Aldo Leopold's Sand County Almanac is a seminal work of wildlife ecology, first published in 1949.

It is a careful study of the Wisconsin wilderness (travelling later through surrounding states), and a general plea for land conservation - the first modern plea of its kind - arising from the lifetime Leopold spent doing practical work both with and for the natural environment. He implores readers to adopt what he calls a 'land ethic,' by which we would develop an 'ecological conscience' and gain 'a conviction of individual responsibility for the health of the land'.

Though Leopold expresses pretty trenchantly his alarm at the way we mistreat the land that sustains us, this is offset by his sheer delight in the details of natural life (the "peenting" woodcock dancing against a golden sky at dusk was the standout moment for me). Noting that we can only care to preserve a thing we have a connection with, Leopold invites us into an enticing world of river-song and plovers and silphium (now extinct!), and the tamarack tree that 'sprinkles gold on October grouse'. I found it absolutely delightful to read, and my avian vocabulary has expanded considerably, which can only be a good thing.

It goes out of copyright next year and I think it would be a very worthwhile addition to the Black Classics list. Since first publication it has sold over 2 million copies and been translated into 14 languages.