Research Articles (Zoology and Entomology)

Permanent URI for this collectionhttp://hdl.handle.net/2263/1740

A collection containing some of the full text peer-reviewed/ refereed articles published by researchers from
the Department of Zoology and Entomology

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Announcing the invasions newsletter
(Springer, 2025-06) Novoa, Ana; Canavan, Susan; Faulkner, Katelyn T.; Genovesi, Piero; Lieurance, Deah; Simberloff, Dan; Wang, Hsiao-Hsuan; Zengeya, Tsungai; Meyerson, Laura A.
No abstract available.
In vitro antiplasmodial activity and cytotoxicity of three Ziziphus (Rhamnaceae) species from South Africa
(Elsevier, 2025-06) Mabuza, Mcebisi Junior; Kaiser, M.; Tshikalange, T.E.; Yusuf, Abdullahi Ahmed; Bapela, Mahwahwatse Johanna
Please read abstract in the article.
Extreme herding behavior in adult male sub-Antarctic fur seals
(Springer, 2025-05) Bester, Marthan Nieuwoudt; Rossouw, G.J.; mnbester@zoology.up.ac.za
We re-analyzed unpublished data on herding behavior in adult male sub-Antarctic fur seals Arctocephalus tropicalis recorded at Gough Island during the 1975/76 austral summer breeding season. The results extend the study of competition and injury in adult males from the same population. Herding behavior is defined and shows that adult males in this population exhibit the most extreme herding behavior of the fur seal genus Arctocephalus. Extreme herding responses result from both human disturbance and in natural settings without human disturbance. Such information is needed for comparative studies about aggression and territorial behavior in otariids.
Maize edible‑legumes intercropping systems for enhancing agrobiodiversity and belowground ecosystem services
(Nature Research, 2024-06-21) Jalloh, Abdul A.; Mutyambai, Daniel Munyao; Yusuf, Abdullahi Ahmed; Subramanian, Sevgan; Khamis, Fathiya
Intensification of staple crops through conventional agricultural practices with chemical synthetic inputs has yielded positive outcomes in food security but with negative environmental impacts. Ecological intensification using cropping systems such as maize edible-legume intercropping (MLI) systems has the potential to enhance soil health, agrobiodiversity and significantly influence crop productivity. However, mechanisms underlying enhancement of biological soil health have not been well studied. This study investigated the shifts in rhizospheric soil and maize-root microbiomes and associated soil physico-chemical parameters in MLI systems of smallholder farms in comparison to maize-monoculture cropping systems (MMC). Maize-root and rhizospheric soil samples were collected from twenty-five farms each conditioned by MLI and MMC systems in eastern Kenya. Soil characteristics were assessed using Black oxidation and Walkley methods. High-throughput amplicon sequencing was employed to analyze fungal and bacterial communities, predicting their functional roles and diversity. The different MLI systems significantly impacted soil and maize-root microbial communities, resulting in distinct microbe sets. Specific fungal and bacterial genera and species were mainly influenced and enriched in the MLI systems (e.g., Bionectria solani, Sarocladium zeae, Fusarium algeriense, and Acremonium persicinum for fungi, and Bradyrhizobium elkanii, Enterobacter roggenkampii, Pantoea dispersa and Mitsuaria chitosanitabida for bacteria), which contribute to nutrient solubilization, decomposition, carbon utilization, plant protection, bio-insecticides/fertilizer production, and nitrogen fixation. Conversely, the MMC systems enriched phytopathogenic microbial species like Sphingomonas leidyi and Alternaria argroxiphii. Each MLI system exhibited a unique composition of fungal and bacterial communities that shape belowground biodiversity, notably affecting soil attributes, plant well-being, disease control, and agroecological services. Indeed, soil physico-chemical properties, including pH, nitrogen, organic carbon, phosphorus, and potassium were enriched in MLI compared to MMC cropping systems. Thus, diversification of agroecosystems with MLI systems enhances soil properties and shifts rhizosphere and maize-root microbiome in favor of ecologically important microbial communities.
Insights into malaria vectors-plant interaction in a dryland ecosystem
(Nature Research, 2024-09-04) Kinya , Fiona; Milugo, Trizah K.; Mutero , Clifford M.; Wondji, Charles S.; Torto, Baldwyn; Tchouassi, David P.
Improved understanding of mosquito–plant feeding interactions can reveal insights into the ecological dynamics of pathogen transmission. In wild malaria vectors Anopheles gambiae s.l. and An. funestus group surveyed in selected dryland ecosystems of Kenya, we found a low level of plant feeding (2.8%) using biochemical cold anthrone test but uncovered 14-fold (41%) higher rate via DNA barcoding targeting the chloroplast rbcL gene. Plasmodium falciparum positivity was associated with either reduced or increased total sugar levels and varied by mosquito species. Gut analysis revealed the mosquitoes to frequently feed on acacia plants (~ 89%) (mainly Vachellia tortilis) in the family Fabaceae. Chemical analysis revealed 1-octen-3-ol (29.9%) as the dominant mosquito attractant, and the sugars glucose, sucrose, fructose, talose and inositol enriched in the vegetative parts, of acacia plants. Nutritional analysis of An. longipalpis C with high plant feeding rates detected fewer sugars (glucose, talose, fructose) compared to acacia plants. These results demonstrate (i) the sensitivity of DNA barcoding to detect plant feeding in malaria vectors, (ii) Plasmodium infection status affects energetic reserves of wild anopheline vectors and (iii) nutrient content and olfactory cues likely represent potent correlates of acacia preferred as a host plant by diverse malaria vectors. The results have relevance in the development of odor-bait control strategies including attractive targeted sugar-baits.
Influence of season, sex, and interspecific interactions on the diel activity patterns of two sympatric African small carnivores
(Nature Research, 2024-11-29) Carvalho, Filipe; Galantinho, Ana; Somers, Michael J.; Do Linh San, Emmanuel
Animal activity patterns vary seasonally and between species, facilitating species coexistence. In Africa, however, factors affecting the activity of many small carnivores remain poorly understood, especially for congeneric and sympatric species whose similar sizes may lead to interspecific competition. Here, we investigated differences and variations in the activity patterns of two sympatric Viverridae species in a seasonal African landscape. We continuously radio-tracked 15 small-spotted genets (Genetta genetta) and five Cape genets (G. tigrina) over 24-h cycles throughout the year. We analysed the effects of season, sex, and interspecific interactions on circadian rhythms using multi-cosinor regression models. Both species maintained a nocturnal activity pattern year-round, decreasing activity significantly during the cold-dry season. This pattern aligns with the thermoregulatory hypothesis—especially for species with an elongated body like genets—suggesting decreased activity under extreme cold weather conditions to conserve energy. Females in both species were less active than males, possibly due to their smaller home ranges, especially during the cold-dry season. These effects were particularly pronounced in Cape genets, which primarily inhabit riverine forests. Female Cape genets adjusted their activity onset, possibly to minimize encounters with males, mostly during the hot-wet season when caring for their offspring. Small-spotted genets shifted their activity onset and peak in riverine forests—areas of potential contact with Cape genets—compared to areas without Cape genets. Overall, our study underscores the critical role of seasonal environmental changes and interspecific interactions in shaping the activity patterns of two carnivore species within a semi-arid Albany Thicket landscape.
Assessment of domestic pig-bushpig (Potamochoerus larvatus) interactions through local knowledge in rural areas of Madagascar
(Nature Research, 2024-07-15) Rakotoarivony, Rianja; Kassie, Daouda; Andriamahefa, Alpha; Andria‑Mananjara , Diana; Rakotoarinoro , Mihaja; Ramaroson, Herilantonirina Solotiana; Raliniaina , Modestine; Rasamoelina , Miatrana; Gomez‑Vazquez, Jose Pablo; Jori, Ferran J.
In many parts of the world, domestic and wild animal populations interact at the interface between natural and agricultural ecosystems. Introduced with the first inhabitants arriving from eastern Africa, the bushpig (Potamochoerus larvatus) is the largest living terrestrial mammal in Madagascar. Bushpigs are regularly reported close to human settlements where they damage crops and gardens. As domestic pigs are often raised in free-ranging conditions around the villages, bushpigs and domestic pigs can interact leading to the transmission and circulation of shared swine pathogens that impact both animal and human health. In this study, we characterized the socio-ecological context of bushpig-domestic pig interactions in two different regions of western Madagascar. We conducted participatory mapping sessions and focus group interviews with 65 hunters, 80 pig farmers and 96 crop farmers in 20 fokontany, the smallest administrative unit in Madagascar. After discussing with participants, we gathered information about the spatialization of interactions and their potential geographical drivers. We explored data by performing multiple correspondence analysis and hierarchical clustering on principal components. Based on the reported occurrence or absence of bushpig-domestic pig interactions we were able to classify areas with high or intermediate levels of interactions or no interactions at all. Interactions between the two pig species were reported in only 25% of the fokontany assessed. Even though both suid species were attracted to fruit trees, crops, and water sources, only indirect interactions in those spots were reported. Direct interactions were reported in 10% of cases and referred to interspecific sexual and/or agonistic behavior. The participatory methods used to acquire local knowledge about natural events were confirmed as valuable, low-cost exploratory methods to characterize areas with wild-domestic animal interactions. The results of this study will help plan future studies to characterize the interface between the two species from an ecological or epidemiological perspective using more sensitive and sophisticated ecological approaches.
A biogeographical appraisal of the threatened South East Africa Montane Archipelago ecoregion
(Nature Research, 2024-03-12) Bayliss, Julian; Bittencourt‑Silva , Gabriela B.; Branch, William R.; Bruessow, Carl; Collins , Steve; Congdon , T. Colin E.; Conradie , Werner; Curran , Michael; Daniels, Savel R.; Darbyshire , Iain; Farooq , Harith; Fishpool , Lincoln; Grantham, Geoffrey; Magombo , Zacharia; Matimele , Hermenegildo; Monadjem, Ara; Monteiro, Jose; Osborne , Jo; Saunders , Justin; Smith , Paul; Spottiswoode , Claire N.; Taylor, Peter J.; Timberlake , Jonathan; Tolley , Krystal A.; Tovela , Erica; Platts, Philip J.
Recent biological surveys of ancient inselbergs in southern Malawi and northern Mozambique have led to the discovery and description of many species new to science, and overlapping centres of endemism across multiple taxa. Combining these endemic taxa with data on geology and climate, we propose the ‘South East Africa Montane Archipelago’ (SEAMA) as a distinct ecoregion of global biological importance. The ecoregion encompasses 30 granitic inselbergs reaching > 1000 m above sea level, hosting the largest (Mt Mabu) and smallest (Mt Lico) mid-elevation rainforests in southern Africa, as well as biologically unique montane grasslands. Endemic taxa include 127 plants, 45 vertebrates (amphibians, reptiles, birds, mammals) and 45 invertebrate species (butterflies, freshwater crabs), and two endemic genera of plants and reptiles. Existing dated phylogenies of endemic animal lineages suggests this endemism arose from divergence events coinciding with repeated isolation of these mountains from the pan-African forests, together with the mountains’ great age and relative climatic stability. Since 2000, the SEAMA has lost 18% of its primary humid forest cover (up to 43% in some sites)—one of the highest deforestation rates in Africa. Urgently rectifying this situation, while addressing the resource needs of local communities, is a global priority for biodiversity conservation.
Removal of organic biomass in Eucalyptus plantations has a greater impact on fungal than on bacterial networks
(Elsevier, 2025-06) Bose, Tanay; Vivas, Maria; Slippers, Bernard; Roux, Jolanda; Dovey, Steven; Kemler, Martin; Begerow, Dominik; Witfeld, Frederick; Brachmann, Andreas; Wingfield, Michael J.; Hammerbacher, Almuth; tanay.bose@fabi.up.ac.za
Complex and stable soil microbial networks are essential for productivity in plantation forestry, but their response to disturbances from harvesting and replanting is not well understood. This study assessed the impact of treatments designed to mitigate these disturbances on microbial biodiversity and networks in Eucalyptus plantation soils at three South African sites. We used high-throughput sequencing to catalogue fungal and bacterial biodiversity from 108 soil samples across three treatments: (i) retention of harvest residues (retained), (ii) removal of residues (removed), and (iii) removal of residues with added fertilizer (fertilized). Bioinformatic and statistical analyses of the sequence data revealed treatment-specific variations in microbial OTU richness, network structure and taxon associations at order-level. Microbiome richness was highest in ‘retained’ plots, and treatment-specific microbial diversity was evident in both fungal and bacterial communities. Network comparisons revealed that treatments to mitigate disturbances caused by harvesting significantly affected fungal networks but not bacterial networks. Fungal networks in ‘retained’ plots exhibited the highest complexity and stability compared to plots where the entire crop was removed. However, bacterial networks did not show significant differences in network structure among treatments. The associations between fungal and bacterial nodes were consistent in the three treatments, as indicated by similar Jaccard indices. However, distinct fungal hub nodes were found when comparing the 'retained' and 'removed' treatments. These findings highlight that retaining harvest residues enhances microbial richness and stabilizes fungal networks, making it a better strategy for managing soil disturbances than residue removal or fertilization.
The nutritional feed gap : seasonal variations in ruminant nutrition and knowledge gaps in relation to food security in Southern Africa
(Springer, 2025-02) Cooke, Andrew S.; Machekano, Honest; Gwiriri, Lovemore C.; Tinsley, Jonathan H.I.; Silva, Gleise M.; Nyamukondiwa, Casper; Safalaoh, Andrew; Morgan, Eric R.; Lee, Michael R.F.
Livestock production is critical to food security and rural livelihoods across Southern Africa. Despite progress in livestock science research in recent years, the seasonal availability and quality of feed remains one of the key challenges to livestock productivity in Southern Africa. In particular, dry weather conditions, the lack of rain and lower temperatures in the dry season cause herbaceous plants to die back and browse species to defoliate, limiting the abundance, quality, and variety of feed available. This creates a ‘Nutritional Feed Gap’, defined here as the combined effect of the sharp reduction in both forage quantity and quality from the wet to the dry season and the risk that it poses to ruminant production systems and the food security of the people and communities reliant on them. Understanding the nature and extent of how seasonality impacts ruminant production potential can thus contribute towards mitigating negative impacts of extreme weather and climate change on food systems. In this review, we characterise this nutritional feed gap in terms of forage abundance and nutrition as well as discussing how climate change may shape the future nutritional landscape. Whilst some forage nutrient concentrations varied little by season, crude protein and phosphorus were consistently found to decrease from the wet season to the dry season. We also identify a shortfall in primary research that assess both forage quality and quantity simultaneously, which forms part of a broader knowledge gap of our limited understanding of the impact of limiting factors to ruminant production on short and long-term food security across Southern Africa.
Territorial movements of African lions : can waterholes shape multiple central-place territories in a savannah ecosystem?
(Elsevier, 2025-06) Dejeante, Romain; Loveridge, Andrew J.; Macdonald, David W.; Madhlamoto, Daphine; Chamaillé-Jammes, Simon; Valeix, Marion
In territorial species, individuals need to regularly patrol their territory to display visual, auditory or olfactory signals or to detect the presence of intruders. Although territorial movements are often conceptualized as animals travelling along the boundaries of their territories (‘border-patrolling’ behaviour), the distribution of territorial cues could also match the distribution of resources when resources are spatially heterogeneous in their availability and found in stable patches, leading to the emergence of ‘multiple central-place territories’. Here, we explored how territoriality may shape the spatial behaviour of African lions, Panthera leo, in a savannah where waterholes are associated with aggregations of large herbivores throughout the year and are therefore well-known prey hotspots and key hunting sites for large carnivores. We hypothesized that male lions would be more likely to patrol a buffer area around the territory core to defend a core area where social interactions with groupmates occur, whereas female lions would more specifically patrol hunting sites, that is, waterhole areas. However, we found that both female and male lions repeatedly moved along straight paths between the waterholes located both in the core and in the periphery of their territories, potentially to defend multiple central-place territories driven by the distribution of waterholes in the landscape. These findings illustrate a case where territorial animals specifically mark feeding sites, increasing the renewal of territorial cues at these key places, potentially using long-distance territorial cues (that is, vocalizations) to mark uncovered areas, and thereby reducing the cost of patrolling large territories. Overall, multiple central-place territories provide new insights into how the spatial distribution of resources shapes space use in territorial animals.
Megagrazer loss drives complex landscape-scale biophysical cascades
(IOP Publishing, 2025-01) Hyvarinen, Olli; Te Beest, Mariska; Le Roux, Elizabeth; Kerley, Graham I.H.; Buitenwerf, Robert; Druce, Dave J.; Chen, Jiquan; Rapp, Linda; Fernandes, Joana; Cromsigt, Joris P.G.M.
Wild animals can modulate ecosystem-climate feedbacks, e.g. through impacts on vegetation and associated carbon dynamics. However, vegetation cover and composition also affect land surface albedo, which is an important component of the global energy budget. We currently know very little about the influence of wild animals on land surface albedo and the resulting climate forcing of these albedo changes. Leveraging a unique, ecosystem-scale, semi-experimental approach, we study how the local removals of the world's largest, terrestrial grazer, white rhinoceros (Ceratotherium simum), affected the coupling between fire dynamics, woody encroachment and surface albedo in Hluhluwe–iMfolozi Park (HiP), South Africa. Our path analysis revealed that areas in the park where more rhinos had been removed showed a stronger increase in burnt area and woody encroachment compared to areas with fewer rhinos removed, which were both related to a decrease in surface albedo. Increasing burnt area was further associated with higher rates of woody encroachment, indirectly reinforcing the negative effect of rhino loss on albedo. Our study demonstrates that removals of megagrazers in HiP were related to complex ecosystem-wide cascades with measurable impacts on land cover and surface albedo and consequences on climate forcing. This highlights the importance of restoring functional ecosystems by reinstating trophic processes.
Crop mixtures influence fall armyworm infestation and natural enemy abundance in maize-based intercropping systems
(Springer, 2024-12) Peter, Emmanuel; Yusuf, Abdullahi Ahmed; Subramanian, Sevgan; Kruger, Kerstin; Karlsson Green, Kristina; Anderson, Peter; Torto, Baldwyn; Tamiru, Amanuel
The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), causes significant damage to maize, threatening the food security and livelihood of millions of smallholder farmers in sub-Saharan Africa (SSA). Crop diversification has been recommended as an ecologically sustainable FAW control option. However, limited information is available on the impacts of companion plants and their control mechanisms against FAW in SSA, being a relatively new pest to the region. Building upon our earlier laboratory study, which elucidated how edible companion intercrops effectively reduce FAW infestation, we conducted field experiments in Kenya to assess the effectiveness of intercropping maize with beans, groundnut, cassava and sweet potato under realistic field conditions. Growing maize with these intercrops consistently resulted in fewer FAW eggs, larvae and lower plant infestation compared to maize monoculture except with cassava. Additionally, maize under these intercrops experienced low FAW damage and higher crop yield compared to maize monoculture. Maize growth stages significantly influenced the population of FAW eggs and larvae, with a peak observed between vegetative stages V4 and V10. Furthermore, intercropped maize plots exhibited a higher presence of FAW predators, such as lady beetles and earwigs. Correlation analysis revealed a significant correlation between temperature, relative humidity, and the population of FAW life stages and natural enemies at the experimental sites. Therefore, intercropping maize with beans, sweet potato, and groundnuts can be incorporated into an integrated FAW management strategy to sustainably control the pest in real farming conditions. These findings are particularly relevant for small-scale farmers in Africa and beyond, who cannot afford expensive FAW control using insecticides.
Small-scale fires interact with herbivore feedbacks to create persistent grazing lawn environments
(Wiley, 2024-07) Singh, Jenia; Donaldson, Jason E.; Archibald, Sally; Parr, Catherine Lucy; Voysey, Michael D.; Davies, Andrew B.
Fire-herbivory feedbacks strongly influence the formation of grazing lawns in savanna ecosystems. Preliminary findings suggest that small-scale (<25 ha) fires can engineer grazing lawns by concentrating herbivores on the post-burn green flush; however, the persistence of such grazing lawns over the longer term and without repeated fire is unknown. We used high-resolution Light Detection and Ranging (LiDAR) to investigate the long-term effects of fire manipulation on short grass structure (height, cover, volume and spatial continuity) and grazing lawn establishment in Kruger National Park, South Africa. We analysed the effects of fire exclusion and experimental burns applied over a 7-year period (2013–2019) followed by a 1-year cessation of burning at varying spatial scales during the early and late dry seasons. Fires contributed a fourfold increase in short grass cover, regardless of fire season or size. The distribution of grass height differed significantly between fire-induced grazing lawns and recently unburnt parts of the landscape where controlled fires were excluded over the experimental period. The volume (corresponding to bulk density) of short grass on the landscape responded strongly to fires, with grass volume <20 cm in height increasing with both early and late dry season fires. Early dry season fires caused larger and more homogeneous short grass patches. Furthermore, early dry season fires were more influential in increasing the cover of the shortest grass height class (1–5 cm). Synthesis and applications. Our results demonstrate that fire-induced grazing lawns can persist over the longer term, even when fires are no longer applied, leading to the creation of vertical and horizontal heterogeneity in the grass layer. Small-scale fires, therefore, represent a feasible management approach to expanding grazing lawn extent, potentially benefiting grazer coexistence and diversity.
High human presence is correlated with lower faecal glucocorticoid metabolite levels in an urban bird population
(Elsevier, 2025-04) Nhlapo, Kagiso B.; Cunningham, Susan J.; Sumasgutner, Petra; Ganswindt, Andre; McKechnie, Andrew E.; Ngcamphalala, Celiwe A.
Urban wildlife must cope with diverse challenges and stressors, including human presence. However, in addition to being a disturbance, humans can provide energy-rich food and protection from predators. We evaluated the impact of human presence on red-winged starlings (Onychognathus morio) in a highly urbanised environment using faecal glucocorticoid metabolite (fGCM) concentrations as a stress-related biomarker. We performed an adrenocorticotropic hormone (ACTH) challenge to validate a non-invasive method for quantifying glucocorticoids in red-winged starlings. Using this method, we quantified fGCMs in excreta collected from free-living starlings during weekdays (high human presence) and weekends (low human presence) to determine the birds' responses to fluctuating human numbers. Following the ACTH challenge, starlings' circulating glucocorticoid (GC) concentrations increased by 127 % within 30 min and the corresponding fGCM concentrations increased within 1 h of injection. Of the four enzyme immunoassays (EIA) tested, an 11-oxoaetiocholanolone EIA, performed best, detecting a 310 % increase in fGCM concentrations post-ACTH challenge and suggested a 1-h lag between injection and peak fGCM excretion in this species. Human foot-traffic was significantly higher on weekdays compared to weekends, yet free-living red-winged starlings showed overall 30.4 % lower fGCM concentrations on weekdays compared to weekends. Red-winged starlings consume a higher proportion of anthropogenic food on weekdays than weekends and we cannot rule out the possibility that diet-related alteration in gut passage time affect fGCM concentrations. However, the correlation between fGCMs and human foot traffic may also suggest urban red-winged starlings benefit from human presence. Our results raise the possibility that, under certain conditions, the benefits associated with human presence outweigh potential negative effects associated with human activity, at least during the non-breeding season.
Steering conservation biocontrol at the frontlines : a fuzzy logic approach unleashing potentials of climate-smart intercropping as a component within the integrated management of fall armyworm in Africa
(Elsevier, 2025-02) Agboka, Komi Mensah; Tonnang, Henri E.Z.; Kimathi, Emily; Abdel-Rahman, Elfatih M.; Odindi, John; Mutanga, Onisimo; Niassy, Saliou
This study introduces a computational index that employs fuzzy sets theory to identify potential deployment sites for push-pull as a component in the integrated management of Fall Armyworm (FAW) in Africa. The index, validated through known push-pull testing sites and informed by insights from field data and practical observations, is primarily based on companion plants (Desmodium intortum and Brachiaria brizantha), livestock, and maize as covariates. The study developed a set of rules linking each selected covariate to the output as membership functions, which are later combined using an algebraic operator. It identifies extensive maize farms across Africa potentially suitable for push-pull technology, although the suitability varies by region. Farms in the eastern and southern regions are predicted to be highly suitable, while the suitability of farms in West Africa is expected to improve over time due to the perennial nature and agronomic benefits of companion plants. The index is proposed as a metric for deploying push-pull technology, providing a roadmap for effective agronomic practices in Africa, and assisting farmers and decision-makers in the integrated management of FAW. Overall, our results indicate that the fuzzy-based computational index is an effective tool for identifying potential areas to maximise the benefits of push-pull technology as a key component of integrated FAW management. Our study identifies appropriate areas for application, allowing for the careful use of resources and increasing the likelihood of effective pest management. This approach will ultimately safeguard cereal crops, boost agricultural productivity, and aid in ensuring food security in Africa.
Integrating habitat suitability modeling with gene flow improves delineation of landscape connections among African savanna elephants
(Springer, 2024-09) De Flamingh, Alida; Alexander, Nathan; Perrin-Stowe, Tolulope I.N.; Donnelly, Cassidy; Guldemond, Robert Abraham Rene; Schooley, Robert L.; Van Aarde, Rudi J.
Across Africa, space for conservation is sometimes limited to formally protected areas that have become progressively more isolated. There is a need for targeted conservation initiatives such as the demarcation of landscape connections, defined as areas that encompass environmental variables that promote the natural movement of individuals between populations, which can facilitate gene flow. Landscape connections can mitigate genetic isolation, genetic drift, and inbreeding, which can occur in isolated populations in protected areas. Promoting gene flow can reduce the risk of extirpation often associated with isolated populations. Here we develop and test models for identifying landscape connections among African savannah elephant (Loxodonta africana) populations by combining habitat suitability modeling with gene flow estimates across a large region including seven countries. We find a pronounced non-linear response to unsuitable habitat, consistent with previous studies showing that non-transformed habitat models are poor predictors of gene flow. We generated a landscape connections map that considers both suitable habitats based on telemetry occurrence data and gene flow estimated as the inverse of individual genetic distance, delineating areas that are important for maintaining elephant population connectivity. Our approach represents a novel framework for developing spatially and genetically informed conservation strategies for elephants and many other taxa distributed across heterogeneous and fragmented landscapes.
A novel integrated computational approach for agroecological similarity
(Elsevier, 2025-06) Tonle, Franck B.N.; Tonnang, Henri E.Z.; Ndadji, Milliam M.Z.; Tchendji, Maurice T.; Nzeukou, Armand; Niassy, Saliou
Assessing agroecological similarity is crucial for shaping sustainable agricultural practices and resource allocation, especially in regions undergoing rapid environmental changes. Current evaluation methods face challenges such as managing large datasets, adjusting for temporal variations across locations, and the need for accessible, comprehensive analytical tools. Addressing these challenges, this paper presents the Agroecology Fourier-based Similarity Assessment (AFSA), an innovative computational approach that applies principles of the Fourier transform to systematically evaluate similarities among agroecological sites. To enhance usability, AFSA is complemented by webafsa, a user-friendly web application designed for researchers and policymakers, emphasizing ease of use and broad applicability. The implementation of AFSA and webafsa aims to improve land suitability assessments, enhance decision-making for resource allocation, and support better adaptation strategies for sustainable agriculture. By offering both a sophisticated computational methodology and an accessible decision-support tool, this study paves the way for more informed and environmentally considerate agricultural practices.
The impact of the lunar cycle and season on small mammal communities near a large metropolitan area
(Wiley, 2025-05) Oosthuizen, Tasha; Oosthuizen, Maria Kathleen; Pillay, Neville
Small mammals are prey to a range of predators and consequently use environmental cues, such as light, to assess the level of predation risk in their environment. The lunar cycle significantly influences the fear landscape for prey species because their risk level varies with visibility. We conducted small mammal surveys in two communities in close proximity to each other on a peri-urban site in South Africa. We investigated the abundance, composition and diversity of these communities across the lunar cycle and seasons. As predicted, we trapped the highest number of individuals and species on new moon nights, which have low light levels and thus indicate a reduced perceived predation risk. Winter showed a higher abundance compared to the other seasons, which could be explained by a decline in naturally available resources in winter. We captured more individuals and species on one site compared to the other site, largely because of the different microhabitats in the two sites; one site had a lower density of trees and more bare soil areas. Our study provides the first evidence of the impact the lunar cycle has on small mammal communities in southern Africa. Based on our findings of decreased activity of small mammals under increased lunar visibility, we hypothesise that small mammal communities in southern Africa will be negatively affected by the increased occurrence of artificial light at night, which could have wider ecosystem impacts.
Birds with distinct ecological traits show varied haemoglobin adaptations along elevation gradients
(Wiley, 2025-04) Bhembe, Zamekile D.; Padidar, Sara; Bebbington, Kat; Kingma, Sjouke A.; Monadjem, Ara
Ecological systems are highly dynamic, with organisms continually adapting to various environmental stressors along natural gradients. Birds along elevation gradients serve as excellent models for examining physiological adaptations, such as elevated haemoglobin concentrations at high altitudes due to lower oxygen availability. This study aimed to examine how various ecological traits influence the haemoglobin concentration responses of multiple bird taxa to an elevation gradient. We measured haemoglobin concentration in 920 birds of 133 species at six sites representing an elevation gradient spanning from 60 to 1,600 m above sea level. Using MCMC Bayesian mixed models, we identified important ecological determinants of haemoglobin concentration and further ran separate models to test whether haemoglobin concentration responses to elevation differ between various functional groups of birds. Our results showed that haemoglobin concentration increased significantly with elevation and was strongly influenced by wing morphology, body mass, season, and primary lifestyle. The rate of increase with elevation varied by lifestyle: terrestrial and perching birds exhibited a steeper increase in haemoglobin concentration with elevation, while aerial birds also increased haemoglobin but at a more gradual rate. However, the remaining traits did not alter how species respond to hypoxia; for example, birds increased haemoglobin at the same rate in both the dry and wet seasons, meaning seasonal changes did not strongly impact elevation-driven haemoglobin adjustments. Elevation is the primary driver of variation, while lifestyle influences baseline levels rather than the rate of change. Despite differences in lifestyle-driven oxygen demands, birds exhibit a similar haemoglobin response to hypoxia at moderate elevations, where adjustments remain within physiological limits, indicating that hypoxia-driven haemoglobin adjustments occur independently of baseline oxygen demands. These findings demonstrate how birds regulate oxygen transport relative to ecological constraints, providing insights into their physiological flexibility across environmental gradients.

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