Copenhagen Zoo

This guide to Copenhagen Zoo turns on the morning of February 9, 2014, when zookeepers walked a healthy young giraffe named Marius into a public yard here, saying his genes made him surplus to the European breeding program. It follows the offers that poured in from other zoos and the public outcry that followed, and asks what a two-century-old institution owes the animals it keeps. Best visited with an eye toward how routine sorting decisions like this one are made, mostly out of view.