African Journal of Ecology最新文献

Understanding environmental drivers of fruit and seed production in wild edible fruit species is essential for their valorisation. Ricinodendron heudelotii is an oilseed plant whose kernels are particularly treasured in cosmetic and medical industries. This study assessed fruits and seeds production patterns of R. heudelotii. Data were collected for three consecutive years on 30 trees in the phytodistricts of Plateau, Pobè and South Borgou where it naturally occurs. Tree dbh, total height, crown diameter, number of fruits and seed mass were measured. Climatic data were obtained from NASA Power Database. Data were analysed using linear (seed mass) and generalised linear (number of fruits) mixed models and structural equation modelling. Fruit and seed production were significantly higher in the South-Borgou phytodistrict (1433 ± 1144 fruits, 4.26 ± 3.39 kg of Dry matter per tree) and Plateau phytodistrict (1.66 ± 0.35 g DM/seed). Tree dbh further significantly mediated the effect of minimum temperature, and relative humidity on seed mass. Tree dbh, irradiance and dry season rainfall were identified as the best-predictors of seed mass production (kg DM). These results improved current knowledge of the fruit and seed production of R. heudelotii and are of significant importance for the exploitation of the species.

Few studies have examined how dung beetle species composition changes across several mammalian dung types. Species composition and abundance of dung beetles were studied in dung samples of seven African mammals along animal trails and using 14 baited-pitfall traps in both the park and the buffer zone resulting in a combined data set of 113 samples. Both the number of species (18) and the number of individual dung beetles (600) encountered were low for an area close to the Equator. Few species (2) and herbivores (13) tunnellers (9) dominated the dung beetles community, feeding and guild structure respectively. Alpha diversity was moderate 2.06 (1 < H′ ≤ 3). Beta diversity ranged from low 0.8 (high similarity) to high (zero, no similarity). Dung beetle species composition varied with dung type with the degree of pairwise similarity between two dung types in 19 of the total (21) dung beetle communities comparisons showing low similarity (0.4) to no similarity (zero). The observed discrepancies may be attributed to dung size, composition and consistency as well as to the low number of dung of the different animal species sampled. Furthermore, further research is needed as rarefaction curves suggest that sampling was incomplete.

A sample of midden contents found in a sink hole on Unguja, Zanzibar were dominated by Crocidura and Mastomys (probably natalensis) and were likely the remains following predation. I suggest that future studies of these middens in the numerous sink holes found throughout Unguja include camera traps which have the potential to greatly expand our understanding of predator–prey relations on this island.

Anthropogenic development throughout African savannahs results in changes to landscapes and wildlife habitat. Linear features (e.g. roads and powerlines) have become more prevalent and can reshape how many mammal species navigate the landscape. This study assesses how mammals use anthropogenic linear features and game trails in a woody savannah via camera traps. We found that a greater number of species, especially carnivores, used linear features rather than game trails. Additionally, 15 mammal taxa were associated with anthropogenic linear features, whereas only four taxa were associated with game trails, suggesting that anthropogenic development throughout the African savannah may alter wildlife landscape use.

Biodiversity conservation in human-inhabited landscapes is increasingly gaining attention due to the global decline of species. Understanding the impact of human activities on avian functional ecology is becoming increasingly important as habitats are transformed. We assessed the influence of habitat fragmentation on avian functional diversity (FD), focusing on metrics like functional richness (FRic), evenness (FEve) and divergence (FDiv). We calculated the FRic, FEve and FDiv across habitats using ‘fundiversity’ R package. We also calculated the Enhanced Vegetation Index (EVI) and estimated land-use cover of the study area from Landsat 8 images. We observed higher FD in minimally disturbed habitats, where among the habitats, woodland had high FD while human settlement had low. This supports the intermediate disturbance hypothesis, which suggests that moderate disturbance can increase species diversity. Our findings emphasise the pivotal role of fragmented habitats in shaping avian functional ecology, with environmental variables such as the EVI influencing diversity across habitats. Hence, we promote sustainable conservation connectivity, proper land management practices and conservation-friendly agricultural practices for sustainable biodiversity conservation.

Leopard (Panthera pardus) dispersal is poorly documented. An amalgamation of independent, mixed-method camera trap data spanning six years provides evidence of male leopard dispersal across the highly fragmented Overberg region, Western Cape, South Africa. Dispersal distances from four individuals ranged from 35.3 to 112.0 km between the origin and destination datapoints. Leopard dispersal across the modified landscape affirms their adaptability and resilience and reveals local functional connectivity. We caution against population status complacency but rather advocate for maintaining and improving functional landscape connectivity for this umbrella species. This study, which collated piecemeal data from four sources, highlights the importance of collaboration and data sharing in conservation.

Land use and land cover (LULC) dynamics using GIS and remote sensing techniques measure extent and spatial structure, which are critical for monitoring biomes. A digital LULC detection technique with multi-temporal satellite imagery analysis was employed at four timepoints from 1987 to 2017 and performed using supervised classifications method in ERDAS imagine 2015. For image classification, the five major LULC types included forests, built-up land, agricultural land, water bodies and grasslands. LULC of grasslands, forests and water bodies reduced, while LULC of agricultural and built-up lands increased. Avifaunal surveys were conducted at 11 sites across the LULC classes to compare species richness and abundance. The decrement of forests and water bodies would result in habitat loss, affecting endemic and threatened avifauna, as forests showed highest avifaunal species diversity (H′ = 3.80). Despite the decrement, grasslands demonstrated higher avifaunal species richness (107) and abundance (2767). Species richness decreased significantly from grasslands to water bodies and agricultural land (p < 0.05), and from forests to agricultural and built-up land (p < 0.05), and water bodies (p < 0.01). Avifaunal abundance decreased significantly from grasslands to all other LULC classes. Regular LULC change assessment is integral to avifaunal habitat and biodiversity conservation efforts, particularly at Lake Tana.

Passive acoustic monitoring (PAM) is a reliable method for studying the behaviour and ecology of vocally active animals, providing insights into species' activity patterns. Here, we utilised a year-long recording programme conducted in six areas of the Afromontane tropical forest of Cameroon to assess the utility of PAM, describe the annual and circadian vocal activity patterns, and assess the relationship between vocal activity and climate conditions for two African turaco species: the endemic and Endangered Bannerman's turaco (Tauraco bannermani) and the common, but locally at risk, Great blue turaco (Corythaeola cristata). The automated software detected 8670 vocalisations of Bannerman's turaco and 374 of the Great blue turaco, proving the ability of passive acoustics, coupled with automated software, for monitoring these species. Our findings suggest that both turacos are sedentary and seasonal breeders, exhibiting larger peaks of vocal activity during the dry season, although both species showed smaller activity peaks during the wet season. Similar circadian patterns were observed for both species, with activity peaks occurring at dawn and dusk. Long-term monitoring programmes of both species should be implemented in the study areas, especially regarding the Great blue turaco, which may soon disappear from Bamenda Highlands.

Maintaining water availability is crucial for sustaining wildlife populations in African savannah ecosystems, especially in semi-arid regions where natural surface water sources are limited. The establishment of Artificial Water Points (AWPs) has become a common management strategy in protected areas to mitigate the effects of water scarcity. This study investigated the spatio-temporal patterns of mammal visitation to AWPs in Majete Wildlife Reserve, Malawi, over an eight-year period using motion-triggered camera traps. The study documented a total of 34 medium- to large-sized mammal species, with warthog, waterbuck, impala and yellow baboon being the most frequently captured. Temporal analysis reveals diurnal visitation patterns, with peak activity during mid-day hours, and seasonal variations, with most species exhibiting increased visitation during the hot-dry season. Spatial analysis identifies preferences for AWPs proximate to perennial rivers and tourist infrastructure, emphasising the role of habitat features and human presence in AWP utilisation. Management implications include the need for tailored strategies addressing species-specific behaviours and habitat conditions, alongside ongoing monitoring efforts to ensure the sustainability of wildlife populations and ecological integrity. Despite the inherent limitations of camera trap methodology, this study provides valuable insights into AWP management strategies essential for conserving biodiversity in semi-arid environments.