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Positive indirect effects of consumers on their resources can stabilize food webs by preventing overexploitation, but the coupling of trophic and non-trophic interactions remains poorly integrated into our understanding of community dynamics. Elephants engineer African savanna ecosystems by toppling trees and breaking branches, and although their negative effects on trees are well documented, their effects on small-statured plants remain poorly understood. Using data on 117 understory plant taxa collected over 7 yr within 36 1-ha experimental plots in a semi-arid Kenyan savanna, we measured the strength and direction of elephant impacts on understory vegetation. We found that elephants had neutral effects on most (83–89%) species, with a similar frequency of positive and negative responses among the remainder. Overall, estimated understory biomass was 5–14% greater in the presence of elephants across a range of rainfall levels. Whereas direct consumption likely accounts for the negative effects, positive effects are presumably indirect. We hypothesized that elephants create associational refuges for understory plants by damaging tree canopies in ways that physically inhibit feeding by other large herbivores. As predicted, understory biomass and species richness beneath elephantdamaged trees were 55% and 21% greater, respectively, than under undamaged trees. Experimentally simulated elephant damage increased understory biomass by 37% and species richness by 49% after 1 yr. Conversely, experimentally removing elephant damaged branches decreased understory biomass by 39% and richness by 30% relative to sham-manipulated trees. Camera-trap surveys revealed that elephant damage reduced the frequency of herbivory by 71%, whereas we detected no significant effect of damage on temperature, light, or soil moisture. We conclude that elephants locally facilitate understory plants by creating refuges from herbivory, which countervails the direct negative effects of consumption and enhances larger-scale biomass and diversity by promoting the persistence of rare and palatable species. Our results offer a counterpoint to concerns about the deleterious impacts of elephant \"overpopulation\" that should be considered in debates over wildlife management in African protected areas: understory species comprise the bulk of savanna plant biodiversity, and their responses to elephants are buffered by the interplay of opposing consumptive and non-consumptive interactions.

Over the past six years, elephant poaching and the illicit ivory trade have attracted global attention and Tanzania has been slated as one of the worst offenders. During the 2013 CITES Conference of the Parties in Bangkok, Tanzania, along with Kenya, Uganda, Malaysia, Vietnam, the Philippines, Thailand and China were labeled “the gang of eight”, singled out as being instrumental in fueling the illegal ivory trade either as suppliers, transit countries, or consumers. Individuals, conservation groups and local and international media have accused the Tanzanian government of inaction and have linked the current slaughter of elephants to increased criminality, corruption, the proliferation of firearms, the failure of the judicial system and a perception that Tanzania is a sanctuary for criminals. Besides tarnishing the image of the country, elephant poaching has undesirable effects on the ecological, economic and security aspects. This paper explores these effects and highlights the need for reversing the current trend of this crime. The paper provides an historical overview of poaching in Tanzania and urges for immediate action to halt the crime. Focusing on factors that are considered key in driving poaching, the paper recommends some proactive measures that should be adopted in order to reverse the current trend. The paper highlights the positive outcomes the adoption of these measures could have for conservation efforts.

A timely documentary that looks at the danger of extinction of the African elephant, not only through the ivory trade but also due to the advance of humanity across the continent. The elephant is crucial to Africa and the solutions offered are controversial.