This zoo is home to around 3 500 animals. Visitors can tour the grounds on the Pioneer Train, which is powered by natural gas. Tropical Discovery, a rainforest habitat beneath a huge glass pyramid, is home to many species, including deep-sea chambered nautiluses, while Primate Panorama features nocturnal lemurs, Asian orangutans and endangered African lowland gorillas. Feeding time at Northern Shores, a habitat for seals, sea lions and otters, is very popular with visitors.