Trophic resource use by sympatric vs. allopatric Pelomedusid turtles in West African forest waterbodies

Organisms that are similar in size, morphological characteristics, and adaptations, including vertebrates, often coexist by partitioning the available resources (food, space, and time). So, studies of the dynamics of these cases of coexistence are scientifically interesting. Here, we study a coexistence case of two species of freshwater turtles inhabiting the forest waterbodies of West Africa, focusing on the dietary habits of the two species. We found that both turtle species are omnivorous generalists, eating both vegetal and animal matter abundantly. However, there were clear interspecific differences, with the larger of the two species (P. cupulatta) eating more vertebrates (mainly fish but occasionally other vertebrates), whereas P. castaneus consumed more invertebrates. These patterns appeared consistently within the species and across sites, highlighting that the same patterns were likely in other conspecific populations from the Upper Guinean forest streams (Côte d’Ivoire and Liberia). Our study also showed that interspecific competition for food does not occur between these two species; instead, previous studies uncovered that a clear partitioning of the habitat niche occurs. We conclude that the food resource is likely unlimited in the study areas, as it is not the case in more arid environments (since food shortages may occur during the dry season). We anticipate that, within the Pelomedusidae communities throughout Africa, intense competition for food probably occurs in the Sahel and Sudanian vegetation zones, particularly during the dry months, but is unlikely within the Guinea and wet savannah region and even less likely in the Guineo-Congolian rainforest region

Exploitation Patterns of Anchovies (Engraulis encrasicolus) by Marine Artisanal Fisheries in Togo (West Africa)

Pelagic fish, including sardines and anchovies (Order Clupeiformes), are the most common species taken by artisanal marine fisheries along the Togolese coast. We investigated fisher involvement as well as fish captures over a period of 10 years, particularly of the European anchovy (Engraulis encrasicolus). Our results indicate that 60% of fishers operated from the Lomé fishing harbour, most fishers being Ghanaians working seasonally in Togo. 63.7% of all the fishers used canoes with outboards, a higher percentage compared to the previous decades. Seven fishing gear type were identified, with bottom gillnet and surface gillnet being the most commonly used. However, in the most important fishing camp in the country in terms of fish production (Lomé fishing harbour), all fishers used shark nets. Overall, fisheries catches did not change significantly across years, but anchovy fishing effort and catch per unit of effort (CPUE) declined over the study period, suggesting some depletion of the species stocks on the Togolese coast and a demotivation of fishers.

Exploring the main threats to the threatened African spurred tortoise Centrochelys sulcata in the West African Sahel

AbstractThe African spurred tortoiseCentrochelys sulcatais the second largest terrestrial turtle, with a scattered distribution across the West African Sahel. This species is threatened and declining consistently throughout its range, but little is known about the causes of its decline. It has been hypothesized that the decline is attributable to (1) competition with domestic cattle, (2) wildfire, and (3) the international pet trade. We conducted a series of analyses to investigate these three causes. Hypotheses 1 and 2 were analysed using a spatially explicit approach, using a database of the Food and Agriculture Organization of the United Nations and logistic regression modelling; hypothesis 3 was tested by analysing the CITES trade database for 1990–2010. We found a significant negative correlation between intensity of grazing (expressed as density of cattle, km−2) and the presence of spurred tortoises, and this negative effect increased when coupled with high fire intensity, whereas wildfires alone did not have a significant influence on the species' distribution at the global scale. There was a decrease in the annual export of wild individuals for the pet trade after the introduction of export quotas by country and by year, but trade data must be considered with caution

A preliminary assessment of bacteria in “ranched” ball pythons (Python regius), Togo, West Africa

Captive reptiles are routinely identified as reservoirs of pathogenic bacteria and reports of reptile-associated infections relating to some species are well documented (e.g., salmonellosis). Currently, relatively little is known about the epidemiology and bacteria of ball pythons. We carried out a survey of ball python farms in Togo, West Africa to assess the presence of any potentially pathogenic bacterial taxa that have been identified in recent scientific literature relating to this species. The presence of bacteria belonging to the genera Acinetobacter, Bacteroides, Citrobacter, Enterobacter, Lysobacter, Proteus, Pseudomonas, Staphylococcus, and Tsukamurella in oral and cloacal samples taken from five individual ball pythons is of potential concern for horizontal transmission given that pathogenic species belonging to these genera have been previously documented. The presence of bacteria belonging to the genera Clostridium, Escherichia, Moraxella, and Stenotrophomonas in the oral and rectal samples taken from five mice used to feed ball pythons suggests that they represent a potential reservoir of infection for wild caught ball pythons and their progeny. Furthermore, possible sources of environmental contamination include other captive amphibians, birds, reptiles and mammals, as well as free ranging birds and small mammals. Additional surveillance of ball pythons in the wild and in captivity at python farms in West Africa will shed light on whether or not this type of commercial activity is increasing pathogen exposure and lowering barriers to transmission. Meanwhile, as a precautionary measure, it is recommended that python farms should immediately establish biosecurity and disease surveillance practices to minimize potential horizontal and vertical bacterial transfer

Diversity and Relative Abundance of Ungulates and Other Medium and Large Mammals in Flooded Forests in the Dahomey Gap (Togo)

"The Dahomey Gap" is a human-derived mostly savannah region that separates the Guineo-Congolian rainforest block into two major units: the Upper Guinean and the Lower Guinean Forest blocks. Several forest patches are distributed throughout this savannah-dominated habitat. The mammal communities in the Dahomey Gap region have been poorly studied. In this paper we analyse the species richness and abundance of, as well as conservation implications for, medium and large mammals (especially ungulates) inhabiting a complex of flooded forests near the Mono river in south-eastern Togo. We use several field methods to describe the species richness of mammals in this area, including camera-trapping, recce transects, Kilometric Index of Abundance (KIA) estimates, examination of hunters' catches and face-to-face hunter interviews. Overall, we directly recorded 19 species that coexist in these forests. Based on interviews, nine other species were confirmed as present in the study area. Only five species were common: Cephalophus rufilatus, Tragelaphus scriptus, Chlorocebus aethiops, Atilax paludinosus and Herpestes ichneumon. The area still contains various threatened species such as Tragelaphus spekii and Hippopotamus amphibius. We stress that to ensure the protection of the Dahomey Gap mammals, it is important to seriously consider protecting not only the forest patches but also the surroundings, mainly savannah landscapes

Herpetofaunal Diversity in a Dahomey Gap Savannah of Togo (West Africa): Effects of Seasons on the Populations of Amphibians and Reptiles

The Dahomey Gap is a human-derived savannah zone, interspersed by patches of moist tropical forest, that separates the forest zone into two blocks, the Upper Guinean and the Lower Guinean forests. Community ecology aspects of amphibians and reptiles are still relatively unexplored in this ecological zone of West Africa. Here, the overall species richness and the variation of the diversity metrics (dominance, evenness) of a whole herpetofaunal community in Togo was studied, with emphasis on the effects of the seasons (wet and dry) on the population structure. Overall, we observed 998 amphibian individuals from 27 species: 148 individuals belonging to 11 species during the dry season and 849 individuals belonging to 25 species during the wet season. For reptiles, we observed 517 individuals belonging to 44 species: 323 individuals belonging to 41 species during the dry season and 194 individuals belonging to 28 species during the wet season. The analyses on the diversity metrics showed opposite patterns between amphibians and reptiles in each season. Indeed, the dry season rank–abundance curve was systematically higher in reptiles than in amphibians for each rank of abundance, while the opposite pattern occurred in the wet season rank–abundance curve. Singletons and doubletons were much more numerous in the reptiles. Concerning the diversity indices, the Dominance index was significantly higher in amphibians during the dry season than in all other pairwise comparisons, whereas the Shannon’s index was significantly lower in dry season amphibians and significantly higher in wet season reptiles. Evenness index was significantly lower in reptiles than in amphibians and the mean number of individuals was significantly higher in amphibians by wet season compared to dry season amphibians or reptiles during both seasons. The ecological implications of these data are discussed. Most species were of minor conservation concern

Herpetofaunal Diversity in a Dahomey Gap Savannah of Togo (West Africa): Effects of Seasons on the Populations of Amphibians and Reptiles

The Dahomey Gap is a human-derived savannah zone, interspersed by patches of moist tropical forest, that separates the forest zone into two blocks, the Upper Guinean and the Lower Guinean forests. Community ecology aspects of amphibians and reptiles are still relatively unexplored in this ecological zone of West Africa. Here, the overall species richness and the variation of the diversity metrics (dominance, evenness) of a whole herpetofaunal community in Togo was studied, with emphasis on the effects of the seasons (wet and dry) on the population structure. Overall, we observed 998 amphibian individuals from 27 species: 148 individuals belonging to 11 species during the dry season and 849 individuals belonging to 25 species during the wet season. For reptiles, we observed 517 individuals belonging to 44 species: 323 individuals belonging to 41 species during the dry season and 194 individuals belonging to 28 species during the wet season. The analyses on the diversity metrics showed opposite patterns between amphibians and reptiles in each season. Indeed, the dry season rank–abundance curve was systematically higher in reptiles than in amphibians for each rank of abundance, while the opposite pattern occurred in the wet season rank–abundance curve. Singletons and doubletons were much more numerous in the reptiles. Concerning the diversity indices, the Dominance index was significantly higher in amphibians during the dry season than in all other pairwise comparisons, whereas the Shannon’s index was significantly lower in dry season amphibians and significantly higher in wet season reptiles. Evenness index was significantly lower in reptiles than in amphibians and the mean number of individuals was significantly higher in amphibians by wet season compared to dry season amphibians or reptiles during both seasons. The ecological implications of these data are discussed. Most species were of minor conservation concern

Figure 4 in Aspects of natural history in a sand boa, Eryx muelleri (Erycidae) from arid savannahs in Burkina Faso, Togo, and Nigeria (West Africa)

Figure 4. Microhabitat use by Eryx muelleri. Sample size would indicate the number of captured specimens.Published as part of Vignoli, Leonardo, Segniagbeto, Gabriel Hoinsoudé, Eniang, Edem A., Hema, Emmanuel, Petrozzi, Fabio, Akani, Godfrey C. & Luiselli, Luca, 2015, Aspects of natural history in a sand boa, Eryx muelleri (Erycidae) from arid savannahs in Burkina Faso, Togo, and Nigeria (West Africa), pp. 749-758 in Journal of Natural History 50 on page 755, DOI: 10.1080/00222933.2015.1082659, http://zenodo.org/record/398975

Who does bask longer? A comparison between elapid and viperid snakes in the field and in experimental conditions

Temperature profoundly influences the biology of ectotherm organisms, for example reptiles, which mostly regulate their body temperature behaviorally by shuttling between heat sources and sinks. The thermal quality of the environment directly affects the amount of time that a reptile takes to keep the body temperature within the optimal range. The foraging strategy of reptiles is often correlated to the thermoregulatory strategies. Depending on their foraging strategy, carnivorous reptiles can be high-energy consumers (active foragers) or low-energy consumers (ambush foragers). Our study allowed to get insights into basking versus non-basking behaviors of (i) snakes belonging to two different families (eight viperids and four elapids) with contrasted life-styles by either field or captive observations, (ii) free-ranging snakes (n = 3245) inhabiting contrasted habitats (forest versus savannah), and (iii) captive snakes (n = 4) outside the feeding activity and during digestion phase. We observed a tendency to spend more time in thermoregulation in the viperids than in the elapids and this pattern were consistent between field and experimental observations. We suggest that the higher basking activity of viperids is correlated to their predominantly nocturnal and ambush habits compared to the diurnal and active-foraging habits of the elapids. We also observed an effect of the thermal environmental quality with the savannah species tending to bask less than forest species. As for postprandial termophily, viperids showed a longer postprandial basking time than elapids even if all the snakes in the captivity sample were fed identically in terms of prey type and relative prey mass. Conservation insights related to the observed pattern are also provided

Figure 2 in Aspects of natural history in a sand boa, Eryx muelleri (Erycidae) from arid savannahs in Burkina Faso, Togo, and Nigeria (West Africa)

Figure 2. Locality records of Eryx muelleri. Black dots indicate original localities from this study; white dots indicate historical records . Symbols: BF = Burkina Faso; RMM = Mali; RPB = Benin; TG = Togo; WAN = Nigeria; RN = Niger. Numbers refer to capture localities as given in Appendix 1.Published as part of Vignoli, Leonardo, Segniagbeto, Gabriel Hoinsoudé, Eniang, Edem A., Hema, Emmanuel, Petrozzi, Fabio, Akani, Godfrey C. & Luiselli, Luca, 2015, Aspects of natural history in a sand boa, Eryx muelleri (Erycidae) from arid savannahs in Burkina Faso, Togo, and Nigeria (West Africa), pp. 749-758 in Journal of Natural History 50 on page 751, DOI: 10.1080/00222933.2015.1082659, http://zenodo.org/record/398975