Burmese pythons in Florida
Pronounced declines in several mammalian species have coincided spatially and temporally with the proliferation of pythons in South Florida, indicating the already devastating impacts upon native animals.
[7] The high reproductive potential, rapid sexual development, and longevity of Burmese pythons results in difficulty controlling the population through removal of individuals.
The flexible dietary requirements of Burmese pythons enable them to survive for long periods of time without food, but when prey is readily available, they will eat regularly.
[12] The overall extent to which the greatly reduced mammalian populations will disrupt the complex food web of the Everglades by indirectly affecting other native species, however, is unclear.
[14] Estimating the population of Burmese pythons in the Everglades is challenging because of the secretive nature of this species and the limited ability to conduct traditional mark-recapture assessments.
[19] Several attempts have been made at better understanding the spatial ecology of Burmese pythons in the Everglades, including capture analysis and radio telemetry studies.
[9] Gut analyses indicate that captured pythons consume nearly any bird, mammal, or alligator found in the Everglades,[4] including nationally endangered Key Largo woodrats (Neotoma floridana smalli) and wood storks (Mycteria americana).
[21][20] Radio telemetry includes the use of small, surgically implanted radiotransmitters to track the movement patterns of captured and released animals over extended periods of time.
[23] In contrast to previous research that documented the poor navigational abilities of terrestrial snakes, the movement behavior of the Burmese python seems to be nonrandom.
One of the most contentious issues related to the Burmese python population in Florida is the potential spread to other areas of the southern United States.
[25] Numerous climate matching models have indicated that most of Florida and vast portions of the coast of the rest of Southeastern United States provide hospitable habitats for Burmese pythons.
[31] Burmese pythons kept throughout winter in an experimental enclosure in South Carolina all died during the study, apparently because they could not properly acclimate to the cold, but most survived extended periods at temperatures below those typical of southern Florida.
[28] A model corrected for these miscalculations showed a greater projected range of Burmese python climate match including nearly all of Florida, much of the lower Coastal Plain of the southeast United States, and southern Texas.
A severe freeze in the southeastern United States during January 2010 provided additional insight into the threat of Burmese python range extension.
In the wake of this extended cold spell, several investigators reported dead snakes coiled along canal banks and in outdoor enclosures.
[9] In addition to behavioral traits, a study in 2018 showed that the surviving pythons showed evidence of: directional selection in genomic regions enriched for genes associated with thermosensation, behavior, and physiology...several of these genes are linked to regenerative organ growth, an adaptive response that modulates organ size and function with feeding and fasting in pythons.
Data published in 2012[38] contradict the initial USGS study[39] which claimed that non-native Burmese pythons could expand as far north as the southern third of the United States.
The National Geographic Society's resident herpetologist, Dr. Brady Barr, said, "Climate data reveal that temperatures found in southern Florida simply are not conducive to the long-term survival of large tropical snakes.
Given that biocontrol methods present a nontrivial and somewhat unpredictable risk to the area's delicate ecosystem, additional research and careful deliberation are necessary before such techniques are used.
Beyond the scientific community, the use of bounty hunters has received a great deal of support from officials and the media, and although the results have not been very significant in the context of the high estimates of python populations, these conservation efforts have increased awareness of the problem.
Environmental chemist Dr. David Krabbenhoft of the U.S. Geological Survey tested tissue samples from a collection of frozen python tails maintained by scientists at Everglades National Park.
[49][50] However as of December 2020[update] the FWC is studying mercury levels again in order to make recommendations about what size, age, and location of origin might be safe to eat.
[54] While an effective and practical control method for South Florida's Burmese python population has yet to be proposed, regulatory measures are in place to prevent its further spread.
Specifically, in 2008 the Florida Fish and Wildlife Commission instituted regulations requiring permits for boas and pythons greater than 2 inches (51 mm) in diameter as well as PIT tags implanted in the snake's skin for identification purposes.
Further, the United States Department of the Interior placed four additional species of snakes, including the Burmese python, under the Lacey Act provisions.
