The solitary and wide-ranging nature of the mountain lion makes it difficult to directly estimate populations. Habitat fragmentation, degradation, lack of connectivity and cultural intolerance of mountain lions even on prime habitat makes it difficult to use habitat density to extrapolate and calculate populations on a large scale. This means we just don't have good estimates of mountain lion numbers in the United States. Nor do we know precisely what population levels are required in order to maintain genetically healthy subpopulations that are ecologically effective on the landscape.
State game agencies have estimated mountain lion populations in the United States to be between 20,000 and 40,000 lions. The main reason game agencies calculate populations is to set quotas for additional kills, and oftentimes the simple fact that more lions are killed each year is used as an indicator that there therefore must be more lions. The agencies' biases are imbedded in these estimations.
Agency numbers show an increasing number of lions over prior decades, regardless of the facts: the number of mountain lions killed annually by humans has increased dramatically everywhere mountain lions are found; their prey populations are down; and habitat is being lost at an astounding pace.
We at the Mountain Lion Foundation prefer not to estimate without good data. However, we can see the need to comment on the estimates of others. We readily admit our estimates will reflect conservation biases: the concern that we need to estimate so conservatively that we will not be taken by surprise when we undertake direct primary research and find that numbers or genetic viability have already begun to suffer—as they have in southern California, Florida, Texas, and South Dakota, for example.
Based on the best available data at this time, Mountain Lion Foundation believes the mountain lion population in the United States is unlikely to exceed 30,000. And, many of those lions depend upon severely fragmented and degraded habitat, are in severe danger of over-hunting and road kill, are imperiled by intolerance of their presence on the landscape, and are so few and unconnected they are on the edge of genetic viability.