• Carrie Gardner

It's an Alien Invasive Hostile Take Over! (part one)

Updated: Mar 14


The next four months I’m writing more of the actions of people than an actual animal - but there is an animal. The Burmese python. Permanent residents of the Everglades now, a decade ago, local and federal agencies exploited these wild snakes to pass laws that severely affected the reptile industry. It was meant as a punishment for what the industry did not cause. Mother Nature did. I was very active with reptiles when this happened, however, I didn’t expect it to be so long when I envisioned this blog. And I left out so much I wanted to mention! I hope you enjoy it.

Background Information

There is an organization called the Convention of International Trade of Endangered Species of Wild Fauna and Flora (CITIES). Their job is to make sure that the international trade of animals and plants don’t threaten their status in the wild. They maintained three lists: Appendix III List - species that are listed after one member country has asked other CITES Parties for assistance in controlling trade in a species. Appendix II List - Species who are not endangered but could be threatened without strict regulation on trade. Appendix I List - these are the most endangered animals and it is illegal to export or import these animals for commercial trade. In 1975, the Indian python was placed on Appendix I. Prior to that, they were popular snakes in the United States. After the ban on Indian pythons, the U.S. began to import the Burmese python. The Burmese python was a subspecies of the Indian python that was darker, larger, and more tropical. They became a hit after the first albino was sold (that helped to begin what became a multi-billion business. In 2000, the Burmese python became established as a breeding population in the Everglades. (Burmese python is in the left and Indian python on the right)

The Burmese python is on the top and the Indian python is on the bottom.

In 1992, Hurricane Andrew roared through southern Florida, destroying about everything, including wildlife refuges, zoos, breeders, etc. They were collecting animals for days and weeks in the aftermath. One business destroyed was an importer. (They supply zoos, wholesalers, pet stores, etc.) that allegedly had 900 hatchling and juvenile Burmese pythons fly into the Everglades (where the Quonset hut was at the edge of). The establishment of the pythons wasn’t released with big fanfare. I also have a hunch that there wasn’t much done to control them, either) I don’t remember hearing anything about it when I moved down here in 2002 and got my first snake in 2004 and became active in educating people about reptiles).

The snake's tail is curved to the left with the front of the snake's body sticking straight out. (forms a rough-looking "U". The alligator's tail and hind feet are protruding from the snake's body at the bottom of the picture.

Let’s fast forward to 2005. A couple of Everglades National Park employees were in a helicopter and flew over an amazing site. It was a headless 13-foot python split open with an alligator protruding from its stomach. Did the alligator split the snake? No one’s sure. Adding to the mystery is that the alligator had its skull crushed. That is not a python injury. The photographs went viral and Floridians woke up to find out that there were big snakes in the Everglades.

In Comes USGS and Invasive (“Alien”?) Biologists - Literally and Figuratively.

I don’t know if you’ve figured it out, but I love reading sciencey things. I have no aptitude for math, but any scientific papers that interest me and I’m there! In the course of my research, I have read so many reports that I’m going to turn into R2D2 after being zapped by an Imperial computer he tried to communicate with on Endor. I’ll issue a little scream and fly backward with smoke coming out of my fried noggin. All the links will be listed after the last blog. Though, I am still linking to the studies or papers mentioned on each blog. If you want a list of all of the links, then please email me at

I will never vacation on Endor or read that many scientific studies at once again.

There are two names you’re going to hear a lot (or read) and they are Gordon Rodda and Robert Reed, two biologists that specialize in invasive animals and that wrote several papers for the United States Geological Survey (USGS) on invasive pythons. Their contributions turned the reptile industry upside down and scared everyone else. Apparently, that is what they wanted. They did not follow the proper protocols by submitting the paper for an internal review with USGS and another review with the Federal Information Quality Act.

What they did do was unprecedented. Instead of sending the report out for their peers to study, they issued official USGS press releases before the report’s release. By the time the first report came out, the press was chomping at the bit and for three or four days they were viral on the internet, with headlines like “The Snake That’s Eating Florida” from The New York Times. The publicity that they got demonstrated perfectly how to use propaganda as a tool for fear-mongering. Most people react negatively when someone says “snake.” Now add “giant”, “alien”, “invasive” into the mix, and..I’m sure you see where I’m going.

What Parts of the U.S. Mainland Are Climatically Suitable for Invasive Alien Pythons Spreading From Everglades Natural Park. Gordon Rodda, Robert Reed, Catherine Jarnevich (USGS) 2008 (Rodda et al.)

The authors used two variables from 149 weather stations in the local geographic range of “Burmese” pythons and then projected it on the United States. By using average temperatures and average rainfall, Rodda et al. claimed that Burmese pythons would be able to spread to 32 states from southern Florida. Now let’s discuss what’s wrong about this study.

  • As mentioned up in the background, Burmese pythons were the subspecies of the Indian python. The study stated that Burmese pythons were a “questionable subspecies” and chose to “combine” the two species: Indian python and Burmese python. However, calculations were made using the Indian python, who are found in more northern climes with cooler temperatures that can attain higher elevations. Using their range allowed the authors to widen the range over the United States. By using Indian pythons, they were using data for a snake that hadn’t been imported since 1975. And it should be mentioned that their “questionable subspecies” was proven wrong the very next year when both snakes were declared their own species.

  • Two studies, one from 1912 and one from 1921, were used by the authors to describe eating habits of, well, it would be the Indian python. You would think more contemporary studies would be available.

  • The expansion of the pythons was dependent on global warming. They said that the snakes would not only increase their migration but increase the number of pythons in Florida. Actually, the projected effect of global warming pretty much floods the whole state with the only thing above water is SeaWorld (How ironic).

  • There were not enough variables. They used only two climatic data sets: average temperature and average rainfall from 149 weather stations. Of course, there will be a wide range. Any average temperature or rainfall that meets with South Florida’s averages will qualify as a place that the pythons can expand to. The more variables used, the tighter that the range can become. Using all the data points would limit any expansion and be more accurate.

My Thoughts - Maybe the rest could’ve barely squeaked by, but by combining two species’ ranges and referring to the two snakes as the Indian python when clearly they are two different species with different habitats was very obvious. If it is obvious to me, then I can tell you for sure that the authors knew exactly what they were doing. Another thing that bothers me was using only temperature and rainfall as their data points. All scientific papers either have control groups or use data sets from, let’s say, weather stations. The less that is used, the broader the range. It isn’t coincidental that Burmese pythons can crawl over and establish new lives in 32 states if only using average temperature and average rainfall. There’s more to where any animal can migrate to than that. Will they do well in snowfall, really low temperatures, what humidity do they need? Applying more datasets shrinks the range. My opinion is that they wanted the range to be large in hopes that legislation will be taken against keeping them. And that is far from being an unbiased scientific paper.

Burmese python hanging in the 'Glades

Claims of Potential Expansion Throughout the U.S. by Invasive Pythons are Contradicted by Ecological Niche Models - City University of New York - Staten Island (CUNY) R Alexander Pyron; Timothy J Guiher; Frank T Burbrink 2008

CUNY released the first opposition to the USGS study. To keep it more accurate, the authors used the range of the Indian python. Gordon Rodda responded, which I’m not going to cover, but I’ll put in the link list.

  • On global warming, they said that the ecological limitations are unknown and any effects on Burmese pythons are not clear. However, their models that they used indicated that global warming will not turn out very well for Burmese python - both in Florida and their natural homes.

  • Models that USGS used showed over-predictability of present-day distribution in the snakes’ home range. Thus, it raises the possibility that the U.S. range will be excessively broad in the python’s expansion.

  • Rodda et al. produced models that did not consider the actual range that would have information on the pythons but relied on weather stations in the range instead.

  • CUNY applied 19 data sets and accepted practices. There’s a lot of complicated explanations of their models, but the end result is the only place in this country where Burmese pythons can exist are southern Florida and the extreme southern part of Texas. Hmm, maybe that’s why the only breeding populations are found in the Everglades? Which is a unique ecosystem not found anywhere else in the U.S. (and I believe the world) that has a sub-tropical marshland that closely resembles where Burmese pythons live in their natural abode. CUNY states that in order to have an expansion of pythons, there must also be an expansion of the Everglades.

  • CUNY also stated that because of the study that Rodda et al. released could not be proven and that by releasing an alarmist paper where giant alien snakes move northward (There are some Burmese that would like to see the apple drop on New Year’s Eve in New York City.) hamper any more studies and conversations on how to deal with the snakes that are in the Everglades, especially in regard to policies and legislation.

So was CUNY right? Did Rodda et al. s paper make things more difficult? I can’t say until the month of May!

"I'll See You Next Month!"

It's an Alien Invasive Hostile Take Over! (part one) (April 2019) It's an Alien Invasive Hostile Take Over! (part two) (May 2019) It's an Alien Invasive Hostile Take Over! (part three) (June 2019) It's an Alien Invasive Hostile Take Over! (part four) (July 2019)

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