Quercus is the Latin name of oaks. Johan Lind, associate professor of ethology and nature photographer, has created a glorious book that is a tribute to the cultural and biological diversity of oaks. Quercus is beautifully illustrated with photographs of oaks and different animals and plants that live on oaks or in their proximity. The life on oaks is very species rich, but here a different aspect of diversity is in focus, the diversity of interactions and behaviour. Animals fend themselves or fight. Some are cattle herders, others shoot love darts and parasites become parasitised! In Quercus the reader will also find other intriguing stories, such as how historical kings of Sweden have affected todays biodiversity, how human preferences for pasta sauces are connected to diversity and how the struggle for sugar can regulate whole societies on oak.