Reticulated python
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Reticulated python ( Malayopython reticulatus ) |
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| Malayopython reticulatus | ||||||||||||
| ( Schneider , 1801) |
The reticulated python ( Malayopython reticulatus ) belongs to the genus Malayopython in the family of the pythons (Pythonidae). He is one of the largest snakes in the world. Reticulated pythons live in the tropics of Southeast Asia. Originally the species lived there in moist rainforests and swamps, but it is very adaptable and also colonizes agricultural areas and settlements.
description
The reticulated python is one of the largest snakes in the world. In terms of body length and weight, the species shows a very strong sexual dimorphism , females are on average considerably larger and heavier than males. In the south of Sumatra , males reached a maximum head-torso length of 4.25 meters and a weight of 20 kilograms in a sample of a total of 1046 individuals, while females reached a head-torso length of 6.08 meters and a maximum weight of 75 kilograms. As with many vertebrates, island forms remain much smaller (→ island dwarfing ). On the island of Jampea , located between Sulawesi and Flores , males reach a maximum total length of 2.10 meters, females a maximum of 3.35 meters.
Reliable information on the maximum length of the species is not yet available. In general, reticulated pythons over 6 m in length are rare. One of the longest seriously measured individuals so far comes from the vicinity of Balkipapan, East Kalimantan , had a total length of 6.95 m in the anesthetized state and weighed 59 kg after a fasting period of 3 months. In some cases, widely published information on much larger specimens with lengths of up to almost 9 m has not withstood a scientific review in any case, and according to a more recent investigation , the reticulated python Colossus was not just under 9 m, but only 6.35 m long when it died.
This python is relatively slim, the head is large, flattened and very clearly set off from the neck. The tail accounts for about 13-14% of the total length. From above the head appears quite elongated, the muzzle is rounded. The nostrils are arranged laterally, but still visible from above. The rostral is barely visible from above. The anterior prefrontalia are also large and longer than wide. Behind it follows a band of irregularly shaped scales, which probably represent the posterior prefrontalia. The frontal itself is large and oval and often divided by a vertical suture . The supraocularia are large and mostly undivided. The parietals are numerous and small.
In the side view, there are two to four large, irregularly shaped Lorealia and two Präocularia between the nasal and eye . There are two to four small and irregularly shaped postocularia . The number of large supralabials can range from 10 to 14, the first four showing deep labial pits with rather narrow, oblique slits. Usually only the seventh supralabial touches the eye. The lower jaw shows 20-23 infralabials , of which the anterior 6 show rounded labial pits.
The number of ventral scales ( ventral shields ) varies depending on the origin of the individuals between 290 and 334, that of the paired subcaudalia between 78 and 102 and the number of dorsal rows of scales in the middle of the body between 64 and 81.
The basic color is very variable from yellow, light and dark brown to almost black. The species shows a complicated drawing of irregular, light rhombuses on the back, which are broadly dark and then lightly edged. This diamond drawing is complemented on the flanks by dark spots with a light center. On the flanks, triangles that are pointed upwards meet between these dark spots. All in all, this creates a network drawing to which the species owes its German name. The head is monochrome and undrawn except for a narrow black stripe from the eye to the corner of the mouth and a dark central line. The iris is mostly orange, but on Sulawesi it is also often golden, in eastern Indonesia it is more whitish-gray. The tongue is mostly almost black with a whitish tip, on the Indonesian islands of Jampea and Selajar the base of the tongue is more pink to dark purple.
The largely unmarked head and the very distinctive back markings distinguish the species from all other pythons.
distribution and habitat
The range of the reticulated python covers large parts of tropical South and Southeast Asia. It stretches from Bangladesh and the state of Assam in India and the Nicobar Islands in the west to the east to the Philippines and east of Indonesia . The northern limit of the distribution is still disputed in detail, so the occurrence in northeast India is partly doubted; There is also controversial discussion as to whether there is a northern limit of distribution in Vietnam and whether the species occurs in China. The species swims very well and has therefore colonized all of the larger islands in this area. As early as 1908 it was discovered as one of the first vertebrate species on the Krakatau archipelago, which was completely destroyed by a volcanic eruption in 1883 .
The species originally inhabited moist tropical rainforests and swamps. Reticulated pythons, however, have proven to be very adaptable and today also colonize secondary forests , agricultural areas and human settlements up to large cities; the species is not uncommon in Bangkok , for example, and has also been identified several times in Jakarta . In all populated habitats , reticulated pythons are tightly bound to water and usually stay near small rivers, canals or ponds.
Systematics
Before the reticulated python by Reynolds et al. 2014 was assigned to the newly introduced genus Malayopython , he was grouped as Python reticulatus in the genus of the actual pythons ( Python ). The monophyly of the genus Python has long been controversial. Among other things, Walls pointed out that at least the reticulated python is much closer to the pythons of the genus Morelia than the other species of the genus Python in a number of morphological features . A recent molecular genetic investigation has confirmed the paraphyly of the genus Python . Accordingly, the closest relative of the reticulated python is the Timor python . These two species form the sister taxon of all pythons in Australia and Papua New Guinea and are therefore more closely related to them than to the other species of the genus Python . On the basis of these results, reticulated python and timor python were first transferred to the genus Broghammerus , which had already been proposed by Hoser , which is, however, invalid, since the genus was described in a journal that does not carry out a peer review process. At the beginning of 2014 the generic name Malayo python was therefore introduced for the reticulated python and the Timor python.
Since then, the reticulated python has had the scientific name Malayopython reticulatus and is a type of the new genus.
Despite the huge distribution area, the question of whether subspecies can be differentiated was only investigated in 2002. On the basis of molecular genetic and morphological investigations, at least two other subspecies were initially proposed in addition to the nominate form :
- M. r. reticulatus (nominate form); Mainland Asia, the Great and Lesser Sunda Islands
- M. r. saputrai ; South-west and south-east of Sulawesi and the island of Selayar south of Sulawesi
- M. r. jampeanus ; only on the island of Jampea between Sulawesi and Flores
The molecular genetic results also suggest a demarcation of the population on the island of Sangihe, about 200 km north of Sulawesi, as a further subspecies.
behavior
Despite the huge distribution area and its abundance in many areas of the area, almost nothing is known about the behavior of the species. There are no studies on the way of life of the species in the field; Even catching the animals alive for measurement or marking is extremely time-consuming and difficult. Reticulated pythons are apparently only nocturnal and move very inconspicuously and mostly in dense vegetation. There is no knowledge about activity phases or about the size of the living space used by individual individuals. The day is spent in hiding. Little is known about these hiding places, but in populated areas the animals regularly rest under houses, where they are often discovered and killed.
Nothing is known about the nocturnal hunting methods either, since many of the prey animals (e.g. monkeys) live on trees, at least occasional hunting in trees is suspected.
nutrition
The diet of the reticulated python consists almost exclusively of mammals and birds; monitor lizards are also occasionally consumed. Intensive studies on the feeding of the reticulated python have only been carried out on Sumatra , where the stomach contents of animals killed for leather production were examined.
After the prey has been ambushed in a surprise attack, it is embraced and then constantly crushed, which stops breathing and blood circulation. Then the prey is swallowed whole, head first. The size of the prey changes as the size of the python increases. In the south of Sumatra, reticulated pythons with a head-to-trunk length of up to around 2.8 meters feed on rats (mainly rice field rats ( Rattus argentiventer ) and Leopoldamys sabanus ). The proportion of rats in the diet decreases sharply in larger individuals, where they also eat pangolins , porcupines , monkeys ( crab- eating macaques ( Macaca fascicularis ), brown Sumatran langurs ( Presbytis melalophos ) and Hanuman langurs ( Semnopithecus cristatus )), wild boars and Kantschile ( Tragulus sp.). Primarily gender-specific differences in diet were not found. Larger proportions of large prey animals in the females were due to their considerably larger body size on average; only females reached head-trunk lengths over 4.25 meters. The authors of the study suspect that this partial change in diet is also associated with a change in the habitats used: While males and young females are predominantly in areas that are heavily influenced by humans and thus rat-rich, older females evidently migrate to more natural habitats with a larger one Spectrum of larger vertebrate species.
However, the species also shows great adaptability in terms of nutrition. In the north of Sumatra, which has hardly any natural habitats due to intensive agricultural use, the diet of large females also consists almost exclusively of rats and domestic chickens.
Prey animals with a weight between 20 and 50 kilograms have been proven several times, u. a. a sun bear weighing 24 kilograms and a full-grown Sulawesi pustular pig ( Sus celebensis ). According to unconfirmed reports from a snake handler in Sumatra, a 60-kilogram wild boar was found in a large reticulated python. The killing of humans by reticulated pythons has also been proven several times, even the complete devouring of adult humans has been proven. The average prey weight, however, is much lower, in the south of Sumatra the average prey weight of 1070 pythons examined was 0.75 kilograms for males and 1.35 kilograms for larger females.
Reproduction
Very little is known about reproduction in the wild; here, too, the known knowledge comes almost exclusively from examinations of dead animals and from captivity. Reticulated pythons become sexually mature at two to four years of age, on Sumatra males then have a head-torso length of at least 137 centimeters, while females are at least 210 centimeters long. In the north of Sumatra, reproductively active females were found from December to March, exceptionally also in June, according to which one clutch is formed predominantly in April and May each year. A significant proportion of the females do not appear to reproduce every year. The clutches in Sumatra comprised mostly 10–40 eggs, on average 24 eggs, extreme values were 8 and 73 eggs; the clutch size was correlated with the size of the females. The eggs weigh 200-300 grams. Observations in captivity have shown that the clutch is incubated for 80–90 days. During this time, the female lies curled up over the eggs, but unlike other python species, it does not ensure even temperatures through muscle tremors. Brood care ends when the young hatch. Freshly hatched young animals are in most of the range 60–83 centimeters long, in the small animals on Tanahjampea less than 30 centimeters.
Age and life expectancy
Information on the average and maximum ages of individuals living in the wild is unknown; Reticulated pythons regularly live to be over 25 years old in captivity. One specimen in the Dessau zoo was almost 40 years old.
Danger
Reticulated pythons are caught in large quantities for leather production, the number of pythons killed for this purpose is estimated at at least 500,000 per year. Most of the animals are captured on the islands of Sumatra and Borneo .
At least in Indonesia , according to the population, reticulated pythons are often used as a source of food or killed in order to "avoid nuisance from animals that would otherwise be eaten by chickens, dogs or children" ("... that might otherwise devour chicken, dogs or children." ). Although the intensive pursuit apparently at least leads to the fact that very large reticulated pythons are rare, there are still no signs of endangerment. Presumably, the losses can be compensated by the rapid growth, the early sexual maturity and the high reproduction. Since reticulated pythons show no close connection to near-natural habitats and can live exclusively on rats and chickens that are very common in human settlement areas, the species could even have been promoted by human activities.
The reticulated python is listed in the Washington Convention on the Protection of Species in Appendix II and is therefore subject to trade restrictions. In Germany the species is specially protected under the Federal Nature Conservation Act.
swell
Individual evidence
- ↑ a b c d R. Shine, PS Harlow, JS Keogh, Boeadi: The influence of sex and body size on food habits of a giant tropical snake, Python reticulatus. In: Functional Ecology. 12, 1998, pp. 248-258.
- ↑ a b c d e f R. Shine, Ambariyanto, PS Harlow, Mumpuni: Reticulated pythons in Sumatra: biology, harvesting and sustainability. In: Biological Conservation. 87, 1999, pp. 349-357.
- ↑ a b c d e M. Auliya, P. Mausfeld, A. Schmitz, W. Böhme: Review of the reticulated python (Python reticulatus Schneider, 1801) with the description of new subspecies from Indonesia. In: Natural Sciences. Volume 89, Issue 5, 2002, p. 202.
- ↑ GM Fredriksson: Predation on Sun Bears by Reticulated Python in East Kalimantan, Indonesian Borneo. In: Raffles Bulletin of Zoology. 53 (1), 2005, pp. 165-168. (pdf)
- ↑ DG Barker, SL Barten, JP Ehrsam, L. Daddono: The Corrected Lengths of Two Well-known Giant Pythons and the Establishment of a New Maximum Length Record for Burmese Pythons, Python bivittatus. In: Bulletin of the Chicago Herpetological Society. 47 (1), 2012, pp. 1-6. (pdf)
- ↑ a b J. G. Walls: The Living Pythons. TFH Publications, 1998, p. 159 ff.
- ↑ JG Walls: The Living Pythons. TFH Publications, 1998, p. 161.
- ↑ a b M. Auliya, F. Abel: Taxonomy, geographical distribution and food ecology of the reticulated python (Python reticulatus). Part 1. In: herpetofauna. 22 (127), 2000, pp. 5-18.
- ^ PA Rawlinson, RA Zann, S. van Balen, IWB Thornton: Colonization of the Krakatau islands by vertebrates. In: GeoJournal. Volume 28, Issue 2, 1992, pp. 225-231. doi: 10.1007 / BF00177236
- ↑ JG Walls: The Living Pythons. TFH Publications, 1998, p. 166.
- ↑ LH Rawlings, DL Rabosky, SC Donnellan, MN Hutchinson: Python phylogenetics: inference from morphology and mitochondrial DNA. In: Biological Journal of the Linnean Society. 93, 2008, pp. 603-619.
- ↑ RT Hoser: A reclassification of the Pythoninae including the descriptions new genera, two new species and nine new subspecies. Continued. In: Crocodilian - Journal of the Victorian Association of Amateur Herpetologists. 4, 2004, pp. 21-39.
- ^ R. Graham Reynolds, Matthew L. Niemiller, Liam J. Revell: Toward a Tree-of-Life for the boas and pythons: Multilocus species-level phylogeny with unprecedented taxon sampling. In: Molecular Phylogenetics and Evolution. Volume 71, February 2014, pp. 201–213. doi: 10.1016 / j.ympev.2013.11.011
- ↑ a b Malayopython reticulatus in The Reptile Database
- ↑ M. Auliya, P. Mausfeld, A. Schmitz, W. Böhme: Review of the reticulated python (Python reticulatus Schneider, 1801) with the description of new subspecies from Indonesia. In: Natural Sciences. Volume 89, Issue 5, 2002, p. 204 and Fig. 2, p. 205.
- ↑ z. BMA Riquier: Status, Population Biology and Conservation of the Water Monitor (Varanus salvator), the Reticulated Python (Python reticulatus), and the Blood Python (Python curtus) in Sumatra and Kalimantan, Indonesia. Project Report Kalimantan. In: Mertensiella. 9, 1998, pp. 119-129.
- ↑ a b c M. Auliya, F. Abel: Taxonomy, geographical distribution and food ecology of the reticulated python (Python reticulatus). Part 2. In: herpetofauna. 22 (128) 2000, pp. 19-28.
- ↑ Cameron Brown: Python reticulatus. Animal Diversity Web. ( online at: animaldiversity.ummz.umich.edu )
- ↑ B. Groombridge, R. Luxmoore: pythons in South-East Asia. A Review of Distribution, Status and Trade in Three Selected Species. A CITES report. Lausanne 1991, ISBN 2-88323-003-X . Quoted in: R. Shine, Ambariyanto, PS Harlow, Mumpuni: Reticulated pythons in Sumatra: biology, harvesting and sustainability. In: Biological Conservation. 87, 1999, pp. 349-357.
literature
- M. Auliya, P. Mausfeld, A. Schmitz, W. Böhme: Review of the reticulated python (Python reticulatus Schneider, 1801) with the description of new subspecies from Indonesia. In: Natural Sciences. Volume 89, Issue 5, 2002, p. 202.
- R. Shine, PS Harlow, JS Keogh, Boeadi: The influence of sex and body size on food habits of a tropical giant snake, Python reticulatus. In: Functional Ecology. 12, 1998, pp. 248-258.
- R. Shine, Ambariyanto, PS Harlow, Mumpuni: Reticulated pythons in Sumatra: biology, harvesting and sustainability. In: Biological Conservation. 87, 1999, pp. 349-357.
Web links
- The reticulated python on Animal Diversity Web (English)
- Video: preying and eating in a giant snake (Python reticulatus) . Institute for Scientific Film (IWF) 1941, made available by the Technical Information Library (TIB), doi : 10.3203 / IWF / C-361 .
