Invasive Burmese snakes in the Everglades consume at least 25 different species of birds thereby posing a challenge to the area's already heavily taxed native wildlife, a study has found.
The research conducted by Smithsonian scientists has indicated that the snakes not only eat the area's birds, but also the birds' eggs straight from the nest.
"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," said Carla Dove, ornithologist at the Smithsonian's Feather Identification Lab in the National Museum of Natural History and lead author of the 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 researchers collected a 14-pound male python that was 8 1/2 feet long near a property with free-ranging guinea fowl. The snake regurgitated 10 whole guinea fowl eggs soon after it was captured.
Similarly, the team found the remains of two bird eggs in another python collected for the study.
Scientists used DNA tests on the membrane of the crushed eggs and comparisons of the shell fragments with egg specimens in the Smithsonian's collection to determine what the female snake had eaten. Their research revealed the species to be the limpkin (Aramus guarauna), a large wading bird found in marshes and listed as a "species of special concern" by the Florida Fish and Wildlife Conservation Commission.
There are several species of snake known to eat bird eggs. Those species are equipped with pointed or blade-like extensions on the vertebrae in their esophagus that punctures the eggshell, making it easy for the snake to crush the egg and digest its contents. Burmese pythons do not have these adaptations. However, the pythons studied were so large in relation to the eggs they ingested that the scientists believe these specialised vertebrae may not have been needed.
"Our observations confirm that invasive Burmese pythons consume not only adult birds but also eggs, revealing a previously unrecognised risk from this introduced predator to nesting birds," said Dove. "How frequently they are predating on bird eggs is hard to know."