49 research outputs found
Breeding performance of the grasshopper buzzard (<i>Butastur rufipennis</i>) in a natural and a human-modified West African savanna
Few studies have examined raptor reproduction in response to land-use change in sub-Saharan Africa, hampering conservation efforts to address regional declines. To further our understanding of mechanisms underlying the dramatic declines of West African raptors, we examined the relationship between environmental conditions, nest density, and measures of reproduction in the Grasshopper Buzzard (Butastur rufipennis). Analyses were based on 244 nest sites divided between transformed and natural habitat in northern Cameroon. At the landscape scale, nest density increased with the density of preferred nest trees. Nests were more widely spaced in transformed than in natural habitat. Dispersion was adjusted to differences in availability of small mammals, which was negatively associated with distance to nearest neighbor, and in the area under cultivation, which was positively associated with distance to nearest neighbor. Productivity was positively associated with rainfall, canopy shielding the nest, availability of grasshoppers, and the nest's visibility from ground level; canopy shielding, grass cover, rainfall, and distance to nearest neighbor were positively associated with nest success. In natural habitat, losses of eggs and nestlings to natural predators were greater than in transformed habitats, while losses through human predation were small. Productivity and nest success were unaffected by land use because of the opposing effects of greater predation pressure, closer spacing of nests, and more food in natural habitat than in transformed habitat. Thus transformed habitat may provide adequate breeding habitat for the Grasshopper Buzzard, but declining rainfall and intensifying anthropogenic land use are likely to affect future reproductive output
Pan-African Genetic Structure in the African Buffalo (Syncerus caffer): Investigating Intraspecific Divergence
The African buffalo (Syncerus caffer) exhibits extreme morphological variability, which has led to controversies about the validity and taxonomic status of the various recognized subspecies. The present study aims to clarify these by inferring the pan-African spatial distribution of genetic diversity, using a comprehensive set of mitochondrial D-loop sequences from across the entire range of the species. All analyses converged on the existence of two distinct lineages, corresponding to a group encompassing West and Central African populations and a group encompassing East and Southern African populations. The former is currently assigned to two to three subspecies (S. c. nanus, S. c. brachyceros, S. c. aequinoctialis) and the latter to a separate subspecies (S. c. caffer). Forty-two per cent of the total amount of genetic diversity is explained by the between-lineage component, with one to seventeen female migrants per generation inferred as consistent with the isolation-with-migration model. The two lineages diverged between 145 000 to 449 000 years ago, with strong indications for a population expansion in both lineages, as revealed by coalescent-based analyses, summary statistics and a star-like topology of the haplotype network for the S. c. caffer lineage. A Bayesian analysis identified the most probable historical migration routes, with the Cape buffalo undertaking successive colonization events from Eastern toward Southern Africa. Furthermore, our analyses indicate that, in the West-Central African lineage, the forest ecophenotype may be a derived form of the savanna ecophenotype and not vice versa, as has previously been proposed. The African buffalo most likely expanded and diverged in the late to middle Pleistocene from an ancestral population located around the current-day Central African Republic, adapting morphologically to colonize new habitats, hence developing the variety of ecophenotypes observed today
Data from: Adaptability of large carnivores to changing anthropogenic food sources: diet change of spotted hyena (Crocuta crocuta) during Christian fasting period in northern Ethiopia
Many large carnivores readily use anthropogenic food sources, which often leads to conflict. Spotted hyenas (Crocuta crocuta) around the regional capital Mekelle, northern Ethiopia, feed on waste and to a lesser degree on livestock, but not on natural prey. We investigated the impact on their diet of the 55 day fasting period prescribed by the Ethiopian Orthodox Tewahedo Church, during which the vast majority of people do not consume animal products. We collected spotted hyena scats before, during and after the fasting period and compared hairs from scat with hairs from a reference collection. We found a significant difference in species composition; donkey and cattle occurrence increased significantly during fasting compared to the non-fasting diet dominated by scavenged remains of goat and sheep. We infer that spotted hyenas opportunistically change their diet from scavenging on waste before and after fasting to predation on larger livestock species that are kept outside at night during fasting. Our findings confirm that spotted hyena are highly adaptable and opportunistic predators
Data from: Adaptability of large carnivores to changing anthropogenic food sources: diet change of spotted hyena (Crocuta crocuta) during Christian fasting period in northern Ethiopia
Many large carnivores readily use anthropogenic food sources, which often leads to conflict. Spotted hyenas (Crocuta crocuta) around the regional capital Mekelle, northern Ethiopia, feed on waste and to a lesser degree on livestock, but not on natural prey. We investigated the impact on their diet of the 55 day fasting period prescribed by the Ethiopian Orthodox Tewahedo Church, during which the vast majority of people do not consume animal products. We collected spotted hyena scats before, during and after the fasting period and compared hairs from scat with hairs from a reference collection. We found a significant difference in species composition; donkey and cattle occurrence increased significantly during fasting compared to the non-fasting diet dominated by scavenged remains of goat and sheep. We infer that spotted hyenas opportunistically change their diet from scavenging on waste before and after fasting to predation on larger livestock species that are kept outside at night during fasting. Our findings confirm that spotted hyena are highly adaptable and opportunistic predators
The use of avian feeding guilds to detect small-scale forest disturbance: a case study in East Kalimantan, Borneo
Volume: 27Start Page: 55End Page: 6
A new species of living peccary (Mammalia: Tayassuidae) from the Brazilian Amazon
Volume: 55Start Page: 105End Page: 11
Interspecific and intraspecific differences in habitat use and their conservation implications for Palaearctic harriers on Sahelian wintering grounds
The floodplains of the West-African Sahel region have experienced extensive habitat transformation during the past four decades, coinciding with an impoverishment of raptor populations. We investigated foraging patterns of Palaearctic migratory Eurasian Marsh Harriers Circus aeruginosus, Pallid Harriers C. macrourus and Montagu’s Harriers C. pygargus on a floodplain system in northern Cameroon to assess species, sex- and age-related habitat preferences. Sex and age have rarely been incorporated into general studies of raptor habitat associations, despite clear evidence of intrasexual and age-related differences in foraging strategies and diet composition, potentially carrying strong conservation implications. We found evidence of sexual differences in foraging preference related to land use, particularly in the most sexually dimorphic Pallid Harrier, and evidence that juveniles used different habitats to adults. This constitutes the first quantitative documentation of such differentiation by Palaearctic raptors on African wintering grounds, indicating that general patterns of habitat use in wintering raptors may obscure sex- and age-specific preferences. Contrary to expectations, we found limited evidence for interspecific foraging segregation. Food partitioning by prey mass was related to harrier body mass and facilitated by a diverse availability of prey on human-transformed floodplains. Anticipated further large-scale conversion of floodplain habitat into predominantly desiccated grasslands raises concerns about the survival of wintering harriers.
Determining the risk of predator attacks around protected areas: the case of Bardia National Park, Nepal
Social Structure of Lions (Panthera leo) Is Affected by Management in Pendjari Biosphere Reserve, Benin
Lion populations have undergone a severe decline in West Africa. As baseline for conservation management, we assessed the group structure of lions in the Pendjari Biosphere Reserve in Benin. This reserve, composed of one National Park and two Hunting Zones, is part of the WAP transboundary complex of protected areas. Overall mean group size was 2.6±1.7 individuals (n = 296), it was significantly higher in the National Park (2.7±1.7, n = 168) than in the Hunting Zones (2.2±1.5, n = 128). Overall adult sex ratio was even, but significantly biased towards females (0.67) in the National Park and towards males (1.67) in the Hunting Zones. Our results suggest that the Pendjari lion population is affected by perturbations, such as trophy hunting