Mohammed Yahya Said

Zoonosis emergence linked to agricultural intensification and environmental change

A systematic review was conducted by a multidisciplinary team to analyze qualitatively best available scientific evidence on the effect of agricultural intensification and environmental changes on the risk of zoonoses for which there are epidemiological interactions between wildlife and livestock. The study found several examples in which agricultural intensification and/or environmental change were associated with an increased risk of zoonotic disease emergence, driven by the impact of an expanding human population and changing human behavior on the environment. We conclude that the rate of future zoonotic disease emergence or reemergence will be closely linked to the evolution of the agriculture–environment nexus. However, available research inadequately addresses the complexity and interrelatedness of environmental, biological, economic, and social dimensions of zoonotic pathogen emergence, which significantly limits our ability to predict, prevent, and respond to zoonotic disease emergence.

Evolution of models to support community and policy action with science: Balancing pastoral livelihoods and wildlife conservation in savannas of East Africa

We developed a “continual engagement” model to better integrate knowledge from policy makers, communities, and researchers with the goal of promoting more effective action to balance poverty alleviation and wildlife conservation in 4 pastoral ecosystems of East Africa. The model involved the creation of a core boundary-spanning team, including community facilitators, a policy facilitator, and transdisciplinary researchers, responsible for linking with a wide range of actors from local to global scales. Collaborative researcher−facilitator community teams integrated local and scientific knowledge to help communities and policy makers improve herd quality and health, expand biodiversity payment schemes, develop land-use plans, and fully engage together in pastoral and wildlife policy development. This model focused on the creation of hybrid scientific−local knowledge highly relevant to community and policy maker needs. The facilitation team learned to be more effective by focusing on noncontroversial livelihood issues before addressing more difficult wildlife issues, using strategic and periodic engagement with most partners instead of continual engagement, and reducing costs by providing new scientific information only when deemed essential. We conclude by examining the role of facilitation in redressing asymmetries in power in researcher−community−policy maker teams, the role of individual values and character in establishing trust, and how to sustain knowledge-action links when project funding ends.

Length of Growing Period over Africa: Variability and Trends from 30 Years of NDVI Time Series

The spatial distribution of crops and farming systems in Africa is determined by the duration of the period during which crop and livestock water requirements are met. The length of growing period (LGP) is normally assessed from weather station data—scarce in large parts of Africa—or coarse-resolution rainfall estimates derived from weather satellites. In this study, we analyzed LGP and its variability based on the 1981–2011 GIMMS NDVI3g dataset. We applied a variable threshold method in combination with a searching algorithm to determine start- and end-of-season. We obtained reliable LGP estimates for arid, semi-arid and sub-humid climates that are consistent in space and time. This approach effectively mapped bimodality for clearly separated wet seasons in the Horn of Africa. Due to cloud contamination, the identified bimodality along the Guinea coast was judged to be less certain. High LGP variability is dominant in arid and semi-arid areas, and is indicative of crop failure risk. Significant negative trends in LGP were found for the northern part of the Sahel, for parts of Tanzania and northern Mozambique, and for the short rains of eastern Kenya. Positive trends occurred across western Africa, in southern Africa, and in eastern Kenya for the long rains. Our LGP analysis provides useful information for the mapping of farming systems, and to study the effects of climate variability and other drivers of change on vegetation and crop suitability.

Mobility and livestock mortality in communally used pastoral areas: the impact of the 2005-2006 drought on livestock mortality in Maasailand

There is consensus that pastoral mobility is beneficial for both pastoralists and the environment. However, rapid change arising from multiple factors, including landscape fragmentation, sedentarization, and demographic drivers might affect the effectiveness of this pastoral coping strategy in times of drought. We investigate livestock mortality rates following the 2005 drought in four areas in Maasailand: the Maasai Mara, the Kitengela plains, the Amboseli, and the Simanjiro plains. The main aim was to assess the mortality of resident livestock in relation to incoming livestock during the drought. Contrary to our expectations, livestock mortality rates were significantly higher (43%) in Kitengela, which experienced above-average rainfall, compared to the other three areas which had below-average rainfall yet experienced mortality rates between 14% and 30%. Two processes might explain this surprisingly high mortality rate. Firstly, the immigration of large numbers of livestock from drought-stricken areas into the highly fragmented Kitengela area increased stocking density, which worsened the shortage of forage and water. Secondly, the more market-oriented but less drought-resistant livestock breeds in Kitengela form another explanation for the increased mortality. These observations suggest that pastoral mobility may lead to greater sensitivity to drought especially in fragmented areas where more market-oriented but less drought-resistant livestock breeds are introduced. We argue that in such areas, there is a crucial need to adopt practices that simultaneously minimize land fragmentation and enhance pastoral mobility and access to information on improved livestock breeds and markets.

Drivers and impacts of land-use change in the Maasai Steppe of northern Tanzania: an ecological, social and political analysis

In this article, we discuss the drivers, causes, and impacts of land-use change in the Maasai Steppe of northern Tanzania. Remote sensing data were used to analyze land-use change, and Geographical Information Systems (GIS) was used to link-up with wildlife population dynamics and livestock distribution data derived from aerial censuses. Agriculture increased fivefold between 1984 and 2000, while human population increased exponentially from 3.3% p.a. in 1988 to 3.4% p.a. in the same period. Wildlife migratory routes declined from nine in 1964 to five in 2000, out of which three were seriously threatened with blockage by the extensive cultivation. Recurrent droughts and diseases have contributed to the declining livestock economy over the years due to livestock loss and the unpredictable and erratic rainfall has limited their recovery. To reverse the on-going trends in land use, proper land-use plans should be instituted in parallel with community-based wildlife ventures to maintain long-term ecosystem viability.

An Assessment of the Accuracy of Volunteered Road Map Production in Western Kenya

The introduction of web based mapping facilities that use satellite imagery, offers local people the possibility to map their environment. However, maps need to be accurate, which is the reason why map making is assigned to professionals. In this paper, we investigated the classification accuracy of road infrastructure from high resolution satellite imagery of an urban area in western Kenya achieved by surveyors and non-surveyors alike, with and without local knowledge. Those with local knowledge classified roads with over 92% accuracy on average, irrespective of surveying background. Professional surveyors and laymen without local knowledge achieved lower accuracies of 67.7% and 42.9% respectively. We argue that local knowledge is also likely to improve the classification accuracy of many other attributes featured in topographic maps and thus conclude that there is reason to consider engaging local expertise in the production and updating of topographic maps.

Wildlife and Livestock Population Trends in the Kenya Rangeland

The rangelands of Kenya are home to over 25% of the human population and are critically important for livestock production and wildlife conservation. Aerial surveys of wildlife and livestock populations in the rangelands have been conducted since 1977 and these data were analysed to determine population trends for the 1970s (1977-81), the 1980s (1985-88) and the 1990s (1992-94). Cattle populations remained static throughout, although the numbers fluctuated at district level. Sheep, goat and donkey numbers declined (10-14%) and camels increased (12%). All wildlife species except wildebeest and ostrich declined significantly. The highest wildlife densities were in protected areas but over 70% of wildlife was found outside these areas. The main contributors to the decline in wildlife were poaching and land use change. In the 1970s and 1980s, poaching was driven by the high international prices for trophies, particularly rhinoceros horn and elephant tusks, and the failure of the Wildlife Department to control it. This led to the total ban on trade in all forms of trophies and uses by the Government in 1977. New land tenure legislation creating group ranches and assigning land rights and ownership to pastoral communities was introduced in the early 1970s in response to growing human and livestock populations. This resulted in the exclusion of wildlife from large areas of land to minimize wildlife livestock competition and to protect and promote the expansion of arable agriculture. The severe droughts in 1984 and 1990 exacerbated the decline. New policies on wildlife management, strengthening of the Kenya Wildlife Service, expansion of community based wildlife programmes, re-introduction of use rights and the development of a comprehensive national land use policy are seen as the ways forward in halting the decline in wildlife in the rangelends and in fostering its conservation through utilization.

Changing wildlife populations in Nairobi national park and adjoining Athi-Kaputiei plains: Collapse of the migratory Wildebeest

There is mounting concern about declines in wildlife populations in many protected areas in Africa. Migratory ungulates are especially vulnerable to impacts of changing land use outside protected areas on their abundance. Range compression may compromise the capacity of migrants to cope with climatic variation, and accentuate both competitive interactions and predation. We analyzed the population dynamics of 11 ungulate species within Kenyas Nairobi National Park, and compared them to those in the adjoining Athi-Kaputiei Plains, where human settlements and other develop- ments had expanded. The migratory wildebeest decreased from almost 30,000 animals in 1978 to around 5,000 currently but the migratory zebra changed little regionally. Hartebeest, impala, eland, Thomsons gazelle, Grants gazelle, water- buck, warthog and giraffe numbers declined regionally, whereas buffalo numbers expanded. Bimonthly counts indicated temporary movements of several species beyond the unfenced park boundaries, especially during very wet years and that few wildebeest entered the park during the dry season following exceptionally wet conditions in 1998. Wildebeest were especially vulnerable to anthropogenic impacts in their wet season dispersal range on the plains. Deterioration in grassland conditions in the park following high rainfall plus lack of burning may have discouraged these animals from using the park as a dry season refuge. Our findings emphasise the interdependency between the park and the plains for seasonal wildlife movements, especially in exceptionally dry or wet years. To effectively conserve these ungulates, we recommend implementation of the new land-use plan for the Athi-Kaputiei Plains by the county government; expansion of the land leasing program for biodiversity payments; collecting poachers snares; negotiation and enforcement of easements, allow- ing both wildlife and livestock to move through the Athi-Kaputiei Plains, providing incentives for conservation to land- owners; and improving grassland conditions within the park through controlled burning so that more wildlife can gain protection there.

Spotting East African mammals in open savannah from space

Knowledge of population dynamics is essential for managing and conserving wildlife. Traditional methods of counting wild animals such as aerial survey or ground counts not only disturb animals, but also can be labour intensive and costly. New, commercially available very high-resolution satellite images offer great potential for accurate estimates of animal abundance over large open areas. However, little research has been conducted in the area of satellite-aided wildlife census, although computer processing speeds and image analysis algorithms have vastly improved. This paper explores the possibility of detecting large animals in the open savannah of Maasai Mara National Reserve, Kenya from very high-resolution GeoEye-1 satellite images. A hybrid image classification method was employed for this specific purpose by incorporating the advantages of both pixel-based and object-based image classification approaches. This was performed in two steps: firstly, a pixel-based image classification method, i.e., artificial neural network was applied to classify potential targets with similar spectral reflectance at pixel level; and then an object-based image classification method was used to further differentiate animal targets from the surrounding landscapes through the applications of expert knowledge. As a result, the large animals in two pilot study areas were successfully detected with an average count error of 8.2%, omission error of 6.6% and commission error of 13.7%. The results of the study show for the first time that it is feasible to perform automated detection and counting of large wild animals in open savannahs from space, and therefore provide a complementary and alternative approach to the conventional wildlife survey techniques.

Toward climate-smart agriculture in West Africa: a review of climate change impacts, adaptation strategies and policy developments for the livestock, fishery and crop production sectors

Many projections of the impact of climate change on the crop, livestock and fishery production sectors of African agriculture are reported in the literature. However, they may be arguably too general to understand the magnitude of impact and to inform adaptation strategies and policy development efforts that are tailored to promoting climate-smart agriculture in the West African region alone. This paper was synthesized from several scholarly literature and aimed at providing up-to-date information on climate change impacts, adaptation strategies, policies and institutional mechanisms that each agriculture subsector had put in place in dealing with climate change and its related issues in West Africa. For each subsector (crop, fishery and livestock), the current status, climate change impacts, mitigation and adaption strategies have been analyzed. In addition, we reviewed recent policy initiatives in the region that foster the development and adoption of climate-smart agricultural options to improve resilience of farming systems and livelihoods of smallholder farmers to climate change risks. From community to national and regional levels, various strategies and policies are also being taken to guide actions and investment for climate-smart agriculture in West Africa.