Draco (lizard)

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Draco
Draco taeniopterus Gunther, 1861 from Bulon.jpg
D. taeniopterus in mid-glide, on Bulon Island, Thailand
Draco spilonotus.JPG
Male D. spilonotus extending the dewlap (throat flap) and patagia ("wings") in Sulawesi, Indonesia
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Agamidae
Subfamily: Draconinae
Genus: Draco
Linnaeus, 1758
Species

41 species (see text)

Draco distribution.svg

Draco is a genus of agamid lizards [1] that are also known as flying lizards, flying dragons or gliding lizards. These lizards are capable of gliding flight via membranes that may be extended to create wings (patagia), formed by an enlarged set of ribs. They are arboreal insectivores.

Contents

While not capable of powered flight they often obtain lift in the course of their gliding flights. Glides as long as 60 m (200 ft) have been recorded, over which the animal loses only 10 m (33 ft) in height which makes for a glide ratio of 6:1. This is done by a lizard of only around 20 cm (7.9 in) in total length, tail included. [2] They are found across Southeast Asia and southern India and are fairly common in forests, areca gardens, teak plantations and shrub jungle.

History of discovery

Skeleton of Draco Flying Dragon Mivart.png
Skeleton of Draco

Carl Linnaeus described the genus in 1758, with the type species being Draco volans. The name of the genus is from the Latin term for dragons of mythology. In the early and mid 20th century, there was controversy about their gliding capabilities, with some authors suggesting that the patagia were solely for display, but research in the late 1950s firmly established the gliding function of the patagia. [3]

Distribution

Species of Draco are widely distributed in the forests of Southeast Asia, with one species, Draco dussumieri, inhabiting Southern India. [4]

Habitat and ecology

Members of Draco are primarily arboreal, inhabiting tropical rainforests, and are almost never found on the forest floor. [3] They are insectivorous, primarily feeding on eusocial insects such as ants and termites. [5] The colour of the patagium is strongly correlated to the colour of falling leaves in their range, which complements their cryptic camouflage resembling tree bark; both are likely to be camouflage against predatory birds. [6]

Gliding

Takeoff and initial stages of gliding, slowed down 10x, showing the attachment of the forelimbs to the gliding membrane Draco takeoff.gif
Takeoff and initial stages of gliding, slowed down 10x, showing the attachment of the forelimbs to the gliding membrane
Landing, slowed down 20x Draco landing.gif
Landing, slowed down 20x

The lizards are well known for their "display structures" and ability to glide long distances using their wing-like, patagial membranes supported by elongated thoracic ribs to generate lift forces. [7] The hindlimbs in cross section form a streamlined and contoured airfoil, and are also probably involved in generating lift. [3] Gliding is both used to escape predators, and as the primary means of moving through their forest habitat. [3] The folding and unfolding of the membrane is controlled by the iliocostalis and intercostal muscles, which in other lizards are used to control breathing. At takeoff, the lizard jumps and descends headfirst, orientating itself so that the underside of the body is parallel to the ground. During flight, the back arches, forming the patagium into a cambered surface, and the forelimbs grab the front of the patagium, forming a straight front edge to the aerofoil. The forelimbs are used to manipulate the patagium in order to adjust the trajectory during flight. Maximum gliding speeds have been found to be between 5.2 and 7.6 metres per second, depending on the species. During the landing process, the glide is mostly horizontal. Immediately before landing, the forelimbs release the patagium. The landing is forefeet-first, followed by hindfeet. [8] The shape of the gliding membrane does not correlate with body size, meaning the larger species have proportionately less lift-generating surface area and consequently higher wing loading. [9]

Life history

Draco lizards are highly territorial, with the home range consisting of one or a few trees. The trees are actively guarded by males, with territory-less males searching the forest landscape in search of vacant areas. Experimental studies have determined that suitable unoccupied territories were claimed within a few hours of the removal of a dominant male. Females move freely through the territories. The patagium is used as a display structure during courtship and territorial disputes between rival males, alongside the opening of a brightly-colored dewlap that contrasts with their camouflaged body scalation. [3] The dewlap is translucent, and deliberately orientated perpendicular to the orientation of the sun during display in order to enhance visibility. [10] Draco is sexually dimorphic, with females being larger than males. [11] [12] The only time a female flying lizard ventures to the ground is when she is ready to lay her eggs. She descends the tree she is on and makes a nest hole by forcing her head into the soil. She then lays a clutch of 2–5 eggs before filling the hole and guards the eggs for approximately 24 hours, but then leaves and has nothing more to do with her offspring. [2]

Phylogenetics

Within Agamidae, Draco is a member of the subfamily Draconinae. Within Draconinae, Draco is most closely related to the genera Japalura and Ptyctolaemus. [13]

Species

Male D. dussumieri displaying for females by extending his dewlap, from Dandeli, India Draco lizard display.gif
Male D. dussumieri displaying for females by extending his dewlap, from Dandeli, India
Size of D. quinquefasciatus in comparison to a human hand, from Sarawak, Malaysia Five-lined Flying Dragon (Draco quinquefasciatus) (14136387745).jpg
Size of D. quinquefasciatus in comparison to a human hand, from Sarawak, Malaysia
Highly camouflaged D. dussumieri from Bandipur National Park, India 2005-Draco-dussumieri.jpg
Highly camouflaged D. dussumieri from Bandipur National Park, India

The following 41 species are recognized: [1] [14]

Nota bene : a binomial authority in parentheses indicates that the species was originally described in a genus other than Draco.

Similar prehistoric reptiles

Life restoration of the weigeltisaurid Weigeltisaurus jaekeli, one of the oldest known gliding reptiles Weigeltisaurus reconstruction.png
Life restoration of the weigeltisaurid Weigeltisaurus jaekeli, one of the oldest known gliding reptiles

Several other lineages of reptile known from the fossil record have convergently evolved similar gliding mechanisms consisting of a patagium or plate flanking the torso; the weigeltisaurids are the oldest of these, living in the Late Permian from around 258 to 252 million years ago. Other lineages include the Triassic kuehneosaurids and Mecistotrachelos, and the Cretaceous lizard Xianglong . [3] [8]

See also

Related Research Articles

<span class="mw-page-title-main">Patagium</span> Membranous structure that assists an animal in gliding or flight

The patagium is a membranous body part that assists an animal in obtaining lift when gliding or flying. The structure is found in extant and extinct groups of flying and gliding animals including bats, birds, some dromaeosaurs, pterosaurs, gliding mammals, some flying lizards, and flying frogs. The patagium that stretches between an animal's hind limbs is called the uropatagium or the interfemoral membrane.

<i>Draco volans</i> Species of reptile

Draco volans, also commonly known as the common flying dragon, is a species of lizard in the family Agamidae. The species is endemic to Southeast Asia. Like other members of genus Draco, this species has the ability to glide using winglike lateral extensions of skin called patagia.

<i>Draco blanfordii</i> Species of lizard

Draco blanfordii, commonly known as Blanford's flying dragon, Blanford’s flying lizard, or Blanford's gliding lizard, is a species of "flying" lizard in the family Agamidae. The species is endemic to Asia, and is capable of gliding from tree to tree.

<i>Draco dussumieri</i> Species of lizard

Draco dussumieri, also known commonly as the Indian flying lizard, the southern flying lizard, and the Western Ghats flying lizard, is a species of lizard in the family Agamidae. The species is capable of gliding from tree to tree. It is found principally in the Western Ghats and some other hill forests of Southern India. It is almost completely arboreal, found on trees in forests and adjoining palm plantations where it climbs trees to forage for insects and glides to adjoining trees by expanding the patagium, loose skin on the sides of the body which is supported by elongated ribs to act as wings. The skin on the sides of the neck is also extended to the sides using the hyoid bones of the tongue as support. During the breeding season males maintain small territories which they defend from other males while courting females. The male has a more colourful patagium than the female, and it prominently extends its yellow dewlap forward in display. Although living almost its entire life in trees, the female descends to the ground to lay eggs in soil. This is the species with the westernmost distribution within the genus Draco, the majority of species occurring in Southeast Asia.

<i>Draco maculatus</i> Species of lizard

Draco maculatus, commonly known as the spotted flying dragon or spotted gliding lizard, is a species of agamid flying lizard endemic to Southeast Asia. It is capable of gliding from tree to tree.

<i>Draco norvillii</i> Species of lizard

Draco norvillii, also known as Norvill's flying lizard, is species of agamid flying lizard endemic to India. This species is capable of gliding from tree to tree, and has been recorded gliding up to 50 metres (160 ft). It feeds on insects and other small invertebrates.

<span class="mw-page-title-main">Flying and gliding animals</span> Animals that have evolved aerial locomotion

A number of animals are capable of aerial locomotion, either by powered flight or by gliding. This trait has appeared by evolution many times, without any single common ancestor. Flight has evolved at least four times in separate animals: insects, pterosaurs, birds, and bats. Gliding has evolved on many more occasions. Usually the development is to aid canopy animals in getting from tree to tree, although there are other possibilities. Gliding, in particular, has evolved among rainforest animals, especially in the rainforests in Asia where the trees are tall and widely spaced. Several species of aquatic animals, and a few amphibians and reptiles have also evolved this gliding flight ability, typically as a means of evading predators.

<i>Sharovipteryx</i> Extinct genus of reptiles

Sharovipteryx is a genus of early gliding reptiles containing the single species Sharovipteryx mirabilis. It is known from a single fossil and is the only glider with a membrane surrounding the pelvis instead of the pectoral girdle. This lizard-like reptile was found in 1965 in the Madygen Formation, Dzailauchou, on the southwest edge of the Fergana Valley in Kyrgyzstan, in what was then the Asian part of the U.S.S.R. dating to the middle-late Triassic period. The Madygen horizon displays flora that put it in the Upper Triassic. An unusual reptile, Longisquama, was also found there.

<i>Coelurosauravus</i> Extinct genus of reptiles

Coelurosauravus is an extinct genus of gliding reptile, known from the Late Permian of Madagascar. Like other members of the family Weigeltisauridae, members of this genus possessed long, rod-like ossifications projecting outwards from the body. These bony rods were not extensions of the ribs but were instead a feature unique to weigeltisaurids. It is believed that during life, these structures formed folding wings used for gliding flight, similar to living gliding Draco lizards.

<i>Draco sumatranus</i> Species of lizard

Draco sumatranus, the common gliding lizard, is a species of agamid lizard endemic to Southeast Asia. It has elongated ribs and skin flaps on the sides of its body. When opened, these skin flaps allow it to glide between tree trunks.

<i>Weigeltisaurus</i> Extinct genus of reptiles

Weigeltisaurus is an extinct genus of weigeltisaurid reptile from the Late Permian Kupferschiefer of Germany and Marl Slate of England. It has a single species, originally named as Palaechamaeleo jaekeli in 1930 and later assigned the name Weigeltisaurus jaekeli in 1939, when it was revealed that Palaeochamaeleo was a preoccupied name. A 1987 review by Evans and Haubold later lumped Weigeltisaurus jaekeli under Coelurosauravus as a second species of that genus. A 2015 reassessment of skull morphology study substantiated the validity of Weigeltisaurus and subsequent authors have used this genus. Like other Weigeltisaurids, they possessed long rod-like bones that radiated from the trunk that were likely used to support membranes used for gliding, similar to extant Draco lizards.

<span class="mw-page-title-main">Philippine flying lemur</span> Species of mammal

The Philippine flying lemur or Philippine colugo, known locally as kagwang, is one of two species of colugo or "flying lemurs". It is monotypic of its genus. Although it is called "flying lemur", the Philippine flying lemur is neither a lemur nor does it fly. Instead, it glides as it leaps among trees.

Gliding flight is heavier-than-air flight without the use of thrust; the term volplaning also refers to this mode of flight in animals. It is employed by gliding animals and by aircraft such as gliders. This mode of flight involves flying a significant distance horizontally compared to its descent and therefore can be distinguished from a mostly straight downward descent like a round parachute.

<i>Draco indochinensis</i> Species of lizard

Draco indochinensis, also known as the Indochinese flying lizard or Indochinese gliding lizard, is a species of agamid lizard endemic to South-east Asia.

<span class="mw-page-title-main">Draconinae</span> Subfamily of lizards

The Draconinae are a subfamily of reptiles in the family Agamidae found in southern Asia and Oceania. Some taxonomists believe these genera belong to the subfamily Agaminae.

<i>Draco mindanensis</i> Species of lizard

Draco mindanensis, commonly known as the Mindanao flying dragon or Mindanao flying lizard, is a lizard species endemic to the Philippines. Characterized by a dull grayish brown body color and a vivid tangerine orange dewlap, this species is one of the largest of the genus Draco. It is diurnal, arboreal, and capable of gliding.

Draco guentheri, commonly known as Günther's flying lizard is a species of "flying dragon" in the family Agamidae. The species is endemic to the Philippines.

<i>Draco spilonotus</i> Species of lizard

Draco spilonotus, the Sulawesi lined gliding lizard, is a lizard endemic to Sulawesi. The species is known from various localities in forested areas of Sulawesi.

<i>Draco cornutus</i> Species of lizard

Draco cornutus is a species of "flying dragon", an agamid lizard. It is endemic to Borneo. It occurs at elevations up to 700 m (2,300 ft) above sea level, although its distribution is poorly known.

Draco boschmai is a species of lizard in the family Agamidae. The species is endemic to Indonesia.

References

  1. 1 2 Draco at the Reptarium.cz Reptile Database . Accessed 8 June 2021.
  2. 1 2 Piper, Ross (2007). 'Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals'. Santa Barbara, California: Greenwood Press [ dubious ].
  3. 1 2 3 4 5 6 McGuire, J. A.; Dudley, R. (2011-07-28). "The biology of gliding in flying lizards (genus Draco) and their fossil and extant analogs". Integrative and Comparative Biology. 51 (6): 983–990. doi: 10.1093/icb/icr090 . PMID   21798987.
  4. Honda, Masanao; Ota, Hidetoshi; Kobayashi, Mari; Nabhitabhata, Jarujin; Yong, Hoi-Sen; Hikida, Tsutomu (June 1999). "Phylogenetic Relationships of the Flying Lizards, Genus Draco (Reptilia, Agamidae)". Zoological Science. 16 (3): 535–549. doi:10.2108/zsj.16.535. hdl: 2241/104136 . ISSN   0289-0003. S2CID   59043102.
  5. Mori, Akira; Hikida, Tsutomu (1994-02-01). "Field Observations on the Social Behavior of the Flying Lizard, Draco volans sumatranus, in Borneo". Copeia. 1994 (1): 124. doi:10.2307/1446678. JSTOR   1446678.
  6. Klomp, D. A.; Stuart-Fox, D.; Das, I.; Ord, T. J. (December 2014). "Marked colour divergence in the gliding membranes of a tropical lizard mirrors population differences in the colour of falling leaves". Biology Letters. 10 (12): 20140776. doi:10.1098/rsbl.2014.0776. PMC   4298188 . PMID   25540157.
  7. Herre, Albert W. (1958). "On the gliding of flying lizards, genus Draco ". Copeia. 1958 (4): 338–339. doi:10.2307/1439979. JSTOR   1439979.
  8. 1 2 Dehling, J. Maximilian (2017-12-13). "How lizards fly: A novel type of wing in animals". PLOS ONE. 12 (12): e0189573. Bibcode:2017PLoSO..1289573D. doi: 10.1371/journal.pone.0189573 . PMC   5728497 . PMID   29236777.
  9. McGuire, Jimmy A. (February 2003). "Allometric prediction of locomotor performance: an example from Southeast Asian flying lizards". The American Naturalist. 161 (2): 337–349. doi:10.1086/346085. PMID   12675377. S2CID   29494470.
  10. Klomp, Danielle A.; Stuart-Fox, Devi; Das, Indraneil; Ord, Terry J. (February 2017). "Gliding lizards use the position of the sun to enhance social display". Biology Letters. 13 (2): 20160979. doi:10.1098/rsbl.2016.0979. PMC   5326517 . PMID   28179410.
  11. Srichairat, Nattawut; Duengkae, Prateep; Jantrarotai, Pattanee; Chuaynkern, Yodchaiy (March 2016). "Sexual dimorphism in the spotted flying lizard Draco maculatus (Gray, 1845) (Squamata: Agamidae) from Thailand". Agriculture and Natural Resources. 50 (2): 120–124. doi: 10.1016/j.anres.2015.08.002 .
  12. Husak, Jerry F.; Mcguire, Jimmy Adair (2014). "Does 'gliding while gravid' explain Rensch's rule in flying lizards?". Biological Journal of the Linnean Society. 113: 270–282. doi: 10.1111/bij.12319 . "Similarly, in some Draco it has been suggested that females have larger heads for their body size than males to counterbalance an increased weight burden that is displaced posteriorly during gravidity."
  13. Wang, Kai; Che, Jing; Lin, Simin; Deepak, V; Aniruddha, Datta-Roy; Jiang, Ke; Jin, Jieqiong; Chen, Hongman; Siler, Cameron D (2019-01-01). "Multilocus phylogeny and revised classification for mountain dragons of the genus Japalura s.l. (Reptilia: Agamidae: Draconinae) from Asia". Zoological Journal of the Linnean Society. 185 (1): 246–267. doi:10.1093/zoolinnean/zly034. ISSN   0024-4082.
  14. "Draco ". Dahms Tierleben. www.dahmstierleben.de.
  15. Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. ISBN   978-1-4214-0135-5. (Draco beccarii, p. 21).

Further reading