The Burmese python (Python bivittatus) is one of the largest species of snakes. It is native to a large area of Southeast Asia and is listed as Vulnerable on the IUCN Red List. Until 2009, it was considered a subspecies of the Indian python, but is now recognized as a distinct species. It is an invasive species in Florida as a result of the pet trade.
Description[]
The Burmese python is a dark-colored non-venomous snake with many brown blotches bordered by black down the back. In the wild, Burmese pythons typically grow to 5 m (16 ft), while specimens of more than 7 m (23 ft) are unconfirmed. This species is sexually dimorphic in size; females average only slightly longer, but are considerably heavier and bulkier than the males. For example, length-weight comparisons in captive Burmese pythons for individual females have shown: at 3.47 m (11 ft 5 in) length, a specimen weighed 29 kg (64 lb), a specimen of just over 4 m (13 ft) weighed 36 kg (79 lb), a specimen of 4.5 m (15 ft) weighed 40 kg (88 lb), and a specimen of 5 m (16 ft) weighed 75 kg (165 lb). In comparison, length-weight comparisons for males found: a specimen of 2.8 m (9 ft 2 in) weighed 12 kg (26 lb), 2.97 m (9 ft 9 in) weighed 14.5 kg (32 lb), a specimen of 3 m (9.8 ft) weighed 7 kg (15 lb), and a specimen of 3.05 m (10.0 ft) weighed 18.5 kg (41 lb). In general, individuals over 5 m (16 ft) are rare. The record for maximum length of a Burmese python is 5.79 m (19 ft 0 in) and was caught 10 July 2023 in South Florida's Big Cypress National Preserve. Widely published data of specimens reported to have been several feet longer are not verified. At her death, a Burmese named "Baby" was the heaviest snake recorded in the world at the time at 182.8 kg (403 lb), much heavier than any wild snake ever measured. Her length was measured at 5.74 m (18 ft 10 in) circa 1999. The minimum size for adults is 2.35 m (7 ft 9 in). Dwarf forms occur in Java, Bali, and Sulawesi, with an average length of 2 m (6 ft 7 in) in Bali, and a maximum of 2.5 m (8 ft 2 in) on Sulawesi. Wild individuals average 3.7 m (12 ft) long, but have been known to reach 5.79 m (19 ft 0 in).
Diseases[]
In both their native and invasive range they suffer from Raillietiella orientalis (a pentastome parasitic disease).
Distribution and habitat[]
The Burmese python occurs throughout Southern and Southeast Asia, including eastern India, southeastern Nepal, western Bhutan, southeastern Bangladesh, Myanmar, Thailand, Laos, Cambodia, Vietnam, northern continental Malaysia, and southern China in Fujian, Jiangxi, Guangdong, Hainan, Guangxi, and Yunnan. It also occurs in Hong Kong, and in Indonesia on Java, southern Sulawesi, Bali, and Sumbawa. It has also been reported in Kinmen.
It is an excellent swimmer and needs a permanent source of water. It lives in grasslands, marshes, swamps, rocky foothills, woodlands, river valleys, and jungles with open clearings. It is a good climber and has a prehensile tail. It can stay in water for 30 minutes but mostly stays on land
As an invasive species[]
Main article: Burmese pythons in Florida
Python invasion has been particularly extensive, notably across South Florida, where a large number of pythons can now be found in the Florida Everglades. Between 1996 and 2006, the Burmese python gained popularity in the pet trade, with more than 90,000 snakes imported into the U.S. The current number of Burmese pythons in the Florida Everglades may have reached a minimum viable population and become an invasive species. Hurricane Andrew in 1992 was deemed responsible for the destruction of a python-breeding facility and zoo, and these escaped snakes spread and populated areas into the Everglades. More than 1,330 have been captured in the Everglades. A genetic study in 2017 revealed that the python population is composed of hybrids between the Burmese python and Indian python. The species also displays cytonuclear discordance which has made phylogenetic studies of its origin more complicated.
By 2007, the Burmese python was found in northern Florida and in the coastal areas of the Florida Panhandle. The importation of Burmese pythons was banned in the United States in January 2012 by the U.S. Department of the Interior. A 2012 report stated, "in areas where the snakes are well established, foxes, and rabbits have disappeared. Sightings of raccoons are down by 99.3%, opossums by 98.9%, and white-tailed deer by 94.1%." Road surveys between 2003 and 2011 indicated an 87.3% decrease in bobcat populations, and in some areas rabbits have not been detected at all. Experimental efforts to reintroduce rabbit populations to areas where rabbits have been eliminated have mostly failed "due to high (77% of mortalities) rates of predation by pythons." Bird and coyote populations may be threatened, as well as the already-rare Florida panther. In addition to this correlational relationship, the pythons have also been experimentally shown to decrease marsh rabbit populations, further suggesting they are responsible for many of the recorded mammal declines. They may also outcompete native predators for food.
For example, Burmese pythons also compete with the native American alligator, and numerous instances of alligators and pythons attacking—and in some cases, preying on—each other have been reported and recorded.
By 2011, researchers identified up to 25 species of birds from nine avian orders in the digestive tract remains of 85 Burmese pythons found in Everglades National Park. Native bird populations are suffering a negative impact from the introduction of the Burmese python in Florida; among these bird species, the wood stork is of specific concern, now listed as federally endangered.
Numerous efforts have been made to eliminate the Burmese python population in the last decade.[when?] Understanding the preferred habitat of the species is needed to narrow down the python hunt. Burmese pythons have been found to select broad-leafed and low-flooded habitats. Broad-leafed habitats comprise cypress, overstory, and coniferous forest. Though aquatic marsh environments would be a great source for prey, the pythons seem to prioritize environments allowing for morphological and behavioral camouflage to be protected from predators.[clarification needed] Also, the Burmese pythons in Florida have been found to prefer elevated habitats, since this provides the optimal conditions for nesting. In addition to elevated habitats, edge habitats are common places where Burmese pythons are found for thermoregulation, nesting, and hunting purposes.
One of the Burmese python eradication movements with the biggest influence was the 2013 Florida Python Challenge. This was a month-long contest wherein a total of 68 pythons were removed. The contest offered incentives such as prizes for longest and greatest number of captured pythons. The purpose of the challenge was to raise awareness about the invasive species, increase participation from the public and agency cooperation, and to remove as many pythons as possible from the Florida Everglades. The challenge has run a few times again since then and is now an annual event over the duration of ten days. Recently, in 2023, it resulted in 209 pythons removed by 1,050 participants.
A study from 2017 introduced a new method for identifying the presence of Burmese pythons in southern Florida; this method involves the screening of mosquito blood. Since the introduction of the Burmese python in Florida, mosquito communities use the pythons as hosts even though they are recently introduced.
Invasive Burmese pythons also face certain physiological changes. Unlike their native South Asian counterparts who spend long periods fasting due to seasonal variation in prey availability, pythons in Florida feed year-round due to the constant availability of food. They are also vulnerable to cold stress, with winter freezes resulting in mortality rates of up to 90%. Genomic data suggests natural selection on these populations favors increased thermal tolerance as a result of these high-mortality freezes.
They have carried Raillietiella orientalis, a pentastome parasitic disease, with them from Southeast Asia. Other reptiles in Florida have become infested, and the parasite appears to have become endemic.
In April 2019, researchers captured and killed a large Burmese python in Florida's Big Cypress National Preserve. It was more than 5.2 m (17 ft) long, weighed 64 kg (140 lb), and contained 73 developing eggs. In December 2021, a Burmese python was captured in Florida that weighed 98 kg (215 lb) and had a length of 5.5 m (18 ft); it contained a record 122 developing eggs. In July 2023, local hunters captured and killed a 5.8 m (19 ft) long Burmese python that weighed 57 kg (125 lb) in Florida's Big Cypress National Preserve.