Angolapython

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Angolapython
Angolan Dwarf Python (Python anchietae) .jpg

Angolapython ( Python anchietae )

Systematics
without rank: Toxicofera
Subordination : Snakes (serpentes)
Superfamily : Python-like (Pythonoidea)
Family : Pythons (Pythonidae)
Genre : Actual Pythons ( Python )
Type : Angolapython
Scientific name
Python anchietae
Bocage , 1887

The Angolapython , also Angola dwarf python ( Python anchietae ) is a species of snake from the family of the pythons (Pythonidae), more precisely, the genus of the real pythons ( Python ). The distribution area of ​​this small python is in South West Africa and is there limited to the relatively dry, rocky plateaus of Angola and Namibia . Very little is known about the biology of this snake. It feeds on small mammals and birds, is egg-laying (oviparous) like all species of the genus Python and belongs to the species in which the females can increase the incubation temperature by trembling muscles. Due to conservation efforts and its remote habitat, the Angolapython has so far been considered safe.

description

Build, length, teeth

The Angolapython is a powerfully built python with a cylindrical body cross-section that is rather flattened on the back and a small, flattened head that is clearly separated from the neck. The relatively short tail can make up at least 10% of the total length in females and up to 12% in males. The anal spurs are prominent in males.

Due to the small amount of data, there is still no well-founded information on the average and maximum length of the species. So far, in captivity, males with a minimum overall length of 109 centimeters and females with a minimum overall length of 135 centimeters have been successfully brought to reproduction. The longest male measured so far in the wild was 143 centimeters long, the longest female 168 centimeters. According to Broadley (1983), Haacke is said to have even caught and measured an animal with a total length of at least 180 centimeters. At the Houston Zoo , a female has also reached a total length of approximately 180 centimeters (6 ft). With regard to body length and weight, the species shows a sexual dimorphism, at least in captivity : females are usually significantly larger and heavier than males.

The bit consists of thin, elongated teeth that are continuously pointed and curved towards the throat and become increasingly smaller from the tip of the mouth to the throat. At the front of the upper oral cavity is the intermaxillary bone with two small teeth. The upper jaw bones each have 18 teeth. Towards the middle of the upper oral cavity, the palatine bone lies parallel to the maxillary bones in front and the wing bone further back . The former has 5 to 6 and the latter 9 to 12 teeth. The lower jaws each have 19 teeth.

Side view of the head
Top of head

Scaling

Characteristic of the species, most of the shields on the top of the head as well as on the back and the flanks are conspicuously arched and only slightly or not at all overlapping. The rostral (nose plate) has, as with most other pythons also two deep Labialgruben . The nostrils are each positioned in the upper rear part of the large nasal (nasal shield) on the head side . Towards the middle of the head, the nasals are separated by a pair of large internasals (intermediate nasal shields ), which are themselves separated by several small shields towards the midline. From the tip of the snout along the middle line of the top of the head, the internalsalia are followed by a large pair of prefrontalia (forehead shields), which have also lost contact with each other due to several small rows of shields on the middle line. Characteristically, the remaining top of the head behind it is completely covered by numerous small, rounded shields; Frontalia (frontal shields) and parietals (crown shields ) can no longer be made out due to the strong fragmentation. Around the eye there is a ring of 15 to 18 similar- sized , small circumorbitalia (shields surrounding the eyes), of which five to six are usually made up of the infraocularia ( lower eye shields). Occasionally one of the circumorbitalia has enlarged a supraocular (over-eye shield). On the side of the head between the eye and the nostril there is an area with numerous smaller and larger Lorealia (rein shields). Of the 14 to 15 supralabials (shields of the upper lip), the foremost three large, deep, triangular labial pits and the two to three behind them have a smaller, more superficial labial pit. Occasionally the supralabial number 11 or 12 is divided horizontally. Infralabials (lower lip shields ) there are 15 to 16, of which 3 to 4, beginning with infralabial number 9 or 10, have relatively superficial labial pits.

The number of ventralia (abdominal shields) varies between 252 and 268, the number of dorsal rows of scales in the middle of the body between 57 and 63. From the cloaca to the tip of the tail there are 46 to 57 mostly paired subcaudalia (underside shields of the tail). The anal (anal shield) can be divided or undivided.

coloring

The upper side of the body of adult animals has a reddish-brown to brown basic color, which becomes increasingly darker and more contrasting towards the middle of the body and towards the tail. On the flanks towards the belly side, the basic color is increasingly lightened. From the underside of the flank, whitish, dark-brown to black-lined bands rise to the back at irregular intervals in their shape and length. These ribbons can partially fuse with ribbons on the opposite side and, on the same side, especially in the lower part of the flanks, fuse with one another and thus form a discontinuous longitudinal strip along the flanks. As a result, the basic color is divided into small to large square, rectangular to polygonal, irregular brown areas in many places. In addition, several whitish, black-rimmed, round to elongated spots are irregularly distributed over the back, which increase in number on the rear half of the body and the tail. The belly side is whitish to white-yellow and has a few brown to dark brown spots along the side edges of the belly.

On the muzzle of the red-brown top of the head arise two high-contrast, black-framed white stripes, each of which runs individually in a straight line from one nostril over the eye to the temple region above the corner of the mouth, then runs abruptly at an angle towards the nape of the neck and here again in gaps to completely meet. These two whitish bands border a large, red-brown, triangular spot on the top of the head. On this triangle there can be one to three indistinct white spots in the center behind the eyes. Often there is a single dark brown colored shield over the eye, which interrupts the white stripe running through here. The upper lip is whitish, especially towards the lower edge of the eye.

Angolapythons undergo a slight ontogenetic color change. Young animals show a dark brown to blackish basic color with a contrasting lemon yellow pattern. With increasing maturation the colors lighten and fade in certain animals. The coloring and patterning generally varies considerably within the species. Behind this, genetic differences along the geographical distribution are suspected.

distribution

Approximate distribution area of ​​the Angolapython

The area of ​​distribution of the Angolapython could only be explored incompletely. It is located in southwest Africa and runs here on the highland belt behind the west coast, in strips over approximately 1250 kilometers, from southern Angola to central Namibia . It is bounded to the east by the Namib Desert and to the east by the Kalahari Desert. According to current knowledge, the northernmost finds in Angola come from Hanha in the Benguela province and the easternmost from Ruacana in the Cunene province . It is very likely, however, that it occurs further north over the plateaus to the province of Cuanza Sul and east through the province of Huambo to the province of Bié . In Namibia, where previous findings occur after about 75% of its range, submits its eastern extension over the Kaokoveld and the Otavi Mountains to Tsumeb and its Southern on the outskirts of the capital Windhoek to the Khomas Hochland and Hakos Mountains . Suitable habitats also exist here further south to the catchment areas of the Orange River and the Fish River near the southern border. There does not appear to be any major gaps in its distribution. Isolated populations would, however, be conceivable on Inselbergs in the west or east of the previously known area.

habitat

Its occurrence is apparently primarily limited to the arid and semi-arid rocky plateaus. These harsh plateaus are known for their low rainfall and their rather strong seasonal temperature fluctuations with daytime temperatures up to over 55 ° C in summer and large temperature jumps to below freezing point on winter nights. Here it lives in climatically favorable areas of scree slopes, rocky landscapes and rugged sandy soils of semi-deserts, bush steppes and savannas. Occasionally, it also encroaches on human-influenced grazing land, farmland, and even farms. The prerequisite for all of its habitats is the proximity to permanent to seasonal water-bearing bodies of water or at least areas with a certain residual moisture. In Angola it lives in forest savannahs ( Miombo ) at up to 2000 meters above sea level and in Namibia it has been detected on the Brandberg massif at 2573 meters above sea level and on the Regenstein mountain at 2479 meters.

behavior

The behavior of the Angolapython is still largely unexplored. He seems to lead a mostly hidden life. According to locals, these pythons often hang out near bodies of water. The same individuals could sometimes be spotted at natural water sources over a period of 10 years. They seemed to be completely resident there, to use the rugged environment as a place of retreat and sometimes ambush thirsty prey at the waterhole during the day. On the other hand, many Angolapythons have also been spotted at night far away from water, where they actively pursued prey in crevices by climbing around in the rubble. Little is known about the activity patterns either. Most animals are spotted during the rainy season from January to April. The cool winter from June to August as well as the season of extreme drought in December, the pythons probably spend relatively inactive in the immediate vicinity of climatically favorable hiding places. Observations in a larger open-air installation within the natural range in Windhoek have shown that the pythons only left their hiding places and became active after sunset at daytime temperatures of over 35 ° C. On very hot days, the pythons occasionally lay down in the cool pond. After brief, heavy summer rains, the animals could be seen sunbathing during the day. On cloudy days they were active in the late afternoon. When threatened, the Angolapython, like the ball python, can curl up into a ball with the head inside and protected by the body loops.

food

The prey spectrum of the Angolapython includes birds and small mammals. These include little cap doves ( Oena capensis ), representatives of the passerine birds ( Passer sp. ), Young rock hyrax ( Procavia capensis ) and white-bellied gerbils ( Gerbilliscus leucogaster ), which are smothered in the handle typical of giant snakes and devoured head first.

Hatchling of the Angolapython
Twin slip

Reproduction

There is also no information available on reproduction in the field. In Namibia zoos, the often repeated mating is observed under relatively natural climatic conditions at the end of winter between August and October. So far, males have not shown any agonistic behavior towards one another. After a gestation period of around four months, eggs are laid in zoos in Namibia from November to January. Depending on the size and condition of the female, between 2 and 10, on average around 6, large eggs are laid. These measure 55–95 × 27–51 millimeters, weigh around 120 grams and can make up a remarkable 49% of the total weight of the pregnant female. The eggs are then surrounded by the female, protected from predators and, if necessary, kept at a constantly increased incubation temperature by muscle tremors. In captive natural broods, the ambient temperature was 28 ° C and the nest temperature was fairly constant, 3 ° C increased, at 31 ° C. Under artificial incubation conditions the incubation period is up to 94 days at approximately 28 ° C and at least 55 days for those between 30 and 33 ° C. In nature, the hatching of the young goes hand in hand with the rainy season in summer. Hatchlings are 38 to 51 centimeters long and weigh around 60 grams.

Age

Information on the average and maximum ages of individuals living in the wild is unknown. Several individuals that have been captured as adults and have been kept in captivity for 12 years since then could now be well over 17 years old.

Danger

In Namibia, Angolapythons were placed under preventive protection as early as 1975 in order to avert a potentially flourishing exploitation by the leather industry and the live animal trade. Since then, this python has been heavily protected by the Namibian nature conservation law and its trade has been almost completely prevented. Between 1965 and 2000, the export of just 6 individuals for education and research was approved. Due to its high rarity in captivity, an estimated 2 to 4 animals are smuggled out of Namibia every year, in some years even up to 15 animals. In order to get hold of these pythons, which were traded between 1990 and 2009 for 2000 U $ to well over 10,000 U $, even Namibian officials were threatened and assaulted. Because the captive population is still very small and growing slowly, the illegal live animal trade is likely to continue for longer.

There is currently no visible danger for these snakes from the population of Namibia. The habitats inhabited by the Angolapython, mostly quite remote, are hardly populated by humans and are rarely used or changed for agriculture and livestock due to the drought. The destruction of habitats by mining operations is apparently still low and locally limited at the moment. Furthermore, the local ethnic groups Damara , Nama , Herero and Himba are hardly or not at all known for consuming these pythons. A local trade in Angolapython meat has not yet been discovered. On the contrary, this small, lazy, completely harmless snake is even seen and protected as a lucky charm in some areas. A protection organization has also successfully spread a story that teaches the Namibian population that the health of a water source is directly linked to the residency and well-being of this python. A story that is gladly believed in a country with a water shortage. Furthermore, these pythons are usually very welcome on farm land and are highly valued for devouring pests. The fact that desertification is increasing in Namibia does not seem to have any major effects for the python, which has adapted to dry habitats, either. Meanwhile, Angolapythons are represented in four game reserves: in the Etosha National Park , in the Namib-Naukluft National Park , in the Daan Viljoen Game Park and the Von Bach Recreation Area .

In Angola, it appears that Angolapythons were rarely exported during the civil war from 1975 to 2002. The negative effects of the war on these pythons are not yet known, but are likely to be minor due to the population of remote areas. In the meantime, the government is trying to develop protective measures for the Angolan flora and fauna. The Angolapython occurs in the Iona National Park and possibly also in other game reserves in Angola.

Although no precise data are yet available about the population size and density, the Angolapython seems to be largely harmless. There are no strong signs of population decline. Since the report from 2000, it has been listed in the Washington Convention on the Protection of Species in Appendix II, which means that it is subject to trade and export restrictions. It is not listed by the IUCN and is therefore considered safe.

Systematics

Bocage described the species in 1887 using two specimens from the area of Catumbela in the Angolan province of Benguela. In honor of the Portuguese natural scientist José Alberto de Oliveira Anchieta (1832–1897) who occasionally collected numerous other plants and animals for Portugal in the former colony of Angola in addition to these specimen copies, the Angolapython was given its scientific name Python anchietae . Due to its apparently largely hidden way of life and its remote area of ​​distribution, it was hardly possible to find new specimen copies for the species over the next 50 years. In 1963, living specimens were available to science for the first time. Until 1983 there were still fewer than 40 specimens in museums around the world and until almost a century later, there were only 16 known sites. Therefore, it has long been believed that this snake was extremely rare in its natural environment. It was only through the survey of the Namibian population by Branch & Griffin in 1996 that it became clear that the Angolapython, at least in Namibia, is more common and more widespread than previously assumed.

No subspecies of the Angolapython are currently recognized. In size, appearance and behavior, this python is very similar to the ball python ( Python regius ), which is also native to parts of Africa . Underwood & Stimson (1990) see the species as sister species due to morphological similarities within the actual pythons, and Kluge (1993) also found a very close relationship in his morphological investigations. A molecular genetic investigation is still pending.

Web links

Commons : Angolapython  - album with pictures, videos and audio files

Individual evidence

  1. ↑ a b c d e f g h i D. Barker, T. Barker: The Maintenance and Reproduction of the Dwarf Python of Angola and Namibia . The Vivarium 7, Issue 1, 1995, pp. 30-34, online, pdf .
  2. ↑ a b c d e f g h J. G. Walls: The Living Pythons - A complete guide to the Pythons of the World . TFH Publications, 1998, ISBN 0-7938-0467-1 , pp. 108-113.
  3. ^ GJ Alexander, J. Marais: A Guide to the Reptiles of Southern Africa. Struik Publishers, Cape Town 2007, ISBN 978-1-77007-386-9 , pp. 61-65.
  4. ↑ a b c d e f g h i j k l H. Finkeldey: Python anchietae Bocage . Cimbebasia 6, 1963, pp. 23-28.
  5. ↑ a b c R. W. Patterson, H. Erasmus: Hatching of Anchieta's dwarf python Python anchietae . International Zoo Yearbook 18, 1978, pp. 99-101.
  6. ↑ a b c d e f D. G. Broadley: FitzSimons' Snakes of Southern Africa . Delta Books 1983, ISBN 0-908387-04-0 , pp. 69-70.
  7. ^ T. Logan: A note on attempted breeding in captive Python anchietae (at Houston Zoological Gardens) . The Journal of the Herpetological Association of Africa 10, 1973, p. 8.
  8. ↑ a b c d e f g h i j H. Jauch: Captive Propagation of Python anchietae in Namibia . African Herp News 48, 2009, pp. 8-14.
  9. ↑ a b A. G. Kluge: Aspidites and the Phylogeny of Pythonine Snakes . Records of the Australian Museum, Supplement 19, 1993, ISBN 0-7310-1164-3 , pp. 44, 45, 48, 50, 65.
  10. ↑ a b W. R. Branch: The Dwarf Angolan Python, Python anchietae: species of endangered . Litteratura Serpentium 3, No. 4, 1983, pp. 121-125.
  11. ↑ a b B. du Bocage: Sur un Python nouveau d'Afrique . Jornal de sciencias mathematicas physicas e naturaes - Academia Real das Sciencias de Lisboa 12, issue 46, 1887, pp. 87-88, full text, online .
  12. ↑ a b c d e f S. Spawls: Python anchietae - Anchieta's dwarf python. Habitat, behavior, color and diet . Journal of the Herpetological Association of Africa 39, 1991, p. 24.
  13. ↑ a b c d e f g h i j k l m n o CITES Secretariat: Review of Python anchietae . in: Periodic Review of Animal Taxa in the Appendices - Evaluation of Species selected at AC15 . Doc. AC.16.8.1. Sixteenth meeting of the Animals Committee Shepherdstown, United States of America, 11-15 December 2000, pp. 47–51, online, pdf ( Memento from June 20, 2010 in the Internet Archive ).
  14. ↑ a b c d e f g h i j k l m W. R. Branch, M. Griffin: Pythons in Namibia: Distribution, Conservation, and Captive Breeding Programs . Advances in Herpetoculture - Special Publications of the International Herpetological Symposium, Inc., 1996, pp. 93-102.
  15. ^ A b c B. Branch, WR Branch: Field guide to Snakes and other Reptiles of Southern Africa . Struik Publishers 1998, ISBN 0-88359-042-5 , p. 59.
  16. ^ W. Steyn, AJ Els: Python anchietae Bocage: a note on prey capture and diet . Cimbebasia 6, 1963, pp. 16-22.
  17. ↑ a b c d S. Hebbard: Python anchietae - Angola or Anchieta's Dwarf Python. Reproduction . African Herp News 35, 2002, pp. 8-9.
  18. ↑ a b c M. Borer: keeping and breeding of the Angolapython - Python anchietae . Reptilia 71, pp. 63-66, online, pdf .
  19. ↑ http://www.fao.org/Legal/prs-ol/lpo77.pdf (link not available)
  20. ^ G. Underwood, AF Stimson: A classification of pythons (Serpentes Pythoninae) . Journal of Zoology 221, 1990, pp. 565-603.