Friday, 22 April 2016
The Life of Birds (1998)
If you've read the previous reviews I've done of David Attenborough's Life series, then you can probably guess the overall assessment: if you're at all interested in nature documentaries, then this is a good one and you should check it out.
For those of you who need a little more information, though, read on.
As the title of the series makes obvious, Attenborough has turned his attention to the modern day descendants of dinosaurs. He begins by discussing 'why' birds developed the ability to fly, and 'why' some have since abandoned it once more. I put the 'why' in quotes because of course there's no design or purpose to evolutionary change: it's just that changes which happen to make the species better at surviving tend to be passed on.
In any case, to use the short-hand of 'why', birds took to the air for the safety it offered, and they generally abandon it when other factors, such as an absence of predators or a largely submarine food source, make the disadvantages of flight (principally the huge energy expenditure it entails) outweigh the advantages. In the course of this summary, Attenborough covers some of the more esoteric birds the world has to offer. My personal favourite: the kakapo. This two-foot tall (60cm) parrot is flightless and lives in burrows. Alas there are only about 100 of these birds left alive, but New Zealand, where they live, is working hard to conserve the species.
This preliminary analysis done, Attenborough moves on to the mechanics of flight, with particular attention on those birds which are especially gifted in that field: whether that gift be speed, silence, manoeuvrability (hummingbirds can literally fly backwards), or endurance. He then moves on to their voracious need for calories, and the various techniques by which they acquire the calories they need.
From there, we cover many of the thematic elements on which Attenborough usually concentrates: how birds communicate, how they find mates, and how they rear their young. This last is a two part process, dealing first with the egg and then the chicks. Fair warning if you're the sentimental sort: some birds are, by human standards, very bad parents indeed.
Attenborough winds up with a discussion of the challenges birds face in the world, be it extreme environments (deserts or tundra) or the arrival of new animals into their ecosystems. The most destructive such 'new arrival', you will probably not be surprised to discover, is human beings. Dodos are perhaps the most famous example of this, but far more astonishing is the tale of the passenger pigeon. They could fly, unlike the dodo, and their population was once somewhere between 3 and 5 billion. Humanity wiped them out just as thoroughly as they did the dodo.