Book excerpt: From the moment the very first animals–two small, bedraggled prairie dogs–arrived at the Bronx Zoo in 1899, history was being made. Zookeeping has steadily been evolving over the years: Today, animals that would once have been kept in iron cages roam freely in habitats similar to real prairies, jungles, and forests. Wild Lives takes readers through a century of zookeeping at one of the most-beloved zoos in the world, and shares what zoologists have learned over the years about keeping wild animals.