Lion and tiger habitats, the Giraffe Savannah, and a 4-acre mixed-species area called the Serengeti Crossing that showcases zebras, ostriches, ibex, and wildebeests keep this zoo roaring. The Tropical Forest, with its Western Lowland Gorilla environment, is a big draw, and wallabies, emus, and kangaroos populate the Australian Outback Trail. From May to September butterflies flit and flutter at Butterfly Landing, where docents are on hand to answer questions and give advice on attracting the colorful insects to your own garden. The Children's Zoo entices with sheep, goats, and other beasts. In winter, call in advance to find out which animals are braving the cold. The park, 4 mi from downtown, is reached by Bus 16 from the Forest Hills (Orange Line) or Andrew (Red Line) T stops; there's plenty of parking.