Burmese pythons are threatening the populations of small animals in the Everglades National Park, with the invasive species causing a change in the balance of the food chain in the park.
In 2013, researchers noted that as the population of pythons in the Everglades increase, the population of small mammals decrease. The researchers, however, could not definitely prove that the two trends were related.
However, a new study that was released this week solidifies the connection between the two incidents, with the report following the fates of 26 rabbits with tracking devices that were released into the Everglades in September of 2012.
The researchers trapped the 26 marsh rabbits in areas outside the Everglades and placed trackers on them, which allowed the researchers to check up on the animals every two days. If the rabbits did not move for six hours, the scientists were alerted by sensors.
The rabbits, native to the Everglades but almost vanished over the past decade, were able to initially sustain their population. They settled into the environment well and began breeding to thrive, according to Robert McCleery, a biologist from the University of Florida and a co-author to the study.
However, as the temperature increase, the rabbits started disappearing as they were hunted by the pythons. The pythons ate the rabbits faster than they can reproduce and faster than the researchers expected.
"None of us would have predicted that 77 percent of the rabbits would be eaten by pythons," revealed McCleery.
In the 17 rabbit deaths detailed in the study, 16 cases led directly to pythons. For the 17th case, the rabbit was found to have been regurgitated, covered with python DNA.
While McCleery did not claim that the pythons were the cause of all the declining populations of small animals in the Everglades, he stated that the report is setting the stage to bring light to the issue as a definite problem.
The researchers chose rabbits to represent small animal populations in their study because of their resilience to predators. Pythons also have no restrictions on their diets, so the consumption of the pythons of rabbits may be a reflection of their consumption of all other small animals.
Debate on the impact of the pythons on the Everglades heated up in 2012, with some scientists suggesting that the research was too indirect and that there are many other threats to the Everglades ecosystem and its small animal populations such as changing water levels.
Photo: William Warby | Flickr