CLIVE ROOTS has been a zoo director for many years. He has travelled the world collecting live animals for zoo conservation programmes. He has acted as a planning and design consultant for numerous zoological gardens and related projects around the world, and has written many books on zoo and natural history subjects.

We share the earth with a wide variety of animal species, each of which brings something special to the diversity of the planet. By knowing more about how animals behave and live, we gain a greater understanding of how life evolved and the importance of biodiversity. "Hibernation" examines those animals that cannot migrate and are forced to remain in a habitat that is inhospitable, and consequently sleep deeply for weeks or months. This unique trait, known as hibernation for winter sleep and estivation for its summer equivalent, involves many special behaviours - how do such animals prepare for sleep? Where do they sleep? How do they store energy? How do they wake up? The book provides a thorough guide, perfect for understanding the behaviour and biodiversity of a fascinating and unusual group of animals. "Hibernation" provides thorough coverage of the animals that have this unusual behaviour, including: mammals of the temperate zones, that can raise their temperature when in danger of freezing; cold-blooded fish, amphibians, and reptiles that have no control over their body temperature, and therefore cannot raise it to avoid being frozen; northern bears, the only animals to raise their young while hibernating; and the animals that live in semi-arid regions which encase themselves in a waterproof membrane to avoid drying out. Beautifully illustrated, "Hibernation" provides copious material for understanding these unusual animals.