Contrasts in Livelihoods and Protein Intake between Commercial and Subsistence Bushmeat Hunters in Two Villages on Bioko Island,Equatorial Guinea

Across West and Central Africa, wildlife provides a source of food and income. We investigated the relation between bushmeat hunting and household wealth and protein consumption in 2 rural communities in Bioko Island, Equatorial Guinea. One village was dedicated to commercial hunting, the other trapped game primarily for food. We tested whether commercial‐hunter households were nutritionally advantaged over subsistence‐hunter households due to their higher income from the bushmeat trade and greater access to wild‐animal protein. We conducted bushmeat‐offtake surveys in both villages (captures by hunters and carcasses arriving to each village). Mammals (including threatened primates: black colobus [Colobus satanas], Preussi's guenon [Allochrocebus preussi], and russet‐eared guenon [Cercopithecus erythrotis]), birds, and reptiles were hunted. The blue duiker (Philantomba monticola), giant pouched rat (Cricetomys emini), and brush‐tailed porcupine (Atherurus africanus) contributed almost all the animal biomass hunted, consumed, or sold in both villages. Monkeys and Ogilbyi's duikers (Cephalophus ogilbyi) were hunted only by commercial hunters. Commercial hunters generated a mean of US$2000/year from bushmeat sales. Households with commercial hunters were on average wealthier, generated more income, spent more money on nonessential goods, and bought more products they did not grow. By contrast, households with subsistence hunters spent less on market items, spent more on essential products, and grew more of their own food. Despite these differences, average consumption of vegetable protein and domestic meat and bushmeat protein did not differ between villages. Our results highlight the importance of understanding the socioeconomic and nutritional context of commercial and subsistence bushmeat hunting to correctly interpret ways of reducing their effects on threatened species and to enable the sustainable offtake of more productive taxa. Contrastes en el Sustento y la Ingesta de Proteínas entre Carne de Caza de Subsistencia y Comercial en Dos Aldeas en Isla Bioko, Guinea Ecuatorial     

Warfare in Biodiversity Hotspots

Abstract:  Conservation efforts are only as sustainable as the social and political context within which they take place. The weakening or collapse of sociopolitical frameworks during wartime can lead to habitat destruction and the erosion of conservation policies, but in some cases, may also confer ecological benefits through altered settlement patterns and reduced resource exploitation. Over 90% of the major armed conflicts between 1950 and 2000 occurred within countries containing biodiversity hotspots, and more than 80% took place directly within hotspot areas. Less than one-third of the 34 recognized hotspots escaped significant conflict during this period, and most suffered repeated episodes of violence. This pattern was remarkably consistent over these 5 decades. Evidence from the war-torn Eastern Afromontane hotspot suggests that biodiversity conservation is improved when international nongovernmental organizations support local protected area staff and remain engaged throughout the conflict. With biodiversity hotspots concentrated in politically volatile regions, the conservation community must maintain continuous involvement during periods of war, and biodiversity conservation should be incorporated into military, reconstruction, and humanitarian programs in the world's conflict zones.     

Decision Making in a Human Population Living Sustainably

Abstract: The Tiwi people of northern Australia have managed natural resources continuously for 6000–8000 years. Tiwi management objectives and outcomes may reflect how they gather information about the environment. We qualitatively analyzed Tiwi documents and management techniques to examine the relation between the social and physical environment of decision makers and their decision‐making strategies. We hypothesized that principles of bounded rationality, namely, the use of efficient rules to navigate complex decision problems, explain how Tiwi managers use simple decision strategies (i.e., heuristics) to make robust decisions. Tiwi natural resource managers reduced complexity in decision making through a process that gathers incomplete and uncertain information to quickly guide decisions toward effective outcomes. They used management feedback to validate decisions through an information loop that resulted in long‐term sustainability of environmental use. We examined the Tiwi decision‐making processes relative to management of barramundi (Lates calcarifer) fisheries and contrasted their management with the state government's management of barramundi. Decisions that enhanced the status of individual people and their attainment of aspiration levels resulted in reliable resource availability for Tiwi consumers. Different decision processes adopted by the state for management of barramundi may not secure similarly sustainable outcomes.     

Toxicity and Repellency of Hot Pepper Extracts to Spider Mite,Tetranychus urticae Koch

Increasing concern about persistence and environmental impact of synthetic pesticide residues require development of biodegradable and environmentally safe alternatives. The potential of using fruit extracts of hot pepper as alternatives to synthetic acaricides for controlling the two-spotted spider mite, Tetranychus urticae Koch, is explored in this study. Twenty-four Capsicum accessions (Solanaceae) were screened for their toxicity and repellency to the spider mites. Crude extracts from fruits of C. chinense, C. frutescens, C. baccatum, C. annuum, and C. pubescens were prepared in methanol and tested for their acaricidal properties. Spider mite mortality was greatest (45%) when fruit extract of accession Grif-9169 (C. annuum) was used. Results from diving board bioassays indicated that mites avoided filter paper strips treated with hot pepper extracts from accessions PI-596057 (C. baccatum), PI-195299 (C. annuum), and Grif- 9270 (C. annuum). This investigation suggests that methanolic extracts of these three accessions may have a great potential for repelling spider mites and should be field-tested on a large-scale to assess their value in managing populations of spider mites, which could reduce reliance on synthetic acaricides. An attempt was made to correlate repellency with chemical constituents of fruit extracts of the most repellent accessions to identify chemical sources of repellency. Capsaicin and dihydrocapsaicin, the pungent components of pepper fruit, were not correlated with toxicity or repellency, indicating that these are not likely related to the toxicity or repellency of the pepper fruit extracts. Other, unidentified chemicals are likely responsible for toxicity and repellency to the two-spotted spider mite     

Effects of Habitat Fragmentation on Effective Dispersal of Florida Scrub‐Jays

Abstract: Studies comparing dispersal in fragmented versus unfragmented landscapes show that habitat fragmentation alters the dispersal behavior of many species. We used two complementary approaches to explore Florida Scrub‐Jay (Aphelocoma c?rulescens) dispersal in relation to landscape fragmentation. First, we compared dispersal distances of color‐marked individuals in intensively monitored continuous and fragmented landscapes. Second, we estimated effective dispersal relative to the degree of fragmentation (as inferred from two landscape indexes: proportion of study site covered with Florida Scrub‐Jay habitat and mean distance to nearest habitat patch within each study site) by comparing genetic isolation‐by‐distance regressions among 13 study sites having a range of landscape structures. Among color‐banded individuals, dispersal distances were greater in fragmented versus continuous landscapes, a result consistent with other studies. Nevertheless, genetic analyses revealed that effective dispersal decreases as the proportion of habitat in the landscape decreases. These results suggest that although individual Florida Scrub‐Jays may disperse farther as fragmentation increases, those that do so are less successful as breeders than those that disperse short distances. Our study highlights the importance of combining observational data with genetic inferences when evaluating the complex biological and life‐history implications of dispersal.     

Translocation as a Tool for Mitigating Conflict with Leopards in Human‐Dominated Landscapes of India

Abstract: We examined the efficacy of a translocation program in which large numbers of leopards (Panthera pardus fusca) were trapped in human‐dominated landscapes where livestock attacks were common and human attacks rare and released into adjoining forested areas in an attempt to reduce leopard presence and mitigate conflicts at the capture site. In the year starting in February of 2001, 29 leopards were captured in the human‐dominated rural landscape of the Junnar region (4275 km², 185 people/km²), Maharashtra, India, and released an average of 39.5 km away in adjoining forests. Eleven leopards were also relocated to the same forests from other districts. Prior to the large‐scale translocation program, an average of four leopard attacks on humans occurred each year between 1993 and 2001. After the translocation program was initiated, the average increased substantially to 17 attacks. Linear and logistic models showed that attack frequency increased in Junnar following nearby releases of leopards and decreased when leopards were removed for releases far away; that attacks became more lethal when the number of leopards introduced from other districts increased; and that attacks were most likely to occur in the regions where the largest number of leopards had been introduced from other areas. These results suggest that leopards did not stay at the release sites and that translocation induced attacks on people. Potential explanations for these results include increased aggression induced by stress of the translocation process, movement through unfamiliar human‐dominated landscapes following release, and loss of fear of humans due to familiarity with humans acquired during captivity. Our results show that reactive solutions to attacks on humans by leopards, such as translocation, could in fact increase human–leopard conflict. Measures to reduce human–carnivore conflicts may include more effective compensation procedures to pay livestock owners for the loss of animals to predation by carnivores, providing better methods of protection for livestock, and encouraging greater social acceptance of the presence of carnivores in human‐dominated landscapes.     

Acceleration of Exotic Plant Invasion in a Forested Ecosystem by a Generalist Herbivore

Abstract: The successful invasion of exotic plants is often attributed to the absence of coevolved enemies in the introduced range (i.e., the enemy release hypothesis). Nevertheless, several components of this hypothesis, including the role of generalist herbivores, remain relatively unexplored. We used repeated censuses of exclosures and paired controls to investigate the role of a generalist herbivore, white‐tailed deer (Odocoileus virginianus), in the invasion of 3 exotic plant species (Microstegium vimineum, Alliaria petiolata, and Berberis thunbergii) in eastern hemlock (Tsuga canadensis) forests in New Jersey and Pennsylvania (U.S.A.). This work was conducted in 10 eastern hemlock (T. canadensis) forests that spanned gradients in deer density and in the severity of canopy disturbance caused by an introduced insect pest, the hemlock woolly adelgid (Adelges tsugae). We used maximum likelihood estimation and information theoretics to quantify the strength of evidence for alternative models of the influence of deer density and its interaction with the severity of canopy disturbance on exotic plant abundance. Our results were consistent with the enemy release hypothesis in that exotic plants gained a competitive advantage in the presence of generalist herbivores in the introduced range. The abundance of all 3 exotic plants increased significantly more in the control plots than in the paired exclosures. For all species, the inclusion of canopy disturbance parameters resulted in models with substantially greater support than the deer density only models. Our results suggest that white‐tailed deer herbivory can accelerate the invasion of exotic plants and that canopy disturbance can interact with herbivory to magnify the impact. In addition, our results provide compelling evidence of nonlinear relationships between deer density and the impact of herbivory on exotic species abundance. These findings highlight the important role of herbivore density in determining impacts on plant abundance and provide evidence of the operation of multiple mechanisms in exotic plant invasion.     

COMBUSTION OF LOW QUALITY COALS IN FLUIDIZED BED STEAM GENERATORS

A new combustion technology has been developed in the last decade that permits the burning of low quality coal, lignite and other fuels, while maintaining stack emissions within reasonable limits. Low quality fuels can be burned directly in fluidized beds, taking advantage of low furnace temperatures and chemical activity within the bed to limit SO₂ and NO_x emissions, thereby eliminating the need for stack gas scrubbing equipment. The excellent heat transfer characteristics of the fluidized beds also result in a reduction of total heat transfer surface requirements, thus reducing the size and cost of steam generators. Tests on beds operating at pressures of one to ten atmospheres, at temperatures as high as 900°C, and with gas velocities in the vicinity of 1.30 to 4 m/s, have proven the concept. Early history of this technology is traced, and the progress that has been made in the development of fluidized bed combustion boilers, as well as work currently underway in the United States and overseas are reviewed. Details of selected fluidized bed boiler installations are presented, test results are discussed and the potential application of fluidized bed boilers in industrial plants using peat, anthracite refuse, lignite and lignite refuse is examined. Dans la demière décennie, une nouvelle technique de combustion a vu le jour, permettant de brûler du charbon de qualité inférieure, de la lignite et d'autres combustibles tout en maintenant les émanations de cheminée dans des normes raisonnables. Des combustibles de qualité inférieure peuvent être brûlés directement dans des lits liquéfiés tout en profitant des basses températures de fourneaux et des réactions chimiques dans le lit afín de limiter les émissions de bioxide de soufre (SO₂) et d'oxide nitreux (NO_x), rendant ainsi inutile tout matériel de nettoyage des émanations de cheminée. Les excellentes possibilités en matiêre de transmission de chaleur que présentent les lits liquéfiés permettent également de réduire la surface totale nécessaire au transfert de chaleur, diminuant ainsi la dimension et le coût des générateurs à vapeur. Des essais concluants ont été effectués dans des lits fonctionnant à des pressions de une à dix atmosphères, à des temperatures aussi élevées que 900°C et avec des vitesses d'émanations avoisinant 1.33 á 4 m/s. L'article fait l'historique de cette technique et considère les progrès réalisés dans la construction des chaudières utilisant le procédé de combustion des chaudières des lits liquéfiés ainsi que les travaux actuellement en cours aux Etats-Unis. L'article fournit des details sur les installations utilisant des chaudières pour lits liquéfiés, analyse les résultats des essais et examine les possibilités d'emploi de ces chaudières dans l'industrie alimentée par la tourbe, les déchets d'anthracite, la lignite et ses résidus. En la última década seha desarrollado una nueva tecnología de combustión que permite quemar carbones de bajo grado, lignitos y otros combustibles, manteniendo al mismo tiempo las emisiones de las chimeneas en niveles razonables. Carbones de bajo grado pueden ser quemados directamente en lechos fluizados aprovechando la ventaja de la baja temperature de la cámara de combustión y de la reacciones químicas en el lecho para limitar las emisiones de SO₂ y NO_x, limitando en consecuencia ia necesidad de equipo de limpieza de los gases de chimenea. Las excelentes caracter ísticas de transferencia de calor de los lechos fluizados reducen también las necesidades de superficie de transferencia de calor, lo que resulta en la disminución de costo y tamaño del sistema de generación de vapor. Este concepto queda demostrado por pruebas realized as a presiones de uno a diez atmósferas y temperatures de hasta 900°C, y velocidades de gas en la vecindad de 1.33 a 4 m/s. En este artículo se presenta el desarrollo temprano de esta tecnología, el progreso alcanzado en el desarrollo de calderos utilizando dicha tecnología y los trabajos que se están llevando a cabo en los Estados Unidos en este campo. Se discuten también detalles de instalación de calderos usando la tecnología de lechos fluidizados, las pruebas realizadas así como el potencial de su aplicación en plantas industriales que usan turba, deshechos de antracita, lignito y deshechos de lignito.