TY - JOUR
T1 - Detecting early warnings of pressure on an African lion (Panthera leo) population in the Queen Elizabeth Conservation Area, Uganda
AU - Braczkowski, Alexander
AU - Gopalaswamy, Arjun M.
AU - Nsubuga, Mustafa
AU - Allan, James
AU - Biggs, Duan
AU - Maron, Martine
N1 - Publisher Copyright:
© 2020 The Authors. Ecological Solutions and Evidence published by John Wiley & Sons Ltd on behalf of British Ecological Society.
PY - 2020/7
Y1 - 2020/7
N2 - African lions are declining across much of their range, yet robust measures of population densities remain rare. The Queen Elizabeth Conservation Area (QECA; 2,400 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 8,243.5 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 > 400%, and > 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.
AB - African lions are declining across much of their range, yet robust measures of population densities remain rare. The Queen Elizabeth Conservation Area (QECA; 2,400 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 8,243.5 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 > 400%, and > 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.
KW - Bayesian spatially explicit capture-recapture
KW - big cat
KW - density
KW - East Africa
KW - felid
KW - lion
KW - Panthera leo
KW - population size
KW - Uganda
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U2 - 10.1002/2688-8319.12015
DO - 10.1002/2688-8319.12015
M3 - Article
AN - SCOPUS:85122084524
SN - 2688-8319
VL - 1
JO - Ecological Solutions and Evidence
JF - Ecological Solutions and Evidence
IS - 1
M1 - e12015
ER -