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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The first teratological case for the Australian Omorgus Erichson, 1847 species (Coleoptera, Scarabaeoidea, Trogidae)
(Senckenberg Deutsches Entomologisches Institut, 2025-05-28) Da Costa-Silva, Vinicius
A new case of hemidystrophy in Trogidae is here described and illustrated. The teratological specimen was identified as a male of Omorgus (Omorgus) alternans (MacLeay, 1827), being the first record of a teratological specimen of a trogid from Australia. While teratological cases provide limited taxonomic insights, they offer significant understanding of the environmental influences on insect development. The study emphasizes the importance of documenting such anomalies, contributing to the broader knowledge of developmental biology in insects, particularly within the under-researched Australian Trogidae.
Population genetic analysis of Aedes aegypti reveals evidence of emerging admixture populations in coastal Kenya
(Public Library of Science, 2025-05) Mulwa, Francis; Balcazar, Dario; Langat, Solomon; Mutisya, James; Chelangat, Betty; McBride, Carolyn S.; Rose, Noah; Powell, Jeffrey; Sang, Rosemary; Bastos, Armanda D.S.; Gloria-Soria, Andrea; Lutomiah, Joel
BACKGROUND : The Aedes aegypti mosquito is widespread in tropical and subtropical regions. There are two recognized subspecies; the invasive Aedes aegypti aegypti (Aaa) and the ancestral Aedes aegypti formosus (Aaf). Aaf is common throughout Kenya whereas Aaa, which was historically confined to coastal regions, has undergone a range expansion. In areas of sympatry, gene flow may lead to admixed populations with potential differences in vectorial capacity. We hypothesize that coastal Ae. aegypti populations have a higher proportion of Aaa ancestry than those from inland locations of Kenya, influenced by their distance to the coast. METHODOLOGY : Adult Ae. aegypti mosquitoes were collected using Biogent (BG) sentinel traps baited with carbon-dioxide (CO2) from cities and towns along the Kenyan northern transport corridor. Aedes aegypti population structure, genetic diversity, and isolation by distance were analyzed using genome-wide single nucleotide polymorphism (SNPs) datasets generated with an Ae. aegypti microarray chip targeting ≈50,000 SNPs. Kenyan Aedes aegypti populations were placed into a global context within a phylogenetic tree, by combining the Kenyan dataset with a previously published global database. RESULTS : A total of 67 Ae. aegypti mosquitoes population from Kenya were genotyped, we found that western Kenya Ae. aegypti constitute a genetically homogenous population that clusters with African Aaf, whereas coastal mosquitoes showed evidence of admixture between the two subspecies. There was a positive correlation (Observation = 0.869, p = 0.0023) between genetic distance (FST) and geographic distance, suggesting isolation by distance. The phylogenetic analysis and the genetic structure analysis suggest that an Asian Aaa population is the source of Aaa invasion into Kenya. CONCLUSIONS : These results provide evidence of an emerging admixed population of Ae. aegypti in coastal Kenya between the sylvatic Aaf and the domesticated-human preferring Aaa. The observed gene flow from Aaa into Kenya may positively influence Ae. aegypti vectorial capacity, potentially increasing human feeding preference, biting rates and vector competence and could be promoting the observed dengue and chikungunya outbreaks. AUTHOR'S’ SUMMARY Aedes aegypti is of great public health concern due the viruses they transmit. The vector is highly invasive and is expanding to new geographic regions, quickly adapting to new environment. This study focuses in understanding the genetic structure of Ae. aegypti in cities along the northern transport corridor in Kenya, which are at risk of vector invasion. We analyzed Ae. aegypti populations using a panel of Single Nucleotide Polymorphism (SNPs) markers distributed across the genome. Our analysis shows admixture population in the coastal region between Aaf and Aaa, with Asian mosquitos being the putative source of Aaa ancestry, while the western populations are more related to African Aaf. This research provides a broad picture of the nature and dynamics of the Ae. aegypti populations across Kenya and sets the bases for further genetic studies focused on improving vector control strategies and developing novel mosquito control methods.
Molecular characterisation of tick-borne pathogens in cattle in Kenya : insights from blood, ticks, and skin swab analyses
(BioMed Central, 2025-10) Getange, Dennis; Mukaratirwa, Samson; Bargul, Joel L.; Khogali, Rua Khogali Ibrahim; Ng'iela, John; Kabii, James; Masiga, Daniel K.; Villinger, Jandouwe
BACKGROUND : Ticks pose a major threat to livestock and human health in sub-Saharan Africa, with climate change and pastoral movements fueling their spread. Few studies have integrated multiple sample types to characterize tick-borne pathogens (TBPs) in cattle in Kenya. This knowledge gap hinders the development of effective surveillance and control strategies, leaving vulnerable populations and their livestock susceptible to these persistent threats. METHODS : We screened 280 bovine blood samples, 589 tick pools, and 284 non-invasive skin swabs from cattle in northern (Marsabit) and southern (Kajiado) Kenya by high-resolution melting analysis and Sanger sequencing of PCR products. RESULTS : Rhipicephalus spp. (47.1%), Hyalomma spp. (30.8%), and Amblyomma spp. (22.1%) were prevalent, with Rhipicephalus evertsi only found in Kajiado and Rhipicephalus camicasi in Marsabit. In blood, Anaplasma spp. (62.9%; A. marginale, A. platys, A. ovis) and Theileria spp. (34.6%; T. velifera, T. mutans) were dominant. Tick pools harbored Coxiella burnetii, Rickettsia africae, Rickettsia aeschlimannii, Anaplasma marginale, Theileria velifera, T. ovis, and Babesia occultans, and for the first time two co-circulating Ehrlichia ruminantium strains (Welgevonden and Kumm2). Notably, C. burnetii and T. ovis were detected only in Marsabit, and T. mutans only in Kajiado. Skin swabs from tick predilection sites (ears, anal region) yielded R. africae, R. aeschlimannii, and T. velifera at low positivity, while nose swabs were negative. CONCLUSIONS : Detection of zoonotic pathogens such as C. burnetii and R. africae underscores critical public health risks, and co-infections in cattle reinforce the need for robust, integrated surveillance. Although skin swabs demonstrated limited diagnostic yield, they remain a promising non-invasive sampling approach. These findings highlight the value of targeted acarological research and coordinated control programs under a One Health framework.
Trophic niche of invasive murid rodents in urban and peri-urban areas in South Africa : insights from stable isotope analysis
(BioMed Central, 2025-10) Ringani, Gordon V.; Chimimba, Christian Timothy; Pirk, Christian Walter Werner; Zengeya, Tsungai Alfred; gordon.ringani@up.ac.za
There are three invasive Rattus species (R. norvegicus, R. rattus, R. tanezumi) that are known to occur in South Africa. The three Rattus species are widespread in urban and peri-urban areas where they have had a significant impact on human health, infrastructure, and biodiversity. There is, however, limited information on their trophic ecology and on how factors that affect access to, and utilization of, food resources facilitate successful establishment. This study applied stable isotope analysis (SIA) to assess the trophic niches of the three Rattus species across selected urban and peri-urban landscapes in Gauteng Province. The three Rattus species occurred allopatrically: R. norvegicus in urban areas (Alexandra and Tembisa townships), R. rattus in the peri-urban University of Pretoria Experimental Farm, and R. tanezumi in peri-urban areas near Hammanskraal. Rattus tanezumi and R. rattus exploited broader food resources in peri-urban areas that are used for agricultural activities, while R. norvegicus had a more restricted niche in urban environments. Niche breadth expanded in summer, reflecting seasonal food availability, while sex- and age-related differences suggested subtle differences in feeding strategies, although the results were inconsistent across species and sites. Although some limitations, such as the fact that the three Rattus species were sampled in allopatry and missing baseline resources constrained interpretation, the study provides insights into how invasive rats adapt to different environments. Future research combining stable isotope analysis with long-term monitoring data will be essential to clarify niche partitioning and guide effective management of invasive rat populations.
Determinants of mating success in a lek-mating species
(Wiley, 2025-11) Queffelec, Josephine; Allison, Jeremy D.; Slippers, Bernard; Greeff, Jacobus Maree
• Leks are male-biased aggregations formed for mating, where sperm is the only resource acquired by visiting females. • One of the many advantages of leks is the possibility to efficiently assess the quality of potential mates by comparing aggregated individuals of the same sex with one another. • When direct mate choice occurs in a lekking species, it is often exhibited by females, but some studies have also demonstrated the presence of male mate choice. • We investigate mate choice in the lek-forming European woodwasp, Sirex noctilio. • We determine the importance of age and size as predictors of mating success. • We demonstrate that mating is not random and that male and female traits affect mating success. • Age plays an important role in mating success in both males and females, with older males mating more and younger females being more attractive and more receptive to mating. • Relative male size seems to play a role in mating success, with males being more successful when attempting to mate with females that are larger than they are.
Unsustainable anthropogenic mortality threatens the long-term viability of lion populations in Mozambique
(Public Library of Science, 2025-06) Almeida, Joao; Briers-Louw, Willem D.; Jorge, Agostinho; Begg, Colleen; Roodbol, Marnus; Bauer, Hans; Loveridge, Andrew; Wijers, Matthew; Slotow, Rob; Lindsey, Peter Andrew; Everatt, Kristoffer; Rosier, Holly; Nazerali, Sean; Roxburgh, Lizanne; Pereira, Hugo; Da Conceicao, Mercia; Araman, Armindo; Abrao, Osvaldo J.; Leslie, Alison J.; Steinbruch, Franziska; Naude, Vincent N.; Nicholson, Samantha K.
Anthropogenic mortality is a pervasive threat to global biodiversity. African lions (Panthera leo) are particularly vulnerable to these threats due to their wide-ranging behaviour and substantial energetic requirements, which typically conflict with human activities, often resulting in population declines and even extirpations. Mozambique supports the 7th largest lion population in Africa, which is recovering from decades of warfare, while ongoing conflicts and broad-scale socio-economic fragility continue to threaten these populations. Moreover, there are concerns that Mozambique represents a regional hotspot for targeted poaching of lions which fuels a transnational illegal wildlife trade. This study aimed to quantify the longitudinal impact of anthropogenic mortality on lion populations in Mozambique. Using national population estimates and monitoring records, we performed forward simulation population viability modelling incorporating detection-dependent population trends and varying scales of anthropogenic mortality. Between 2010–2023, 326 incidents of anthropogenic mortality involving 426 lions were recorded. Bushmeat bycatch and targeted poaching for body parts were the greatest proximate causes of lion mortality (i.e., 53% of incidents), increasing significantly over time and acting as cryptic suppressors of regional population recovery, followed by legal trophy hunting (i.e., 33%), and retaliatory killing (i.e., 13%). Our findings suggest that resilience to anthropogenic threats is largely a function of lion population size as well as resource and management capacity. For instance, projections suggest that the lion population in Niassa Special Reserve will likely remain stable despite comparatively high levels of anthropogenic mortality, although further escalation may precipitate decline. Conversely, the lion population in Limpopo National Park is projected to become extirpated by 2030 without the buffering effect of its neighbouring source population in Kruger National Park. These unsustainable levels of anthropogenic mortality threaten the long-term viability of lion populations in Mozambique, requiring urgent national-level action and public-private partnerships to support site security, monitoring, and policy enforcement.
An intensified cereal push-pull system reduces pest infestation and confers yield advantages in high-value vegetables
(Springer, 2025-02) Chidawanyika, Frank; Omuse, Evanson R.; Agutu, Lavender O.; Pittchar, Jimmy O.; Nyagol, Dickens; Khan, Zeyaur R.
Crop diversification is associated with ecosystem services that can improve yield. We integrated tomatoes and kales within the cereal push-pull technology (PPT), to form the vegetable integrated push-pull (VIPP), and explored the influence of these cropping systems on pest and disease management, and subsequent yield of the vegetables. Aphids and diamondback moths (DBM), the major pests in kale production, together with grasshoppers were consistently lower in the VIPP plots. Low incidences and damage by leafminers, whiteflies and fruitflies on tomatoes were observed in VIPP plots compared to plots of tomato intercropped with maize (control). The severity of black rot and leaf curl on kales and leaf spots on tomatoes were less in VIPP compared to control. We recorded good quality and high yield of tomato and kale grown in VIPP plots rather than control plots. We demonstrate that spatial crop diversification such as integrating vegetables such as kale and tomato in a push-pull system can boost yield and maintain crop integrity.
Include scorpions in global conservation plans
(American Association for the Advancement of Science, 2025-09) Blasco-Arostegui, Javier; Moreno-Gonzalez, Jairo A.; Loria, Stephanie F.; Carvalho, Leonardo S.; Bird, Tharina L.
Invertebrates are undergoing a rapid and mostly undocumented decline. Among the oldest terrestrial organisms, scorpions survived all five mass extinctions, but contemporary threats are testing their resilience. Most of the nearly 2900 scorpion species are ecologically specialized and geographically restricted, and some are confined to a single island, cave, or mountaintop. Anthropogenic pressures threaten many scorpion species, yet conservation efforts have largely overlooked them. Global protective measures are urgently needed to prevent the extinction of these “living fossils.”
Semiochemical-based strategies for sustainable management of the fall armyworm, Spodoptera frugiperda (J.E Smith) (Lepidoptera: Noctuidae)
(Springer, 2025-10) Sisay, Birhanu; Nakamura, Akihiro; Mihretie, Aderajew; Tamiru, Amanuel; Weldon, Christopher William; Ashton, Louise A.
Semiochemicals are produced by diverse taxa to mediate intra- and interspecific communication. These chemical cues are becoming increasingly important in integrated pest management (IPM) for manipulating key behaviors such as mating, foraging, and host selection in both plant–insect and insect-insect interactions. Semiochemical-based approaches regulate pest populations through techniques such as monitoring, mass trapping, and mating disruption. Understanding the chemical cues that mediate these interactions is crucial for developing sustainable and targeted pest management options. This review explores the role of semiochemicals in managing insect pests, with a focus on the fall armyworm (Spodoptera frugiperda), a globally significant pest native to the Americas. We discuss composition, variability, efficacy, specificity, and applications of plant volatiles and sex pheromones in pest management. Additionally, we address challenges associated with the adoption of semiochemical-based approaches and highlight emerging research directions to enhance their integration into IPM programs. By synthesizing current knowledge, this review underscores the potential of semiochemical-based strategies to reduce reliance on conventional insecticides while improving pest control efficiency. The strategic application of plant volatiles and sex pheromones in agricultural systems offers an opportunity to develop more ecologically sound and sustainable pest management practices, thereby fostering resilient cropping systems with minimal environmental impact.
Dietary modulation of gut microbiota and functional enzymes in savannah honey bees (Apis mellifera scutellata Lepeletier)
(Springer, 2025-10) Khumalo, Nolwandle N.; Obi, Linda U.; Yusuf, Abdullahi Ahmed; Adeleke, Rasheed A.
Honey bees gather pollen from flowering plants, using it as a vital protein source and, in turn, acquire pollen-associated microbes that interact with their existing gut microbiota. Despite their ecological importance, limited information exists regarding the gut microbiota of African savannah honey bees (Apis mellifera scutellata Lepeletier) and how diet and its associated microbial community influence this crucial internal ecosystem. This study aimed to investigate the differences in gut microbiota between wild honey bees collected during the flowering season and microbially depleted honey bees reared under semi-sterile conditions and fed various protein diets. To achieve this, freshly hatched worker bees were maintained in hoarding cages and assigned one of four protein diets: fresh sunflower pollen, casein, sterilised casein, or sterilised pollen. High-throughput DNA metabarcoding was then employed to compare the microbial composition of the honey bee gut across these groups. Our findings revealed that the gut of microbially depleted honey bees exhibited higher species diversity and richness. Conversely, the non-core gut microbial community predominated in wild bees and those fed the different protein diets. Specifically, Commensalibacter, Bartonella, and Bifidobacterium were the most dominant bacterial genera across all treatments. Interestingly, Gilliamella, a common core gut bacterium, was undetected, while Apibacter was exclusively found in wild honey bees. Furthermore, pollen-associated microbes such as Devosia and Pedobacter were identified solely in the gut of honey bees fed a pollen diet. Functional predictions of the gut microbial community also indicated the presence of key enzymes such as β-glucosidase, β-galactosidase, pyruvate dehydrogenase and phosphoglycerate mutase, which are crucial for enhancing nutrient absorption, digestion, and carbohydrate metabolism. These results underscore the intricate relationship between honey bees, microbes, and plants, offering valuable insights into how diet and its associated microbial communities could shape the gut microbiota of African honey bees. KEY POINTS • The non-core gut microbiota dominates the African savannah honey bee • The type of diet influenced the microbial diversity and community abundance in the honey bee gut • Key enzymes involved in digestion, nutrition absorption, and carbohydrate metabolism were enhanced in the gut • Pollen-associated microbes found in the diet present potential avenues for probiotic development to improve honey bee health
Spatiotemporal variation of small hive beetle infestation levels in honeybee host colonies
(Springer, 2025-09) Palonen, Aura; Papach, Anna; Muturi, Michael N.K.; Weinstein Teixeira, Erica; Williams, Geoffrey R.; Jacobsen, Rachel; Evans, Jay D.; Posada-Florez, Francisco J.; Pirk, Christian Walter Werner; Lattorff, H. Michael G.; Lawrence, Akinwande K.; Oluseyi, Murele O.; Spooner-Hart, Robert; House, Clarissa M.; Federico, Giovanni; Formato, Giovanni; Neumann, Peter
High infestation levels of small hive beetle (SHB), Aethina tumida, can cause more damage to honeybee, Apis mellifera, host colonies. However, the spatiotemporal variation of SHB infestations is poorly understood. Here, we show that SHB infestations can be equally high in native and invasive ranges, suggesting that differences between host populations are the key criterion for damage. The data reveal that spatial variation within locations was not correlated with migratory beekeeping, SHB management strategies, nor the number of colonies at an apiary. Despite no annual changes in SHB infestations, the data confirm seasonal variation in infestations in two locations probably due to environmental factors affecting SHB. Infestations are lower in Italy than elsewhere, possibly due to strongly implemented management strategies. It is apparent that our understanding of varying SHB infestations is still limited. This suggests that further efforts are required to elucidate our knowledge of this important host-parasite system.
Underrepresentation of bats in Africa's protected areas
(Wiley, 2025) Montauban, Cecilia; Budinski, Ivana; Webala, Paul W.; Laverty, Theresa M.; Tanshi, Iroro; Torrent, Laura; Bakwo-Fils, Eric; Taylor, Peter J.; Kane, Adam; Monadjem, Ara
Biodiversity is severely threatened globally, with habitat loss and other human pressures accelerating species extinctions. Protected areas (PAs) are a critical conservation tool; however, their effectiveness in safeguarding many taxa, such as bats, remains unclear. Using georeferenced occurrence records and species distribution models (SDMs) for 263 sub-Saharan African bat species, we evaluated the coverage of bats in 7875 terrestrial PAs. Eighty-nine percent of bat species were recorded in at least 1 PA, yet 28 species, including 5 threatened and 15 data deficient species, were absent from all PAs. Species with large extents of occurrence were represented in more PAs, and fruit bats occupied significantly more PAs than clutter, edge, or open-air insectivorous foragers. The SDMs revealed high species richness in some undersurveyed areas, particularly in West and Central Africa and the Albertine Rift, emphasizing the need for targeted surveys. Our findings underscore critical data deficiencies related to bat conservation and stress the urgency of integrating bats into broader conservation planning. More surveys, enhanced data-sharing, and tailored conservation strategies are needed to improve bat representation in PAs and safeguard their ecological roles in Africa's biodiverse landscapes.
Early detection of Phytophthora root rot in Eucalyptus using hyperspectral reflectance and machine learning
(Elsevier, 2025-10) Esterhuizen, Hendrik J.; Slippers, Bernard; Bosman, Anna Sergeevna; Roux, Jolanda; Jones, Wayne; Bose, Tanay; Hammerbacher, Almuth; tanay.bose@fabi.up.ac.za
The rising prevalence of Phytophthora diseases in forests highlights the need for rapid, non-invasive detection methods. Early-stage root infections are difficult to detect due to the absence of visible above-ground symptoms, while current diagnostics remain slow and invasive. This study investigated whether hyperspectral leaf reflectance could detect root rot caused by Phytophthora alticola in Eucalyptus benthamii. Nineteen commercially planted families were inoculated, and leaf spectra were collected using an ASD FieldSpec 4 sensor. A machine learning pipeline was developed to identify diagnostic spectral signals. Key wavelengths were identified using permutation importance, a genetic algorithm, and self-attention network (SAN) scores. Spectral signals linked to root rot revealed that infection was correlated with leaf pigment accumulation and moisture stress. Three algorithms, random forest (RF), support vector machine (SVM), and SAN, were trained on hyperspectral data to predict P. alticola infection. The SAN achieved 97 % accuracy on a reduced dataset, which included the diagnostic wavelengths from the feature selection step, surpassing the RF (96 %) and SVM (94 %) models. This study demonstrates hyperspectral sensing as an effective tool for detecting Phytophthora root rot using spectra from the foliage and highlights the application of advanced machine learning techniques for plant disease classification. HIGHLIGHTS • Hyperspectral sensing detects Phytophthora root rot before symptoms appear. • SAN model achieved 97 % accuracy using selected wavelengths from leaf spectra. • Key wavelengths correlated with pigment shifts and moisture stress in leaves. • Machine learning identified spectral markers for early disease detection. • Vegetation indices NDNI and MSI are strongly linked to infection status.
Increases in humidity will intensify lethal hyperthermia risk for birds occupying humid lowlands
(Oxford University Press, 2025-06) Coulson, Bianca; Freeman, Marc Trevor; Conradie, Shannon Rose; McKechnie, Andrew E.; andrew.mckechnie@up.ac.za
Please read abstract in the article. LAY SUMMARY Many tropical birds will experience hotter and more humid wet-season conditions in future. In an African forest frugivore, we found the maximum tolerable wet-bulb temperature is 31.7°C and risks of lethal hyperthermia will increase substantially by 2100. These findings reveal a pervasive but understudied threat facing birds inhabiting humid lowlands.
Neonatal antipredator tactics shape female movement patterns in large herbivores
(Nature Research, 2025-01) Atmeh, Kamal; Bonenfant, Christophe; Gaillard, Jean-Michel; Garel, Mathieu; Hewison, A.J. Mark; Marchand, Pascal; Morellet, Nicolas; Anderwald, Pia; Buuveibaatar, Bayarbaatar; Beck, Jeffrey L.; Becker, Matthew S.; Van Beest, Floris M.; Berg, Jodi; Bergvall, Ulrika A.; Boone, Randall B.; Boyce, Mark S.; Chamaillé-Jammes, Simon; Chaval, Yannick; Buyanaa, Chimeddorj; Christianson, David; Ciuti, Simone; Cote, Steeve D.; Diefenbach, Duane R.; Droge, Egil; Du Toit, Johan T.; Dwinnell, Samantha; Fennessy, Julian; Filli, Flurin; Fortin, Daniel; Hart, Emma E.; Hayes, Matthew; Hebblewhite, Mark; Heim, Morten; Herfindal, Ivar; Heurich, Marco; Von Hoermann, Christian; Huggler, Katey; Jackson, Craig; Jakes, Andrew F.; Jones, Paul F.; Kaczensky, Petra; Kauffman, Matthew; Kjellander, Petter; LaSharr, Tayler; Loe, Leif Egil; May, Roel; McLoughlin, Philip; Meisingset, Erling L.; Merrill, Evelyn; Monteith, Kevin L.; Mueller, Thomas; Mysterud, Atle; Nandintsetseg, Dejid; Olson, Kirk; Payne, John; Pearson, Scott; Pedersen, Ashild Onvik; Ranglack, Dustin; Reinking, Adele K.; Rempfler, Thomas; Rice, Clifford G.; Roskaft, Eivin; Saether, Bernt-Erik; Said, Sonia; Santacreu, Hugo; Schmidt, Niels Martin; Smit, Daan; Stabach, Jared A.; St-Laurent, Martin-Hugues; Taillon, Joelle; Walter, W. David; White, Kevin; Peron, Guillaume; Loison, Anne
Caring for newborn offspring hampers resource acquisition of mammalian females, curbing their ability to meet the high energy expenditure of early lactation. Newborns are particularly vulnerable, and, among the large herbivores, ungulates have evolved a continuum of neonatal antipredator tactics, ranging from immobile hider (such as roe deer fawns or impala calves) to highly mobile follower offspring (such as reindeer calves or chamois kids). How these tactics constrain female movements around parturition is unknown, particularly within the current context of increasing habitat fragmentation and earlier plant phenology caused by global warming. Here, using a comparative analysis across 54 populations of 23 species of large herbivores from 5 ungulate families (Bovidae, Cervidae, Equidae, Antilocapridae and Giraffidae), we show that mothers adjust their movements to variation in resource productivity and heterogeneity according to their offspring’s neonatal tactic. Mothers with hider offspring are unable to exploit environments where the variability of resources occurs at a broad scale, which might alter resource allocation compared with mothers with follower offspring. Our findings reveal that the overlooked neonatal tactic plays a key role for predicting how species are coping with environmental variation.
Interactions among nutrients govern the global grassland biomass-precipitation relationship
(National Academy of Sciences, 2025-04-11) Fay, Philip A.; Gherardi, Laureano A.; Yahdjian, Laura; Adler, Peter B.; Bakker, Jonathan D.; Bharath, Siddharth; Borer, Elizabeth T.; Harpole, W. Stanley; Hersch-Green, Erika; Huxman, Travis E.; Macdougall, Andrew S.; Risch, Anita C.; Seabloom, Eric W.; Bagchi, Sumanta; Barrio, Isabel C.; Biederman, Lori; Buckley, Yvonne M.; Bugalho, Miguel N.; Caldeira, Maria C.; Catford, Jane A.; Chen, Qingqing; Cleland, Elsa E.; Collins, Scott L.; Daleo, Pedro; Dickman, Christopher R.; Donohue, Ian; Dupre, Mary E.; Eisenhauer, Nico; Eskelinen, Anu; Hagenah, Nicole; Hautier, Yann; Heckman, Robert W.; Jonsdottir, Ingibjoerg S.; Knops, Johannes M.H.; Laungani, Ramesh; Martina, Jason P.; Mcculley, Rebecca L.; Morgan, John W.; Venterink, Harry Olde; Peri, Pablo L.; Power, Sally A.; Raynaud, Xavier; Ren, Zhengwei; Roscher, Christiane; Smith, Melinda D.; Spohn, Marie; Stevens, Carly J.; Tedder, Michelle J.; Virtanen, Risto; Wardle, Glenda M.; Wheeler, George R.
Ecosystems are experiencing changing global patterns of mean annual precipitation (MAP) and enrichment with multiple nutrients that potentially colimit plant biomass production. In grasslands, mean aboveground plant biomass is closely related to MAP, but how this relationship changes after enrichment with multiple nutrients remains unclear. We hypothesized the global biomass–MAP relationship becomes steeper with an increasing number of added nutrients, with increases in steepness corresponding to the form of interaction among added nutrients and with increased mediation by changes in plant community diversity. We measured aboveground plant biomass production and species diversity in 71 grasslands on six continents representing the global span of grassland MAP, diversity, management, and soils. We fertilized all sites with nitrogen, phosphorus, and potassium with micronutrients in all combinations to identify which nutrients limited biomass at each site. As hypothesized, fertilizing with one, two, or three nutrients progressively steepened the global biomass–MAP relationship. The magnitude of the increase in steepness corresponded to whether sites were not limited by nitrogen or phosphorus, were limited by either one, or were colimited by both in additive, or synergistic forms. Unexpectedly, we found only weak evidence for mediation of biomass–MAP relationships by plant community diversity because relationships of species richness, evenness, and beta diversity to MAP and to biomass were weak or opposing. Site-level properties including baseline biomass production, soils, and management explained little variation in biomass–MAP relationships. These findings reveal multiple nutrient colimitation as a defining feature of the global grassland biomass–MAP relationship. SIGNIFICANCE Understanding how multiple interacting nutrients regulate the global relationship between mean annual precipitation and aboveground biomass is crucial for forecasting how ecosystem functioning will be altered by ongoing global changes. We fertilized with nitrogen, phosphorus, and potassium plus micronutrients in all combinations in 71 grasslands representing a global precipitation gradient. The grassland biomass–precipitation relationship became steeper with an increasing number of added nutrients. Increases in steepness corresponded to the form of interaction among added nitrogen and phosphorus. We found weak evidence that variation in plant species diversity mediated changes in the biomass–precipitation relationship. Multiple nutrient colimitation, particularly by nitrogen and phosphorus, is a defining feature of grassland biomass–precipitation relationships, and crucial to predicting grassland responses to global change.
A heat-sensitive songbird's risk of lethal hyperthermia increases with humidity
(Royal Society, 2025-10) Liddle, Nazley; Freeman, Marc Trevor; Cunningham, Susan J.; Conradie, Shannon Rose; McKechnie, Andrew E.
Please read abstract in the article.
Climate-driven potential for tularemia in East Africa : skill testing and ecological consistency of a transferred risk model
(Elsevier, 2025-11) Agboka , Komi Mensah; Ng´anga, Allan Muohi; Sokame, Bonoukpoe Mawuko; Baleba, Steve B.S.; Landmann , Tobias; Abdel-Rahman, Elfatih M.; Tanga , Chrysantus M.; Diallo, Souleymane
Tularemia, a neglected zoonosis, remains underreported in Africa despite growing concern over its climate-driven expansion. This study aims to quantify the specific contribution of climate to tularemia risk using a climate attribution framework. We trained a Least Squares Dummy Variable (LSDV) fixed-effects panel model on United States (U.S.) county-level tularemia incidence data from 2011–2020 (n = 500, R² = 0.90), incorporating only climatic predictors: cumulative temperature, cumulative precipitation, and their respective variabilities. The climate-only model explained 86% of variance in the training data, demonstrating strong climate influence on tularemia disease dynamics. We then applied the model to East Africa, using environmental similarity analysis to assess transferability. Results show moderate-to-high climatic analogues in northern Kenya, eastern Uganda, and South Sudan. Between 2017 and 2020, predicted tularemia suitability increased by a median of +0.18 compared to the 2012–2015 baseline, particularly in arid and semi-arid zones. Low interannual variability suggests persistent climatic suitability. A thermal plausibility test showed strong agreement (r = 0.82) between predicted risk and the Gaussian thermal profile of Francisella tularensis. Our findings suggest that climate alone can spatially explain tularemia risk across Africa’s drylands. This method provides a transferable framework for early warning in data-poor regions and supports anticipatory surveillance in the context of climate change.
Honey bee colony losses and causes during the active beekeeping season 2022/2023 in nine Sub-Saharan African countries
(Public Library of Science, 2025-05) Nganso, Beatrice T.; Ayalew, Workneh; Wubie, Abebe J.; Assefa, Freweini; Belayhun, Lulseged; Ndungu, Nelly N.; Toroitich, Daniel; Otieno-Ayayo, Z. Ngalo; Wambua, Mbatha B.; Oyieyo, Yudah O.; Elie, Ntirenganya; Sikirou, Rachidatou; Idrissou, Souradji B.; Mwiza, Willy; Turner, S.; Bobadoye, Bridget O.; Fameni, Sidonie T.; Gaboe, Sayemie; Agbodzavu, Mawufe K.; Mafwila, Patrick; Taboue, Geraud C. Tasse; Emily, Kimathi; Henri, Tonnang Z.E.; Niassy, Saliou; Fonkou, Simplice N.; Pirk, Christian Walter Werner; Gray, Alison; Brodschneider, Robert; Soroker, Victoria; Subramanian, Sevgan
This study reports for the first-time a multi-country survey of managed honey bee colony loss rates and associated risk factors during the active beekeeping season 2022/2023 in nine Sub-Saharan African countries, namely Kenya, Ethiopia, Rwanda, Uganda, Benin, Liberia, Nigeria, Cameroon and Democratic Republic of the Congo. It also evaluates the sustainability of bee swarm catches as a primary source for expanding apiary size by African beekeepers. In this survey, the 1,786 interviewed beekeepers across these countries collectively managing 41,761 colonies registered an overall loss rate of 21.3%, which varied significantly among countries (from 9.7 to 45.3%) and hive types (from 10.6% in hives with movable frames to 17.9% in frameless hives). The perceived causes of losses in order of significance were issues beyond the beekeeper’s control (mostly theft, drought, and bushfire), absconding and pests (mostly wax moth, small and large hive beetles, ants and Varroa destructor mite), but this pattern varied greatly across countries. Among the management practices and characteristics, migratory beekeepers and professional beekeepers experienced lower losses than beekeepers practicing stationary beekeeping and semi-professionals and hobby beekeepers, respectively. Insights into the number of bee swarms caught revealed a significant decrease in swarm availability over the past three years in Kenya, while some regions in Ethiopia showed the opposite trend, requiring further investigation. Overall, this comprehensive survey highlights the complexities and challenges faced by beekeepers in Sub-Saharan Africa, underscoring the need for targeted interventions and sustained research to support the resilience and growth of the apicultural sector.
Mathematical assessment of co-dynamics of deformed wing virus variants A and B infections in honeybees
(Elsevier, 2026-03) Hussaini, Nafiu N.; Yusuf, Abdullahi Ahmed; Ishaku, Adamu; abdullahi.yusuf@up.ac.za
This study presents a mathematical model to assess the co-dynamics of infections with Deformed Wing Virus (DWV) Variants A and B within a honeybee hive. The model is analyzed via submodels, DWV A only and DWV B only. Our qualitative analysis results demonstrate that the disease-free equilibrium of each submodel is locally asymptotically stable when the corresponding reproduction number is below one. In addition, the submodels exhibit backward bifurcation. A numerical simulation shows that breeding bees for resistance reduces the number of infected brood and adults. The simulation further suggests that enhancing the efficiency of breeding bees for hygienic and grooming behavior in bees could be an effective strategy for controlling the spread of both DWV variants and mite populations. The sensitivity analysis results show that the most important parameters that contribute to the generation of more DWV infections are the transmission rate of DWV-B, the rate of maturation to infected adult bees, and the egg-laying rate. Furthermore, the uncertainty analysis result highlights that focusing on interventions like breeding bees for resistance, hygienic, and grooming behavior could lead to a relatively lower reproduction number. Finally, the result obtained from cost-effectiveness analysis suggests that implementing all interventions concurrently (the universal strategy) is the most cost-effective when resources are available. Otherwise, breeding bees for hygiene and grooming behavior is the most cost-effective strategy. However, the choice of which strategy to implement depends on policymakers’ budget constraints. HIGHLIGHTS • Deformed Wing Virus A and B co-dynamics model is proposed and analyzed. • Intervention strategies: breeding for resistance, hygienic and grooming behavior are incorporated in the model. • Numerical simulation was used to assess the impact of the intervention strategies. • Concurrent implementation of all the aforementioned strategies is the most cost effective strategy if the resources are available.

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