December 6, 2017

Seventy years ago today, on Dec. 6, 1947, United States President Harry S. Truman officially opened southwestern Florida’s Everglades National Park. The park was established to conserve parts of the Everglades wetlands and the Big Cypress Swamp, as well as many coastal islands along the Gulf of Mexico. Covering 1,508,976 acres (610,661 hectares), the junglelike plant life of Everglades National Park includes saw grass, delicate orchids, lacy cypress trees, pines, palms, and thick tangles of mangrove trees. Crocodiles, alligators, manatees, and many other animal species live there.

Everglades National Park is in the Florida Everglades, one of the few subtropical regions of the United States. The southern part of the park includes many red mangrove trees, whose spreading roots catch and hold soil. Credit: National Park Service

In the late 1800’s and early 1900’s, land developers tried to drain parts of the Everglades wetlands, intending to turn the area into valuable real estate properties. Canals and levees diverted water from both the Everglades and nearby Lake Okeechobee, damaging the wetlands. Conservation efforts led to the creation of Royal Palm State Park in 1916, a protected area that steadily expanded and became the basis for Everglades National Park.

Everglades National Park includes large areas of wetlands that provide a home for wildlife. In this picture, roseate spoonbills wade near a young alligator. Credit: © Shutterstock

Further degradation of the Everglades—made worse by rising sea levels and heavy traffic on the park’s roads and waterways—sparked the Comprehensive Everglades Restoration Plan in 2000, a 35- to 50-year project meant to “restore, preserve, and protect the south Florida ecosystem while providing for other water-related needs of the region.”

February 22

The Florida Fish and Wildlife Commission announced this week that 68 Burmese pythons had been captured in the Florida Everglades in its 2013 Python Challenge. The Burmese python, the target of the hunt, is an invasive species–that is, it is not native to Florida. Most of the pythons in the wild in Florida are either snakes that escaped from captivity or pets that were deliberately released into the wild when owners could no longer care for them. Because the Burmese python is not native, it has no predators itself. Thus, the python has spread quickly throughout the Everglades, causing harm to the ecosystem and to native species in the region. According to a 2012 study, sightings of bobcats, opossums, rabbits, raccoons, and other mammals in the Everglades are down as much as 99% in areas where pythons live.

The Burmese python, a subspecies of the Indian python shown, has spread quickly through the Florida Everglades, threatening the ecosystem and the animals native to the area. (J. H. Robinson, Animals Animals)

Florida’s Fish and Wildlife Commission held its first python hunt from January 12 to February 10 in 2013. Any adult who wanted to try to harvest the nonvenomous snake was encouraged to do so, and nearly 1,000 people, mostly amateurs, signed on. Given how well camouflaged the snake is in the Everglades environment, experts were surprised that the hunt had found 68 pythons in the wild by the end date.

Most of the captured snakes were humanely euthanized. However, several snakes–including the longest, at 11 feet (3.3 meters)–were fitted with transmitters and released back into the wild. Scientists planned to track these snakes, hoping that they would lead to nests of breeding females, who could also then be captured before their young went into the wild.

Additional World Book articles:

• ecology
• environment
• Everglades
• python

August 17, 2012

The recent discovery of the biggest Burmese python ever found in Florida is convincing evidence of just how well established these highly destructive reptiles have become in Everglades National Park and other parts of South Florida, according to Florida scientists. The snake was 17 feet 7 inches (5.35 meters) long and weighed 164 1/2 pounds (76 kilograms). Scientists recovered 87 eggs from the snake–also  a record for the state. The pythons “are surviving a long time in the wild,” said snake expert Kenneth Krysko of the Florida Museum of Natural History. “There’s nothing stopping them.” About 1,825 Burmese pythons were discovered in Everglades National Park from 2000 to 2011. However, scientists think the python population is many times higher.

Native to Southeast Asia, the python is classified as an invasive species in North America. From 1999 to 2004, pet exporters met a growing American demand for Burmese pythons by shipping more than 144,000 baby snakes to the United States. However, new owners were frequently unprepared or unwilling to care for the massive snakes in adulthood. Many owners dumped their snakes into the wild. Pythons released into the Everglades, a region with a climate similar to that of the snakes’ native habitat, flourished. Pythons also have escaped into the wild during hurricanes.

Young Indian pythons hatch from eggs outside the mother's body. The leathery shells of snake eggs expand as the young snakes grow inside. When they are ready to hatch, young snakes slash their shells with a special tooth that grows on the upper jaw. (AP/Wide World)

The pythons have devastated the mammal population of the Everglades and were targeting the park’s birds, according to a study released in April 2012. The study was the first to provide evidence linking a sharp decline in populations of medium- and large-sized mammals in the park to an explosion in the number and range of the large snakes. The record-holding snake found recently had feathers in its stomach.

Wildlife experts agree that eliminating the secretive and hard-to-hunt snakes from the park would be impossible. They are unsure if the spread of the snakes, which have no natural predators in North America, can be halted. In January, the administration of President Barack Obama outlawed the import and interstate commerce of Burmese pythons, two other pythons, and the yellow anaconda. Reptile importers are still allowed to trade in reticulated pythons and boa constrictors. Florida permits residents to hunt pythons under certain conditions.

Additional World Book articles:

• Ecology
• Invasive Species (A Special Report)
• Reptile

April 9, 2012

After devastating the mammal population of Everglades National Park in Florida, Burmese pythons are targeting the park’s birds. They are not only eating area birds but also taking their eggs straight from the nest.

Researchers from the Smithsonian Museum of Natural History have monitored the invasive snake’s diet by examining the stomach contents of captured pythons. They found that the diets of some 300 captured snakes consisted of more than 25 species of birds. They also found eggs inside the snakes, proof that they are attacking nests. Most snakes that eat eggs puncture the shells with fangs and suck out the contents. However, the researchers found shell fragments inside the snakes, suggesting that they eat the eggs whole. “This finding is significant because it suggests that the Burmese python is not simply a sit-and-wait predator, but rather is opportunistic enough to find the nests of birds,” noted Carla Dove, a researcher with the Smithsonian study. “Although the sample size is small, these findings suggest that the snakes have the potential to negatively affect the breeding success of native birds.” The study was reported in the March 2012 issue of the journal Reptiles & Amphibians: Conservation and Natural History.

An earlier study, published in March 2012 by two Florida university researchers, revealed that pythons were battling alligators for the position of top predator in the Everglades. That study was the first to provide evidence linking a sharp decline in populations of medium- and large-sized mammals in the park to an explosion in the number and range of the large snakes.

Egrets are among the most beautiful birds in the Everglades. (World Book illustration by Trevor Boyer, Linden Artists Ltd.)

Native to Southeast Asia, the Burmese python is classified as an invasive species in North America. From 1999 to 2004, pet exporters met a growing American demand for Burmese pythons by shipping more than 144,000 baby snakes to the United States. However, new owners were frequently unprepared or unwilling to care for the grown snakes, which can measure 23 feet (7 meters) in length and weigh 200 pounds (91 kilograms). Many owners dumped their snakes into the wild. Pythons released into the Florida Everglades, a region with a climate similar to that of the snakes’ native habitat, flourished. Pythons also have escaped into the wild during hurricanes.

Researchers surveyed native mammal populations over 313 nights during an eight-year period by counting live and dead animals along a road that runs to the southern tip of the park. They then compared their tallies to population surveys done in 1996 and 1997. In areas of the Everglades where pythons have lived the longest, populations of raccoons had fallen by 99.3 percent. The number of opossums had dropped by 98.9 percent, and bobcat populations had fallen by 88.5 percent. The researchers were unable to find any rabbits or foxes. Populations of native animals were larger in areas more recently or not yet invaded by the snakes.

The U.S. Association of Reptile Keepers disputed the findings of the study. The organization contended that mercury pollution in the Everglades has played a major role in the disappearance of the mammals.

Young Indian pythons hatch from eggs outside the mother's body. (AP/Wide World)

Wildlife experts agree that eliminating the secretive and hard-to-hunt snakes from the park would be impossible. They are unsure if the spread of the snakes, which have no natural predators in North America, can be halted. In January, the federal government outlawed the import and interstate commerce of Burmese pythons, two other pythons, and the yellow anaconda. Reptile importers are still allowed to trade in reticulated pythons and boa constrictors.

Additional World Book articles:

• Ecology
• Invasive Species (A Special Report)
• Reptile

Feb. 6, 2012

Pythons are battling alligators for the position of top predator in Everglades National Park in Florida, and native mammals are paying the price, according to a new study by two Florida university researchers. The study is the first to provide evidence linking a sharp decline in populations of medium- and large-sized mammals in the park to an explosion in the number and range of the large snakes.

Native to Southeast Asia, the python is classified as an invasive species in North America. From 1999 to 2004, pet exporters met a growing American demand for Burmese pythons by shipping more than 144,000 baby snakes to the United States. However, new owners were frequently unprepared or unwilling to care for the grown snakes, which can measure 23 feet (7 meters) in length and weigh 200 pounds (91 kilograms). Many owners dumped their snakes into the wild. Pythons released into the Florida Everglades, a region with a climate similar to that of the snakes’ native habitat, flourished. Pythons also have escaped into the wild during hurricanes.

The study’s researchers surveyed native mammal populations over 313 nights during an eight-year period by counting live and dead animals along a road that runs to the southern tip of the park. They then compared their tallies to population surveys done in 1996 and 1997. In areas of the Everglades where pythons have lived the longest, populations of raccoons had fallen by 99.3 percent. The number of opossums had dropped by 98.9 percent, and bobcat populations had fallen by 88.5 percent. The researchers were unable to find any rabbits or foxes. Populations of native animals were larger in areas more recently or not yet invaded by the snakes.

The U.S. Association of Reptile Keepers disputed the findings of the study. The organization contended that mercury pollution in the Everglades has played a major role in the disappearance of the mammals.

Young Indian pythons hatch from eggs outside the mother's body. The leathery shells of snake eggs expand as the young snakes grow inside. When they are ready to hatch, young snakes slash their shells with a special tooth that grows on the upper jaw. AP/Wide World

Wildlife experts agree that eliminating the secretive and hard-to-hunt snakes from the park would be impossible. They are unsure if the spread of the snakes, which have no natural predators in North America, can be halted. In January, the administration of President Barack Obama outlawed the import and interstate commerce of Burmese pythons, two other pythons, and the yellow anaconda. Reptile importers are still allowed to trade in reticulated pythons and boa constrictors.

Additional World Book articles:

• Ecology
• Invasive Species (A Special Report)
• Reptile