First assessment of age and sex structures of elephants by using dung size analysis in a West African savannah

1. An age and sex structure study of the West African savannah elephant (Loxodonta africana africana) population of the Nazinga Game ranch (Burkina Faso) was carried out using direct sightings of individuals near water points, where they group during hot periods of the day, and droppings circumference measurements of dung pile along line transects, during the dry seasons of 2007 and 2008. The age structure, from direct observation data, was estimated by classifying the individuals into 9 age-class-categories based on body size and eruption (length) of tusks.2. The frequency distribution of number of individuals into the age-class-categories showed high similarity with the distribution of circumference measurements of dung-piles that the individuals were seen depositing. Fifty dung-piles measured soon after they were deposited (Class A) and after they dried (to class C) showed a significant difference between the circumference measurements in relation to the time elapsed between the measurements.3. The frequency distribution of dung circumference classes of the observed elephants was similar to that of the dung-piles measured along the transects in 2008. Therefore, dung-piles measurements were used to estimate the Nazinga Game Ranch savanna elephant population’s age and sex structures at the end of dry seasons of 2007 and 2008. We advocated that the Nazinga elephant population consisted mainly of sub-adults.4. The sex ratio was estimated to be in favour of females (1/2). The age-class-specific sex ratio was uneven for calves and young individuals, while being in favour of females with adults. Individuals of less than 1 year represented 6% of the population during the study period

First camera survey in Burkina Faso and Niger reveals human pressures on mammal communities within the largest protected area complex in West Africa

The dearth of ecological data from protected areas at relevant scales challenges conservation practice in West Africa. We conducted the first camera survey for Burkina Faso and Niger to elucidate interactions between resource users and mammals in the largest protected area complex in West Africa (W-Arly-Pendjari, WAP). We differentiated direct (e.g., poaching) and indirect (e.g., domestic animals) human activities to determine their effects on species richness, composition, and behavior. Livestock was the dominant human pressure while gathering was the most prevalent direct human activity. Human pressure did not influence species richness or composition, but reduced mammal activity with greater consequences from indirect activities. We also found distinct differences among guilds in their behavioral responses to human pressures as wild ungulates exhibited the greatest sensitivities to livestock presence. Our findings, that aggregated socioecological data, transition the WAP complex from the singular mandate of nature conservation to a dynamic coupled human-natural ecosystem.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151966/1/conl12667.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151966/2/conl12667_am.pd

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

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

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

Raiding or not raiding ? A study of the ecological correlates of human-elephant conflict at Nazinga Game Ranch (Burkina Faso)

Human-elephant conflict represents a noteworthy issue in many developing countries, but very little is known concerning its dynamics in West African countries. In this paper, we analyse the ecological correlates of Elephant (Loxodonta africana) raiding at ten villages situated in the surroundings of Nazinga Game Ranch, southern Burkina Faso, during the years 2002 and 2006. In both years, the correlates of elephant raiding were consistent : elephants attacked preferentially three southern villages, whereas seven northern villages were practically ignored despite no significant difference in the distance from the ranch between these groups of villages. In addition, elephants focused especially on yam plantations or yam-cassava mixed plantations, and, in at least one year, they even actively avoided other crops (sorghum, corn, millet and cotton). Elephants also targeted preferentially smaller than larger plantations, whereas human population size in each village did not influence the probability of their raids (as the three southern targeted villages were not smaller in terms of population size than the non-or rarely-targeted villages). Group size of raiding elephants was larger in 2006 than in 2002. The ecological and conservation implications of these patterns are discussed in this paper. _________________________________________________Incursion ou non ? Étude des corrélations écologiques du conflit Homme-Éléphant dans le Ranch de Gibier de Nazinga (Burkina Faso) Le phénomène de conflit Homme-Éléphant constitue une préoccupation majeure dans de nombreux pays en voie de développement. Cependant, on ne dispose que de peu d’informations sur sa dynamique dans les pays de l’Afrique de l’Ouest. Dans cet article, nous analysons les corrélations écologiques de la conservation de l’Éléphant (Loxodonta africana) dans dix villages riverains du Ranch de Gibier de Nazinga, au sud du Burkina Faso, au cours des années 2002 et 2006. Pour chacune des deux années, les corrélats de dégât d’éléphants étaient consistants : les éléphants ont attaqué préférentiellement trois villages du sud, tandis que sept villages du nord ont été pratiquement ignorés bien qu’aucune différence significative n’existait entre les distances de ces groupes de villages par rapport au Ranch. De plus, les éléphants ont surtout ciblé les plantations d’igname ou les plantations mixtes d’igname et de manioc; et pendant au moins un an, ils ont activement évité d’autres cultures (sorgho, maïs, mil et coton). Ils ont également ciblé les petites plantations. La taille de la population humaine dans chaque village n’a pas influencé la probabilité des dégâts (les trois villages-cibles du sud n’étaient pas plus petits en termes de taille de la population que les villages qui n’ont pas ou rarement été ciblés). La taille des groupes d’éléphants qui causaient les dégâts a été plus importante en 2006 qu’en 2002 . Les implications écologiques et en matière de conservation de ces patterns sont discutées dans cet article.Hema Emmanuel M., Sirima Djiama, Niagabarè Banzourou, Nama Néti, Petrozzi Fabio, Di Vittorio Massimiliano, Guenda Wendengoudi, Luiselli Luca. Raiding or not raiding ? A study of the ecological correlates of human-elephant conflict at Nazinga Game Ranch (Burkina Faso). In: Revue d'Écologie (La Terre et La Vie), tome 73, n°1, 2018. pp. 3-11

Effects of competitor density and rainfall regime on the long-term population dynamics of an herbivore community in a western African Savannah

Despite many scientific articles were devoted to study aspects of community ecology of ungulates in African savannahs , only very few studies focused on communities from Western Africa . In this paper , we analyse the interspecific interactions of savannah ungulates in the Nazinga Game Ranch (Burkina Faso) in relation to rainfall patterns and potential competitor density, using long-term (1985-2008) line-transect data. We estimated the population sizes of all species by using distance sampling . There was no effect of the year on the population sizes of all the species , but , when 5-year-period groups were analyzed, there were significant fluctuations over time intervals for at least some of the species. Generalized Linear Models on the interspecific relationships (either positive or negative) between pairs of species would suggest that interannual population size fluctuations of the various ungulates were likely attributable to fluctuations in poaching intensity, the influences of rainfall regimes (for at least three browser species ), and negative density dependence.Effets de la densité des compétiteurs et du régime des pluies sur la dynamique de population à long terme d’une communauté d’herbivores dans une savane ouest-africaine En dépit de beaucoup d ’ articles scientifiques consacrés à l’écologie des communautés des ongulés dans les savanes africaine, seules quelques études se sont focalisées sur l’Afrique de l’Ouest. Dans cet article, sur la base de line-transects sur le long terme (1985-2008 ), nous analysons les interactions entre les espèces d’ongulés de savane dans le Ranch de Gibier de Nazinga (Burkina Faso) en relation avec les pluies et la densité de leurs compétiteurs potentiels. Nous avons estimé la taille des populations de toutes les espèces par comptage à distance. Il n’est pas apparu d’effet année sur la taille des populations pour toutes les espèces mais, en analysant par groupes de cinq années, des fluctuations significatives ont été décelées au moins pour certaines espèces. Des modèles linéaires généralisés sur les relations interspécifiques (tant positives que négatives) entre paires d’espèces suggèrent que les fluctuations interannuelles de la taille des populations des divers ongulés seraient vraisemblablement imputables aux variations de l’intensité du braconnage, à l’influence du régime des pluies (pour au moins trois espèces brouteuses) et à une densitédépendance négative.Hema Emmanuel M., Ouedraogo Boukare, Belemsogbo Urbain, Di Vittorio Massimiliano, Dendi Daniele, Guenda Wendengoudi, Petrozzi Fabio, Luiselli Luca. Effects of competitor density and rainfall regime on the long-term population dynamics of an herbivore community in a western African Savannah . In: Revue d'Écologie (La Terre et La Vie), tome 73, n°4, 2018. pp. 492-503