Guy A. Mensah

Stable Carbon Isotope Analysis of the Diets of West African Bovids in Pendjari Biosphere Reserve, Northern Benin

Bovid diets have been studied for decades, but debate still exists about the diets of many species, in part because of geographical or habitat-related dietary variations. In this study we used stable carbon isotope analyses of faeces to explore the seasonal dietary preferences of 11 bovid species from a West African savanna, the Pendjari Biosphere Reserve (PBR), along the browser/grazer (or C3/C4) continuum. We compare our carbon isotope values with those for eastern and southern African bovids, as well as with dietary predictions based on continent-wide averages derived from field studies. Oribi and reedbuck, expected to be grazers were found to be predominantly C3-feeders (browsers) in the PBR. Bushbuck, common duiker and red-flanked duiker consumed more C4 grass than reported in previous studies. When comparing wet and dry season diets, kob, roan and oribi showed the least variation in C3 and C4 plant consumed proportions, while red-flanked duiker, bushbuck, reedbuck and waterbuck showed the most marked shifts. This study shows that animals in the betterstudied eastern and southern African savannas do not exhibit the full range of possible dietary adaptations. Inclusion of data from a wider geographical area to include less well-studied regions will inform our overall picture of bovid dietary ecology.

Wild Mammals Trade for Zootherapeutic and Mythic Purposes in Benin (West Africa): Capitalizing Species Involved, Provision Sources, and Implications for Conservation

A common problem affecting many animal species is the soaring demand for their body parts for use in medicinal products. In Benin, in spite of intense commercial exploitation of wildlife for medicinal purposes, no official statistics on the use of animals for medicinal and magic/religious purposes are available and consequently, there is little consideration of the issue in laws, decision-making processes, and conservation strategies. The aim of this study was to list the mammal species sold on the medicinal market and the conservation implications of the use of mammal species in traditional folk medicines. Among the 87 mammal species traded on the traditional medicine market in Benin, 46 were sold by at least half of those traders surveyed; the conservation status of these animals included rare, vulnerable, and threatened species. Moreover, it was noticed that the source of animals is not limited to Benin since some species available at markets are not listed in the Benins fauna. This study also found that rarer species were more costly and this constitutes an economic motivation for sellers to develop strategies for the availability of threatened species on their displays. Urgent conservation actions are needed to reduce the pressure that this activity sector might contribute to biodiversity loss.

Seasonal Habitat and Diet Partitioning between Two Sympatric Bovid Species in Pendjari Biosphere Reserve (Northern Benin): Waterbuck and Western Kob

Niche theory suggests differential use of shared resources facilitates coexistence of species in a community. In this study we used the faecal stable isotope analysis with observations along transect lines perpendicular to the Pendjari River. This was to examine seasonal habitat features and diet partitioning between two sympatric bovid species waterbuck (Kobus ellipsiprymnus) and western kob (Kobus kob) in the Pendjari Biosphere Reserve. In support of niche partition hypothesis, diets of western kob and waterbuck diverged significantly along both faecal selection axes (d13C and d15N) during the resource-limited period of the dry season as opposed to wet season when there is resource abundance. Western kob and waterbuck resource partitioning does not occur only on the basis of diet segregation but also some habitat variables play an important role in the coexisting system. Findings support the niche partition hypothesis, where morphologically, ecologically and closely related sympatric species segregate at least in one of the niche dimensions to allow coexistence. The two bovid species were observed to diverge largely along distance to water source gradient. The results provided empirical evidence that habitat features acts as an additional dimension over which herbivores partition resources.

Mongoose species in southern Benin: Preliminary ecological survey and local community perceptions

Abstract Information on the ecology and local perception of particular species is required for their conservation and management in tropical forests, where their range has either disappeared or their numbers are shrinking due to anthropogenic factors. We combined indigenous knowledge and wildlife observations to record four species of mongooses in the Lama and Niaouli forests. Three diurnal species, such as the cusimanse (Crossarchus obscurus), the ichneumon mongoose (Herpestes ichneumon), and the marsh mongoose (Atilax paludinosus), were directly observed, and one nocturnal species (the white-tailed mongoose: Ichneumia albicauda) was identified by interviews. Factorial correspondence analysis shows that the marsh and the white-tailed mongooses are more frequent in the lowland habitat, whereas the ichneumon mongoose is often sighted near villages and the cusimanse is more generalist. Mongooses are used for food, medicine, and mythic purposes. They are recognized as snake predators and thus their presence is appreciated by local communities to reduce snake bites (84.3% of interviews in Niaouli). Some species, such as cusimanse, are seen as natural pesticides. Our results suggest that the larger area of the Lama classified forest (4777 ha) allows for more intra-site movements as opposed to the inter-site movements observed in the Niaouli forest due to its small size (120 ha). We suggest further investigations of the ecology and ethology of the conservation of mongoose in Benin.

Hunting Affects Dry Season Habitat Selection by Several Bovid Species in Northern Benin

Multiple land uses including tourism, hunting, and agriculture around protected areas can be a serious complication for wildlife management. We calculated habitat selection indices (Manlys alpha) for 10 bovid species in the Pendjari Biosphere Reserve in Benin, west Africa, to assess if habitat use differed in each bovid species between hunting and non-hunting zones. Presence/absence data was used in resource-selection functions based on a generalized linear mixed effect model to examine factors that explained bovid species distribution. We observed stronger avoidance of open habitat types in the hunting zone than in the non hunting zone for the hartebeest Alcelaphus buselaphus, oribi Ourebia ourebi, roan Hippotragus equines, kob Kobus kob, Waterbuck Kobus ellipsiprymnus defassa and reedbuck Redunca redunca. In contrast, in grey duiker Sylvicapra grimmia, red-flanked duiker Cephalophus rufilatus, bushbuck Tragelaphus scriptus and buffalo Syncerus caffer we found no differences in habitat use between hunted and non-hunted areas. This may indicate that the latter species show more pronounced ecological and behavioural plasticity. Further, resource selection of bovid species on a small scale was influenced by other factors such as habitat structure, landscape characteristics, and human disturbance. This preliminary assessment of bovid habitat relationships in west Africa suggests that human hunting activities may cause species to alter their habitat selection. We therefore suggest habitat models may need to incorporate this source of variation if they are to accurately predict habitat use or distribution of a species.

Preliminary study on the tick population of Benin wildlife at the moment of its invasion by the Rhipicephalus microplus tick (Canestrini, 1888)

Background and Aim: Rhipicephalus microplus (Rm) is one of the most problematic livestock tick species in the world. Its rapid propagation and resistance to acaricides make it control difficult in the sub-region and Benin particularly. The aim of this work was to check its presence in wildlife and to confirm the possible role of reservoir wildlife may play in the propagation of the parasite. This will help to design more efficient control strategy. Materials and Methods: This study was conducted from February to March 2017 in the National Parks of Benin (Pendjari and W Park) and wildfowl’s assembly and selling point in Benin. Ticks were manually picked with forceps from each animal after slaughtering by hunters then stored in 70° ethanol. Collected ticks were counted and identified in the laboratory using the identification key as described by Walker. Results: Overall, seven species of ticks (Amblyomma variegatum, Boophilus decoloratus, Rm, Boophilus spp., Hyalomma spp., Rhipicephalus sanguineus, Rhipicephalus spp.) were identified on nine wild animal species sampled (Cane rat, wildcat, Hare, Doe, Cricetoma, Buffalo, Buffon Cobe, and Bushbuck and Warthog). The average number of ticks varies from 3 to 6 between animal species, 3 to 7 between localities visited, and 2 to 5 between tick species. However, these differences are statistically significant only for localities. Considering tick species and animal species, the parasite load of Rm and Rhipicephalus spp. is higher; the buffalo being more infested. The analysis of deviance reveals that the abundance of ticks observed depends only on the observed localities (p>0.05). However, the interactions between animal species and localities on the one hand and between animal and tick species on the other hand, although not significant, have influenced the abundance of ticks as they reduce the residual deviance after their inclusion in the model. Conclusions: This study reported the presence of Rm in wildlife of Benin and confirmed its role in the maintenance and spread of the parasites. It is, therefore, an important risk factor that we must not neglect in the epidemiological surveillance and ticks control strategies in the West African sub-region and particularly in Benin.

In vitro evaluation of the acaricidal effect of vegetal oils extracted from the kernel of Thevetia peruviana and Annona muricata on the Rhipicephalus (Boophilus) microplus larvae

The objective of this work was to study the acaricide activity of oils extracted from kernels of T. peruviana and A. muricata with the hexane at different concentrations on Rhipicephalus (Boophilus) microplus larvae aged from 14 to 21 days. For this purpose, the Larva Immersion Test was performed. Twice dilutions of both oils were tested from a starting dilution of 40% to 2.5%. There were three repetitions for each concentration and for each oil. The control solution in which these larvae were treated consisted of Tween-20, diluted at 2% in distilled water. The experimental groups were stored in an incubator at 27 ± 1 °C and at 85-90% of relative humidity for 24 hours. The larvae mortality was greater than 55% in all tested groups and reached 100% at the 40% concentration for A. muricata , while the control group had a 0% mortality. The LC 50 and CL 90 obtained were respectively 4.0331% and 10.7594% for A. muricata and 7.0942% and 41.4247% respectively for T. peruviana . These results clearly indicate that these oils all have acaricidal effects on Rhipicephalus (Boophilus) microplus larvae. However, A. muricata oil is the most toxic. It can therefore be used as an effective alternative to control the Rhipicephalus (Boophilus) microplus tick and there is a high probability that it can be used for other ticks affecting cattle and even other ectoparasites in Benin and worldwide, thereby reducing the use of synthetic acaricides which are toxic to the environment and ineffective against this tick.

Vigilance efficiency and behaviour of Bohor reedbuck Redunca redunca (Pallas 1767) in a savanna environment of Pendjari Biosphere Reserve (Northern Benin)

Abstract. This study was performed to gain more knowledge about the Bohor reedbuck time budget and vigilance in a savanna habitat. Detailed data on the time-budget were collected through focal animal observation technique to determine whether the time budget activities of Bohor reedbuck was affected by vegetation cover and to test if herd size, position in herd, the age and sex affect vigilance efficiency. We fit generalized linear mixed-effect models to assess how herd size, sex, animal position in the herd and age affected individual time allocation to vigilance behaviour. The most parsimonious model averaging clearly showed how vigilance behaviour among Bohor reedbuck was strongly affected by age, sex, the total herd size and animal position in the herd accounting for the lowest value of Akaike Information Criterion (AIC). Vigilance and feeding behaviour occupied the largest percent of Bohor reedbuck daylight time budget. Herd size effects were significant on different behaviour categories only when the Bohor reedbuck was observed in sympatric association. Our findings support the herd size effect hypothesis only in sympatric grouping system. However, further study is needed to investigate the possible sex-specific functions and targets of vigilance behaviour with respect to the herd direction in the field.