile foam–cored carbon fiber. Surf kayaking has become popular in traditional surfing locations, as well as new locations such as the Great Lakes. A variation on the closed cockpit surf kayak is called a waveski. Although the waveski offers dynamics similar to a sit–on–top, its paddling technique and


title: Kayak content: surfing performance and construction can be similar to surfboard designs. Whitewater kayaks are rotomolded in a semi-rigid, high impact plastic, usually polyethylene. Careful construction ensures that the boat remains structurally sound when subjected to fast-moving water. The plastic hull allows these kayaks to bounce off rocks without leaking, although they scratch and eventually puncture with enough use. Whitewater kayaks range from long. There are two main types of whitewater kayak: One type, the "playboat", is short, with a scooped bow and blunt stern. These trade speed and stability for high maneuverability. Their primary use is performing tricks in individual water


title: Kayak content: features or short stretches of river. In playboating or "freestyle" competition (also known as "rodeo" boating), kayakers exploit the complex currents of rapids to execute a series of tricks, which are scored for skill and style. The other primary type is the creek boat, which gets its name from its purpose: running narrow, low-volume waterways. Creekboats are longer and have far more volume than playboats, which makes them more stable, faster and higher-floating. Many paddlers use creekboats in "short boat" downriver races, and they are often seen on large rivers where their extra stability and speed may be necessary to


title: Kayak content: get through rapids. Between the creekboat and playboat extremes is a category called "river–running" kayaks. These medium–sized boats are designed for rivers of moderate to high volume, and some, known as "river running playboats", are capable of basic playboating moves. They are typically owned by paddlers who do not have enough whitewater involvement to warrant the purchase of more–specialized boats. Squirt Boating involves paddling both on the surface of the river and underwater. Squirt boats must be custom-fitted to the paddler to ensure comfort while maintaining the low interior volume necessary to allow the paddler to submerge completely in the


title: Kayak content: river. White water racers combine a fast, unstable lower hull portion with a flared upper hull portion to combine flat water racing speed with extra stability in open water: they are not fitted with rudders and have similar maneuverability to flat water racers. They usually require substantial skill to achieve stability, due to extremely narrow hulls. Whitewater racing kayaks, like all racing kayaks, are made to regulation lengths, usually of fiber reinforced resin (usually epoxy or polyester reinforced with Kevlar, glass fiber, carbon fiber, or some combination). This form of construction is stiffer and has a harder skin than non-reinforced


title: Kayak content: plastic construction such as rotomolded polyethylene: stiffer means faster, and harder means fewer scratches and therefore also faster. Sprint kayak is a sport held on calm water. Crews or individuals race over 200 m, 500 m, 1000 m or 5000 m with the winning boat being the first to cross the finish line. The paddler is seated, facing forward, and uses a double-bladed paddle pulling the blade through the water on alternate sides to propel the boat forward. In competition the number of paddlers within a boat is indicated by a figure besides the type of boat; K1 signifies an


title: Kayak content: individual kayak race, K2 pairs, and K4 four-person crews. Kayak sprint has been in every summer olympics since it debuted at the 1936 summer olympics. Racing is governed by the International Canoe Federation. Slalom kayaks are flat–hulled, and—since the early 1970s—feature low profile decks. They are highly maneuverable, and stable but not fast in a straight line. A specialized variant of racing craft called a "surf ski" has an open cockpit and can be up to long but only wide, requiring expert balance and paddling skill. Surf skis were originally created for surf and are still used in races in


title: Kayak content: New Zealand, Australia, and South Africa. They have become popular in the United States for ocean races, lake races and even downriver races. The term "kayak" is increasingly applied to craft that look little like traditional kayaks. Inflatables, also known as the "duckies" or "IKs", can usually be transported by hand using a carry bag. They are generally made of hypalon (a kind of neoprene), Nytrylon (a rubberized fabric), PVC, or polyurethane coated cloth. They can be inflated with foot, hand or electric pumps. Multiple compartments in all but the least expensive increase safety. They generally use low pressure air,


title: Kayak content: almost always below 3 psi. While many inflatables are non-rigid, essentially pointed rafts, best suited for use on rivers and calm water, the higher end inflatables are designed to be hardy, seaworthy vessels. Recently some manufacturers have added an internal frame (folding-style) to a multi-section inflatable sit-on-top kayak to produce a seaworthy boat. The appeal of inflatable kayaks is their portability, their durability (they don't dent), ruggedness in white water (they bounce off rocks rather than break) and their easy storage. In addition, inflatable kayaks generally are stable, have a small turning radius and are easy to master, although some


title: Kayak content: models take more effort to paddle and are slower than traditional kayaks. Because inflatable kayaks aren't as sturdy as traditional, hard-shelled kayaks, a lot of people tend to steer away from them. However, there have been considerable advancements in inflatable kayak technology over recent years. Folding kayaks are direct descendants of the skin-on-frame boats used by the Inuit and Greenlandic peoples. Modern folding kayaks are constructed from a wooden or aluminum frame over which is placed a synthetic skin made of polyester, cotton canvas, polyurethane, or Hypalon. They are more expensive than inflatable kayaks, but have the advantage of greater


title: Kayak content: stiffness and consequently better seaworthiness. Walter Höhn (English Hoehn) had built, developed and then tested his design for a folding kayak in the white-water rivers of Switzerland from 1924 to 1927. In 1928, on emigrating to Australia, he brought 2 of them with him, lodged a patent for the design and proceeded to manufacture them. In 1942 the Australian Director of Military operations approached him to develop them for Military use. Orders were placed and eventually a total of 1024, notably the MKII & MKIII models, were produced by him and another enterprise, based on his 1942 patent (No. 117779)


title: Kayak content: A kayak with pedals allows the kayaker to propel the vessel with a rotating propeller or underwater "flippers" rather than with a paddle. In contrast to paddling, kayakers who pedal kayaks use their legs rather than their arms. Traditional multi-hull vessels such as catamarans and outrigger canoes benefit from increased lateral stability without sacrificing speed, and these advantages have been successfully applied in twin hull kayaks. "Outrigger kayaks" attach one or two smaller hulls to the main hull to enhance stability, especially for fishing, touring, kayak sailing and motorized kayaking. Twin hull kayaks feature two long and narrow hulls, and


title: Kayak content: since all their buoyancy is distributed as far as possible from their center line, they are stabler than mono hull kayaks outfitted with outriggers. While native people of the Arctic regions hunted rather than fished from kayaks, in recent years kayak sport fishing has become popular in both fresh and salt water, especially in warmer regions. Traditional fishing kayaks are characterized by wide beams of up to that increase their lateral stability. Some are equipped with outriggers that increase their stability, and others feature twin hulls enabling stand up paddling and fishing. Compared with motorboats, fishing kayaks are inexpensive and


title: Kayak content: have few maintenance costs. Many kayak anglers like to customize their kayaks for fishing, a process known as 'rigging'. Kayaks were adapted for military use in the Second World War. Used mainly by British Commando and special forces, principally the Combined Operations Pilotage Parties (COPPs), the Special Boat Service and the Royal Marines Boom Patrol Detachment. The latter made perhaps the best known use of them in the Operation Frankton raid on Bordeaux harbor. Both the Special Air Service (SAS) and the Special Boat Service (SBS) used kayaks for reconnaissance in the 1982 Falklands War. US Navy SEALs reportedly used


title: Kayak content: them at the start of Unified Task Force operations in Somalia in 1992. The SBS currently use Klepper two-man folding kayaks that can be launched from surfaced submarines or carried to the surface by divers from submerged ones. They can be parachuted from transport aircraft into the ocean or dropped from the back of Chinook helicopters. US Special Forces have used Kleppers but now primarily use Long Haul folding kayaks, which are made in the US. The Australian Military MKII and MKIII folding kayaks were extensively used during the 1941-1945 Pacific War for some 33 raids and missions on and


title: Kayak content: around the South-East Asian islands. Documentation for this will be found in the National Archives of Australia official records, reference No. NAA K1214-123/1/06. They were deployed from disguised watercraft, submarines, Catalina aircraft, P.T. boats, motor launches and by parachute. Kayak A kayak is a small, narrow watercraft which is propelled by means of a double-bladed paddle. The word kayak originates from the Greenlandic word "qajaq" (). The traditional kayak has a covered deck and one or more cockpits, each seating one paddler. The cockpit is sometimes covered by a spray deck that prevents the entry of water from waves or


title: "Klein bottle" content: the intersection along the fourth dimension, out of the original three-dimensional space. A useful analogy is to consider a self-intersecting curve on the plane; self-intersections can be eliminated by lifting one strand off the plane. Suppose for clarification that we adopt time as that fourth dimension. Consider how the figure could be constructed in "xyzt"-space. The accompanying illustration ("Time evolution...") shows one useful evolution of the figure. At the wall sprouts from a bud somewhere near the "intersection" point. After the figure has grown for a while, the earliest section of the wall begins to recede, disappearing like the Cheshire


title: Luxembourg content: IMF, Luxembourg was the second richest country in the world, with a per capita GDP on a purchasing-power parity (PPP) basis of $80,119. Luxembourg is ranked 13th in The Heritage Foundation's Index of Economic Freedom, 26th in the United Nations Human Development Index, and 4th in the Economist Intelligence Unit's quality of life index. External debt of Luxembourg is $14,385,000,000, or a per capital debt of $24,308. The debt to GDP is 23%. The industrial sector, which was dominated by steel until the 1960s, has since diversified to include chemicals, rubber, and other products. During the past decades, growth in


title: Language content: Morphemes can be classified according to whether they are independent morphemes, so-called roots, or whether they can only co-occur attached to other morphemes. These bound morphemes or affixes can be classified according to their position in relation to the root: "prefixes" precede the root, suffixes follow the root, and infixes are inserted in the middle of a root. Affixes serve to modify or elaborate the meaning of the root. Some languages change the meaning of words by changing the phonological structure of a word, for example, the English word "run", which in the past tense is "ran". This process is


title: "History of Lithuania" content: a pagan at the start of his reign. He agreed to become a Catholic when offered the Polish crown and the child queen Jadwiga by leading Polish nobles, who were eager to take advantage of Lithuania's expansion. For the near future, Poland gave Lithuania a valuable ally against increasing threats from the Teutonic Knights and the Grand Duchy of Moscow. Lithuania, in which Ruthenians outnumbered ethnic Lithuanians by several times, could ally with either the Grand Duchy of Moscow or Poland. A Russian deal was also negotiated with Dmitry Donskoy in 1383–1384, but Moscow was too distant to be able


title: LimeWire content: to shut down the LimeWire Pirate Edition website. A court order was issued to close down the website, and, to remain anonymous, Meta Pirate, the developer of LimeWire PE, did not contest the order. According to its SourceForge website, WireShare is the newest fork of the original LimeWire open source project (a successor of LPE: LimeWire Pirate Edition, which name was dropped for legal reasons). The software was developed to help keep the Gnutella network alive and to maintain a good faith continuation of the original project (without adware or spyware). On February 15, 2010, LimeWire reversed its previous anti-bundling


title: "Liquid crystal" content: manner similar to that of soap. The word "smectic" originates from the Latin word "smecticus", meaning cleaning, or having soap-like properties. The smectics are thus positionally ordered along one direction. In the Smectic A phase, the molecules are oriented along the layer normal, while in the Smectic C phase they are tilted away from it. These phases are liquid-like within the layers. There are many different smectic phases, all characterized by different types and degrees of positional and orientational order. The chiral nematic phase exhibits chirality (handedness). This phase is often called the "cholesteric" phase because it was first observed


title: Lydia content: Lycia. After the Persian conquest the River Maeander was regarded as its southern boundary, and during imperial Roman times Lydia comprised the country between Mysia and Caria on the one side and Phrygia and the Aegean Sea on the other. The Lydian language was an Indo-European language in the Anatolian language family, related to Luwian and Hittite. Due to its fragmentary attestation, the meanings of many words are unknown but much of the grammar has been determined. Similar to other Anatolian languages, it featured extensive use of prefixes and grammatical particles to chain clauses together. Lydian had also undergone extensive


title: "Land's End" content: Land's End Land's End ( or "Pedn an Wlas") is a headland and holiday complex in western Cornwall, England. It is the most westerly point of mainland Cornwall and England, situated within the Penwith peninsula about west-south-west of Penzance at the western end of the A30 road. The actual Land’s End or Peal Point, is a modest headland compared with nearby headlands such as Pedn-men-dhu overlooking Sennen Cove and Pordenack, to the south. The present hotel and tourist complex is at Carn Kez, 200 m south of the actual Land’s End. Land's End has a particular resonance because it is


title: "Land's End" content: often used to suggest distance. Land's End to John o' Groats in Scotland is a distance of by road and this "Land's End to John o' Groats" distance is often used to define charitable events such as end-to-end walks and races in the UK. Land's End to the northernmost point of England is a distance of by road. Land's End is a popular venue for rock climbers. The Longships, a group of rocky islets are just over offshore, and together with the Seven Stones Reef and the Isles of Scilly which lie about southwest — are part of the mythical


title: "Land's End" content: lost land of Lyonesse, referred to in Arthurian literature. The area around Land's End has been designated part of an Important Plant Area, by the organisation Plantlife, for rare species of flora. The cliffs are made of granite, an igneous rock, which means that the cliffs will be more resistant to weathering, and will have steeper cliff faces. There are two varieties of granite represented at Land's End. Adjacent to the hotel the granite is coarse-grained with large phenocrysts of orthoclase, sometimes more than in length. To the north, at the First and Last House, there is a finer grained


title: "Land's End" content: granite with fewer and smaller phenocrysts, and the different granites can be seen from a distance by the smoother weathering of the finer variety. The granite dates to 268–275 million years ago of the Permian period. The contact zone between the Land's End granite pluton and the altered ″country rocks″ is nearby and the Longships Lighthouse, offshore, is built on the country rock. In 1769, the antiquarian William Borlase wrote: Of this time we are to understand what Edward I. says (Sheringham. p. 129.) that Britain, Wales, and Cornwall, were the portion of Belinus, elder son of Dunwallo, and that


title: "Land's End" content: that part of the Island, afterwards called England, was divided in three shares, viz. Britain, which reached from the Tweed, Westward, as far as the river Ex; Wales inclosed by the rivers Severn, and Dee; and Cornwall from the river Ex to the Land's-End. Tourists have been visiting Land’s End for over three hundred years. In 1649, an early visitor was the poet John Taylor, who was hoping to find subscribers for his new book "Wanderings to see the Wonders of the West". In 1878 people left Penzance by horse-drawn vehicles from outside the Queens and Union hotels and travelled


title: "Land's End" content: via St Buryan and Treen, to see the Logan Rock. There was a short stop to look at Porthcurno and the Eastern Telegraph Company followed by refreshments at the First and Last Inn in Sennen. They then headed for Land’s End, often on foot or horse, because of the uneven and muddy lanes. Over one hundred people could be at Land's End at any one time. At Carn Kez, the First and Last Inn owned a small house which looked after the horses while visitors roamed the cliffs. The house at Carn Kez developed into the present hotel. The earliest


title: "Land's End" content: part of the house was damaged by the Luftwaffe when a plane returning from a raid on Cardiff jettisoned its remaining bombs. 53 fisherman were injured or killed. In the build-up to D-Day American troops were billeted in the hotel leaving the building in a bad state. Land's End was owned by a Cornish family until 1982, when it was sold to David Goldstone. In 1987, Peter de Savary outbid the National Trust to purchase Land’s End for almost £7 million from David Goldstone. He had two new buildings erected and much of the present theme park development was instigated


title: "Land's End" content: by him. He sold both Land's End and John o' Groats to businessman Graham Ferguson Lacey in 1991. The current owners purchased Land's End in 1996 and formed a company named Heritage Great Britain PLC. Attractions at the theme park include children's playgrounds and recorded music. Twice a week in August, Land's End hosts 'Magic in the Skies', a night-time firework spectacular with music by British composer Christopher Bond and narrated by actress Miriam Margolyes. Within the complex is the Land's End Hotel. In May 2012, Land's End received worldwide publicity as the starting point of the 2012 Summer Olympics


title: "Land's End" content: torch relay. Land's End is either the start or finishing point, of end to end journeys with John o'Groats in Scotland. One of the earliest was by Carlisle who left Land's End on 23 September 1879, went to John O'Groats House and arrived back at Land's End on 15 December; taking 72 days (exclusive of Sundays); covering . To prove his journey, he kept a log book which was stamped at any Post Office he passed. An early end to end on bicycle was completed by Messrs Blackwell and Harman of Canonbury Bicycle Club. Starting at Land's End they covered


title: "Land's End" content: in thirteen days in July/August 1880. Nearly two years later the Hon I Keith-Falconer travelled . from Land's End, in twelve days, 23¼ hours, on a bicycle. On the south side of Carn Kez the land slopes away to a shallow valley containing a small stream and the former Greeb Farm. In 1879 a derrick was used for hauling seaweed from the beach 40 feet below; for use as a soil improver. Land's End Land's End ( or "Pedn an Wlas") is a headland and holiday complex in western Cornwall, England. It is the most westerly point of mainland Cornwall


title: Lizard content: Lizard Lizards are a widespread group of squamate reptiles, with over 6,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic as it excludes the snakes and Amphisbaenia; some lizards are more closely related to these two excluded groups than they are to other lizards. Lizards range in size from chameleons and geckos a few centimeters long to the 3 meter long Komodo dragon. Most lizards are quadrupedal, running with a strong side-to-side motion. Others are legless, and have long snake-like bodies. Some such as the forest-dwelling "Draco" lizards are able


title: Lizard content: to glide. They are often territorial, the males fighting off other males and signalling, often with brightly colours, to attract mates and to intimidate rivals. Lizards are mainly carnivorous, often being sit-and-wait predators; many smaller species eat insects, while the Komodo eats mammals as big as water buffalo. Lizards make use of a variety of antipredator adaptations, including venom, camouflage, reflex bleeding, and the ability to sacrifice and regrow their tails. The adult length of species within the suborder ranges from a few centimeters for chameleons such as "Brookesia micra" and geckos such as "Sphaerodactylus ariasae" to nearly in the


title: Lizard content: case of the largest living varanid lizard, the Komodo dragon. Most lizards are fairly small animals. Lizards typically have four legs, feet and external ears, though some are legless, while snakes lack both of these characteristics. Lizards and snakes share a movable quadrate bone, distinguishing them from the sphenodonts, which have more primitive and solid diapsid skulls. Some lizards such as chameleons have prehensile tails, assisting them in climbing among vegetation. As in other reptiles, the skin of lizards is covered in overlapping scales made of keratin. This provides protection from the environment and reduces water loss through evaporation. This


title: Lizard content: adaptation enables lizards to thrive in some of the driest deserts on earth. The skin is tough and leathery, and is shed (sloughed) as the animal grows. Unlike snakes which shed the skin in a single piece, lizards slough their skin in several pieces. The scales may be modified into spines for display or protection, and some species have bone osteoderms underneath the scales. The dentitions of lizards reflect their wide range of diets, including carnivorous, insectivorous, omnivorous, herbivorous, nectivorous, and molluscivorous. Species typically have uniform teeth suited to their diet, but several species have variable teeth, such as cutting


title: Lizard content: teeth in the front of the jaws and crushing teeth in the rear. Most species are pleurodont, though agamids and chameleons are acrodont. The tongue can be extended outside the mouth, and is often long. In the beaded lizards, whiptails and monitor lizards, the tongue is forked and used mainly or exclusively to sense the environment, continually flicking out to sample the environment, and back to transfer molecules to the vomeronasal organ responsible for chemosensation, analogous to but different from smell or taste. In geckos, the tongue is used to lick the eyes clean: they have no eyelids. Chameleons have


title: Lizard content: very long sticky tongues which can be extended rapidly to catch their insect prey. Three lineages, the geckos, anoles, and chameleons, have modified the scales under their toes to form adhesive pads, highly prominent in the first two groups. The pads are composed of millions of tiny setae (hair-like structures) which fit closely to the substrate to adhere using van der Waals forces; no liquid adhesive is needed. In addition, the toes of chameleons are divided into two opposed groups on each foot (zygodactyly), enabling them to perch on branches as birds do. Aside from legless lizards, most lizards are


title: Lizard content: quadrupedal and move using gaits with alternating movement of the right and left limbs with substantial body bending. This body bending prevents significant respiration during movement, limiting their endurance, in a mechanism called Carrier's constraint. Several species can run bipedally, and a few can prop themselves up on their hindlimbs and tail while stationary. Several small species such as those in the genus "Draco" can glide: some can attain a distance of , losing in height. Some species, like geckos and chameleons, adhere to vertical surfaces including glass and ceilings. Some species, like the common basilisk, can run across water.


title: Lizard content: Lizards make use of their senses of sight, touch, olfaction and hearing like other vertebrates. The balance of these varies with the habitat of different species; for instance, skinks that live largely covered by loose soil rely heavily on olfaction and touch, while geckos depend largely on acute vision for their ability to hunt and to evaluate the distance to their prey before striking. Monitor lizards have acute vision, hearing, and olfactory senses. Some lizards make unusual use of their sense organs: chameleons can steer their eyes in different directions, sometimes providing non-overlapping fields of view, such as forwards and


title: Lizard content: backwards at once. Lizards lack external ears, having instead a circular opening in which the tympanic membrane (eardrum) can be seen. Many species rely on hearing for early warning of predators, and flee at the slightest sound. As in snakes and many mammals, all lizards have a specialised olfactory system, the vomeronasal organ, used to detect pheromones. Monitor lizards transfer scent from the tip of their tongue to the organ; the tongue is used only for this information-gathering purpose, and is not involved in manipulating food. Some lizards, particularly iguanas, have retained a photosensory organ on the top of their


title: Lizard content: heads called the parietal eye, a basal ("primitive") feature also present in the tuatara. This "eye" has only a rudimentary retina and lens and cannot form images, but is sensitive to changes in light and dark and can detect movement. This helps them detect predators stalking it from above. Until 2006 it was thought that among lizards, only the Gila monster and the Mexican beaded lizard were venomous. However, several species of monitor lizards, including the Komodo dragon, produce powerful venom in their oral glands. Lace monitor venom, for instance, causes swift loss of consciousness and extensive bleeding through its


title: Lizard content: pharmacological effects, both lowering blood pressure and preventing blood clotting. Nine classes of toxin known from snakes are produced by lizards. The range of actions provides the potential for new medicinal drugs based on lizard venom proteins. Genes associated with venom toxins have been found in the salivary glands on a wide range of lizards, including species traditionally thought of as non-venomous, such as iguanas and bearded dragons. This suggests that these genes evolved in the common ancestor of lizards and snakes, some 200 million years ago (forming a single clade, the Toxicofera). However, most of these putative venom genes


title: Lizard content: were "housekeeping genes" found in all cells and tissues, including skin and cloacal scent glands. The genes in question may thus be evolutionary precursors of venom genes. Recent studies (2013 and 2014) on the lung anatomy of the savannah monitor and green iguana found them to have a unidirectional airflow system, which involves the air moving in a loop through the lungs when breathing. This was previously thought to only exist in the archosaurs (crocodilians and birds). This may be evidence that unidirectional airflow is an ancestral trait in diapsids. As with all amniotes, lizards rely on internal fertilisation and


title: Lizard content: copulation involves the male inserting one of his hemipenes into the female's cloaca. The majority of species are oviparous (egg laying). The female deposits the eggs in a protective structure like a nest or crevice or simply on the ground. Depending on the species, clutch size can vary from 4–5 percent of the females body weight to 40–50 percent and clutches range from one or a few large eggs to dozens of small ones. In most lizards, the eggs have leathery shells to allow for the exchange of water, although more arid-living species have calcified shells to retain water. Inside


title: Lizard content: the eggs, the embryos use nutrients from the yolk. Parental care is uncommon and the female usually abandons the eggs after laying them. Brooding and protection of eggs does occur in some species. The female prairie skink uses respiratory water loss to maintain the humidity of the eggs which facilitates embryonic development. In lace monitors, the young hatch close to 300 days and the female returns to help them escape the termite mound were the eggs were laid. Around 20 percent of lizard species reproduce via viviparity (live birth). This is particularly common in Anguimorphs. Viviparous species give birth to


title: Lizard content: relatively developed young which look like miniature adults. Embryos are nourished via a placenta-like structure. A minority of lizards have parthenogenesis (reproduction from unfertilised eggs). These species consist of all females who reproduce asexually with no need for males. This is known in occur in various species of whiptail lizards. Parthenogenesis was also recorded in species that normally reproduce sexually. A captive female Komodo dragon produced a clutch of eggs, despite being separated from males for over two years. Sex determination in lizards can be temperature-dependent. The temperature of the eggs' micro-environment can determine the sex of the hatched young:


title: Lizard content: low temperature incubation produces more females while higher temperatures produce more males. However, some lizards have sex chromosomes and both male heterogamety (XY and XXY) and female heterogamety (ZW) occur. The majority of lizard species are active during the day, though some are active at night, notably geckos. As ectotherms, lizards have a limited ability to regulate their body temperature, and must seek out and bask in sunlight to gain enough heat to become fully active. Most social interactions among lizards are between breeding individuals. Territoriality is common and is correlated with species that use sit-and-wait hunting strategies. Males establish


title: Lizard content: and maintain territories that contain resources which attract females and which they defend from other males. Important resources include basking, feeding, and nesting sites as well as refuges from predators. The habitat of a species affects the structure of territories, for example, rock lizards have territories atop rocky outcrops. Some species may aggregate in groups, enhancing vigilance and lessening the risk of predation for individuals, particularly for juveniles. Agonistic behaviour typically occurs between sexually mature males over territory or mates and may involve displays, posturing, chasing, grappling and biting. Lizards signal both to attract mates and to intimidate rivals. Visual


title: Lizard content: displays include body postures and inflation, push-ups, bright colours, mouth gapings and tail waggings. Male anoles and iguanas have dewlaps or skin flaps which come in various sizes, colours and patterns and the expansion of the dewlap as well as head-bobs and body movements add to the visual signals. Some species have deep blue dewlaps and communicate with ultraviolet signals. Blue-tongued skinks will flash their tongues as a threat display. Chameleons are known to change their complex colour patterns when communicating, particularly during agonistic encounters. They tend to show brighter colours when displaying aggression and darker colours when they submit


title: Lizard content: or "give up". Several gecko species are brightly coloured; some species tilt their bodies to display their coloration. In certain species, brightly coloured males turn dull when not in the presence of rivals or females. While it is usually males that display, in some species females also use such communication. In the bronze anole, head-bobs are a common form of communication among females, the speed and frequency varying with age and territorial status. Chemical cues or pheromones are also important in communication. Males typically direct signals at rivals, while females direct them at potential mates. Lizards may be able to


title: Lizard content: recognise individuals of the same species by their scent. Acoustic communication is less common in lizards. Hissing, a typical reptilian sound, is mostly produced by larger species as part of a threat display, accompanying gaping jaws. Some groups, particularly geckos, snake-lizards, and some iguanids, can produce more complex sounds and vocal apparatuses have independently evolved in different groups. These sounds are used for courtship, territorial defense and in distress, and include clicks, squeaks, barks and growls. The mating call of the male tokay gecko is heard as "tokay-tokay!". Tactile communication involves individuals rubbing against each other, either in courtship or


title: Lizard content: in aggression. Some chameleon species communicate with one another by vibrating the substrate that they are standing on, such as a tree branch or leaf. Lizards are found worldwide, excluding the far north and Antarctica, and some islands. They can be found in elevations from sea level to . They prefer warmer, tropical climates but are adaptable and can live in all but the most extreme environments. Lizards also exploit a number of habitats; most primarily live on the ground, but others may live in rocks, on trees, underground and even in water. The marine iguana is adapted for life


title: Lizard content: in the sea. The majority of lizard species are predatory and the most common prey items are small, terrestrial invertebrates, particularly insects. Many species are sit-and-wait predators though others may be more active foragers. Chameleons prey on numerous insect species, such as beetles, grasshoppers and winged termites as well as spiders. They rely on persistence and ambush to capture these prey. An individual perches on a branch and stays perfectly still, with only its eyes moving. When an insect lands, the chameleon focuses its eyes on the target and slowly moves towards it before projecting its long sticky tongue which,


title: Lizard content: when hauled back, brings the attach prey with it. Geckos feed on crickets, beetles, termites and moths. Termites are an important part of the diets of some species of Autarchoglossa, since, as social insects, they can be found in large numbers in one spot. Ants may form a prominent part of the diet of some lizards, particularly among the lacertas. Horned lizards are also well known for specializing on ants. Due to their small size and ingestible chitin, ants must be consumed in large amounts, and ant-eating lizards have larger stomachs than even herbivorous ones. Species of skink and alligator


title: Lizard content: lizards eat snails and their power jaws and molar-like teeth are adapted for breaking the shells. Larger species, such as monitor lizards, can feed on larger prey including fish, frogs, birds, mammals and other reptiles. Prey may be swallowed whole and torn into smaller pieces. Both bird and reptile eggs may also be consumed as well. Gila monsters and beaded lizards climb trees to reach both the eggs and young of birds. Despite being venomous, these species rely on their strong jaws to kill prey. Mammalian prey typically consists of rodents and leporids; the Komodo dragon can kill prey as


title: Lizard content: large as water buffalo. Dragons are prolific scavengers, and a single decaying carcass can attract several from away. A dragon is capable of consuming a carcass in 17 minutes. Around 2 percent of lizard species, including many iguanids, are herbivores. Adults of these species eat plant parts like flowers, leaves, stems and fruit, while juveniles eat more insects. Plant parts can be hard to digest and as they get closer to adulthood, juvenile iguanas eat faeces from adults to acquire the microflora necessary for their transition to a plant-based diet. Perhaps the most herbivorous species is the marine iguana which


title: Lizard content: dives to forage for algae, kelp and other marine plants. Some non-herbivorous species supplement their insect diet with fruit, which is easily digested. Lizards have a variety of antipredator adaptations, including running and climbing, venom, camouflage, tail autotomy, and reflex bleeding. Lizards exploit a variety of different camouflage methods. Many lizards are disruptively patterned. In some species, such as Aegean wall lizards, individuals vary in colour, and select rocks which best match their own colour to minimise the risk of being detected by predators. The Moorish gecko is able to change colour for camouflage: when a light-coloured gecko is placed


title: Lizard content: on a dark surface, it darkens within an hour to match the environment. The chameleons in general use their ability to change their coloration for signalling rather than camouflage, but some species such as Smith's dwarf chameleon do use active colour change for camouflage purposes. The flat-tail horned lizard's body is coloured like its desert background, and is flattened and fringed with white scales to minimise its shadow. Many lizards, including geckos and skinks, are capable of shedding their tails (autotomy). The detached tail, sometimes brilliantly coloured, continues to writhe after detaching, distracting the predator's attention from the fleeing prey.


title: Lizard content: Lizards partially regenerate their tails over a period of weeks. Some 326 genes are involved in regenerating lizard tails. The fish-scale gecko "Geckolepis megalepis " sheds patches of skin and scales if grabbed. Many lizards attempt to escape from danger by running to a place of safety; for example, wall lizards can run up walls and hide in holes or cracks. Horned lizards adopt differing defences for specific predators. They may play dead to deceive a predator that has caught them; attempt to outrun the rattlesnake, which does not pursue prey; but stay still, relying on their cryptic coloration, for


title: Lizard content: "Masticophis" whip snakes which can catch even swift prey. If caught, some species such as the greater short-horned lizard puff themselves up, making their bodies hard for a narrow-mouthed predator like a whip snake to swallow. Finally, horned lizards can squirt blood at cat and dog predators from a pouch beneath its eyes, to a distance of about ; the blood tastes foul to these attackers. The earliest known fossil remains of a lizard belong to the iguanian species "Tikiguania estesi", found in the Tiki Formation of India, which dates to the Carnian stage of the Triassic period, about 220


title: Lizard content: million years ago. However, doubt has been raised over the age of "Tikiguania" because it is almost indistinguishable from modern agamid lizards. The "Tikiguania" remains may instead be late Tertiary or Quaternary in age, having been washed into much older Triassic sediments. Lizards are most closely related to the Rhynchocephalia, which appeared in the Late Triassic, so the earliest lizards probably appeared at that time. Mitochondrial phylogenetics suggest that the first lizards evolved in the late Permian. It had been thought on the basis of morphological data that iguanid lizards diverged from other squamates very early on, but molecular evidence


title: Lizard content: contradicts this. The position of the lizards and other Squamata among the reptiles was studied using fossil evidence by Rainer Schoch and Hans-Dieter Sues in 2015. Lizards form about 60% of the extant non-avian reptiles. Both the snakes and the Amphisbaenia (worm lizards) are clades deep within the Squamata (the smallest clade that contains all the lizards), so "lizard" is paraphyletic. The cladogram is based on genomic analysis by Wiens and colleagues in 2012 and 2016. Excluded taxa are shown in upper case on the cladogram. In the 13th century, lizards were recognized in Europe as part of a broad


title: Lizard content: category of "reptiles" that consisted of a miscellany of egg-laying creatures, including "snakes, various fantastic monsters, […], assorted amphibians, and worms", as recorded by Vincent of Beauvais in his "Mirror of Nature". The seventeenth century saw changes in this loose description. The name Sauria was coined by James Macartney (1802); it was the Latinisation of the French name "Sauriens", coined by Alexandre Brongniart (1800) for an order of reptiles in the classification proposed by the author, containing lizards and crocodilians, later discovered not to be each other's closest relatives. Later authors used the term "Sauria" in a more restricted sense,


title: Lizard content: i.e. as a synonym of Lacertilia, a suborder of Squamata that includes all lizards but excludes snakes. This classification is rarely used today because Sauria so-defined is a paraphyletic group. It was defined as a clade by Jacques Gauthier, Arnold G. Kluge and Timothy Rowe (1988) as the group containing the most recent common ancestor of archosaurs and lepidosaurs (the groups containing crocodiles and lizards, as per Mcartney's original definition) and all its descendants. A different definition was formulated by Michael deBraga and Olivier Rieppel (1997), who defined Sauria as the clade containing the most recent common ancestor of Choristodera,


title: Lizard content: Archosauromorpha, Lepidosauromorpha and all their descendants. However, these uses have not gained wide acceptance among specialists. Suborder Lacertilia (Sauria) – (lizards) Lizards have frequently evolved convergently, with multiple groups independently developing similar morphology and ecological niches. "Anolis" ecomorphs have become a model system in evolutionary biology for studying convergence. Limbs have been lost or reduced independently over two dozen times across lizard evolution, including in the Anniellidae, Anguidae, Cordylidae, Dibamidae, Gymnophthalmidae, Pygopodidae, and Scincidae; snakes are just the most famous and species-rich group of Squamata to have followed this path. Most lizard species are harmless to humans. Only the largest


title: Lizard content: lizard species, the Komodo dragon, which reaches in length and weighs up to , has been known to stalk, attack, and, on occasion, kill humans. An eight-year-old Indonesian boy died from blood loss after an attack in 2007. Numerous species of lizard are kept as pets, including bearded dragons, iguanas, anoles, and geckos (such as the popular leopard gecko). Lizards appear in myths and folktales around the world. In Australian Aboriginal mythology, Tarrotarro, the lizard god, split the human race into male and female, and gave people the ability to express themselves in art. A lizard king named Mo'o features


title: Lizard content: in Hawaii and other cultures in Polynesia. In the Amazon, the lizard is the king of beasts, while among the Bantu of Africa, the god Unkulunkulu sent a chameleon to tell humans they would live forever, but the chameleon was held up, and another lizard brought a different message, that the time of humanity was limited. A popular legend in Maharashtra tells the tale of how a common Indian monitor, with ropes attached, was used to scale the walls of the fort in the Battle of Sinhagad. Green iguanas are eaten in Central America, where they are sometimes referred to


title: Lizard content: as "chicken of the tree" after their habit of resting in trees and their supposedly chicken-like taste, while spiny-tailed lizards are eaten in Africa. In North Africa, "Uromastyx" species are considered "dhaab" or 'fish of the desert' and eaten by nomadic tribes. Lizards such as the Gila monster produce toxins with medical applications. Gila toxin reduces plasma glucose; the substance is now synthesised for use in the anti-diabetes drug exenatide (Byetta). Another toxin from Gila monster saliva has been studied for use as an anti-Alzheimer's drug. Lizards in many cultures share the symbolism of snakes, especially as an emblem of


title: Lizard content: resurrection. This may have derived from their regular moulting. The motif of lizards on Christian candle holders probably alludes to the same symbolism. According to Jack Tresidder, in Egypt and the Classical world they were beneficial emblems, linked with wisdom. In African, Aboriginal and Melanesian folklore they are linked to cultural heroes or ancestral figures. Lizard Lizards are a widespread group of squamate reptiles, with over 6,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic as it excludes the snakes and Amphisbaenia; some lizards are more closely related to these