Life in Cold Blood

We tend to think of evolution as a positive thing, as a continuous thing, as upward progress, as the sloughing off the old and worn out and the developing of the new and practical. And we tend to think of anything static and unchanging as outmoded, hopelessly simple and doomed.

We also tend to put ourselves at the top of the evolutionary chain, as being the species most adept and successful at adaptation. And subsequently, we may tend to put our cold blooded friends, the reptiles and amphibians, somewhere further down the chain, perhaps close to the bottom of the pile.

But consider the crocodile. Consider that it has existed in basically the same form, and persevered quite well, thank you, by doing the same thing it was doing since the time of the dinosaurs. Consider its, and its cousin the alligator’s, success in colonizing the world; consider the fear and respect it commands; and consider that it will probably outlast us by tens, if not hundreds, of thousands of years. Consider that perhaps it found perfection, long ago, and just stopped evolving at that point. So, then, who’s the more highly evolved species?

Underestimate the crocodile and other reptiles, and underestimate the amphibians at your own peril. I certainly don’t, not since I’ve watched Life in Cold Blood, and neither does Sir David Attenborough. But you probably already figured the latter.

Consisting of five 50 minute programs, accompanied each by 10-minute addendums of “making of” footage, Attenborough’s latest, and reportedly last, major series is a consistently fascinating, if only a tad bit repetitive, tour of the rich and varied lives of crocodiles, frogs, turtles, chameleons, snakes, and other assorted cold blooded creatures.

As with others of his “Life” series, and with Planet Earth, Attenborough’s presentation tends to be engagingly discursive, enthralling more in its tangents, in its uncovering of rare sights and behavior, than in covering the basics. The first episode, The Cold Blooded Truth, does a good job of surveying the latter, though, covering the fundamentals of reptile and amphibian life: the advantages and disadvantages of being by necessity “solar powered” (acquiring their internal heat and energy from the sun, either directly or indirectly); the fact that one group is entirely beholden to water (amphibians) while the other has conquered the most arid, inhospitable places on earth; the common link of laying eggs instead of live full formed young (well, except when they do, and that’s exciting stuff, the live births).

The other four episodes highlight both major branches, and then subgroups within, moving from amphibians, to lizards, on to snakes, and concluding with an episode about turtles and crocodiles. Most of the excursions into the animals lives, while rich in the details, tend to revolve around the twin foci of food and sex. Attenborough’s fascination with how animals eat, and how the procreate, is, apparently, boundless.

But as always, he finds new tangents that fascinate. This time out, he also seems oddly fixated on extreme pygmy versions of animals. We are treated to rare sights of miniscule, nearly microscopic, lizards and chameleons, which are the evolutionary equivalent of their normal sized cousins. Attenborough makes no larger (ahem) point about his obsession with the miniscule, other than its just amazing that these animals exist. You can’t help but agree with him.

As with other BBC wildlife specials produced under the purview of Attenborough, the joy in watching Life in Cold Blood is in its collection of rare moments of wonder that seem so effortlessly captured on film, shots of animals in action that inspire nothing but jaw-agape amazement. Like the weirdly hilarious arm gestures of the endearing (and tragically endangered) golden frog in Panama. Though frogs, of course, normally croak and creak to communicate, golden frogs’ constant proximity to loud running water has forced them to adopt other methods of finding mates and warding of competitors.

When one golden frog encounters another, they begin an elaborate exchange of arm gestures that make them look like they are attached to marionette strings — oddly herky-jerky, almost like stop motion animation, these gestures convey ownership and challenge from one male frog to another, or, enticement if directed towards a female. Its hypnotic stuff, and also quite fun to imitate with your friends and loved ones (no, really).

And then here we have the grotesque horror of watching a massive seven-foot long python devour an adult antelope whole. Think about that for a second. The snake somehow is able to expand its mouth to such a degree that it can start devouring and breaking down the entire body of the antelope (hooves, horns, bones and all!) and keep pushing it (the antelope) down its gullet until it the whole thing can be seen in outline in its distended “belly” – and this all in one sitting!

Except that it doesn’t exactly chew and swallow the antelope, but once it gets its grotesquely flexible mouth around it, the snake just slowly moves itself forward over the stationary carcass. So, though it takes over a day to finally consume the whole thing, and probably another week to digest the antelope, the python doesn’t have to eat again for an entire year. How efficient!

And this is one clue to the success of amphibians and lizards in colonizing the globe. Though reliant on the sun, with no self-sustaining internal combustion engine like warm blooded animals, they utilize considerably less energy than mammals in maintaining vital body heat. And this they’ve managed to do just about everywhere — on dry land, in water, in the sun and in the dark (by getting their “solar energy” from the heat released by rocks that have sat in the sun all day, for example), while living both above and below ground.

These creatures are remarkable engines of survival, and they make you stop and wonder whether we mammals made some wrong turn on the evolutionary highway after our much distant evolutionary (and decidedly amphibian) ancestors crawled out of the primordial muck.

But all is not well in the cold blooded kingdom. The series ends on a somewhat somber note. Attenborough laments the fate of amphibians in particular, which are endangered world-wide. Reptiles are still in pretty good shape, but the passing of amphibians would be, of course, disastrous, not just for the ecosystems they inhabit, but also simply for the joy and beauty their colorful multiplicity and unique behaviors add to the world.

As with most Attenborough specials, he let’s the animals “speak” for themselves. He is not didactic, just soberly matter of fact beneath his normal ebullient enthusiasm. The golden frogs, the giant sea turtles, the outrageously colored chameleons — they are their own best advocates, if only we’d open our eyes to truly see them. Thank goodness, then, for Sir David Attenborough, who throughout his prolific career has always given us this opportunity to see and hear what we might not otherwise even realize exists.