Tanzania boasts the Great Migration, the Big Five (with the Ngorongoro Crater being the most reliable place to spot rhino on the Northern Circuit) and primate tracking in Mahale and Gombe. Serious birders and amateurs alike will enjoy the myriad of endemics and migratory species who fly South to take advantage of the longer days at near the equator. The most accessible and reliable months to catch the migration in Tanzania are from December/January through late June. During some years when rainfall is unpredictable, some of the northernmost properties in the Serengeti are excellent through October. Arusha National Park is known for its black and white colobus monkey, while Lake Manyara is still known for its tree climbing lions (although you may see lions in trees throughout Tanzania). Tarangire National Park, Chem Chem and Manyara Ranch benefit greatly from the elephant migration during the dry months, peaking in August-October when you can spot herds up to several hundred individuals.