Sumatran short-tailed python
| Sumatran short-tailed python | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Sumatran short-tailed python ( Python curtus ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Python curtus | ||||||||||||
| Schlegel , 1872 |
The Sumatran short-tailed python ( Python curtus ), also blood python or colored python , belongs to the python family (Pythonidae) and is part of the genus Real Pythons ( Python ). It is a stout snake with a short tail and mostly melanistic markings . The species lives exclusively on Sumatra and originally inhabited moist rainforests and swamps. But today it is also common on oil palm plantations. Its closest relatives are the Borneo short-tailed python and the blood python of the same name .
description
Sumatran short-tailed pythons have a long, flattened head, a strong, muscular neck, a stocky body, and a short tail. Despite the German name, their tail is longer than that of blood pythons. The body tapers towards the spine and appears triangular in cross-section. There is a sexual dimorphism with regard to body length and weight: females are on average slightly larger and heavier than males. Both sexes have prominent anal spurs. In adult males these are thicker and more curved towards the abdomen than in adult females. Typically, the anal spurs of adult males are more worn, blunt, and therefore shorter than those of females.
Length and weight
The maximum length of the Sumatran short-tailed python is slightly over 2 meters. Exceptionally, large females weigh between 15 and 18 kilograms. Among 99 adult males captured in the wild, the average head-to-torso length was 120.7 cm. Their average weight was 2.99 kg. In 54 adult females living in the wild, the average head-torso length was 130.1 cm and their weight was 3.85 kg.
Coloring and patterning
Most adult Sumatran short-tailed pythons are very dark, almost black, snakes. Adult heads from the Bandar Lampung District in South Sumatra are gray to black. In contrast, the top of the head of individuals from Central Sumatra is yellow-brown, brown to red-brown in color. In young animals and animals with a light basic head color, there is a thin, dark central stripe on the top of the head, which extends from the rear edge of the snout to the occiput. Here it can run out at right angles to the temple on both sides. The median strip widens towards the neck, encloses a light spot in the center and then merges with the dark mark on the neck. The side of the snout can be darkly spotted or uniformly black. From the back of the eyes to the corner of the mouth, a thin, light gray to cream-colored stripe that is speckled dark extends. This is followed by a black band, which runs from the back of the eyes on the side of the head to the neck and merges there with the side patches on the neck. On the front of the muzzle, to the side of the tongue groove, there is a light spot on both sides. A second patch follows on the first upper lip shield and a third may be on the second upper lip shield. In contrast to the blood python and Borneo short-tailed python, the bottom of the labial pit of the upper lip in this species is darkly pigmented. The lower edge of the upper lip is drawn uniformly light. The front section of the lower lip edge consists of a series of dark spots and optionally merges into numerous dark spots in the area below the eye. The chin is colored homogeneously white.
The basic color of young animals and young adults is light brown, gray-brown or gray and darkens drastically with age. In general, the basic color is the lightest on the spine and on the flanks towards the abdomen. Irregular, rectangular gray-brown to black saddle spots run along the back. These correspond roughly to the width of the back in the respective segment. The flank spots are large, provided with a 2 to 4 scale black border on top and on the sides and brightened from the center to the belly. They reach up about half the height of the flank, but can also be fused with the saddle spots. A typically white to light gray ring always remains around the flank spots, even with increasing black pigmentation of the body. In contrast to the Borneo short-tailed python, this white does not affect the drawing on the back. Some individuals also show isolated black spots that are scattered over the entire flank area. The tail is darkly colored all around and partly decorated with small, irregular spots. The belly is completely white or cream in color. Paraventralia (secondary abdominal shields) usually have gray speckles.
The color of the iris ranges from yellow-orange to orange to orange-red. A black spot on the lower edge of the iris makes the pupil appear wider in the lower area.
Color change
During postnatal development, Sumatran short-tailed pythons undergo an ontogenetically determined color change. Young animals have a light basic color and have a dark pattern. Their head is usually dark yellow, their saddle spots mostly dark brown. The basic color consists of a light brown and is sometimes provided with a rose-red to reddish sheen. The centers of the flank spots are slightly more yellow than the basic color. With increasing age, the basic color on the back in particular becomes darker and darker.
Scaling
The rostral (nose plate) has, as with most other pythons also two deep Labialgruben . An uninterrupted seam runs centrally from the muzzle to the occiput. Large paired plates on the top of the head are in contact with it. From the muzzle, these are the internasalia (intermediate nasal shields ), the anterior and posterior prefrontalia (forehead shields), the frontalia (forehead shields), and 3 to 4 posterior parietals (crown shields ). In contrast to the blood python and Borneo short-tailed python, the anterior parietal characteristically has no contact with the central seam. The nostrils are arranged upwards and backwards and are each surrounded by a large nasal (nasal shield). Towards the middle of the head, the nasals are separated by a pair of smaller internalsals (intermediate nasal shields ). In the side view, the nasal scales are followed by a pit with 5 to 27 small Lorealia (rein shields) towards the eye . The front part of this pit is bordered by 1 to 3 large rein shields below. About two eyes is ever a great Supraoculare (via eye shield). There are 1 to 3 Präocularia (forehead shields), of which the top is the largest and extends to the top of the head. Postocularia (posterior eye shields) are 1 to 3, with the top one being the clearly largest. Subocularia (under eye shields) are 9 to 12 present. Occasionally there are also small granular scales, which prevent certain under-eye shields from direct contact with the eye. Of the 9 to 12 supralabials (shields of the upper lip), the foremost two bear deep labial pits. The 16 to 19 infralabials (lower lip shields ) have 3 to 5 anterior and 3 to 7 posterior labial pits from the second lower lip shield.
The number of ventralia (abdominal shields) varies between 152 and 163, the number of dorsal scales in the middle of the body between 55 and 61. From the cloaca to the tip of the tail there are 28 to 33 subcaudalia (underside shields of the tail) on the abdomen .
distribution and habitat
This python lives exclusively on the island of Sumatra in the Malay archipelago . Its occurrence is limited to the western and southern part. The tropical climate on Sumatra has a characteristic constant high average temperature of more than 26 ° C and high precipitation rates of more than 2000 mm annually. Here he inhabits marshland , swamp forest, dense jungle and secondary forest . He also lives along streams and rivers.
The natural habitats on the Indonesian islands have been severely affected by human activities for some time. Studies in North Sumatra show that Sumatran short-tailed pythons are now more common in oil palm plantations than in natural areas. The reason for this is, on the one hand, the enormous density of rats (more than 400 per hectare ) and, on the other hand, suitable hiding places under dead palm leaves. Since the oil palm plantations throughout Sumatra have expanded, the number of Sumatran short-tailed pythons has been increasing steadily, while the reticulated pythons originally resident are decreasing .
In Sumatra, the Sumatran short-tailed python is sympathetic to the reticulated python in some places . However, the reticulated python usually stays away from the oil palm plantations.
Sumatran short-tailed pythons and blood pythons appear to be allopatric in Sumatra . The geographical delimitation of these two species is due to the high central mountain range that extends over the entire length of Sumatra. Since none of these species has been seen at over 2000 meters above sea level, an overlap in the mountains is practically impossible. Interferences would theoretically be possible in the mountain foothills in the southeast of the island, but this part has not yet been explored. However, there is much to suggest that the distribution areas of the Sumatran short-tailed python and the blood python are increasingly artificially mixed through trade. For example, slaughterhouses in western Sumatra often receive deliveries of numerous Sumatran short-tailed pythons from the east. If these escape on the journey or on site, they penetrate into areas inhabited by the blood python.
behavior
Almost nothing is known about the behavior of this python. There are no studies on the way of life of the species in the field. It is generally described as loyal to its location and active at twilight and night. In order to hide or ambush prey, he likes to dig himself into the damp ground or lie under dense vegetation.
nutrition
Sumatran short-tailed pythons are prey hunters . Nearly 95% of the diet of naturally-caught pythons was made up of rodents . Including rice field rats ( Rattus argentiventer ), brown rats ( R. norvegicus ), Pacific rats ( R. exulans ), Rattus timanicus , giant long-tailed rats ( Leopoldamys sabanus ), barbed rats ( Maxomys rajas ) and mice . Likewise a striped roller ( Arctogalidia trivirgata ) belonging to the predatory animal species . The frequency of food consumption was examined in a study. The frequency increases with increasing body size. In adult animals, the feeding intervals seem to be consistently high and do not depend on sex, season and time of reproduction.
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. In its range, the breeding season is highly seasonal. The testicles of the males examined in December were significantly enlarged compared with measurements in the other months. Accordingly, the mating season is around December. Apparently, a significant proportion of the females only reproduce every other year. Eggs are laid between April and May. The clutch of 15 females from Sumatra contained 8 to 17 eggs. The average was 12. These eggs had an average weight of 90 grams. According to observations in captivity, the clutch is incubated for about 75 days. During this time, the female lies curled up over the eggs and ensures uniform temperatures through muscle tremors. Brood care ends when the young hatch. Freshly hatched pythons of the blood python and the short-tailed python have been described in the literature as 30 to 48 centimeters long.
Age and life expectancy
Information on the average and maximum ages of individuals living in the wild is unknown; In captivity there are individuals among blood pythons and short-tailed pythons that are over 27 years old.
Danger
Sumatran and Borneo short-tailed pythons as well as blood pythons are heavily exploited for the leather industry in their area of distribution. On Sumatra and Borneo, 70,000 to 200,000 blood and short-tailed pythons are slaughtered and exported every year. Usually, these pythons are not specifically hunted; instead, they are picked up on occasion in oil palm plantations. In Sumatra, only 8% of the commercial leather trade in blood pythons and Sumatran short-tailed pythons is based on Sumatran short-tailed pythons. These pythons also seem to find new ecological niches on areas cultivated by humans, which means they can compensate for habitat losses to a certain extent.
Systematics
The Sumatran short-tailed python got its scientific name Python curtus because of its shortened body. Curtus is Latin and means shortened .
In 1872 Schlegel described the species Python curtus after an animal caught in Sumatra. 1880 Python breitensteini of Steindachner described as a separate species and Python curtus split. With the new description of Python curtus brongersmai in 1938, Stull granted these three pythons subspecies status. In 2001 all three subspecies were granted species status.
The blood python ( Python brongersmai ), the Borneo short-tailed python ( Python breitsteini ) and the Sumatran short-tailed python ( Python curtus ) clearly differ from one another due to their body size, scale, color and geographical distribution . Using a section of the mitochondrial cytochrome b gene , it was shown that the Borneo short-tailed python and the Sumatran short-tailed python are more closely related than to the blood python. On the genetic level, the differences in relationship between the blood python and the short-tailed python are almost as great as that of the reticulated python. Phylogenetically , the blood python is the sister group of the two short-tailed pythons.
It is believed that several million years ago a common ancestor inhabited the mainland of Southeast Asia and, across land bridges, Borneo . The exchange of genes was stopped by a rise in the sea and the blood python developed on the mainland and an ancestor of the two short-tailed pythons on Borneo. The latter also immigrated to West Sumatra via land bridges . The rest of Sumatra was then still under water. The land bridges later sank, dividing the population into Borneo short-tailed pythons and Sumatran short-tailed pythons. When the eastern part of Sumatra later rose from the sea, it made it possible for the blood pythons living on the mainland to immigrate to this island. Because a high central mountain range always stretched over the entire length of Sumatra, it was never possible for the blood python to spread to the east and vice versa of the Sumatran short-tailed python to the west.
Short-tailed and blood pythons differ from all other pythons by a pit with small scales, which runs from the back of the nose to the eye. Their tails are also significantly shorter than other pythons.
See also
swell
Individual evidence
- ↑ a b c d e f g h i j k l m n o p q r s J. Scott Keogh, David G. Barker and Richard Shine: Heavily exploited but poorly known: systematics and biogeography of commercially harvested pythons (Python curtus group ) in Southeast Asia. Biological Journal of the Linnean Society, 73: 113-129, 2001.
- ↑ a b c d e f g h Richard Shine, Ambariyanto, Peter S. Harlow and Mumpuni: Ecological Attributes of Two Commercially-Harvested Python Species in Northern Sumatra . Journal of Herpetology, Vol. 33, No. 2 (Jun., 1999), pp. 249-257.
- ^ A b B. Groombridge, L. Luxmoore: "Pythons in South-East Asia - A review of distribution, status and trade in three selected species"; Lausanne, Switzerland: Secretariat of CITES, 1991.
- ↑ a b c JG Walls: The Living Pythons - A complete guide to the Pythons of the World . TFH Publications, 1998: pp. 122-128; ISBN 0-7938-0467-1 .
literature
- JS Keogh, DG Barker, R. Shine: Heavily exploited but poorly known: systematics and biogeography of commercially harvested pythons (Python curtus group) in Southeast Asia. Biological Journal of the Linnean Society 73, 2001, online, pdf , pp. 113-129.
- R. Shine, Ambariyanto, PS Harlow, Mumpuni: Ecological Attributes of Two Commercially-Harvested Python Species in Northern Sumatra . Journal of Herpetology 33, No. 2, 1999, pp. 249-257.
