Density estimates of African lions in Queen Elizabeth National Park

<p><span><span><span><span><span><span><span><span><span><span><span>African lions are declining across much of their range, yet robust measures of population densities remain rare. The Queen Elizabeth Conservation Area (QECA; 2400 km²) in East Africa's Albertine Rift has potential to support a significant lion population. However, QECA lions are threatened, and information on the status of lions in the region is lacking. Here, we use a spatially explicit search encounter approach to estimate key population parameters of lions in the QECA. We then compare home range sizes estimated from our models to those from a radio-collaring study implemented a decade earlier. We recorded 8243.5 km of search effort over 93 days, detecting 30 individual lions (16 female and 14 male) on 165 occasions at a rate of 2 lion detections/100 km². Lion density in the QECA was 2.70 adult lions/100 km²(SD=0.47), while mean abundance was 71 individuals (SD=11.05). Worryingly, the movement parameter for male lions was 3.27 km and 2.22 km for females, suggesting &gt;400%, and &gt;100% increases in home range size, respectively, compared to a decade earlier. Sex ratio of lions in the QECA was lower (1 male: 0.75 females), when compared to a previously published review (mean=1:2.33). The large movements and skewed sex ratios we report on in this paper are likely a result of human driven prey depletion. Our results suggest lions in the QECA are in a precarious state and the lion densities are significantly lower than what they could be. As lions are under pressure throughout much of Africa, our study presents the utility of a census technique that could be used elsewhere as an early warning of lion declines. </span></span></span></span></span></span></span></span></span></span></span></p>