There are six remaining subspecies of tiger, explains Williams (author/illustrator of similar books on sharks, polar bears, elephants, and bees). After a range map locates their habitats, we zoom in on Karnataka, India, where a family observes Bengal tigers from a jeep and on foot. The endangerment faced by tigers in Karnataka and elsewhere is starkly communicated. Their numbers declined by 96 percent between 1900 and 2000, a sad detail followed by the scenario encapsulated in the book's title: a world with no tigers. Populations tigers' prey would grow out of control, which would cause waterways to be changed as their banks are eroded by those animals, and the surrounding landscapes would be damaged. Insect populations could be pushed into human-inhabited areas, and the world as we know it would be changed. Williams' vibrant, painterly digital images focus on tigers and the people who watch and photograph them, while verdant foliage crams the rest of each page, beautifully demonstrating the lush environment that so needs saving. Closing notes and a glossary teach readers more about tigers and their conservation and the effects of that work on indigenous Indians. A lovely and necessary resource.