Precipitous declines in Africa's native fauna and flora are recognized, but few comprehensive records of these changes have been compiled. Here, we present population trends for African elephants in the 6,213,000 km2 Sudano-Sahelian range of West and Central Africa assessed through the analysis of aerial and ground surveys conducted over the past 4 decades. These surveys are focused on the best protected areas in the region, and therefore represent the best case scenario for the northern savanna elephants. A minimum of 7,745 elephants currently inhabit the entire region, representing a minimum decline of 50% from estimates four decades ago for these protected areas. Most of the historic range is now devoid of elephants and, therefore, was not surveyed. Of the 23 surveyed elephant populations, half are estimated to number less than 200 individuals. Historically, most populations numbering less than 200 individuals in the region were extirpated within a few decades. Declines differed by region, with Central African populations experiencing much higher declines (−76%) than those in West Africa (−33%). As a result, elephants in West Africa now account for 86% of the total surveyed. Range wide, two refuge zones retain elephants, one in West and the other in Central Africa. These zones are separated by a large distance (∼900 km) of high density human land use, suggesting connectivity between the regions is permanently cut. Within each zone, however, sporadic contacts between populations remain. Retaining such connectivity should be a high priority for conservation of elephants in this region. Specific corridors designed to reduce the isolation of the surveyed populations are proposed. The strong commitment of governments, effective law enforcement to control the illegal ivory trade and the involvement of local communities and private partners are all critical to securing the future of elephants inhabiting Africa's northern savannas.

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Twelve multiparous Holstein cows calving in fall and 12 calving in summer were blocked into four groups and used in a 2 x 2 x 2 factorial to determine the effects of season of calving, dietary fat, and protein degradability on milk production and efficiency of NEL utilization in a 16-wk study. Blocks were assigned randomly to one of four dietary treatment combinations: 1) control concentrate plus soybean meal (high degradability protein supplement); 2) control concentrate plus a mixture of heated soybean meal and corn gluten meal (low degradability protein supplement); 3) a blend of the control concentrate and a concentrate containing 12.1% fat to provide 1 kg d-1 fat, plus soybean meal; and 4) concentrate as in diet 3 plus heated soybean meal and corn gluten meal. Nutrient intake, milk yield and composition, BW changes, and daily ambient temperature were monitored. Intake of DM appeared to be related to NDF intake but was not affected by fat, protein degradability, or calving season. Intake of NEL was increased by feeding fat. Digestabilities of DM and CP were increased and fiber was decreased by feeding fat. Percentage and yields of milk fat, SNF, and protein and 4% FCM production were higher in cows calving in fall. Milk fat percentage was low in all cows in the study. Efficiency of energy utilization for milk production was decreased in cows fed fat and calving in the summer and by low protein degradability during wk 5 to 8 of lactation. At high concentrate intake, calving season had more effect on milk production than level of fat or protein degradability.

Une alimentation diversifiée est nécessaire pour apporter à l'organisme l'essentiel des nutriments dont il a besoin pour son fonctionnement. L'objectif de ce travail a été d'évaluer la consommation alimentaire des ménages dans la partie Nord du Burkina Faso et d'identifier les déterminants de la diversité alimentaire. L'évaluation de la diversité alimentaire a été réalisée à partir du calcul du score de diversité alimentaire des ménages à l'aide de l'outil RHoMIS (Rural Household Multiple Indicator Survey). Une enquête a été conduite auprès de 300 ménages pour caractériser le profil socio-économique et la consommation alimentaire au sein de ces ménages. La valeur moyenne du score de diversité alimentaire des ménages pour une période de référence de 7 jours, a été de 7,3 (0,1) durant la période favorable et de 5,7 (0,1) durant la période de soudure. Les céréales ont constitué l'aliment énergétique de base et le niébé a représenté l'essentiel des aliments protéiques, la consommation des produits d'origine animale étant faible. Les résultats montrent que le nombre de cultures produites par le ménage et les revenus agricoles ne sont pas positivement associés à la diversité alimentaire élevée. Seul le revenu provenant de l'orpaillage est associé positivement à une diversité alimentaire élevée.

Pratiques agricoles et risque de dégradation des ressources naturelles