Lions are increasingly endangered, mainly due to persecution, habitat modification & fragmentation. These animals require large areas of suitable habitat in order to survive, holding good game populations upon which they feed.
The future does not look promising for wild Lions, with populations in West Africa being particularly endangered & in a precarious position. As human population increases Lion populations decrease as they come into direct contact & often conflict with man.
Large conservation areas are rare, with only the Kruger National Park, the Serengeti, Selous & Ruha Game Reserves in Tanzania; the Luwanga National Parks in Zambia and parks in Botswana & Namibia holding good populations of Lions.
I am lucky enough to live next to the Kruger National Park, where Lion populations appear to be stable. A threat within the Kruger ecosystem is the infrequent outbreaks of tuberculosis which infect the Cape Buffalo populations, which the Lions contract this disease by feeding on the meat. When these outbreaks occur Lion populations obviously decline, but within a protected area appear to have the capacity to bounce back.