Tuesday, February 21, 2012

Everglades' Top Predator


Full moon in the Everglades
On the night of February’s full moon, Richard and I went for a ranger-led walk at the Everglades National Park in Florida.  Our group strolled along the Anhinga Trail boardwalk, and though we are in the heart of winter, we heard a dozen different insects chirping and buzzing.  Anhingas and herons croaked gutturally, complaining about our disturbance – or was it a night-prowling predator?

Anhinga at night
Predators abound in the Everglades, most of them nocturnal.  The region’s few panthers and bears are rarely seen.  Raccoons and smaller scavengers are also rarer than they used to be, thanks to one of the park’s newest predators – the Burmese Python.  These monsters arrived in the park as unwanted or escaped pets, and are now a permanent part of Florida’s ecosystem.  They grow up to 30’ long, and will eat anything they can swallow. 


Everglades Burmese Python (photo from USA Today)
Pythons’ numbers are estimated at 10,000 – 100,000, which means that nobody really knows how many of these voracious snakes are in southern Florida.  (Ironically, the pythons are endangered in Burma)  Also, nobody knows how far north they will eventually range – South Carolina?  Virginia?  What the specialists do know is that deer, herons, small mammals, and even alligators are on the pythons’ menu.

Alligator eyeshine
The coolest thing Richard and I learned is that alligators’ eyes reflect light, glowing red when we aim our flashlight at them.  These reptiles lounge at the top of the Everglades food chain, and will eat anything they can swallow (including pythons).  They are a keystone species for the region, because much of the Everglades’ wildlife can’t survive without alligators.  They dig holes which retain water through the driest months, providing that precious commodity for fish, birds, turtles, and all types of animals.  If a few of those animals feed the owner of the gator hole, then that’s how the food chain works.
This photo shows the most feared critter in the Everglades.  No, I’m not talking about the big lizard – check the enlargement.   Caught in my camera’s flash is the park’s most dreaded predator  – the mosquito.  They aren’t so bad in the winter – there are only a half dozen of them in my photo – but when the wet season arrives, I will not be standing here.  

Mosquito lunchtime
There are 43 species of mosquito in southern Florida.  They hatch in salt or fresh water, and in 13 of those species, females bite people for a blood meal to perpetuate their species.  Florida’s sprawling coastal cities depend on two things to make them habitable – air-conditioning and insecticide.

I submit to you that mosquitoes are also keystone species for the Everglades.  How much of the park would still exist without them?  A few choice hardwood hammocks, perhaps the most inaccessible marshes, but humans have already dug, diked, and drained ¾ of the Everglades.  Perhaps the only thing that stops the rest of that beautiful, austere ecosystem from being turned into farmland or housing tract is the humble mosquito in its uncountable trillions.

Thank you, Madame Mosquito, for saving the Everglades from development.  Thank you, dry season, for knocking down the bloodsuckers’ numbers to tolerable levels so we humans can visit this incredible place.  Now, let me out of here before the rains begin, and the Everglades’ true rulers take to the air – the mosquitos.

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