34 research outputs found
Ikpan wetland rainforest: an area of high biodiversity importance in south-eastern Nigeria
Un inventaire détaillé des mammifères, reptiles et amphibiens a été conduit dans les zones humides et de forêt de terre ferme du bloc forestier d'Ikpan (Cross River State, sud-est du Nigéria) durant la période 1998-2001. Les prospections ont montré que l'Ikpan Forest, bien que formellement non protégée tant au niveau régional qu'au plan national, héberge une remarquable biodiversité qui inclut de nombreux vertébrés de grand intérêt écologique et biogéographique et qui sont importants en termes de conservation. Parmi les mammifères, les taxons les plus importants sont les primates (11 espèces différentes dont Mandrillus leucophaeus, Pan troglodytes, Procolobius badius preussi), les éléphants et les buffles de forêt et beaucoup d'ongulés. Des lamantins et des panthères sont vraisemblablement aussi présents. Parmi les reptiles, Osteolaemus tetraspis, Kinixys spp., Varanus niloticus ornatus, Python sebae, et des caméléons sont particulièrement importants du point de vue de la conservation. De plus, cette forêt abrite une remarquable diversité d'espèces de serpents (27) et d'amphibiens (27), dont beaucoup sont de bons indicateurs de qualité écologique forestière et certaines n'avaient fait l'objet jusqu'ici que de rares mentions au Nigéria (e.g. les anoures Bufo superciliaris et Conraua crassipes). La zone montre de grandes potentialités en matière de conservation et de développement durable (écotourisme) mais doit être soigneusement gérée dans les toutes prochaines années pour éviter les effets négatifs de l'exploitation forestière, de la chasse locale, de l'agriculture et de la pêche à la dynamite.A careful survey for marnmals, reptiles, and amphibians, was conducted at the wetlands
and rainforests of Ikpan Forest block, Cross River State (south-eastern Nigeria), during the period 1 998-200 1 . The surveys proved that Ikpan Forest, although formally not protected at either regional or national levels, bouses an extraordinarily rich biodiversity, including many vertebrates of ecological, biogeographie, and conservation importance. Among mammals, the most important taxa are primates ( 1 1 different species, including Mandrillus leucophaeus, Pan troglodytes, Procolobus badius preussi), forest elephants, forest buffalos, and many ungulates. Manatees and leopards may also be present. Among reptiles, Osteolaemus tetraspis, Kinixys spp . , Varanus niloticus amatus, Python sebae, and chameleons are especially important in conservation terms. Moreover, the study forest bouses a conspicuous diversity of species of snakes (27) and arnphibians (27), including many species which are good ecological indicators of forest quality, and sorne species which were rarely recorded in Nigeria before (e.g. , the anurans Bufo superciliaris and Conraua crassipes) . The study area bas potentials for conservation and sustainable development (eco-tourism), but should certainly be monitored carefully in the next years to avoid the negative effects of timber extraction, local hunting, farming, and fishing with dynamites
Trophic niches of four sympatric rainforest anurans from southern Nigeria: does resource partitioning play a role in structuring the community ?
Le partage des ressources est un mécanisme qui peut réduire l'intensité de la compétition interspécifique dans un cortège d'espèces syntopiques, morphologiquement et éco-éthologiquement semblables. La documentation du partage des ressources, entre quatre espèces d'Anoures sympatriques, a été recherchée par l'examen du régime alimentaire (par dissection stomacale) de spécimens obtenus auprès de fournisseurs de viande de brousse dans le sud-est du Nigéria. Pour l'ensemble des quatres espèces, nous avons trouvé au total 32 différents types de proies. Ptychadena oxyrhynchus en a consommé 28, contre 17 pour P. aequiplicata, 15 pour Bufo maculatus et 10 seulement pour Hoplobatrachus occipitalis. Pour les courbes cumulatives de diversité des trois premières espèces un plateau a été atteint, montrant que la composition des régimes pouvait être considérée comme correctement établie. Les proies communes, consommées par les quatre espèces d'Anoures, étaient des Formicoidea, des Coléoptères adultes, des Aranéides, des Isopodes, des Oligochètes et des Pulmonés. Les proies communes, consommées par trois des quatre amphibiens, étaient des Dermaptères, des Hémiptères, des Odonates adultes et des Orthoptères. Les largeurs de tête variaient significativement entre les espèces d'Anoures ; toutefois, les deux espèces de Ptychadena ne montraient pas de différence significative entre elles sur ce point Pour trois espèces, la largeur de tête était significativement corrélée au volume de proies dans l'estomac. Le partage des ressources (en termes de types de proies) a été trouvé particulièrement net entre deux espèces de Ptychadena étroitement apparentées. La divergence entre Ptychadena oxyrhynchus et P. aequiplicata apparut telle que des analyses multivariées ont placé chacune d'elles, du point de vue alimentaire, plus près de Hoplobatrachus occipitalis ou de Bufo maculatus que de son congénère. Une divergence si forte semblerait jouer un rôle majeur dans le maintien de la structure de ce peuplement mixte d'Anoures.Resource partitioning is a mechanism that can reduce the intensity of inter-specifie competition between morphologically and eco-ethologically similar, syntopic species . Evidence for resource partitioning, between four syntopic anuran species, was investigated by examining
the diet (through stomach dissection) of frogs bought from bush meat traders in southeastern Nigeria . Considering the four species together, a total of 32 different prey types were found. Ptychadena oxyrhynchus consumed 28 of them, while P. aequiplicata consumed 17 , Bufo maculatus 15 and Hoplobatrachus occipitalis only 10. For the first three species, the cumulative-diversity curves indicated that a plateau phase was reached, i .e . that the prey composition could be considered reliably assessed. Common prey items, which were consumed by all four anuran species, were : Formicoidea, Coleoptera adults, Araneidae, Jsopoda, Oligochaeta, and Pulmonata. Common prey items, which were consumed by three of the four amphibians, were : Dermaptera, Hemiptera, Odonata adults, and Orthoptera. Head width varied significantly between species, but there was no statistical difference between the two Ptychadena species. Head width was significantly correlated with prey volume in the stomach in each of three species. Resource partitioning (in terms of prey types) was found to be particularly strong between two closely related species of Ptychadena. The divergence bewteen Ptychadena oxyrhynchus and P. aequiplicata was such that multivariate analyses placed each one of them closer in feeding ecology to either Hoplobatrachus occipitalis or Bufo maculatus, than to their congener. Such strong divergence is hypothesized to play a major role in maintaining the structure of this mixed anuran community
Types d’aliments et écologie alimentaire de la Civette africaine (Civettictis civetta) en région de Jimma, Éthiopie
Les types d'aliments et l'écologie alimentaire de Civettes africaines ont été étudiés d'août 2005 à février 2006 dans trois zones (Kito, Beda Buna et Jeran) dans la région de Jimma en province d'Oromia, Éthiopie. Des fèces
fraîches ont été récoltées et analysées au laboratoire. Il n'y avait aucune différence significative entre les différents sites dans la variété des aliments. Durant la saison des pluies, 21 types de proie ont été identifiés contre 26 durant la saison sèche. Des variations significatives
entre les saisons dans les proportions des types d'aliments ont été observées dans tous les sites. Les civettes éthiopiennes étudiées se sont avérées omnivores, complétant par des fruits, des oeufs, des poissons et des insectes leur régime carné (issu de la chasse, e.g. rongeurs et oiseaux,
ou d'un comportement charognard
Distribution and status of the African forest buffalo Syncerus caffer nanus in south-eastern Nigeria
AbstractAlthough not categorized as threatened on the IUCN Red List, the African forest buffalo Syncerus caffer nanus is declining across its range. In Nigeria its distribution, abundance and status are virtually unknown. We conducted interviews with experienced hunters, and field surveys (linear and recce transects), to study the buffalo's distribution and ecology in the montane forests of Cross River State. General linear modelling indicated that the number of individuals varied significantly across survey areas and habitat types but not with the survey period, and there was no study area × study period interaction. Buffalo were found most commonly in mature and secondary forests. Given the species' scattered distribution, fragmentation of its habitat, and the relatively low numbers observed, Nigerian populations require a separate, regional categorization on the IUCN Red List
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
La viande de brousse : des enquêtes révèlent des points de controverse sur la dynamique de son commerce au Nigéria
Sur la base d’enquêtes dans le sud du Nigéria, cet article examine (i) si la viande de brousse est toujours une source cruciale de protéines pour les communautés locales, (ii) si elle est toujours culturellement bien justifiée et (iii) si, selon les préférences des consommateurs, des valeurs différentes sont attribuées aux divers types d’espèces constituant cette viande de brousse. De plus, cet article fournit des informations sur la question de savoir (iv) si le commerce de la viande de brousse épuise localement les populations des espèces ciblées, et (v) si la disparition sur les marchés de grands animaux est signe de leur extermination locale. Une combinaison d’entretiens avec des hommes et des femmes de différentes classes d’âge, incluant des chasseurs, consommateurs et vendeurs, a été conduite dans divers localités nigérianes correspondant à différentes conditions d’habitat et de caractéristiques socio-économiques et ethniques. Les résultats suggèrent que la consommation de viande de brousse, en particulier dans les zones urbaines, n’a pas une grande valeur de subsistance, sauf pour une petite sous-section de la communauté. De fait, même dans les zones rurales, moins de 30 % des personnes de moins de 50 ans interrogées ont répondu consommer fréquemment de la viande de brousse. L’importance culturelle de la viande de brousse a substantiellement diminué dans les années récentes, comme en témoigne le fait que (i) cette source de nourriture a été rapidement abandonnée durant la crise d’Ebola en 2014 et (ii) la plupart des personnes interrogées ont affirmé n’en manger que rarement voire pas du tout. Les données recueillies vont dans le sens de ce que le prix d’une carcasse serait principalement déterminé par la taille de l’animal et non pas par la préférence des consommateurs. L’utilisation et le commerce de la viande de brousse peuvent certainement épuiser localement les populations des espèces animales ciblées. Néanmoins, il n’y a toujours pas suffisamment de preuves empiriques de la notion selon laquelle quand les grands animaux disparaissent des marchés cela signifierait que leurs populations auraient été considérablement épuisées voire exterminées. De fait, sur la base d’éléments culturels exposés par les chasseurs interrogés, il semblerait que cette notion soit erronée, du moins en ce qui concerne les régions ouest-africaines les plus riches et les plus économiquement dynamiques. Il est conseillé à ceux qui étudient la viande de brousse d’explorer plus en profondeur la flexibilité culturelle des communautés humaines avant de généraliser des conclusions, évitant ainsi d’extrapoler à grande échelle des conclusions insuffisamment fondées car basées sur des données collectées à très petite échelle spatiale et durant de courtes périodes de temps.Using questionnaire surveys in southern Nigeria, this paper explores whether: (i) bushmeat is still a crucial source of animal protein for local communities; (ii) is still culturally very relevant; and (iii) if people value differently the various kinds of bushmeat species because of customer preferences. In addition, this paper provides information on whether (iv) the bushmeat trade locally depletes target game species; and (v) whether the disappearance of large animals from the markets would indicate their local extirpation from the wild. A combination of interviews was carried out with both men and women of different age classes including hunters, consumers and sellers, from different Nigerian locations with different habitat conditions, socio-economic and ethnic characteristics. Results of these interviews suggest that the consumption of bushmeat has little subsistence value, especially in urban areas, except for a small sub-section of the community. Indeed, even in rural areas less than 30 % of the interviewees of less than 50 years age answered that they frequently eat bushmeat. Cultural importance of bushmeat decreased substantially in recent years, as shown by that (i) this food source was quickly abandoned by people during the 2014 Ebola crisis, and (ii) most of questionnaire respondents affirmed that they would have eaten bushmeat only rarely or even not at all. There was support for the notion that the price of a carcass was mainly determined by the animal size and not by the consumer preference. Bushmeat utilization and trade may certainly deplete target animal species at the local scale. Nonetheless, there is still no sufficient empirical evidence for the notion that, when large animals disappeared from the markets, it meant that their populations were heavily depleted or even extinct. Indeed, based on cultural elements highlighted by interviewed hunters, there is evidence that this notion may be wrong, at least in the richest and economically more dynamic regions of West Africa. It is advised that bushmeat studies should explore more in depth the cultural flexibility of human communities before drawing generalized conclusions, thus avoiding unsupported large-scale conclusions based on data collected at a very small spatial scale and during short time periods
Bushmeat consumption in large urban centres in West Africa
Bushmeat consumption in large Sub-Saharan African cities is perceived as a major threat to the conservation of many species because their considerable population sizes can generate a significant demand for bushmeat. The study of the effect of age, sex and geographic location in bushmeat eating in African cities may offer valuable insights on which population groups to target in behaviour change campaigns. Using 2,040 interviews in six West African cities from four countries, in forest and savannah settings, we analysed the differences between age and sex in people’s frequency of bushmeat consumption. Overall, we found similar patterns in all sampled cities. As many as 62.2 % males and 72.1% females replied that they ‘would not eat bushmeat at all’, though only 12.8% males and 8.8% females mentioned they regularly ate bushmeat. Younger generations of both sexes answered that they ‘would never eat bushmeat’ more often than older age groups, independently of their city of origin. These trends are encouraging though further research needs to be undertaken to find out whether bushmeat volumes consumed in cities are unsustainable and having a serious impact of prey populations
Bushmeat consumption in large urban centres in West Africa
Bushmeat consumption in large Sub-Saharan African cities is perceived as a major threat to the conservation of many species because their considerable population sizes can generate a significant demand for bushmeat. The study of the effect of age, sex and geographic location in bushmeat eating in African cities may offer valuable insights on which population groups to target in behaviour change campaigns. Using 2,040 interviews in six West African cities from four countries, in forest and savannah settings, we analysed the differences between age and sex in people’s frequency of bushmeat consumption. Overall, we found similar patterns in all sampled cities. As many as 62.2 % males and 72.1% females replied that they ‘would not eat bushmeat at all’, though only 12.8% males and 8.8% females mentioned they regularly ate bushmeat. Younger generations of both sexes answered that they ‘would never eat bushmeat’ more often than older age groups, independently of their city of origin. These trends are encouraging though further research needs to be undertaken to find out whether bushmeat volumes consumed in cities are unsustainable and having a serious impact of prey populations
Impact of COVID-19 on wild meat trade in Nigerian markets
Wild meat plays a crucial role in the food security and cash income of subsistence hunters in the tropics and subtropics in Africa, South America, and SE Asia (Coad et al., 2019; Fa et al., 2022). This meat is regularly traded in markets in many towns and cities (see Fa et al., 2019). In Nigeria, the amount of meat sold from most species crashed dramatically after the Ebola virus outbreak in 2014, highlighting the awareness of the general public of a link between disease risk and wild meat (Akani et al., 2015; Funk et al., 2021). The opportunities for zoonotic spill-over have increased in parallel with the increase of the intensity and extent of bushmeat trade over the last decades (Karesh & Noble, 2009). The report by UNEP, International Livestock Research Institute (2020) on preventing the next pandemic lists increasing human demand for animal protein among seven human-mediated factors as the most likely driving the emergence of zoonotic diseases, which includes wild meat hunting
Oates, J.F. — Myth and reality in the rain forest : How conservation strategies are failing in West Africa. University of California Press, Berkeley. 1999
Eniang Edem A., Nwufoh Ernest I. Oates, J.F. — Myth and reality in the rain forest : How conservation strategies are failing in West Africa. University of California Press, Berkeley. 1999. In: Revue d'Écologie (La Terre et La Vie), tome 56, n°3, 2001. pp. 311-312