Burmese pythons can consume prey even larger than scientists realized, according to a new study published in the journal Reptiles & Amphibians. 

This means that more animals are on the menu across southern Florida, where the nonnative, invasive snakes have decimated populations of foxes, bobcats, raccoons and other animals.

Pythons swallow deer, alligators and other prey whole. What they can eat is limited to and dependent on how big the Burmese python’s mouth opening can stretch. Researchers call this the snake’s gape.

Conservancy of Southwest Florida Biologists Ian Bartoszek and Ian Easterling recently conducted a study in collaboration with Dr. Bruce Jayne from the Department of Biological Science at the University of Cincinnati, Ohio, to better understand the ecological impacts of the invasive Burmese python. The team measured the greatest maximum gape recorded in Burmese pythons to date. 

University of Cincinnati Professor Bruce Jayne said measurements of the longest Burmese python (19 feet) and two other very large snakes (15 and 17 feet) captured in South Florida show that the pythons have a gape bigger than even previous mathematical models would suggest.

Previous studies of pythons found the largest gape diameter was 22 centimeters (8.7 inches). But the big snakes in the current study by Jayne and his colleagues Bartoszek and Easterling at the Conservancy had a maximal gape of 26 centimeters (10.2 inches). These measurements equate to a circumference of 32 inches. Knowing the limits on the size of prey that predators can eat can help researchers predict the ecological impact the invasive snakes might have as they move into new areas.

Three large adult female Burmese pythons researched at the Conservancy were examined and used for the data and observations of this study, including the longest documented capture on record. One python measured for data was found by Conservancy biologists while it was ingesting a 77 pound (35-kg) white-tailed deer. The deer was 66.9% of the snake’s mass.  

Conservancy’s Bartoszek states, “Watching an invasive apex predator swallow a full-sized deer in front of you is something that you will never forget. 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.”

In the past 12 years, the Conservancy’s Burmese Python Research and Removal team has removed 770 adult pythons (totaling more than 36,000 pounds). If each of these snakes ate only one deer as big as they could swallow, Jayne estimates that would be a total of more than 13,000 pounds of deer. But of course, these snakes eat many meals during their lifetime. 

What gives pythons the ability to eat such large animals is their incredible mouths. The lower jawbones are not fused at the front, allowing the jaws to stretch wide. Their skin is also elastic that it accounts for more than half the circumference of the maximal gape in large pythons, allowing the snakes to consume prey six times larger than similar sized snakes of some other snake species.

Jayne states, “Besides the large absolute size of the deer that was eaten being impressive, our anatomical measurements indicate this deer was very near the size limit on the prey that could be consumed by this snake. Hence, these snakes resemble over achievers by sometimes testing the limits of what their anatomy allows rather than being slackers that eat only ‘snack size’ prey.”

The Conservancy researchers have documented one other Burmese python in 2018 with a similar story. Although, the Conservancy has seen firsthand two cases of Burmese pythons with a larger native prey species, how often this occurs is still up for questioning. The Conservancy of Southwest Florida is an evidence-based organization, and the python tracking team is staying close to the science. 

“We have been removing pythons and advancing invasive snake science for over a decade. These animals continue to impress us each season and one thing we’ve learned for certain is to not underestimate the Burmese python,” Bartoszek says. 

The Conservancy began its Burmese python research and removal efforts within the bio-region in 2013. As of October 2024, the team has removed over 36,000 pounds (18 tons) of python from an approximately 150-square-mile area in Southwest Florida. Using radio telemetry fieldwork to document behavior and biology, 120 adult Burmese pythons (known as scout snakes) have been radio tagged and tracked to better understand the invasive population. The Conservancy of Southwest Florida’s primary objective is to create a database of behavior and habitat use to better understand python activity. This research helps to inform decision-makers, other biologists, and land managers to develop a control strategy on the apex predator.