On Pythons in the Everglades

An adult female Burmese python captured in the Everglades

Photo: Wayne Lynch / Getty Images / All Canada Photos

As a life-long ophidiophile, any newspaper headline that contains the words hybrid python or super-snake is sure to attract my attention. 

And thus it was that I found myself excitedly reading a story in today's Guardian about a recent US study into non-native species that has discovered that some specimens of python slithering around the Florida Everglades are a genetic mixture of two species, potentially making it an even more formidable creature; one that is perfectly adapted to its sub-tropical environment;        

I appreciate that the good people of the Sunshine State may feel that they already have enough exotic fauna to contend with - a million alligators, giant carnivorous lizards and poisonous tree frogs, etc. - but I couldn't help smiling at the thought of this new and improved (all-American) snake feasting on the local wildlife and asserting itself as the region's apex predator, full of hybrid vigour.         

Apparently, researchers had expected to discover the snakes were pure Burmese python. Instead, they were surprised to discover the genetic signature of the Indian rock python also present; a smaller, faster, more aggressive creature that prefers to live on higher, dryer ground than its Burmese cousin. 

For those who hate the thought of invasive species and hybridisation - and who would, if they could, exterminate every last python in Florida - this is obviously an unwelcome development. But there's not much that can be done; the estimated 300,000 pythons that occupy the waterways of a 1.5 million acre wilderness cannot all be captured or killed. The population is thus only likely to grow, expanding its range northwards.

Still, every Eden needs its serpent, as they say ... And besides, Florida's 500,000 feral pigs are probably a bigger threat to the Everglades than pythons - at least until the latter eat them.

See: Richard Luscombe, 'Super-snake: hybrid pythons could pose new threat to Florida Everglades', The Guardian (25 Aug 2018): click here to read online.  

Two Inconvenient Truths

Poster by Stanislav Petrov 

deviantart.com 

I: Habitat Heterogeneity Leads to Greater Biodiversity 

According to the ecologist and evolutionary biologist Chris D. Thomas, paradise hasn't been lost because we never had it to begin with: "The harmonious coexistence of humans and the rest of nature in the distant past is a romanticized and largely fictional notion" [59].

Thus it is that the relationship between man and nature remains an often violent one, involving environmental destruction and species extinction. Having said that, human beings have also (inadvertently perhaps) created a "world of new opportunities for those animals and plants capable of seizing them" [59].

Already I can hear the obvious objection from the green lobby: There were once huge areas of land covered by dense forest. Animals and plants wouldn't need new opportunities if only we conserved what remained of these primordial environments.

And, yes, it's true, ancient woodland does contain a great number of trees and many rare species.

However, it's only by converting it into a mixed landscape consisting of a patchwork of forest and various human-created habitats, that the number of species significantly increases: "This is because new species move into human-created habitats faster than the previous residents of the region die out." [67]

This, obviously, is an inconvenient truth for those who oppose all deforestation, for example, and dream of protecting pristine nature as they imagine it. But it's a truth, nevertheless, that if you want to maximise the number of animals and plants, then accelerating habitat heterogeneity is the way to go.


II: Life Prefers Warm and Wet

To say that the world's climate is getting hotter is to state a scientific fact. But to claim that global warming will prove catastrophic for life on Earth is a moral and ideological interpretation of that fact - and a misinterpretation too. For most animals and plants like it warm and wet and will exhibit enhanced physiological performance if the global thermostat is nudged up a degree or two.

Of course, there will be climate change casualties; "at least 10 per cent of all species that live on the land are expected to perish, and possibly double this number" [78]. But the rest - being naturally more dynamic and adaptable - are likely to survive and prosper by migrating, if necessary, to where the conditions best suit them.

Conservationists may not like it, but life is chaotic and in a state of constant flux. Nothing has ever stayed the same and as soon as you begin to think on grand timescales you realise that species are essentially nomadic: "Biological communities are transient. ... That is how species survive climate change. They move around. ... Any attempt by humans to keep things just as they are is utterly pointless." [84]

Thanks to human activity, it's going to get warmer. And wetter. Warmer and wetter than it has been for three million years. But, amazingly, around two-thirds of the species that researchers have studied in recent decades have already wised up to the fact and "shifted their distributions in response" [91].

At the present rate of movement, within just a few centuries we will have a "new biological world order" [92] as subtropical species, for example, move into the temperate zones and former inhabitants of the temperate region "try their luck in the polar world" [92-3]. And this will very likely increase biodiversity, even if the total number of species on Earth is likely to be lower.

I'm not trying to pick a fight with Al Gore or cause Vivienne Westwood to get her knickers in a twist by pointing out this inconvenient truth concerning global warming; I'm not even advocating that we should stop thinking seriously about climate change and its likely consequences.

I'm simply saying - in agreement with Chris Thomas - that we need to accept the reality of the world we live in and encourage the movement of so-called invasive species "because botanical and zoological world travellers will form the basis of the world's new ecosystems, just as they have when the climate has changed in the past" [94].

See: Chris D. Thomas, Inheritors of the Earth: How Nature is Thriving in an Age of Extinction (Allen Lane, 2017). All page numbers given in the text refer to this work. 

To read a related post to this one - on biodiversity in the Anthropocene - click here.