African Wildlife Foundation

About: African Wildlife Foundation is a nonprofit organization based out in Washington D.C., District of Columbia, United States. It is known for research contribution in the topics: Population & Wildlife. The organization has 74 authors who have published 97 publications receiving 4749 citations. The organization is also known as: AWF.

Matriarchs As Repositories of Social Knowledge in African Elephants

Abstract: Despite widespread interest in the evolution of social intelligence, little is known about how wild animals acquire and store information about social companions or whether individuals possessing enhanced social knowledge derive biological fitness benefits. Using playback experiments on African elephants (Loxodonta africana), we demonstrated that the possession of enhanced discriminatory abilities by the oldest individual in a group can influence the social knowledge of the group as a whole. These superior abilities for social discrimination may result in higher per capita reproductive success for female groups led by older individuals. Our findings imply that the removal of older, more experienced individuals, which are often targets for hunters because of their large size, could have serious consequences for endangered populations of advanced social mammals such as elephants and whales.

Asynchronous carbon sink saturation in African and Amazonian tropical forests

Abstract: Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions. Climate-driven vegetation models typically predict that this tropical forest ‘carbon sink’ will continue for decades. Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53–0.79), in contrast to the long-term decline in Amazonian forests. Therefore the carbon sink responses of Earth’s two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature. Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth’s intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth’s climate.

Livestock predation by lions, leopards, spotted hyenas, and their vulnerability to retaliatory killing in the Maasai steppe, Tanzania

Abstract: The African lion Panthera leo, spotted hyena Crocuta crocuta and leopard Panthera pardus are all killed in retaliation for livestock predation, but each species suffers differently from these impacts due to differences in predatory behavior and cultural attitudes of pastoralists. Using detailed data on livestock predation in the Maasai steppe landscape in Northern Tanzania, I investigated how prey preference, location and timing of livestock attacks contributed to the vulnerability of lions, leopards and spotted hyenas to retaliatory killing. Lions mostly preyed upon adult cattle and donkeys. In contrast, hyenas and leopards primarily killed small stock (goat, sheep and calves) and dogs. Hyenas and leopards mostly attacked livestock at night, whereas lions often attacked grazing livestock during the daytime. These behaviors made lions the most vulnerable to direct retaliatory killing, although some villages specifically targeted hyenas with poison, and the cultural traditions of pastoralists also exacerbate the retaliatory killing of lions. I highlight the complex interactions of social (human) and ecological dimensions of livestock predation and retaliation against predators. Any conservation intervention should strive to address human–carnivore conflicts at the appropriate social scale.

Devastating decline of forest elephants in Central Africa

Abstract: African forest elephants– taxonomically and functionally unique–are being poached at accelerating rates, but we lack rangewide information on the repercussions. Analysis of the largest survey dataset ever assembled for forest elephants (80 footsurveys; covering 13,000 km; 91,600 person-days of fieldwork) revealed that population size declined by ca. 62% between 2002–2011, and the taxon lost 30% of its geographical range. The population is now less than 10% of its potential size, occupying less than 25% of its potential range. High human population density, hunting intensity, absence of law enforcement, poor governance, and proximity to expanding infrastructure are the strongest predictors of decline. To save the remaining African forest elephants, illegal poaching for ivory and encroachment into core elephant habitat must be stopped. In addition, the international demand for ivory, which fuels illegal trade, must be dramatically reduced.