Wednesday, February 29, 2012

Stop It - The Burmese Python - Part II

In 2008 the USGS released a potential range map for Burmese Pythons (Python molurus bivittatus) in the United States. The startling suggestion was that the lower third of the continental US could be prime habitat. What it neglected to point out was that this tropical weather-loving snake can’t take the cold.

As evidence, in 2000 the Everglades National Park removed two Burmese Pythons. In 2005 they removed 94 more. In 2009 they removed the highest number ever at 367 followed by a decline in 2010 to 322 and in 2011 only 169 were found. (Click for ENP Removal Data) In 2010 Florida suffered a sustained period of cold weather. For ten days, the temperature remained un-Florida like and the consequence was the death of many of the invasive species (as well as many of our native one like the West Indian Manatee (Trichechus manatus) and American Crocodile (Crocodylus acutus).

The snakes are a huge problem. Necropsies have found the endangered Florida Woodrat (Neotoma floridana), Big Cypress Fox Squirrel (Sciurus niger avicinnia), Wood Storks (Mycteria americana), Everglades Mink (Mustela vison evergladensis) and recently a 76 pound deer in the belly of the snakes. 

Compounding the problem is the protective nature and prodigious offspring output of a female Python. One female can lay up to ninety eggs. Cold will keep them from spreading north. Strict laws are being put in place to ban the importation of the largest and most dangerous of the invaders and most of the locals are intent on dispatching them.

If only I could enlighten the media a little.
1)      Alligators rule the Everglades
2)      A handful of pet Anacondas have been found and they are not known to be breeding in the Everglades.
3)      The Everglades is over four million acres. The study of mammal population declines occurred in the Everglades National Park. The pythons do not have “voracious appetites”, nor are they “picking the Everglades clean”.
4)      The media has a stranglehold on their readers. We have a right to well researched, well written information. Not sensationalism.

To those that would release invasive snakes into the Everglades and to those in the media who perpetuate the python myths – Stop it. 

Tuesday, February 28, 2012

Stop It - The Burmese Python - Part I

We must do everything we can to rid the Everglades of all invasive plant and animal species. That’s a seemingly impossible task at this point for the supposed invasive species capitol of the world. We must also prevent the importation and introduction of any new species to protect the currently out of whack balance of South Florida’s ecosystem. Having said that, I am enraged by the ignorant media coverage regarding the “big snakes” in the Everglades. In December of 2011 an article titled Severe mammal declines coincide with proliferation of invasive Burmese pythons in Everglades National Park was published and the media-led hysteria that followed offered tabloid style headlines that fed into people’s natural fears.

A local NBC anchor suggested without a trace of skepticism that the population of the invasive giants was well over 200,000. This is a stunning climb up the food chain from a few years ago when the estimate was 9000, then 15,000, 30,000 and then inexplicably 150,000. Now 200,000 plus? Stop it.

Burmese Pythons (Python molurus bivittatus) are endangered in their native Southeast Asian range, thanks to poaching and exportation for the pet trade. People buy them as pets because they’re cuddly or they’re constricting. Sometimes it’s hard to tell the difference. They get to be big, growing to lengths over 20 feet. Eventually they’re the ideal pet they once were and owners dump them in the Everglades. Many were thought to have escaped into the swamp in 1992 when Hurricane Andrew devastated Homestead, Florida, home of many reptile breeders and importers.

The scientific paper that has flamed the frenzy claimed that Northern Raccoons (Procyon lotor), Virginia Opossums (Didelphis virginiana) and bobcat sightings (both live and road kill) are down about 99% from a period of time that predated the python infestation. Now one of the co-authors is distancing himself from the suggestion that pythons are to blame. He says it’s possible, but he blames the media for drawing a correlation between the two.

They did note that top predators like the Florida Panther (Puma concolor coryi) and Coyote (Canis latrans) (an Everglades new comer), populations had increased but did not suggest that they could be culprits in the population declines of prey species such as raccoons and opossums. Nor did they mention the severe drought the Everglades National Park has experienced and what effect that might have on the need for certain species to seek out better habitat.

The analysis of the scientific paper was lacking and the media did not do their due diligence to understand the entire issue. The shocking headline was enough to craft an exciting tale of reptile Armageddon. I’ll explain more about the biology of the pythons, the threat they pose and what we need to do to stop it - Tomorrow.

Sunday, February 26, 2012

Obnoxious Weed - Water Lettuce

People are often surprised to find that I don’t like to swim. Considering I was born and raised in South Florida it shouldn’t be a surprise. When the ocean is warm enough to swim in it, the air is disgustingly hot and humid. In the winter when Florida is full of Canadians the water feels Polar Bear cold (anything below 68 for me). To add to it, just about every fresh water lake, pond or river is occupied by an alligator, which leaves swimming pools. I didn’t have one and the local community pool was full of something far more insidious than alligators, public pool peers.

Aquatic wildlife species have it tough when it comes to waterways choked with Water Lettuce (Pistia stratiotes). The floating plant, which is often found in Bald Cypress swamps, grows vegetatively as well as sexually and can blanket the surface of fresh waterways. It looks like a head of lettuce growing on the water and has the green vibrancy of a week-dead treefrog trapped between my sliding and screen door.

There is debate as to the origin of the plant’s native status in the United States with some saying it was introduced from the ballast of ships coming from Africa or South America. Native or otherwise, it is considered a noxious weed in many U.S. locations where it is found clogging up waterways.

Water Lettuce makes life tough for the Pied-billed Grebe (Podilymbus podiceps), a freshwater diver that seeks crayfish, fish and aquatic insects. Not only does the Water Lettuce block the light and limit visibility for diving birds, it also prevents the growth of other plants, leading to the reduction of nutrients and biological diversity.

For the carnivorous American Alligator (Alligator mississippiensis), there’s no chance in partaking of a salad but I have watched gator pups lounge about on several heads of water lettuce like they were tubing down a slow-flowing river. Sounds like fun, but still no chance of me going in that water. 

Saturday, February 25, 2012

McEgret's - The Cattle Egret

There are certain birds that you can say with certainty exactly where you will find them. As their name suggests, where there are cattle there are Cattle Egret (Bubulcus ibis). Spot a roadside mower or a tractor in a field and there will be Cattle Egret and where there is smoke in the grasslands, there will be Cattle Egret. Much to my surprise, after departing a well-known fast food chain drive-thru, I discovered that the habitat of this bird can be extended to here as well.

Cattle Egret found their way to the New World from Africa sometime in the late 19th century and flapped and grazed their way north into the US by the mid 20th century. They have a distinctive head bob that makes them appear to strut like a chicken. In addition to the bovine company they keep and their amusing gait, adult Cattle Egret are easily identified by the colorful plumage on their chest and cap that has the appearance of lightly toasted marshmallow.

The habit of following in the wake of cattle, mowers, tractors or wildfires tremendously assists the birds as they forage for insects. As they are stirred up by each, the egrets take advantage of the chaos in the insect world. While most birds are escaping a wildfire, the Cattle Egret will swoop in soon after and enjoy the BBQ.

When the egrets are full or have tired of walking the tall grass prairies, they hitch a ride and go cattle surfing. The grazing goliaths seemingly ignore one bird on their back but a second bird is the start of a party and a tail slap rectifies the situation.

I don’t make a habit of eating anything that comes from a drive-thru nor do I use Photoshop for any of my Audubon Guides photos, but in this instance, for my amusement and to avoid commercial endorsement I have touched it up a bit.  

Why was the Egret in the drive-thru? I hope it wasn’t looking for its surfing partner. 

Monday, February 6, 2012

Aquatic Ferrari - The Florida Softshell Turtle

There’s a tremendous advantage to having a tall carapace (upper shell) and sturdy plastron (bottom shell) if you’re a turtle in the southeastern United States. Here there be alligators and despite the fact that an alligator can exert thousands of pounds of pressure of chomping power on their prey, if they can’t slam their jaw shut on their oversized meal, they have to look for lunch elsewhere.

Sliders and Cooters are the SUVs of the turtle world. They’re hefty, relatively slow moving but strong bodied. I’ve often seen tooth marks where an alligator has cracked a hole in the carapace but got no further. Florida Softshell Turtles (Apalone ferox) on the other hand have soft, flexible upper and lower parts that are covered in skin as opposed to the keratinous, fingernail-like covering on other turtle shells. Softshells are the Ferraris of the turtle world. While the shell doesn’t afford them much protection against the crushing bite of an alligator, I have seen them use their speed to their advantage. The bottom right photo shows the head of a large female softshell in the toothy grasp of the alligator. The turtle didn’t panic and seemed content to be escorted around. Instead of struggling and wasting energy, it was biding its time. When the alligator opened up to get a better bite, the softshell took off with a burst of speed. Sorry gator.
The Florida Softshell Turtle can be distinguished from other softshells by the bumpy ridge above the head on the carapace. Males grow to be around 12 inches while females are sizably larger at 20 inches. Florida softies are omnivorous and aquatic, although they do bask out of the water and cross roads as necessary. In the spring the females will find a soft-soiled area to lay their eggs or if they’re feeling lucky, the female will sneak her eggs into the side of an alligator’s nest where ironically they are protected from nest predators by the mama alligator. Ultimately it doesn’t matter if you’re an SUV or a Ferrari. What matters is how long you’re in the race.