An unexpected predator is raiding Burmese python nests in the Everglades

A scavenger bird could become an ally in South Florida’s fight against the spread of invasive Burmese pythons. By feeding on their eggs, it may help slow the reproduction of one of the Everglades’ greatest ecological threats.

The finding was documented in the Francis S. Taylor Wildlife Management Area in Broward County during python tracking conducted as part of an ongoing University of Florida (UF) radio telemetry program using scout snakes.

Researchers arrived at a python nest to remove the eggs before they hatched and prevent the dispersal of hatchlings. When they arrived, they observed at least four vultures circling the site and actively feeding on the eggs.

The vegetation covering the clutch had been removed, likely by the vultures. Researchers documented at least 17 eggs; three had been displaced from the nest, with only shell fragments remaining.

The remaining 14 eggs stayed inside the nest cavity, all punctured and with their contents exposed or missing, suggesting total or partial consumption by the vultures, according to the case study published in Reptiles and Amphibians, an international journal specializing in herpetology research.

The female python was found submerged in shallow water about 12 meters from the nest.

After a closer inspection, researchers found no signs of other possible predators or scavengers besides the vultures. They also noted that the punctures in the eggs were consistent with marks made by the birds’ beaks.

The discovery was made in 2023 by a University of Florida Department of Wildlife Ecology and Conservation team that included Brandon Welty, W. James Whelpley, Elizabeth Sutton, Cynthia A. Fussell Persuad, Eric Suarez, Frank J. Mazzotti and Melissa A. Miller.

Since then, researchers have continued monitoring nests to gather key data, including clutch size, location and hatchling survival.

Melissa Miller, assistant professor of invasive wildlife ecology at UF, told el Nuevo Herald: “We continue to monitor python nests to increase our understanding of Burmese python reproduction, as well as to remove the eggs before hatchling pythons emerge.”

“Monitoring python nests allows for observations such as our report of vultures feeding on python eggs. Our observation constitutes the first documented case of a bird preying on a python nest and adds to the growing body of evidence supporting the idea that native wildlife consumes invasive pythons at all stages of their life cycle,” she said.

Read more: Three hunters capture this huge invasive species in Everglades swamps

Other predators of pythons

A study by the United States Geological Survey (USGS), cited by Everglades National Park, found that cottonmouth snakes — also known as water moccasins — abundant in the Everglades swamps feed on young pythons.

USGS researchers discovered several cottonmouths with juvenile Burmese pythons in their stomachs.

Researchers have also documented a bobcat removing eggs from the nest of a massive python and devouring them despite a confrontation with the snake.

The incident was captured by a wildlife monitoring camera in Big Cypress National Preserve in June 2021.

The American alligator and the eastern indigo snake are also among the predators of the giant reptiles. The Florida black bear may also feed on the invasive species, according to a report by Reptiles Magazine.

The high fertility of pythons

Adult pythons have high reproductive potential, with females capable of laying between 50 and 100 eggs per year, according to the Florida Fish and Wildlife Conservation Commission (FWC).

Their mating season in Florida occurs mainly between December and April, while nesting takes place in late spring and hatching occurs between July and August.

After laying eggs, pythons coil around them to prevent them from drying out. In addition, they use shivering thermogenesis to regulate embryonic temperature and actively defend the eggs from potential predators, UF researchers noted.

In the observed case involving the python and the vultures, researchers still do not know whether the snake abandoned the nest because of the disturbance caused by the birds or moved away for other reasons, allowing the vultures access to the eggs.

The removal of female pythons plays a key role in disrupting the species’ reproductive cycle and reducing its impact on the Everglades ecosystem.

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