Blood python
| Blood python | ||||||||||||
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Blood python ( Python brongersmai ) |
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| Python brongersmai | ||||||||||||
| Stull , 1938 |
The blood python ( Python brongersmai ) belongs to the family of the pythons (Pythonidae) and is there in the genus of the actual pythons ( Python ). It is a stocky, short-tailed snake. Many animals show red hues, from which the German name is derived. Blood pythons live in the tropics of Southeast Asia. Originally the species lived there in moist rainforests and swamps, but today it is also often found on oil palm plantations. Its closest relatives are the Sumatran short-tailed python and the Borneo short-tailed python .
description
Blood pythons have a long, flattened head, a strong, muscular neck, a stocky body, and a short tail. Their tail is shorter than that of short-tailed pythons, although the German name suggests the opposite. 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 blood python is approximately 2.6 meters. Exceptionally, large females weigh between 14 and 22 kilograms. Among 1,037 adult males captured in the wild, the average head-to-torso length was 132.4 cm. Their average weight was 3.59 kg. In 732 adult females living in the wild, the average head-torso length was 143.9 cm and their weight averaged 4.66 kg.
Scaling
The Scutum Rostrale (snout shield) has, like most other pythons, two deep labial pits . 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 snout, these are the internasalia (intermediate nasal shields ), the anterior and posterior prefrontalia (forehead shields), the frontalia (forehead shields) and the anterior large and 2 to 3 posterior small parietals ( parietal shields ).
The nostrils are arranged upwards and backwards and are each surrounded by a large nasal (nasal shield). The nasal can show a clearly recognizable seam from the nostril to the rear edge of the shield or it can be fragmented into several granular shields. Towards the middle of the head, the nasals are separated by a pair of internals which begin at the edge of the nostril. In the side view, the nasal scales are followed by a pit with 4 to 14 small Lorealia (rein shields) towards the eye . The front part of this pit is bordered by 1 to 2 large rein shields below. Characteristically, there is a large supraocular at the front and a small one at the back above both eyes . There are 2 to 3 Präocularia (forehead shields), of which the top is the largest and extends to the top of the head. Postocularia (rear eye shields) are 1 to 3. The absence of subocularia (lower eye shields) is the most obvious difference between this species and the Borneo short-tailed python and Sumatran short-tailed python. Of the 9 to 13 supralabials (shields of the upper lip), the foremost two bear deep labial pits. Depending on the individual, the fifth and sixth, the sixth and seventh or only the sixth or seventh shield of the upper lip border directly on the eye. Of the 17 to 22 infralabialia (lower lip shields ), 3 to 6 anterior and 3 to 7 posterior labial pits.
The number of ventralia (abdominal shields) varies between 167 and 178, the number of dorsal scales in the middle of the body between 53 and 61. From the cloaca to the tip of the tail there are 24 to 36 subcaudalia (underside shields of the tail) on the abdomen .
Muster
This python shows a variable pattern. The top of the head is colored dark gray, light gray, brown or reddish brown. With the exception of the animals with a very dark top of the head, a fine, thin dark central stripe runs from the tip of the nose to the occiput. Most animals are followed by a thin, light line that extends to the dark pattern on the neck. Usually the side surface of the head is uniformly dark in color from the muzzle to below the eye. In certain individuals, however, it can also be light gray or brown and is heavily darkened towards the eye.
A thin, light gray stripe extends from the back of the eye to the corner of the mouth, which can be framed in a reddish color. This is followed by a black band, which runs from the back of the eye on the side of the head to the neck.
The top of the neck and the back are darkly colored and have small bright spots along the spine. These bright, mostly yellowish spots on the spine are either widened or merge into extensive spots and stripes. A series of dark spots runs along the lightened side of the front half of the body. Each of these spots has its origin on the side of the abdomen and rises to about the middle of the flanks. The dark flank spots get higher and higher towards the tail and some, sometimes even all, merge with the dark back markings. The bright recesses of the flanks have round black spots with 2 to 6 scales in their center. Depending on the individual, these spots appear sporadically to continuously.
The tail is single-colored dark. Certain animals also continue the bright spine pattern. The chin and neck are completely white. Towards the tail, the belly becomes increasingly darker with an increasing number of gray speckles and indistinct spots.
The color of the iris is light in the upper area and darkens towards the bottom to gray to black. The pupil is wider in all its degrees of position on the lower part than on the upper part. The tongue is dark in color.
Color types and color change
The coloration varies significantly within this species and is independent of location. It ranges from intense yellow to brown, orange-red, red, blood-red to dark gray. The majority of adult blood pythons are reddish in color.
During postnatal development, blood pythons undergo an ontogenetically determined color change. The heads and dark patterns of young animals are typically light brown, brown-orange to brown. Many animals change their color drastically to red within the first two to three years of their life. Between the ages of five and seven, the color darkens. Blood pythons can also change the intensity of their head color within hours. For example, a black-headed individual can switch to silver-gray and back to black again in one day.
distribution and habitat
In contrast to the Borneo and Sumatran short-tailed python, it also inhabits the mainland of Southeast Asia. Its distribution area includes the southern tip of Thailand , the Malay Peninsula , small islands in the Malacca Strait and the eastern part of Sumatra .
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 blood pythons are now more common in oil palm plantations than in natural areas. The reason for this is, on the one hand, the huge 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 blood pythons has been increasing, while the reticulated pythons that originally lived there are becoming fewer.
In Sumatra, the blood python is sympathetic to the reticulated python in some places . However, the reticulated python usually stays away from the oil palm plantations.
Blood pythons and Sumatran short-tailed 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 blood python and the Sumatran short-tailed python are increasingly being 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
Blood pythons are ambulance 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 . He also captured small native mammals such as belonging to the predator-like strips Roller ( Arctogalidia trivirgata ) and banded palm civet ( Hemigalus debryanus ), the counting of the predators Yellow-throated marten , one associated to the genus of primate slow loris ( Nycticebus coucang ) and the tree shrews ( Tupata javanica ). He also occasionally hunts domestic chickens . 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 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. The breeding season on Sumatra is highly seasonal. In December, the testicles of the males examined were significantly enlarged compared with measurements in the other months. Accordingly, the mating season on this island is around December. Apparently, a significant proportion of Sumatra females only reproduce every other year. Eggs are laid between April and May. The clutch of 143 females from Sumatra contained between 4 and 28 eggs. The mean was 15.58. These eggs weighed an average of 83 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
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, but are picked up in oil palm plantations when the opportunity arises. In Sumatra, the commercial leather trade in blood pythons and Sumatran short-tailed pythons is 92% made from blood pythons. This is worrying for the continued existence of this species. Fortunately, these pythons also seem to find new ecological niches in areas cultivated by humans, whereby they can compensate for habitat losses to a certain extent.
Systematics
The blood python was given its scientific name Python brongersmai in honor of Leo Daniel Brongersma (1907-1994), former professor of systematic zoology at the University of Leiden , director of the National Museum for Natural History in Leiden and chairman of Dutch and European herpetologists .
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 re-description of Python curtus brongersmai in 1938, Olive Griffith 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 in terms of 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.
Blood and short-tailed 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 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 i 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 J. G. Walls: The Living Pythons - A complete guide to the Pythons of the World . TFH Publications, 1998: pp. 122-128; ISBN 0-7938-0467-1 .
- ↑ MS Hoogmoed: In memoriam Prof. Dr Leo Daniel Brongersma . Zoologische Mededelingen Leiden 69, 1995, pp. 177-210, online, pdf .
literature
- 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 (online publication) (PDF; 257 kB)
- 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
Web links
- Python brongersmai in The Reptile Database
- Python brongersmai inthe IUCN Red List of Threatened Species 2013.2. Posted by: Grismer, L. & Chan-Ard, T., 2011. Retrieved March 26, 2014.