Papers by Caroline Ng'weno
1. Citizen science is gaining increasing prominence as a tool for science and engagement but has ... more 1. Citizen science is gaining increasing prominence as a tool for science and engagement but has little visibility in many developing countries, despite being a potentially valuable tool for sustainable development. 2. We undertook a collaborative prioritization process with experts in conservation and the environment to assess the potential of environmental citizen science in East Africa including its opportunities, benefits and barriers. This provided principles that are applicable across developing countries, particularly for large-scale citizen science. 3. We found that there was great potential for citizen science to add to our scientific knowledge of natural resources and biodiversity trends. Many of the important benefits of citizen science were for people, as well as the environment directly. Major barriers to citizen science were mostly social and institutional, although projects should also consider access to suitable technology and language barriers. 4. Policy implications. Citizen science can provide data to support decision-making and reporting against international targets. Participation can provide societal benefits, informing and empowering people, thus supporting the United Nations’ Sustainable Development Goals. In developing countries there needs to be innovation to develop culturally-relevant citizen science benefitting participants and end-users. This should be supported through regional networks of stakeholders for sharing best practice
The Bulletin of the Ecological Society of America, 2019
The vulnerability of an individual to predation depends on the availability of other prey items i... more The vulnerability of an individual to predation depends on the availability of other prey items in the surrounding environment. Interspecific prey aggregations or "neighborhoods" may therefore affect an individual's vulnerability to predation. We examined the influence of prey neighborhood structure (i.e., the densities and identities of prey neighborhoods) on spatial variation in predation in a multi-prey system with a primary apex predator. We combined GPS locations of lions (Panthera leo), kill-site surveys, and spatially explicit density estimates of five species of ungulates for which a significant level of predation was attributable to lions. In addition to the dual influence of predator activity and vegetation, predation risk was attributable to the structure of prey neighborhoods for at least two of the five species of prey. Along with traditionally recognized components of predation (the rate of predator-prey encounters and prey catchability), we encourage ecologists to consider how prey neighborhood structure influences spatial variation in predation risk.
Frontiers in Ecology and Evolution, 2019
Predator restorations often result in apparent competition, where co-occurring prey populations e... more Predator restorations often result in apparent competition, where co-occurring prey populations experience asymmetric predation pressure driven by predator preferences. In many rangeland ecosystems, livestock share the landscape with wildlife, including ungulates and the large carnivores that consume them. We examined whether apparent competition reorganized prey communities following restoration of lions (Panthera leo) to a savanna ecosystem, and whether and how livestock management could alter this indirect interaction between lions and their prey. Three lines of evidence supported the hypothesis that Jackson's hartebeest (Alcelaphus bucelaphus lelwel; an ungulate of conservation concern) are suppressed via lion-mediated apparent competition. First, hartebeest exhibited an Allee effect where they were exposed to lions, but displayed negative density-dependent population growth where they were protected from lions. Second, spatial overlap between plains zebra (Equus burchelli; the primary prey of lions) and hartebeest further exacerbated lion predation on hartebeest. Finally, hartebeest were killed selectively by lions, whereas zebra were killed by lions in proportion to their abundance. We then tested whether glades [nutrient-rich hotspots created by abandoned cattle (Bos indicus) corrals] could be used to manipulate top-down control of hartebeest via their influence on the spatial distribution of zebra. Zebra aggregated at glades, and survival of hartebeest increased with increasing distance from glades, suggesting that corrals may be placed on the landscape away from hartebeest to create spatial refuges from lions. Our findings demonstrate how informed placement of livestock corrals can be used to manipulate the spatial distribution of primary prey (zebra), thereby reducing apparent competition suffered by hartebeest. Our work further provides an example of how integrating apparent competition theory with proactive livestock management can improve conservation efforts in multiple-use landscapes.
Journal of Applied Ecology, 2018
Citizen science is gaining increasing prominence as a tool for science and engagement. However, d... more Citizen science is gaining increasing prominence as a tool for science and engagement. However, despite being a potentially valuable tool for sustainable development, citizen science has little visibility in many developing countries. We undertook a collaborative prioritisation process with experts in conservation and the environment to assess the potential of environmental citizen science in East Africa, including its opportunities, benefits and barriers. This provided principles that are applicable across developing countries, particularly for large‐scale citizen science. We found that there was great potential for citizen science to add to our scientific knowledge of natural resources and biodiversity trends. Many of the important benefits of citizen science were for people, as well as the environment directly. Major barriers to citizen science were mostly social and institutional, although projects should also consider access to suitable technology and language barriers. Policy ...
Journal of Mammalogy, 2017
kuitikia wazo letu kuwa kupungua kwa kongoni kumechangiwa pakubwa na kurejeshwa kwa simba. Kutoka... more kuitikia wazo letu kuwa kupungua kwa kongoni kumechangiwa pakubwa na kurejeshwa kwa simba. Kutokana na kuongezeka kwa miti katika eneo la Laikipia kwa kipindi cha miaka hamsini iliyopita, tunashauri kwamba kupungua kwa idadi ya kongoni kutokana na simba kumechangiwa zaidi na mabadiliko ya mazingira.
International Journal of Science and Research (IJSR)
Climate Change Management, 2011
Growing scientific evidence suggests that climate change will accelerate weather extremes and inc... more Growing scientific evidence suggests that climate change will accelerate weather extremes and increase human vulnerability to disasters. Exposure of agro-pastoralists to erratic rainfall and cyclical droughts leads to frequent crop failures and livestock losses, with additional shocks from economic perturbations and erosion of household assets depriving this vulnerable group of “insurance” against adverse risks, driving them from a state of
Ecology Letters, 2013
Conservationists often advocate for landscape approaches to wildlife management while others argu... more Conservationists often advocate for landscape approaches to wildlife management while others argue for physical separation between protected species and human communities, but direct empirical comparisons of these alternatives are scarce. We relate African lion population densities and population trends to contrasting management practices across 42 sites in 11 countries. Lion populations in fenced reserves are significantly closer to their estimated carrying capacities than unfenced populations. Whereas fenced reserves can maintain lions at 80% of their potential densities on annual management budgets of $500 km−2, unfenced populations require budgets in excess of $2000 km−2 to attain half their potential densities. Lions in fenced reserves are primarily limited by density dependence, but lions in unfenced reserves are highly sensitive to human population densities in surrounding communities, and unfenced populations are frequently subjected to density‐independent factors. Nearly ha...
African Journal of Ecology, 2010
Invasive plants have invaded swathes of grasslands in Lake Nakuru National Park thus necessitatin... more Invasive plants have invaded swathes of grasslands in Lake Nakuru National Park thus necessitating the Park management to institute measures to control them. Despite this, information on the status and impact of invasive plants in these grasslands is lacking. Six grassland types were identified and assigned random numbers. Five study sites were then randomly selected from each grassland type. The Point‐Centre Quarter method was used to determine the distribution and density of seven major invasive plants, whilst their impact was assessed by comparing biomass and crude protein content of important forage grasses in invaded and noninvaded grasslands. Results show that the distribution of invasive plants did not differ among the grasslands (F5, 30 = 1.47, P = 0.229) but their densities differed among the plants (F6, 30 = 20.99, P < 0.001). The mean biomass in invaded and noninvaded grasslands (22 g m−2 versus 37.2 g m−2) was significantly different (t‐test, P < 0.05), while crude...
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Papers by Caroline Ng'weno