For the last four decades, invasive Burmese python snakes have terrorized mammals and the greater ecosystem of the Everglades National Park and throughout South Florida.
Now, a recent study shows what is biting back.
The Southeast Asian apex predator can grow up to 19 feet long, weigh more than 150 pounds and eat everything from rabbits to deer. The pythons and their appetites are also blamed for the disappearance of almost all the fur-bearing mammals in the Everglades and surrounding areas.
A new study by the U.S. Geological Survey and partner organizations in Florida studied the deaths of 19 baby Burmese pythons from May 2021 to February 2022 to see how this part of the python population might meet its fate.
Burmese pythons are difficult to track or monitor, according to Mark Sandfoss, Biologist at Fort Collins Science Center stationed in Everglades National Park. But studies like this provide data points to fill in the gaps of their life cycle.
"It takes a lot of time and effort to collect these data," Sandfoss said in an emailed statement to USA TODAY. "We need more information and are continuing to track juvenile pythons in Southern Florida to understand their ecology, particularly movement, habitat use, and survival."
Burmese pythons have destroyed native populations for decades
Burmese pythons are native to Southeast Asia. They were imported to Florida to be sold to pet owners, and were likely released or escaped. They established a wild population in the 1980s, according to the study, and Sandfoss said they can grow to be 19 feet long and weigh more than 150 pounds.
Since then, they have wreaked havoc on the natural environment, eating everything from rabbits to deer with few species being able to check the population. The USGS estimates there are tens of thousands living in the Everglades.
A 2012 study showed that pythons' diets have drastically cut the populations of Everglades-area mammals. Raccoon, opossum and bobcat populations had dropped 85%-99%, and rabbits and foxes had "effectively disappeared."
Humans may be one known predator of the python, but the recent USGS study shows there are more, at least for the babies.
What is killing the baby pythons?
Juvenile Burmese pythons were opportunistically collected throughout more than a year. They were implanted with high-frequency radio transmitters equipped with mortality sensors that notified researches when the snake stopped moving for 24 hours.
During the length of the study, 19 baby snakes died. At that point, scientists would go to the scene of the crime and conduct some detective work to discover the cause of death.
Here is what they found:
Five pythons died from alligators.
Three died from carnivorous mesomammals. There are many small mammals in the Big Cyprus National Preserve, though the prints nearby often belonged to feline varieties.
Seven deaths were "unattributed." In some cases the transmitter was found without any trace of python remains.
Three died from Florida cottonmouth snakes.
One died from eating an animal that was too big.
The snake whose eyes were bigger than its stomach
Among the deceased juveniles recorded as part of the study, one ambitious snake set a new record for pythons that size. It attempted to eat a hispid cotton rat that weighed 106% of the python's body weight.
The study says this is notable in more ways than one. Its failure to accurately assess prey could be a sign of a maladaptive behaviors due to different prey sizes in the new environment compared to their native environment.
Maladaptive behaviors provide scientists the opportunity to identify potential weaknesses in an invasive species that have otherwise thrived in a new environment, Sandfoss said. While maladaptive behaviors are naturally selected out of the population overtime, the native species can also adapt to the invasive species in that time.
What this means for the invasive python population
Sandfoss said that, given the wide range of prey that adult pythons eat, scientists did no know if native species had learned to adapt to avoid becoming prey or even become a predator.
He said that the range of predators they found in the study was a pleasant surprise. A cottonmouth snake, for example, would never be able to eat an adult python, but did consume one of the juveniles in the study.
Sandfoss also said that this data is part of a long journey to understand the Burmese python's life cycle in Florida to better aid their population mitigation strategies.
"Our role as scientists is to try to tip the scales in the direction of the native species and identify the weaknesses of the invasive species that we can exploit for management purposes," he said.
Contributing: Amy Bennett Williams, Naples Daily News; Kim Luciani, Chad Gillis Fort Myers News-Press
This article originally appeared on USA TODAY: Florida Burmese pythons could have predators in gators, snakes: Study