Python sebae

Geographic Range

African rock pythons occur throughout sub-Saharan Africa, although they avoid the driest deserts and the coolest mountain elevations. Two subspecies are recognized: Python sebae sebae , northern African rock pythons, and Python sebae natalensis , southern African rock pythons. The northern subspecies is found from south of the Sahara to northern Angola, and from Senegal to Ethiopia and Somalia. The southern subspecies is found from Kenya, Zaire and Zambia south to the Cape of Good Hope. The two subspecies overlap in some areas of Kenya and northern Tanzania. Some authorities recognize them as full species, P. sebae and P. natalensis .

• Biogeographic Regions
• ethiopian ethiopian
  • native native

Habitat

African rock pythons prefer evergreen forests or moist, open savannahs. These snakes often frequent rocky outcrops that can be utilized for hiding purposes, or they may use mammal burrows in less rocky areas. African rock pythons reportedly have a close association with water and often are found near rivers and lakes. The highest elevation at which an African rock python was observed is 2300 meters, although most pythons are found well below that elevation.

• Habitat Regions
• temperate temperate
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• forest forest

• Other Habitat Features
• riparian riparian

Physical Description

The largest snake in Africa, Python sebae averages 3 to 5 m in length. There are reports of much larger African rock pythons, including a record from the Ivory Coast of a 7.5 m specimen, and a questionable report of another individual from the same country reaching a length of 9.8 m. Hatchlings are approximately 35 to 45 cm in length. As adults, African rock pythons average 44 to 55 kg in weight, with reports of some reaching well over 91 kg (200 lbs).

African rock pythons have a relatively small, triangular head that is covered in irregular scales that are typically blackish to brownish-gray in color. The head also has two light-colored bands that form a spearhead shape from the snout to the back of the head just above the eyes, as well as a yellow, inverted V under each eye. There are two heat-sensing pits on the supralabial scales on the upper lip and four to six more pits on the infralabial scales. The body is yellowish, gray-brown, or gray-green, with dark blotches that form a staircase-like pattern on the back. Belly scales are a white color with black specks producing a salt-and-peppery pattern. On the tip of the tail, there are two dark bands that are separated by a lighter band. Juveniles are more brightly marked than adults.

It has been noted that individuals found in the central and western parts of Africa are somewhat more brightly marked than their northern, eastern and southern counterparts. Of the two subspecies, P. s. sebae , of northern and western Africa, is generally larger, has larger head scales, and is more brightly colored than P. s. natalensis .

• Other Physical Features
• heterothermic heterothermic

• Sexual Dimorphism
• female larger

Development

African rock python eggs are laid in hollows and protected by the coils of their mother during development. Once the young hatch they are independent.

Reproduction

Some authors have reported large, seasonal congregations of African rock pythons and have suggested that these are mating aggregations, but little is known about mating in the wild.

Male and female African rock pythons reach sexual maturity at three to five years of age. Males will begin breeding at a size of 1.8 m, while females will wait until they have exceeded at least 2.7 m. Breeding usually takes place between November and March. Declining temperature and changing photoperiod act as signals for snakes to begin breeding. During the breeding season, both males and females cease feeding, with females continuing to fast until the eggs hatch. The female lays her eggs about three months after copulation. Clutches are, on average, 20 to 50 eggs in number, although a large female can lay as many as 100 eggs in a single clutch. The eggs are quite large, often weighing 130 to 170 grams, and about 100 mm in diameter.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• sexual sexual
• oviparous oviparous

The female will lay her eggs in a tree hollow, termite nest or mammal burrow and coil around them. This coiling behavior may be largely for protection, as the female does not "shiver" to create extra heat for incubation as reported for some other python species. However, a Cameroon specimen had a body temperature 6.5 degrees C higher than ambient temperature. Desired incubation temperature is 31 to 32 degrees C (88 to 90 degrees F). In 65 to 80 days the eggs will hatch, at which time the female will leave the young to fend for themselves. Hatchlings average 450 to 600 mm in length.

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

African rock pythons can live for up to 30 years in captivity.

Behavior

Like many other snake species, African rock pythons are fairly solitary snakes, seeking out their own kind only during the breeding season. Being a large-bodied snake, rock pythons mainly stay on the ground, but sometimes climb if the need arises. They can swim well and stay submerged for a long time, which is advantageous for avoiding potential threats. Although primarily nocturnal as adults, rock pythons may be active during the day to bask in the sun for thermoregulation. Juveniles, however, are mostly active at dawn and dusk, preferring to retreat to the safety of a rock formation or hollow tree during the day and night.

African rock pythons have a reputation for being particularly aggressive snakes, with pronounced feeding responses and spirited defensive behavior. If unable to escape when threatened, an African rock python will bite and constrict with great ferocity. They have large, recurved teeth and bites are excruciatingly painful and can become easily infected if not treated promptly. Due to the sizes that this species can reach, their constricting power must be respected. When in captivity, a wild-caught individual will rarely acclimate to being handled or confined to a cage. Captive-bred individuals may become docile with a lot of handling, but overall these are aggressive snakes and generally a poor choice for captive husbandry.

• Key Behaviors
• terricolous
• nocturnal nocturnal
• crepuscular crepuscular
• sedentary sedentary
• solitary solitary

Home Range

Home range size in the wild is unknown.

Communication and Perception

As in all snakes, African rock pythons have a well-developed vomeronasal (Jacobson's) organ system, supplied by the tongue. This allows perception of chemicals (odors) in the environment, such as prey odors and pheromones produced by other pythons. Pythons also possess heat-sensing pits in the labial scales that detect infrared (heat) patterns given off by endothermic predators and prey.

• Communication Channels
• visual visual
• tactile tactile
• chemical chemical

• Other Communication Modes
• pheromones pheromones
• scent marks scent marks

• Perception Channels
• visual visual
• infrared/heat infrared/heat
• tactile tactile
• acoustic acoustic
• vibrations vibrations
• chemical chemical

Food Habits

African rock pythons are carnivores and feed primarily on terrestrial vertebrates. As juveniles, these pythons feed on small mammals, especially rats. Once adult sized, they will move onto larger prey, such as monkeys, crocodiles, large lizards, and antelope. They will sometimes take fish as well. If African rock pythons live near humans, family pets and livestock may be eaten.

African rock pythons generally hunt at twilight using their heat-sensing pits. Once a prey item has been found, the python will sit patiently or move slowly toward the prey. Once in range, the python will strike with devastating speed and accuracy, sinking its long curved teeth into the prey's flesh and coiling around it. The power of these snakes is incredible. A large adult snake can tackle an antelope weighing up to 59 kg.

African rock pythons constrict their prey as do other members of the family Boidae (boas, pythons and anacondas) . Contrary to popular belief, large constricting snakes do not crush their prey to death, but rather asphyxiate or compress them until they die of cardiovascular shock. As the prey breathes out, the snake tightens its coils so that the prey cannot breathe in again. Eventually, the prey suffocates or expires from heart failure and is swallowed whole. These snakes can go long periods of time between meals if necessary. A captive specimen reportedly fasted for over 2.5 years.

• Primary Diet
• carnivore carnivore
  • eats terrestrial vertebrates

• Animal Foods
• birds
• mammals
• reptiles
• fish

Predation

Aside from humans, adult African rock pythons have few natural predators due to their large size. However, during long digestion periods a python may become vulnerable to predation by hyenas or African wild dogs .

Juveniles are probably subject to attack by more predators.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

These snakes are predators on small to moderately large vertebrates. As ectotherms, they feed infrequently compared to endothermic predators (such as mammalian predators), and over-all effects on prey populations are presumably minimal in comparison.

Juvenile pythons are prey for numerous predators; adults are much less vulnerable but are occasionally killed by larger mammals.

Economic Importance for Humans: Positive

Humans exploit Python sebae in a number of ways. The most lucrative use is its skin and meat. The skin especially is highly desired by consumers, with the number of skins exported reaching near 9,300 in 2002. Humans also attempt to make pets out of African rock pythons. While a captive born python may be docile if accustomed to handling, wild-caught individuals do not make good pets because of their aggression. Another benefit provided to humans comes from juvenile snakes. Since younger African rock pythons eat rats, they help to control pests in areas of human habitation. Pythons are venerated and protected in some cultures.

• Positive Impacts
• pet trade pet trade
• food food
• body parts are source of valuable material
• controls pest population

Economic Importance for Humans: Negative

These snakes sometimes will feed on livestock and pets of local human residents, particularly if natural prey has become scarce. In the past, rock pythons have been observed feeding on dogs, goats, poultry and other livestock that are important to the livelihood of the native peoples.

African rock pythons can also be a danger to humans. Although it is rare that a python will attack without provocation, there are several reports of rock python attacks on humans. Often, a human will startle a snake, causing it to bite. More rarely, the python may even constrict a human to death, and smaller humans have been eaten in extremely unusual circumstances. Although people are occasionally killed by pythons, the pythons are not always killed in retaliation. The offending snake may be transported to a different area where it is less likely to come into contact with humans.

• Negative Impacts
• injures humans
  • bites or stings

Conservation Status

African rock pythons are no longer as widespread as they once were. Python sebae is now restricted mainly to hunting reserves, national parks and secluded sections of the African savannah. Reduction in available prey animals and hunting for its meat and skin has caused this species to decline in numbers over the years. Larger individuals are increasingly rare in many areas. African rock pythons have been placed on Appendix II of CITES and are legally protected in certain countries where populations have become increasingly vulnerable (such as South Africa).

Additional Links

Encyclopedia of Life

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Patrick Sherman (author), Michigan State University, James Harding (editor, instructor), Michigan State University.

References

Areste, M., R. Cebrian. 2003. Snakes of the World . New York: Sterling Publishing Co., Inc..

Branch, B. 1998. Field Guide to Snakes and Other Reptiles of Southern Africa . Sanibel Island, Florida: Ralph Curtis Books.

Branch, W., D. Hacke. 1980. A fatal attack on a young boy by an African rock python Python sebae . Journal of Herpetology , 14(3): 305-307.

Cogger, H., R. Zweifel. 1998. Encyclopedia of Reptiles and Amphibians . San Diego, California: Academic Press.

Luiselli, L., F. Angelici, G. Akani. 2001. Food habits of Python sebae in suburban and natural habitats. African Journal of Ecology , 39: 116-118.

McCurley, K. 2003. "New England Reptile" (On-line). Accessed October 22, 2006 at http://www.newenglandreptile.com .

Murphy, J., R. Henderson. 1997. Tales of Giant Snakes . Malabar, Florida: Krieger Publishing Company.

Spawls, S., K. Howell, R. Drewes, J. Ashe. 2002. A Field Guide to Reptiles of East Africa . San Diego, California: Academic Press.

Spawls, S., B. Branch. 1995. The Dangerous Snakes of Africa . South Africa: Southern Book Publishers, Ltd..