Developing fencing policies in dryland ecosystems

The daily energy requirements of animals are determined by a combination of physical and physiological factors, but food availability may challenge the capacity to meet nutritional needs. Western gorillas (Gorilla gorilla) are an interesting model for investigating this topic because they are folivore-frugivores that adjust their diet and activities to seasonal variation in fruit availability. Observations of one habituated group of western gorillas in Bai-Hokou, Central African Republic (December 2004-December 2005) were used to examine seasonal variation in diet quality and nutritional intake. We tested if during the high fruit season the food consumed by western gorillas was higher in quality (higher in energy, sugar, fat but lower in fibre and antifeedants) than during the low fruit season. Food consumed during the high fruit season was higher in digestible energy, but not any other macronutrients. Second, we investigated whether the gorillas increased their daily intake of carbohydrates, metabolizable energy (KCal/g OM), or other nutrients during the high fruit season. Intake of dry matter, fibers, fat, protein and the majority of minerals and phenols decreased with increased frugivory and there was some indication of seasonal variation in intake of energy (KCal/g OM), tannins, protein/fiber ratio, and iron. Intake of non-structural carbohydrates and sugars was not influenced by fruit availability. Gorillas are probably able to extract large quantities of energy via fermentation since they rely on proteinaceous leaves during the low fruit season. Macronutrients and micronutrients, but not digestible energy, may be limited for them during times of low fruit availability because they are hind-gut fermenters. We discuss the advantages of seasonal frugivores having large dietary breath and flexibility, significant characteristics to consider in the conservation strategies of endangered species

Spatial distribution of heavy metals in soil with distance from Tazama pipeline through the Mikumi National Park, Tanzania

Journal of Soil Science and Environmental Management, Vol. 10(5), pp. 75-81, July 2019A total concentration of six studied heavy metals Arsenic (As), Lead (Pb), Chromium(Cr), Mercury (Hg) Cadmium (Cd) and Copper (Cu) were measured in soil across distances from TAZAMA pipeline in transects which have incidences of oil spillage and those which have no history of oil spillage. All studied heavy metals were detected in the study area. As, Pb and Cr were detected in both transects, that is, with oils spills and those with no history of oil spillage to a distance of 0-35 m from the edge of the pipeline, with higher mean concentration in transects with oil spillage compared to those with none. From 50-200 m away from the pipeline these four metals were detected in transects with oil spillage only. Hg and Cd were detected in transects with history of oil spillage only. Cu was detected in all transects and at all ranges of distance. Concentration of studied heavy metals decreased with increased distance from the edge of the pipeline in both transects to all directions. The decrease was statistically significant in transects with oil spillage and insignificant with transects of no history of oil spillage

Spatial distribution of heavy metals in soil with distance from Tazama pipeline through the Mikumi National Park, Tanzania

Journal of Soil Science and Environmental Management, Vol. 10(5), pp. 75-81, July 2019A total concentration of six studied heavy metals Arsenic (As), Lead (Pb), Chromium(Cr), Mercury (Hg) Cadmium (Cd) and Copper (Cu) were measured in soil across distances from TAZAMA pipeline in transects which have incidences of oil spillage and those which have no history of oil spillage. All studied heavy metals were detected in the study area. As, Pb and Cr were detected in both transects, that is, with oils spills and those with no history of oil spillage to a distance of 0-35 m from the edge of the pipeline, with higher mean concentration in transects with oil spillage compared to those with none. From 50-200 m away from the pipeline these four metals were detected in transects with oil spillage only. Hg and Cd were detected in transects with history of oil spillage only. Cu was detected in all transects and at all ranges of distance. Concentration of studied heavy metals decreased with increased distance from the edge of the pipeline in both transects to all directions. The decrease was statistically significant in transects with oil spillage and insignificant with transects of no history of oil spillage

Conserving large populations of lions - the argument for fences has holes

Packer et al. reported that fenced lion populations attain densities closer to carrying capacity than unfenced populations. However, fenced populations are often maintained above carrying capacity, and most are small. Many more lions are conserved per dollar invested in unfenced ecosystems, which avoid the ecological and economic costs of fencing