If the Planet Zoo series has taught me anything it’s that I’m rubbish at animals. Sure, I’m okay with the simple stuff – I do, you’ll be relieved to hear, know the difference between an elephant and a flamingo – but the more exotic they get, the second we start dabbling in subspecies, the more clueless I am. That was one of the joys of the original Planet Zoo: a chance to discover a vibrant menagerie of unusual animals, all…