Even in the four populations of west African lions that have somehow survived, those in Senegal are separated by thousands of kilometres from lions in Nigeria. And three of these populations are so small that they may not be viable in the longer term.
At the micro level, the situation is similarly dispiriting. One of the parks where the lions do survive is Niokolo-Koba National Park in Senegal, where just 16 remain.
''What says it all, concerning the rarity of the lion in the park is that not one of my four survey team members, all long-serving national park service staff, had ever seen a lion in their lives,'' Henschel says.
West African lions are one thing, but it is the report's implications for lion populations elsewhere in Africa that has some lion experts worried.
While it is estimated that no more than 30,000 lions remain in Africa, these figures do not accurately reflect the species' prospects for survival. For a start, no one really knows how many lions there really are left.
''There are several large landscapes in east and southern Africa that are potentially key lion areas, and have never been systematically surveyed,'' Henschel says. ''Estimates of lion numbers for those areas go back to informed guesses by managers, made, at times, more than 20 years ago.'' And, in any event, says Hunter, rather than asking how many lions there are it is far more important to ask about the trajectory for the species and about the state of the ecosystems in which they are living.