As young and enthusiastic students of geography and biology respectively, my sister and I often used to spar over which of us was studying the biggest, most important subject. Since neither of us was reading maths or physics we couldn't go so far as to claim our subject would yield a universal theory of everything, but we did go to great lengths to establish links from our respective disciplines to all sorts of other obscure areas. Perhaps as a result of those occasionally heated discussions, I am continually drawn to the blurry No Man's Land between disciplines – it is a place to discover startling new truths, follow inviting lines of thought to exotic destinations and meet extraordinary people with otherworldly perspectives of your own familiar territory that can set everything in a new light. Not surprisingly it is also extraordinarily fertile ground for ideas to take seed and grow. The Animal series from Reaktion Books is mining these rich seams of interdisciplinary gold, touching on social, economic and political history, conservation, art and pop culture – to name a few. There are now over 60 of these distinctive and well marketed volumes, spotlighting a range of species from Camel and Cockroach to Tortoise and Trout. Some titles even have a matching t-shirt. The latest two titles are Gorilla and Ostrich. Both contain the series’ trademark blend of zoology and cultural information. If it's only the former that appeals, you may find more detailed and arguably more authoritative information elsewhere. Less than a third of either book constitutes what you could call biology. Neither Willams, nor Gott and Weir are full-time ostrich/gorilla specialists, but in both cases they offer an excellent introduction to their species, alongside a cultural and historical account you simply won't find in any other single source. In Ostrich, you'll discover not only how the male birds use their distinctive plumes, and how the trade in those same feathers gave rise to a huge industry – but also the subtleties of plucking vs. clipping, the absurdities of feather fashion and fascinating insights into ostrich symbolism. I'd never stopped to wonder whose feathers those were on the back of a two pence piece, and I'll bet hardly anyone notices the ostrich on the Bayeux tapestry. Ever wondered how many people you could feed with an ostrich egg omelette? Look no further. But perhaps my favourite story is the extraordinary tale of a clandestine expedition 100 years ago, which aimed to smuggle 156 uncooperative birds of a particularly desirable North African strain overland to Lagos and then by sea to a farm in South Africa. The boat was unsuitable and food ran out mid voyage, forcing the crew to spend weeks peeling thousands of onions to feed to their ungrateful cargo, who repaid them with further attempts to escape as soon as they reached land. There must be a movie script here, surely. Gorilla offers an equally eclectic look at its subject – incorporating a good overview of what we know of these gentle giants, and more poignantly, what they continue to teach us about ourselves, both in fictional contexts and in real life. This book is a great example of why the Animal series works so well – the content is highly informative, but the format frees authors from any requirement to be purely ‘scientific’. The final chapter of Gorilla deals with our relationship with this close cousin, and the apparently shrinking differences between us. With these magnificent great apes being afforded the equivalent of basic human rights in many countries, but still inching closer to extinction in the wild, it makes for a deeply thought-provoking read. So if you've not started your own Animal series library yet – these could be a good place to begin. I just wish I'd had them 20 years ago, when my little sister was claiming geography covered economics, culture and pretty much everything anyone on Earth had ever done. I could have explained (with a carefully measured dose of lofty condescension) that such a statement could only be made by someone woefully ignorant of the cultural significance of the ostrich. A knockout blow, surely.