In something straight out of a horror movie, scientists have found that Burmese pythons can open their mouths even wider than we previously thought.
These snakes' enormous jaws may be able to open as wide as 10.2 inches in diameter, large enough to fit a human head inside, according to a new paper in the journal Reptiles & Amphibians.
This gives these giant serpents a mouth circumference equivalent to a 32-inch waist on a pair of pants. The circumference of the average human head is 22 inches, for comparison.
Previous research before now had only found that these pythons' mouths opened to 8.7 inches in diameter, making this a 1.5-inch increase in their maximum gape.
"That doesn't sound like a lot—just 18% bigger," study co-author Bruce Jayne, a professor at the University of Cincinnati, said in a statement.
However, this increase in diameter results in the area of their gape increasing by 40 percent.
This means that these snakes, which have rapidly invaded Florida, might be able to eat larger and larger prey, and therefore have more of an impact on the ecosystem.
"Knowing the size of prey that predators can consume facilitates understanding and predicting their ecological impact. Burmese pythons (Python bivittatus) are apex predators that are larger than all but a few snake species, and their prey, which are swallowed whole, cannot exceed the size of their maximal gape," the researchers wrote in the paper.
Burmese pythons are one of the largest snakes in the world, growing up to 23 feet long and weighing over 200 pounds, though most in the wild average around 12 to 16 feet. They are non-venomous, but belong to the constrictor family, killing their prey by wrapping their muscular bodies around it and squeezing tightly until the prey can no longer breathe.
"Big pythons longer than 16 feet are very rare. Of the more than 9,000 pythons that contractors have captured in Florida, less than 1% were of that extreme size," Jayne said. "One of the challenges of studying Burmese pythons is the tremendous range in size within the species."
Pythons swallow their prey whole thanks to their jaw structure being highly flexible, allowing them to open their mouths much wider than their heads. As a result, Burmese pythons can consume prey as large as deer, alligators, and even small livestock. These pythons are limited in the size of their prey not by their body size, but by how wide they can stretch out their jaws.
"It's almost a certainty that we have yet to capture the biggest Burmese python in Florida," Jayne said. "So, it seems very plausible that a record-breaking python with a gape of 30 centimeters could eat a 120-pound deer."
Originally native to Southeast Asia, these pythons were introduced into the wild in Florida and are now an invasive species in the Everglades and beyond. Studies show that they have caused severe declines in native populations, such as foxes, bobcats, and raccoons, as they compete with native predators for food sources and excessively prey on others.
The fact that these snakes can open their mouths wider than we thought means that they can eat even larger prey than we imagined. The researchers mention how they saw one snake swallowing a 77-pound deer, which was about two-thirds of the snake's total weight.
"Watching an invasive apex predator swallow a full-sized deer in front of you is something that you will never forget," co-author Ian Bartoszek, a researcher at the Conservancy of Southwest Florida, said in the statement. "The impact the Burmese python is having on native wildlife cannot be denied. This is a wildlife issue of our time for the Greater Everglades ecosystem."
Knowing the true limits of these python's mouth gapes could help researchers predict the impact they will have as they expand further into new areas.
"That's the tip of the iceberg of this phenomenal impact on prey populations in Florida," Jayne said. "Researchers are trying to get a handle on where the spread might stop."
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References
Jayne, B. C., Easterling, I. C., & Bartoszek, I. A. (2024). Big pythons, big gape, and big prey. Reptiles & Amphibians, 31(1), e21867. https://doi.org/10.17161/randa.v31i1.21867