Invasive Pythons Decimating Native Species in the Everglades

By Kim Smiley

Have you ever dreamed of hunting pythons?  If so, Florida is hosting the month-long 2016 Python Challenge and all you need to do to join in is to pay a $25 application fee and pass an online test to prove that you can distinguish between invasive pythons and native snake species.

The idea behind the python hunt is to reduce the population of Burmese pythons in the Florida Everglades.  As the number of pythons has increased, there has been a pronounced decline in native species’ populations, including several endangered species.  Researchers have found that 99% of raccoons and opossums have vanished along with 88% of bobcats, along with declines in nearly every other species.  Pythons are indiscriminate eaters and consume everything from small birds to full-grown deer.  The sheer number of these invasive snakes in the Florida Everglades is having a huge environmental impact.

The exact details of how pythons were released into the Everglades aren’t known, but genetic testing has confirmed that the population originated from pet snakes that were either released or escaped into the wild. Once the pythons were introduced into the Everglades, their number quickly grew as the python population thrived.  The first Burmese python was found in the Florida Everglades in 1979 and now there are estimated to be as many as 100,000 of the snakes in the area.

There are many factors that have led to the rapid growth in the python population.  They are able to live in the temperate Florida climate, have plentiful food available, and are successfully reproducing.  Pythons produce a relatively large number of eggs (an average of 40 eggs about every 2 years) and the large female python protects them.  Hatchling pythons are also larger than most hatchling snakes, which increases their chance of surviving into adulthood.  There are very few animals that prey on adult pythons.  Researchers have found that alligators occasionally eat pythons, but that the relationship between these two top predators can go both ways and pythons have occasionally eaten alligators up to 6 feet in length.  The only other real predators capable of taking down a python are humans and even that is a challenge.

Before a python can be hunted, it has to be found and that is often much easier said than done. Pythons have excellent camouflage and are ambush predators that naturally spend a large percentage of the day hiding.  They also are semi-aquatic and excellent climbers so they can be found in both the water and in trees.  Despite their massive size (they can grow as long as 20 feet and weigh up to 200 pounds), they blend in so well with the environment that researchers even have difficulty finding snakes with radio transmitters showing their locations.

The last python challenge was held about 3 years ago and 68 snakes were caught.  While that number may not sound large, it is more snakes than have been caught in any other month.  The contest also helped increase public awareness of the issue and hopefully discouraged any additional release of pets of any variety into the wild.  For the 2016 contest, officials are hoping to improve the outcome by offering prospective hunters on-site training with a guide who will educate them on swamps and show them areas where snakes are most likely to be found.

To view a Cause Map, a visual root cause analysis format, of this issue click on “Download PDF” above.  A Cause Map intuitively lays out the cause-and-effect relationships that contributed to the problem.

You can check out some of our previous blogs to view more Cause Maps for invasive species if you want to learn more:

Small goldfish can grow into a large problem in the wild

Plan to Control Invasive Snakes with Drop of Dead Mice