Environmental books tend to fall into three categories: works of reflection(Whither Our Poor Planet?), of reference (The Smaller Insects of the Isle of Man) or visual splendour (Glorious Greenland!). It is a measure of the merit of Birds Britannica (Chatto & Windus, £35), the outstanding green book of 2005, that it combines all three ways of advancing our understanding of the natural world. There are two author's names on the cover: Mark Cocker and Richard Mabey. The latter strikes the immediate chord: Mabey is our outstanding nature writer and the man who a decade ago dreamt up Flora Britannica, the encyclopaedic guide to the cultural significance of Britain's wild flowers.
Mabey set out to repeat the trick for Britain's birds. But a depressive illness overtook him and his project was taken over by a younger, rising writer. The achievement of the finished Birds Britannica is all Mark Cocker's, and it is considerable: a beautifully-written, encyclopaedic account of Britain's bird folklore. Why does the robin symbolise Christmas, and the raven, death? That's all here; but so is much that is less familiar. The photographs, by Chris Gomersall, are magnificent.
There are many bird books every year, and many dazzle the eye. But only a few stand out for their writing. Two more from 2005 are Birds: a complete guide to all British and European Species (Collins, £30), a pictorial feast graced by the deep knowledge and literary skill of Dominic Couzens, and A Bad Birdwatcher's Companion (Short Books, £9.99), a quirky account of 50 common birds by Simon Barnes, which may let non-birders see the point. For literary birdwatchers, The Bedside Book of Birds by Graeme Gibson (Bloomsbury, £20) is an attractive anthology of avian writings.
The market for wild flowers may be smaller, but still brings gems. This year, three separate guides, all excellent, have been published to Britain's most ravishing flowers: wild orchids. Britain's Orchids by David Lang (WILDGuides, £15) will just about fit in your pocket; Orchids of Britain and Ireland by Anne and Simon Harrap, (A&C Black, £29.99) gives more detailed descriptions; Orchids of the British Isles by Michael Foley and Sidney Clarke, (Griffin Press, £45) aims to be the textbook for the 21st century, while still resplendently illustrated.
A very different volume is another of the year's botanical highlights. The Naming of Names by Anna Pavord, the Independent's gardening correspondent (Bloomsbury, £30), is a fascinating and truly scholarly account of how the way the world of plants fits together was painfully unravelled over 2,000 years.
Best book on mammals in 2005? Without a doubt, The World Atlas of Great Apes (available via the World Conservation Monitoring Centre in Cambridge), which details how quickly man's nearest animal relatives are disappearing. The top-selling book on invertebrates is likely to be Sir David Attenborough's Life in the Undergrowth (BBC, £20), the spin-off from the old whispering maestro's TV series. The best reflective work was Richard Mabey's Nature Cure (Chatto, £12.99), detailing in moving terms how he recovered from his illness.
Finally, a personal favourite: Lapland: A Natural History by Derek Ratcliffe (Poyser, £40), a rare window onto one of Europe's most unspoiled areas, by the outstanding British field naturalist of the late 20th century. He died this year, mourned by all who knew him and knew his work.Reuse content