|
|||||||
 · Green Anaconda |
|||||||
|
Description: This is a large snake with greenish to yellow-brown scales and darker blotches that may take the form of rings, encircling scales that are orange to red. On their sides, they also have dark circles, but these circles have yellow centers. Anacondas can be identified by their yellow and black underside which is unique to each anaconda. Anacondas have a streak of red scales that trail backwards from the eye, crossed with darker stripes. Growing to a length of at least 29.5 feet (9 m) and weighing up to 550 pounds (250 kg), green anacondas are considered to be the world’s largest snakes. They can be up to 12 inches (31 cm) or more in diameter! The females are typically larger than the males of the same age. The eyes and nostrils are both located on top of the anaconda’s head. The jaws of the anaconda are very strong and designed to hold large prey underwater. Diet: Anacondas are known to eat mammals (especially peccaries and deer), birds, freshwater turtles, caimans, frogs, and fish. Anacondas do not feed frequently due to their slow digestive system. Typically, an anaconda will wait several weeks, or possibly months, between meals. The record for the longest time between meals is two years. Anacondas have also been known to be cannibalistic. Diet at Como: At the Como Park Zoo, anacondas are offered food every two weeks. Small anacondas are fed rats or quail, while large anacondas are offered rats, quail, and rabbits. To prevent potential harm to the snakes, they are not fed live prey. To make feeding habits more consistent with those found in the wild, the zookeepers are currently trying to switch to a once monthly feeding of a single, large meal (at least 4 lbs or 1.8 kg). Behavior: This snake is non-venomous and nocturnal. They are not active hunters; but rather, they wait for their prey to come to the water and ambush, killing prey by constriction or drowning. Once the prey has come within 15-25 feet (4.5-7.6 m) of the snake, it strikes and holds onto its prey with its strong jaws. It then pulls its prey into the water and drowns or constricts it. Anacondas are solitary creatures except during the breeding season. On land, the anaconda may appear to be slow, but in the water it is very quick. It can stay completely submerged under water for up to 10 minutes. Breeding: Mating takes place during the cooler months of the year (June, July, and August). At the onset of the annual rains, females secrete pheromones that may attract several males for breeding. The males respond by courting the females and making loud “booming” sounds. During this time, many males (up to 12) are attracted to the female and “ball up” around her. Courtship and copulation generally take place in the water. When the male and female are ready to mate, the male’s spurs around his cloacal region become erect. He holds the female by wrapping his tail around the female and rubbing his spurs on her cloacal region to encourage copulation. Gestation is dependent upon temperature, but is usually six months or more (182-288 days). Anacondas produce litters of 20-80 young. Anacondas have given birth underwater in captivity, but also on land in the wild. Young anacondas are about 26 inches (0.7 m) long at birth and are able to swim immediately. Sexual maturity is reached at 3-4 years. Adaptations: Their large size allows them to occupy the niche of the largest predator in their range. The greenish tinge to their scales and their mottled pattern make for effective camouflage. Their eyes and nostrils on the top of their heads allow them to lay underwater to ambush their prey. Anacondas can stay underwater for 10 minutes without breathing. Strong jaws and muscular bodies allow them to hold onto their prey once they have caught it. Like all snakes, the green anaconda has an excellent sense of smell. Snakes smell by sticking out their tongue. Miscellaneous:The title of the world’s largest snake is a subject of contention. The largest anaconda reported was 62 feet (18.9 m), killed by Colonel Percy Fawcett of the Royal Artillery in Brazil in 1907. Anacondas of 54 feet (16.5 m) have been reported by a man named Lange in Peru in 1910 and by an explorer named de Graff in 1927. Far more realistic reports, made by scientists with more credibility, range from 30-35 feet (9-10.7 m). Reports of 37.5-38 feet have been accepted by many who wish to give this snake as much credit as possible. It should be noted that another large snake, the reticulated python (Python reticulatus) is considered to be the longest snake in the world, but is of a more slender build and is not as heavy as a large anaconda.Even though attacks on humans are very rare, there have been confirmed reports of anacondas eating small children. Snakes are very particular about their prey, and humans are not often recognized as food. In the few cases in which anacondas have acted aggressively toward humans, their behavior is more easily explained as self defense rather than predation. The lifespan of a wild green anaconda is 15-20 years and a captive anaconda could live up to 30 years. Threats to Survival : Young anacondas are very vulnerable and become the prey for many animals. Due to their large size, healthy, adult anacondas have no natural predators.Populations are stable throughout most of their range, although they are susceptible to over-hunting. Anacondas are listed in CITES Appendix II, meaning that the species could be threatened with extinction if trade is not strictly controlled. The trade of green anacondas is no longer allowed, except for research and to fill pet trade quotas. Anaconda meat is eaten by indigenous populations and has even appeared on menus in the restaurants of French Guiana. Anacondas are also hunted for the production of traditional medicines. There is some demand for anacondas as pets; however, this is especially unwise, considering that anacondas grow to be quite large and can be aggressive and difficult to handle. By far, the greatest threat to anacondas is the skin trade. The US and Italy are the major importers of anaconda leather, much of which is shipped from countries that have no native anaconda populations (i.e. Panama and Argentina). Most likely, anacondas are hunted in Brazil and shipped to these countries for export. It is estimated that the leather trade was responsible for the death of nearly 29,000 anacondas per year during the mid 1980s. Sources: Murphy, John C. and Robert W. Henderson. Tales of Giant Snakes: A historical Natural History of anacondas and Pythons. Malabar, Florida: Krieger Publishing Company. 1997 Whitfield, Philip, ed. The Simon & Schuster Encyclopedia of Animals: A Visual Who’s Who of the World’s Creatures. New York: Simon & Schuster Editions. 1998. www.nashvillezoo.org/anaconda.htm www.sfzoo.org/cgi-bin/animals.py?ID=51 pages.prodigy.net/anaconda/canib.htm |
|||||||
 |
|||||||
