Browsing by Author "Mweetwa, Thandiwe"

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Conserving large populations of lions - the argument for fences has holes
(2013-07-09) Creel, Scott; Becker, Matthew S.; Durant, S. M.; M'soka, Jassiel; Matandiko, Wigganson; Dickman, A. J.; Christianson, David A.; Dröge, E.; Mweetwa, Thandiwe; Pettorelli, N.; Rosenblatt, Elias G.; Schuette, Paul; Woodroffe, R.; Bashir, S.; Beudels-Jamar, R. C.; Blake, S.; Borner, M.; Breitenmoser, C.; Broekhuis, F.; Cozzi, G.; Davenport, T. R. B.; Deutsch, J.; Dollar, L.; Dolrenry, Stephanie; Douglas-Hamilton, I.; Fitzherbert, E.; Foley, C.; Hazzah, L.; Henschel, P.; Hilborn, R.; Hopcraft, J. G. C.; Ikanda, D.; Jacobson, A.; Joubert, B.; Kelly, M. S.; Lichtenfeld, L.; Mace, G. M.; Milanzi, J.; Mitchell, N.; Msuha, M.; Muir, R.; Nyahongo, J.; Pimm, S.; Purchase, G.; Schenck, C.; Sillera-Zubiri, C.; Sinclair, A. R. E.; Songorwa, A. N.; Stanley-Price, M.; Tehou, C. A.; Trout, C.; Wall, J.; Wittemyer, G.; Zimmermann, A.
Packer et al. reported that fenced lion populations attain densities closer to carrying capacity than unfenced populations. However, fenced populations are often maintained above carrying capacity, and most are small. Many more lions are conserved per dollar invested in unfenced ecosystems, which avoid the ecological and economic costs of fencing.
Detecting declines of apex carnivores and evaluating their causes: An example with Zambian lions
(Elsevier, 2014) Rosenblatt, Elias G.; Becker, Matthew S.; Creel, Scott; Droge, Egil; Mweetwa, Thandiwe; Schuette, Paul; Watson, Fred; Merkle, Johnathan; Mwape, Henry
Large carnivores are in rapid global decline, with a broad array of consequences for the ecosystems they inhabit. To efﬁciently detect and address these declines requires unbiased and precise demographic data. Unfortunately, the characteristics that make large carnivores extinction-prone also pose serious challenges to obtaining these data. Rapid survey methods exist, but provide only relative measures of abundance, cannot detect declines before they become large, and provide little or no information about the causes of decline. African lions (Panthera leo) are declining throughout their range, making accurate monitoring of remaining populations urgent. We provide statistically rigorous estimates of population size, trends, survival rate and age–sex structure from Zambia’s South Luangwa lion population from 2008 to 2012, just prior to cessation of hunting in 2013. Mark-recapture models ﬁt to data from intensive monitoring of 210 individual lions in 18 prides and 14 male coalitions indicated a declining population, low recruitment, low sub-adult and adult male survival, depletion of adult males, and a senescing adult female population. Trophy hunting was the leading cause of death, with 46 males harvested. Based on these data we recommend continuing the hunting ban at least to 2016 to allow recovery, with substan-tially reduced quotas, age-limits, and effective trophy monitoring mandated thereafter should hunting resume. Similar data from intensive monitoring of key Zambian lion populations is required to evaluate effects of the hunting ban and provide management guidance. Effectively integrating intensive long-term monitoring and rapid survey methods should be a priority for future management and monitoring of carnivore species.
Effects of de-snaring on the demography and population dynamics of African lions
(Elsevier BV, 2023-10) Banda, Kambwiri; Creel, Scott; Sichande, Mwamba; Mweetwa, Thandiwe; Mwape, Henry; Reyes de Merkle, Johnathan; Mwansa Bwalya, Lengwe; Simpamba, Twakundine; McRobb, Rachel; Becker, Matthew S.
Lions and other African large carnivores are in decline, due in part to effects of illegal hunting with snares, which can reduce prey availability and directly kill or injure carnivores. It is difficult to effectively remove snares from large ecosystems by patrolling, but an additional approach to reduce effects on large carnivores is to monitor the population closely and de-snare individuals who are found in a snare or have broken free but still carry the wire (often with serious injury). The effectiveness of de-snaring programs to reduce impacts on large carnivores has not been directly tested. Here, we used long-term demographic data from 386 individually identified lions in the Luangwa Valley Ecosystem to test the effects on population growth (λ) and population size (N) of a program to remove snares from injured lions and treat their wounds. Stochastic Leslie matrix projections for a period of five years showed that the population grew with the benefits of de-snaring, but was expected to decline without de-snaring. Mean annual growth (λ) with de-snaring was 1.037 (with growth in 70% of years), closely matching observed changes in population size. Mean annual growth was 0.99 (with growth in 47% of years) for a model that assumed snared animals would have died if not treated, and 0.95 (with growth in 37% of years) for models that also accounted for super-additive effects via the death of dependent cubs and increased infanticide with increased male mortality. De-snaring requires intensive effort, but it can appreciably reduce the effect of snaring on lion population dynamics.
Quantifying lion (Panthera leo) demographic response following a three-year moratorium on trophy hunting.
(2018-05) Mweetwa, Thandiwe; Christianson, David A.; Becker, Matthew S.; Creel, Scott; Rosenblatt, Elias G.; Merkle, Johnathan; Droge, Egil; Mwape, Henry; Masonde, Jones; Simpamba, Twakundine
Factors that limit African lion populations are manifold and well-recognized, but their relative demographic effects remain poorly understood, particularly trophy hunting near protected areas. We identified and monitored 386 individual lions within and around South Luangwa National Park, Zambia, for five years (2008-2012) with trophy hunting and for three additional years (2013-2015) during a hunting moratorium. We used these data with mark-resight models to estimate the effects of hunting on lion survival, recruitment, and abundance. The best survival models, accounting for imperfect detection, revealed strong positive effects of the moratorium, with survival increasing by 17.1 and 14.0 percentage points in subadult and adult males, respectively. Smaller effects on adult female survival and positive effects on cub survival were also detected. The sex-ratio of cubs shifted from unbiased during trophy-hunting to female-biased during the moratorium. Closed mark-recapture models revealed a large increase in lion abundance during the hunting moratorium, from 116 lions in 2012 immediately preceding the moratorium to 209 lions in the last year of the moratorium. More cubs were produced each year of the moratorium than in any year with trophy hunting. Lion demographics shifted from a male-depleted population consisting mostly of adult (â‰¥4 years) females to a younger population with more (>29%) adult males. These data show that the three-year moratorium was effective at growing the Luangwa lion population and increasing the number of adult males. The results suggest that moratoria may be an effective tool for improving the sustainability of lion trophy hunting, particularly where systematic monitoring, conservative quotas, and age-based harvesting are difficult to enforce.