Occupancy and habitat use by six species of forest ungulates on Tiwai Island, Sierra Leone

Forest ungulates in West Africa are common bushmeat species and are subject to habitat degradation through deforestation. Based on historical data, there are possibly 12 species of forest Bovidae and Tragulidae found in eastern Sierra Leone. We used camera trapping to assess occupancy by forest ungulates on and around a small protected area, Tiwai Island, Sierra Leone. We then assessed habitat over two field seasons during 2008–2011 for those species where we had sufficient numbers of detections. We detected 6 of 12 potential species and obtained enough data to further assess the habitat of two species. Species detected included the black duiker (Cephalophus niger), bongo (Tragelaphus eurycerus), bushbuck (Tragelaphus scriptus), Maxwell’s duiker (Philantomba maxwellii), water chevrotain (Hyemoschus aquaticus) and yellow-backed duiker (Cephalophus silvicultor). Among detected species, the bongo is considered near threatened. Several of the species not detected might be extirpated from the region, but for several species we found no records of them in the area. For the two species with sufficient detections for analysis, we found that Maxwell’s duikers were common throughout woody and swamp habitat and yellow-backed duikers preferred old growth forests with open understory. Despite widespread deforestation in Sierra Leone, a recent civil war and continued bushmeat trade, it appears that small wildlife refuges such as Tiwai Island continue to provide sanctuary for many of the forest ungulates of the region. Conservation implications: The Guinea Rainforest ecosystem of West Africa has undergone significant human impact and deforestation, negatively impacting all aspects of the biodiversity of the region. In addition, a long-standing civil war in Sierra Leone further exacerbated conservation concerns of many wildlife species. There are some recognised reserves in Sierra Leone, but small reserves managed by local people and conservation organisations have a role to play. Our work on Tiwai Island, along the Moa River in Sierra Leone, demonstrated that a significant proportion of the forest dwelling ungulate biodiversity of the region has been maintained in a small reserve despite isolation and effects of the war. Our work also suggests that Tiwai Island continues to have significant ecological value for ungulate conservation in the region and should be considered a model for establishment of other small reserves to help maintain the region’s biodiversity

Local awareness of and attitudes toward pygmy hippopotamus conservation in the Moa River Island Complex, Sierra Leone.

Abstract The pygmy hippopotamus Choeropsis liberiensis is an Endangered species found only in the Upper Guinea rainforests of West Africa. Using a two-phase approach, with initial semi-structured interviews followed by more extensive questionnaires, we examined local residents’ awareness of and attitudes towards the pygmy hippopotamus along the Moa River near Tiwai Island Wildlife Sanctuary in Sierra Leone. The interviews and questionnaires addressed human–hippopotamus interactions, local knowledge and awareness of pygmy hippopotamus ecology and behaviour, and public attitudes towards hippopotamus conservation. Overall, 22% of questionnaire respondents acknowledged benefits related to hippopotamus conservation; factors affecting the perception of benefits included age, livestock ownership, distance from Tiwai Island and exposure to conservation programmes. The results of this study could be used to inform the conservation of the pygmy hippopotamus and highlight the critical role of local support in the management of threatened species in biodiversity hotspots

Occupancy and habitat use by six species of forest ungulates on Tiwai Island, Sierra Leone

Forest ungulates in West Africa are common bushmeat species and are subject to habitat degradation through deforestation. Based on historical data, there are possibly 12 species of forest Bovidae and Tragulidae found in eastern Sierra Leone. We used camera trapping to assess occupancy by forest ungulates on and around a small protected area, Tiwai Island, Sierra Leone. We then assessed habitat over two field seasons during 2008–2011 for those species where we had sufficient numbers of detections. We detected 6 of 12 potential species and obtained enough data to further assess the habitat of two species. Species detected included the black duiker (Cephalophus niger), bongo (Tragelaphus eurycerus), bushbuck (Tragelaphus scriptus), Maxwell’s duiker (Philantomba maxwellii), water chevrotain (Hyemoschus aquaticus) and yellow-backed duiker (Cephalophus silvicultor). Among detected species, the bongo is considered near threatened. Several of the species not detected might be extirpated from the region, but for several species we found no records of them in the area. For the two species with sufficient detections for analysis, we found that Maxwell’s duikers were common throughout woody and swamp habitat and yellow-backed duikers preferred old growth forests with open understory. Despite widespread deforestation in Sierra Leone, a recent civil war and continued bushmeat trade, it appears that small wildlife refuges such as Tiwai Island continue to provide sanctuary for many of the forest ungulates of the region. Conservation implications: The Guinea Rainforest ecosystem of West Africa has undergone significant human impact and deforestation, negatively impacting all aspects of the biodiversity of the region. In addition, a long-standing civil war in Sierra Leone further exacerbated conservation concerns of many wildlife species. There are some recognised reserves in Sierra Leone, but small reserves managed by local people and conservation organisations have a role to play. Our work on Tiwai Island, along the Moa River in Sierra Leone, demonstrated that a significant proportion of the forest dwelling ungulate biodiversity of the region has been maintained in a small reserve despite isolation and effects of the war. Our work also suggests that Tiwai Island continues to have significant ecological value for ungulate conservation in the region and should be considered a model for establishment of other small reserves to help maintain the region’s biodiversity

Carbon nutrition of \u3cem\u3eEscherichia coli\u3c/em\u3e in the mouse intestine

Whole-genome expression profiling revealed Escherichia coli MG1655 genes induced by growth on mucus, conditions designed to mimic nutrient availability in the mammalian intestine. Most were nutritional genes corresponding to catabolic pathways for nutrients found in mucus. We knocked out several pathways and tested the relative fitness of the mutants for colonization of the mouse intestine in competition with their wild-type parent. We found that only mutations in sugar pathways affected colonization, not phospholipid and amino acid catabolism, not gluconeogenesis, not the tricarboxylic acid cycle, and not the pentose phosphate pathway. Gluconate appeared to be a major carbon source used by E. coli MG1655 to colonize, having an impact on both the initiation and maintenance stages. N-acetylglucosamine and N-acetylneuraminic acid appeared to be involved in initiation, but not maintenance. Glucuronate, mannose, fucose, and ribose appeared to be involved in maintenance, but not initiation. The in vitro order of preference for these seven sugars paralleled the relative impact of the corresponding metabolic lesions on colonization: gluconate \u3e N-acetylglucosamine \u3e N-acetylneuraminic acid = glucuronate \u3e mannose \u3e fucose \u3e ribose. The results of this systematic analysis of nutrients used by E. coli MG1655 to colonize the mouse intestine are intriguing in light of the nutrient-niche hypothesis, which states that the ecological niches within the intestine are defined by nutrient availability. Because humans are presumably colonized with different commensal strains, differences in nutrient availability may provide an open niche for infecting E. coli pathogens in some individuals and a barrier to infection in others

Respiration of \u3cem\u3eEscherichia coli\u3c/em\u3e in the Mouse Intestine

Mammals are aerobes that harbor an intestinal ecosystem dominated by large numbers of anaerobic microorganisms. However, the role of oxygen in the intestinal ecosystem is largely unexplored. We used systematic mutational analysis to determine the role of respiratory metabolism in the streptomycin-treated mouse model of intestinal colonization. Here we provide evidence that aerobic respiration is required for commensal and pathogenic Escherichia coli to colonize mice. Our results showed that mutants lacking ATP synthase, which is required for all respiratory energy-conserving metabolism, were eliminated by competition with respiratory-competent wild-type strains. Mutants lacking the high-affinity cytochrome bd oxidase, which is used when oxygen tensions are low, also failed to colonize. However, the low-affinity cytochrome bo3 oxidase, which is used when oxygen tension is high, was found not to be necessary for colonization. Mutants lacking either nitrate reductase or fumarate reductase also had major colonization defects. The results showed that the entire E. coli population was dependent on both microaerobic and anaerobic respiration, consistent with the hypothesis that the E. coli niche is alternately microaerobic and anaerobic, rather than static. The results indicate that success of the facultative anaerobes in the intestine depends on their respiratory flexibility. Despite competition for relatively scarce carbon sources, the energy efficiency provided by respiration may contribute to the widespread distribution (i.e., success) of E. coli strains as commensal inhabitants of the mammalian intestine

Comparison of Carbon Nutrition for Pathogenic and Commensal ,\u3cem\u3eEscherichia coli\u3c/em\u3e Strains in the Mouse Intestine

The carbon sources that support the growth of pathogenic Escherichia coli O157:H7 in the mammalian intestine have not previously been investigated. In vivo, the pathogenic E. coli EDL933 grows primarily as single cells dispersed within the mucus layer that overlies the mouse cecal epithelium. We therefore compared the pathogenic strain and the commensal E. coli strain MG1655 modes of metabolism in vitro, using a mixture of the sugars known to be present in cecal mucus, and found that the two strains used the 13 sugars in a similar order and cometabolized as many as 9 sugars at a time. We conducted systematic mutation analyses of E. coli EDL933 and E. coli MG1655 by using lesions in the pathways used for catabolism of 13 mucus-derived sugars and five other compounds for which the corresponding bacterial gene system was induced in the transcriptome of cells grown on cecal mucus. Each of 18 catabolic mutants in both bacterial genetic backgrounds was fed to streptomycin-treated mice, together with the respective wild-type parent strain, and their colonization was monitored by fecal plate counts. None of the mutations corresponding to the five compounds not found in mucosal polysaccharides resulted in colonization defects. Based on the mutations that caused colonization defects, we determined that both E. coli EDL933 and E. coli MG1655 used arabinose, fucose, and N-acetylglucosamine in the intestine. In addition, E. coli EDL933 used galactose, hexuronates, mannose, and ribose, whereas E. coli MG1655 used gluconate and N-acetylneuraminic acid. The colonization defects of six catabolic lesions were found to be additive with E. coli EDL933 but not with E. coli MG1655. The data indicate that pathogenic E. coli EDL933 uses sugars that are not used by commensal E. coli MG1655 to colonize the mouse intestine. The results suggest a strategy whereby invading pathogens gain advantage by simultaneously consuming several sugars that may be available because they are not consumed by the commensal intestinal microbiota

Occupancy and habitat use by six species of forest ungulates on Tiwai Island, Sierra Leone

Forest ungulates in West Africa are common bushmeat species and are subject to habitat degradation through deforestation. Based on historical data, there are possibly 12 species of forest Bovidae and Tragulidae found in eastern Sierra Leone. We used camera trapping to assess occupancy by forest ungulates on and around a small protected area, Tiwai Island, Sierra Leone. We then assessed habitat over two field seasons during 2008–2011 for those species where we had sufficient numbers of detections. We detected 6 of 12 potential species and obtained enough data to further assess the habitat of two species. Species detected included the black duiker (Cephalophus niger), bongo (Tragelaphus eurycerus), bushbuck (Tragelaphus scriptus), Maxwell’s duiker (Philantomba maxwellii), water chevrotain (Hyemoschus aquaticus) and yellow-backed duiker (Cephalophus silvicultor). Among detected species, the bongo is considered near threatened. Several of the species not detected might be extirpated from the region, but for several species we found no records of them in the area. For the two species with sufficient detections for analysis, we found that Maxwell’s duikers were common throughout woody and swamp habitat and yellow-backed duikers preferred old growth forests with open understory. Despite widespread deforestation in Sierra Leone, a recent civil war and continued bushmeat trade, it appears that small wildlife refuges such as Tiwai Island continue to provide sanctuary for many of the forest ungulates of the region. Conservation implications: The Guinea Rainforest ecosystem of West Africa has undergone significant human impact and deforestation, negatively impacting all aspects of the biodiversity of the region. In addition, a long-standing civil war in Sierra Leone further exacerbated conservation concerns of many wildlife species. There are some recognised reserves in Sierra Leone, but small reserves managed by local people and conservation organisations have a role to play. Our work on Tiwai Island, along the Moa River in Sierra Leone, demonstrated that a significant proportion of the forest dwelling ungulate biodiversity of the region has been maintained in a small reserve despite isolation and effects of the war. Our work also suggests that Tiwai Island continues to have significant ecological value for ungulate conservation in the region and should be considered a model for establishment of other small reserves to help maintain the region’s biodiversity

Local awareness of and attitudes toward pygmy hippopotamus conservation in the Moa River Island Complex, Sierra Leone.

Abstract The pygmy hippopotamus Choeropsis liberiensis is an Endangered species found only in the Upper Guinea rainforests of West Africa. Using a two-phase approach, with initial semi-structured interviews followed by more extensive questionnaires, we examined local residents’ awareness of and attitudes towards the pygmy hippopotamus along the Moa River near Tiwai Island Wildlife Sanctuary in Sierra Leone. The interviews and questionnaires addressed human–hippopotamus interactions, local knowledge and awareness of pygmy hippopotamus ecology and behaviour, and public attitudes towards hippopotamus conservation. Overall, 22% of questionnaire respondents acknowledged benefits related to hippopotamus conservation; factors affecting the perception of benefits included age, livestock ownership, distance from Tiwai Island and exposure to conservation programmes. The results of this study could be used to inform the conservation of the pygmy hippopotamus and highlight the critical role of local support in the management of threatened species in biodiversity hotspots

Human-wildlife Conflict, Conservation Attitudes, and a Potential Role for Citizen Science in Sierra Leone, Africa

Protection of tropical biodiversity is often difficult due to persistent gaps in ecological data and complex conflicts between wildlife conservation and human livelihoods. To better understand the nature and extent of these conflicts, we conducted intercept surveys (n = 522) with local villagers around the Tiwai Island Wildlife Sanctuary in Sierra Leone (August - December, 2010). Results revealed high levels of crop depredation, retaliatory killing, and bushmeat harvesting in villages surrounding the protected area. We also found that pro-conservation attitudes were less prevalent among younger adults and immigrants to the region. Efforts to mitigate human-wildlife conflict could emphasise an enhanced awareness and appreciation of wildlife resources among these particular socio-demographic groups. In the second part of our study (May 2012), we interviewed a subset of local residents (n = 14) to explore the feasibility and utility of expanding our initial survey effort to create a more comprehensive and sustainable framework for monitoring human-wildlife interactions based on Public Participation in Scientific Research (PPSR) principles. Findings highlighted the challenges of implementing a PPSR-type model in this difficult management context and the potential benefits of using “citizen science” to improve data collection capacity, increase local empowerment, and influence wildlife conservation