Wednesday, April 24, 2019

Burmese Python Update

Stepping Stones

One of the most interesting and diverse ecosystems on earth is the area in South Florida known as the Everglades. What a thrill it must have been to see it 100 years ago! The grass prairies, hardwood hammocks, lakes, rivers and bays teeming with birdlife and a variety of mammals. As Marjory Stoneman Douglas wrote, and James Audubon witnessed, the bird populations were so vast that they would block out the sun when they took flight!

That was 100 years ago. The development of farms and ranches and the influx of settlers has changed things drastically for the native wildlife. As human expansion flourished, the loss of habitat began to dwindle the native animals’ ability to thrive. More and more species found themselves on the endangered or threatened lists. But man, and his need for space, was and still is not the only obstacle for mammals and birds.





In the last 30 years or so an invasive species, an apex predator, has wreaked havoc on smaller animals and birds. There are several theories on how their population became so vast so quickly, eating just about everything in its path from the east coast to the west, a main danger is the Burmese Python.

It is breeding season for them now and concerns are high as to how many more of these snakes will be added to a population estimated to be in the tens of thousands. In the Miami-Dade area of Florida’s east coast, 99% of small mammals are gone. Rabbits, raccoons, foxes and even deer have been eliminated from that environment. The pythons, in search of food, have expanded their territory to mid-state and even Florida’s west coast.

Efforts to stop, or even contain, these voracious feeders are ongoing, and with some success. Several males have been captured and then released back into the wild. Why would scientists do that? Before turning them loose they were implanted with a tracking device. This allows the trackers to follow the movement of the males, eventually leading to a den where several females can be found, thus eliminating the breeding ladies and their eggs from the environment. It’s certainly better to remove several hundred eggs and reproducing females rather than that one original male. One male named Argo lead a research team to a female weighing 99 pounds. Later, that same male lead the team to a 115-pound lady.

Submitted Photo | Bob McConville gets up close and personal with a python.

There is also a group of professional hunters, mostly military veterans, called the Swamp Apes, who track down these pythons, mostly at night. These snakes like to come out and warm themselves and these guys have caught more than 1,100 of these invaders. Among scientists, conservationists and Swamp Apes, the pythons are being eliminated, but not fast enough. Ask any of the above groups and they will tell you that these invaders are here to stay. Quite simply, it’s a numbers game. They are reproducing faster than they can be caught.

Let’s create a not-so-make-believe scenario. Imagine it is the year 2000 and the first two Burmese Pythons are the only ones in the wild. They will mate. Although some females will produce 60 to 80 eggs, let’s say this first female lays 40 eggs. When the eggs hatch, let’s guess that 20 of those 40 eggs are females. As the young ladies mature in the year 2004, we will surmise that these 20 females will lay 40 eggs, half of which are female. Twenty females producing 20 young females each equals 400 females in the wild in 2004.

Moving forward to 2008, 400 females are producing another 20 female hatchlings each which gives us 8,000 ladies roaming South Florida. Fast forward to 2012 and 8,000 females producing 20 female eggs each gives us a count of 160,000. Should we continue with this mathematical game?

Of course, the unknown factor is the attrition rate of the young…how many actually make it to physical maturity. The hatchlings do have predators such as egrets and herons. But wait! Ninety-nine percent of the mammals and birds have already been devoured by the pythons.

It’s the standard rule of the food chain. When nature is balanced, one level of this chain will eat another, which will eat the next in line and so on. When a species like the python removes that level in the food chain that eats them, the system becomes unbalanced and, in order to survive, these snakes will move to find their next source of food. Since their natural habitat is tropical and sub-tropical, they have moved east to west, with more and more being seen in the central Everglades and into Collier County. Some have taken a southerly turn and are showing up in the Florida Keys.

A huge tip of the hat to the scientists and hunters who work to remove this invasive predator from our midst. There are only so many of you and only so many hours in a day. However, it seems that time is on the side of the Burmese Pythons. There are too many to be caught in the time it takes to reproduce. Hopefully science will find an answer to eliminate these undesirables more quickly, giving the rest of the food chain a chance to rebalance and restore a sense of normality to our fragile ecosystems.

Bob is a Naturalist for a dolphin study team on board the Dolphin Explorer. He is the author of two popular books, “Beyond The Mangrove Trees” and “Beneath The Emerald Waves,” both available locally. Bob loves his wife very much!

 

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