Madagascar separated from other landmasses long enough ago that most of its wildlife exists nowhere else — lemurs above all, along with baobabs and the limestone tsingy formations in the west. The island is large, and roads are the main constraint on any itinerary.
The guides on this page cover Madagascar as a whole. The dry season runs roughly April to November; cyclones affect the east coast between January and March. Overland travel is slow — journeys that look short on the map routinely take a full day — so domestic flights are common despite their unreliability. National park visits require local guides, which is a rule rather than a suggestion.