January 31, 2012 | 7:00am
It's no secret that Burmese pythons have been wreaking havoc in the Everglades, but the extent of their destruction has been hard to grasp. A new study
provides some of the first hard statistics on how these invasive reptiles are altering the food chain, and the numbers are downright scary.
Between 2003 and 2011, a team of scientists reported a 99.3 percent drop in the frequency of raccoon observations, a 94 percent drop in white-tailed deer observations, a 98.9 percent drop in opossum observations, and an 87.5 percent drop in bobcat observations. Even more grim is that sightings of species like marsh rabbits and foxes were nearly nonexistent in areas known to be hotbeds of python activity.
This really shouldn't come as a surprise, given the appetite these killer constrictors can maintain.
A few years back, the South Florida Water Management District estimated that a newly hatched Burmese python would need to eat the following
to grow 13 feet within five to seven years: one raccoon, one opossum, four five-foot alligators, five American coots, six little blue herons, eight ibises, ten squirrels, 15 rabbits, 15 wrens, 30 cotton rats, and 72 mice.
Yup. Four five-foot alligators.
The new study, published in the Proceedings of the National Academy of Sciences, compared sightings between 1993 and 1999 of various species -- both dead and alive -- with sightings of the same species between 2003 and 2011. The team can't definitively pin the decline in sightings on Burmese pythons, though pictures of exploded snakes tying to swallow alligators and stories of 80-pound deer being devoured seem to support their hypothesis.
One of the problems, as noted by USA Today
, is that critters in the Everglades "have no natural fear of large snakes because they haven't existed in the area for about 16 million years, when a boa-like snake that used to live there became extinct."
There's a good chance that the changes these snakes have made to the Everglades food chain is permanent.
raises the following concern
: "This is probably just the tip of the iceberg. Raccoons and opossums are easy to spot; there may be dozens of other species, including local birds, which are also being affected in less detectable ways. But beyond Dorcas' hard statistics, it's difficult to predict what impact the pythons would have. They could eat some species to extinction. They could outcompete other predators for food. They could allow mid-tier animals to boom in numbers, by getting rid of predators."
One step in the right direction is that U.S. Interior Secretary Ken Salazar announced earlier this month a nationwide ban on importing yellow anacondas, Burmese pythons, and northern and southern African pythons.
Now overwhelmed pet owners need to stop using the Everglades as their personal dumping ground.