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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Climate change-induced distribution shifts of keratin-feeding beetle Omorgus (Omorgus) suberosus : implications for olive ridley sea turtle Lepidochelys olivacea conservation
Alencar, Janderson Batista Rodrigues; De Albuquerque Correa, César Murilo; Baccaro, Fabrício Beggiato; Sole, Catherine L.; Da Costa-Silva, Vinicius (Wiley, 2025-12)
ENGLISH : The sea turtle Lepidochelys olivacea (Eschscholtz, 1829) is particularly threatened by egg predation from the invasive beetle Omorgus (Omorgus) suberosus (Fabricius, 1775). However, the impact of global climate change on the distribution and overlap of these speciesis still poorly understood. Our study aimed to predict the global distributions of O. suberosus and L. olivacea under various climate change scenarios, to examine their distribution overlap and to assess the conservation status of L. olivacea. We analysed a dataset of 2896 O. suberosus records and 15,329 L. olivacea records, using three modelling algorithms: Maximum entropy default (MXD),DOMAIN (DOM) and generalised linear models (GLM) to project their global distributions under the SSP2–4.5 and SSP5–8.5 sce-narios. Results revealed shifts in the distribution of O. suberosus by 2100. As temperatures increased, the species expanded its range northward into Europe and North America, while substantial habitat losses occurred in tropical and subtropical regions. Under amild climate change scenario (SSP2–4.5), the suitable habitat for O. suberosus decreased globally by 9.5%, whereas under a ‘business-as-usual’ scenario (SSP5–8.5) projected a 20.8% reduction. Our projections indicate that by 2100, L. olivacea will experience signifi-cant reductions in suitable coastal habitats under the SSP245 (12.11%) and SSP585 (24.63%) scenarios, with particularly severe lossesin northern South America and southern Europe under SSP245 (12.11%). The overlap of O. suberosus and L. olivacea ranges indicates a significant decline. Under the SSP245 scenario for 2081–2100, the overlap area is projected to decrease by 20.66%. The SSP585 scenario forecasts a further reduction of 37.56%. Understanding the interactions between O. suberosus and L. olivacea is vital for guiding field studies and informing conservation strategies. Although our results suggest a reduction in the overlap of these species, the decline in the suitable area of L. olivacea raises concerns. Our findings emphasise the importance of targeted research and strategic management to mitigate the impacts of invasive species and climate change on vulnerable turtle populations globally.
Comparing seismic survey mitigation regulations : lessons for South Africa from international frameworks
Purdon, Jean; Somers, Michael J.; Shabangu, Fannie Welcome; Doh, Y.; Scheun, J. (Taylor and Francis, 2025-11-24)
Underwater seismic surveys generate high-intensity, low-frequency noise that can negatively affect a range of marine fauna. As a result, countries have implemented mitigation regulations to reduce the potential impacts of this activity. This study examines seismic survey mitigation regulations from Australia, the United States, Brazil, New Zealand, Canada and the United Kingdom, and compares them with the current regulations in South Africa. We focused on setting the radii of exclusion zones, ‘soft-start’ procedures, passive acoustic monitoring, marine mammal observer qualifications and standards, and regulatory oversight. Of the six countries reviewed, Australia and New Zealand have implemented the most robust mitigation measures. Furthermore, Australia stands out for its independent regulatory authority overseeing offshore environmental compliance. We recommend the establishment of an independent regulatory board in South Africa to oversee the development of environmental impact assessment guidelines and mitigation protocols. By adopting these measures and aligning with international best practice, South Africa could become a regional, if not global, leader in science-based environmental regulation and the protection of marine fauna from seismic surveys.
Exported illegally, threatened locally : South Africa in the global reptile pet trade
Willoughby, Sian; Selier, SA Jeanetta; Zondi, Zwelakhe; Hall, Grant (Taylor and Francis, 2025)
The global illegal exotic pet trade is a major driver of biodiversity loss, particularly affecting reptile species listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II. CITES is an international agreement used to monitor the import and export of listed fauna and flora, ensuring trade is not detrimental to the survival of listed species in the wild. This study investigates South Africa’s role in the international trade of reptiles, using the endemic Sungazer lizard (Smaug giganteus) as a case study. Analysis of CITES Trade Database records reveals systemic reporting in accuracies, including discrepancies between importer and exporter data, misuse of source and purpose codes, and evidence of wildlife laundering. Trade peaks in 1988 and 2013 correspond to increased species visibility due to CITES listing and cultural associations with popular media, respectively, illustrating the influence of anthropogenic and media-driven factors on global wildlife trade demand. Evidence of potentially illegal exports from non-range countries and suspicious declarations of captive-bred specimens suggests that South Africa may be both a source and transit country in illicit reptile trade networks. The lack of enforcement, coupled with the ease of smuggling, exacerbates the threat to S. giganteus and similar threatened reptile species. These findings underscore the urgent need to strengthen CITES data reliability, enforce trade regulations, and enhance protection for South African reptile species vulnerable to overexploitation.
Afrotropical Culicoides (Diptera: Ceratopogonidae): description of Culicoides baltusi sp. n. and Culicoides theileri sp. n., two new species related to Culicoides brucei from southern Africa
Labuschagne, Karien; Van Schalkwyk, A.; Scholtz, Clarke H.; Labuschagne, K. (Academy of Science of South Africa, 2025)
The genus Culicoides Latreille is represented by 160 described species in the Afrotropical region. Evidence suggests that there may be at least 30 species still need to be described in South Africa. Culicoides baltusi Labuschagne and Meiswinkel†* sp. n. and Culicoides theileri Labuschagne and Meiswinkel sp. n. are described and illustrated for both sexes from material collected in South Africa, Botswana, Namibia and Zimbabwe since 1990. We propose that both species be placed in the subgenus Culicoides Latreille. Morphological and molecular evidence indicate that these two species are related to Culicoides brucei Austen. Culicoides theileri sp. n. is restricted to the drier western areas of the Northern and Western Cape provinces, while C. baltusi sp. n. on the other hand is widely distributed across southern Africa, as is C. brucei. These three species can be separated based on size and wing pattern. Breeding habitat of all three species is not known. Published research utilising precipitin tests and PCR indicate that the adult female blood feeding preferences of C. baltusi sp. n. and C. brucei are large mammals, including bovines and equids. Those of C. theileri sp. n. are not known, though it likely also feeds on large mammals. Extensive light trap data, collected over 30 years, were extracted from the National Collection of Insects of Veterinary Importance (NCIVI) database and are used to map the distribution ranges of C. baltusi sp. n., and C. theileri sp. n. and C. brucei in southern Africa. The description of these two new species increases our understanding of the diversity and distribution of Culicoides species in southern Africa.
Transforming African food systems : perspectives from the Food Systems Network for Africa (FSNet-Africa)
Dorvlo, Selorm Yaotse; Mkandawire, Elizabeth; Mentz-Coetzee, Melody; Dougill, Andrew; Swanepoel, Frans; Emmambux, Mohammad Naushad; Boakye, Abena; Anim-Jnr, Antoinette Simpah; Lungu, Nobuhle Sharon; Tchuwa, Frank; Kwapong, Nana Afraana; Isingizwe, Frederic; Jokonya, Osden; Maina, Joyce; Du Toit, Andrea; John, Innocensia; Mwanri, Akwilina Wendelin; Mzumara, Tiwonge I.; Holt, Diane; Jordaan, Daniel Du Plessis Scheepers; Schonfeldt, H.C. (Hettie Carina); Yusuf, Abdullahi Ahmed; Sait, Steven; Greathead, Henry; Vilakazi, Nokuthula; Jew, Eleanor; Nkukwana, Thobela T.; Papargyropoulou, Effie; Alphonce, Roselyne; Quinn, Claire Helen (Elsevier, 2025-10)
African food systems face significant challenges, including poverty, inequality, climate change, and unsustainable practices. To ensure access to safe and nutritious food while addressing socio-economic and environmental issues, fundamental changes are necessary. A collaborative and inclusive research agenda that engages diverse stakeholders through case-study research, aligning with continent-wide frameworks such as Agenda 2063, the CAADP, and the Sustainable Development Goals (SDGs), is vital. There are few cross-case analyses that bring together empirical case study research to evaluate and provide holistic appraisals of African food systems. This perspectives paper aims to provide such a synthesis from the empirical case studies generated under the Food Systems Research Network for Africa (FSNet-Africa) project. 19 case study projects in six African countries, were conducted by 83 researchers. Five key focus areas were identified: food system governance, indigenous crops and African foods, innovations for sustainable production among small-scale farmers, consumer preferences, and food loss and waste. The findings emphasise an urgent need for collaboration to address food security and nutrition challenges in Africa. Major priorities for transforming African food systems include inclusive engagement and the integration of indigenous knowledge to improve local food choices and resilience, and reducing food loss through capacity-building efforts and changing perceptions of waste. Future research should focus on governance, indigenous crops, and innovations in sustainable production to drive a transformative shift in African food systems. These priority areas will be critical for the next global and regional development agenda, reflecting the needs and aspirations of underrepresented communities across Africa.
Intensive feeding modifies nutrient patterns in a strictly protected area
Trepel, Jonas; Abraham, Andrew J.; Di Nicola, Walter; Gelin, Uriel; Gahbauer, Martin; Heurich, Marco; Le Roux, Elizabeth (Elsevier, 2025-09)
Recovering deer populations are causing conflict across Europe, especially in the vicinity of protected areas where densities are generally higher. Consequently, a variety of management approaches, such as the provision of winter feeding, have been deployed to keep deer from foraging in undesired areas in an attempt to mitigate conflicts. However, as large ungulates play a key role in nutrient recycling and redistribution, management actions that affect their space use and introduce additional nutrients into a system may translate into changes in the biogeochemistry of protected areas. Yet, little is known about the implications of such deer-management strategies on nutrient patterns. Here, we tested the effects of intensive supplementary feeding in combination with winter enclosures on nutrient distribution in a strictly protected area in Central Europe, the Bavarian Forest National Park. We found significant effects of the current management approach on plant nutrients with elevated nutrient concentrations not only within, but, importantly, extending up to several hundred meters around the enclosures/feeding stations. The increased nutrient concentrations could have cascading consequences for soil microbial activity, plant community composition and other herbivores. Our results illustrate that management actions designed to solve a specific problem (mitigating human-wildlife conflict), may alter local landscape chemistry and influence broader ecosystem functions. Ultimately, this may compromise conservation success, highlighting the need to critically evaluate all potential consequences of common management approaches such as supplementary feeding.
Comparison of methods for assessing the active space of spruce budworm and spongy moth pheromone-baited traps
Goodwin, J.D.L.; MacQuarrie, C.J.K.; Kerr, J.L.; O’Connor, B.C.; Smith, S.M.; Allison, Jeremy D. (Springer, 2025-11-10)
Active space, the area over which a stimulus elicits a behavioural reaction in a receiving individual, is an important yet seldom investigated aspect of insect behaviour. It defines the spatial scale over which an individual interacts with a stimulus and can influence mating success and population dynamics. From an applied perspective, active space is an important component of the effective range of semiochemical-baited traps used for surveillance of forest and agricultural insects. This study used wing fanning assays, competitive trapping, and portable electroantennography to investigate the active space of spruce budworm, Choristoneura fumiferana Clemens (Lepidoptera: Tortricidae) and spongy moth, Lymantria dispar dispar L. (Lepidoptera: Erebidae) pheromone-baited traps. Wing fanning assays and competitive trapping had similar outcomes for active space distance for both species. For spruce budworm, wing fanning assays estimate an active space of 18.4 m and competitive trapping experiments showed interference at distances less than 20 m. For spongy moth, wing fanning assays suggest an active space of 81.5 m, corroborating results from a previous study that estimated trap interference to occur at distances less than 80 m. Portable electroantennography displayed an increase in neural depolarization amplitude at distances less than 30 m for spruce budworm and 130 m for spongy moth. Overall, the three methods used showed similar results for the active space distance of each species.
Biomass distribution of sympatric mammals in a European temperate forest
Pleskalt, Andro; Farias, Sebastião; Vicedo, Toni; Álvarez-Martínez, Jose Manuel; Roces-Díaz, José Valentín; Meloro, Carlo; Pereira, Soraia; Cruz, Antonio; García, Jesús; Gómez, Pablo; Lamillar, María Ángel; Marsella, Elena; Varas, Manuel Jesús; Álvarez, Elena; Dalerum, Fredrik (The Royal Society, 2025-08)
The distribution of biomass among trophic levels and different types of organisms is a key characteristic of ecosystems. However, such biomass distributions might exhibit large perturbations owing to human activities. We used long-term camera trap data from a temperate forest ecosystem within the Cantabrian range, northern Spain, to quantify the biomass distribution of 10 mammal species ranging in body mass from 300 g to almost 100 kg. The species are representative of three distinct orders and include trophic levels from primary to secondary consumers. The observed biomass distribution was bottom-heavy with a disproportionally low biomass of secondary consumers, in particular large-bodied predators. In addition, the ratio of plant biomass to the biomass of mammalian primary consumers was over 6000 : 1 for total above-ground-plant biomass and over 700 : 1 for plant biomass available for mammal consumption. We suggest that the observed biomass distribution both among mammals and between mammals and plants provide an example of trophic downgrading, and highlight the radical effects human activities might have on the structure of terrestrial ecosystems.
Territoriality in adult male sub-Antarctic fur seals at Gough Island
Bester, Marthan Nieuwoudt; Rossouw, G.J. (Springer, 2025-03)
We analysed unpublished data on territory size and tenure in adult male sub-Antarctic fur seals Arctocephalus tropicalis recorded at Gough Island, Southern Ocean, during the 1975/76 austral summer breeding season. Adult males (n=15) remained on their territories for between 35–56 days (mean 45.4±6.7 days). Territory size during the peak breeding season was 21.9 m2 on average (n=42), but when partitioned by beach type, average territory sizes were 13.8 (n=9), 20.1 (n=17) and 28.3 m2 (n=16). Both territory tenure and territory size fall within the reported range of values established in fur seal species which hold territories on land as the predominant male reproductive strategy. We highlight numerous confounding factors that impact comparative studies which should be considered when interpreting theoretical, conceptual, and modelling approaches about territorial behaviour in otariids.
Seasonal occurrence and condition of leopard seals at an extralimital Sub‑Antarctic Island
Ross, Michael D.; Leitner, Monica; Oosthuizen, W. Chris; Bester, Marthan Nieuwoudt; Jordaan, Rowan Keith; Voysey, Michael D.; Conradie, Everhard C.; Dosi, Banele; Evans, Sean; Lloyd, Kyle J.; Monier, Zafar; Purdon, Jean; Reisinger, Ryan R.; Shihlomule, Yinhla Desmond; Van der Vyver, J.S. Fredrik; De Bruyn, P.J. Nico (Springer, 2025-06)
Leopard seals (Hydrurga leptonyx) occur mainly south of the Antarctic Polar Front, but immatures, in particular, seasonally move beyond this range during the austral winter and spring, typically under increased sea ice conditions. Extralimital occurrences of leopard seals can be observed at several sub-Antarctic islands where they haul out to rest. We present new records of leopard seal sightings at Marion Island, southern Indian Ocean, from 2006 to 2024 and discuss fluctuations in their seasonal and annual abundance (drawing on data collected since 1980) and body condition based on regular surveys. The eastern beaches at Marion Island were surveyed every 7–10 days while the western beaches were visited monthly. Observed leopard seals were photographed and given a body condition score based on the visibility of bony protrusions. From 2006 to 2024, we identified 35 presumed unique immature leopard seals between July and November, with a peak in September, all being immatures. Individuals to which we could assign body condition scores were either in good or excellent condition. This contrasted with the prevailing hypothesis that leopard seal body condition deteriorates with decreasing latitude. However, we could not determine whether this was because of an actual shift in body condition or because we used a different scoring system from other studies. We recommend adopting a standardised scoring system for visually estimating pinniped body condition and a global repository to monitor leopard seal haul-outs. As an apex predator, leopard seals may be important indicators in Antarctic and sub-Antarctic ecosystems, and monitoring changes in their distribution and body condition may indicate environmental and biological changes in these remote regions.
Monitoring of vagrant seals on mid-oceanic islands of the South Atlantic Ocean
Bester, Marthan Nieuwoudt; Somers, Michael J. (Springer, 2025-09)
Extra-limital sightings of seals breeding on the Antarctic pack- and fast ice and on sub-Antarctic and temperate islands of the South Atlantic Ocean are summarised. Particular life history events of four vagrant seal species that have turned up on Mid-Atlantic Ridge islands are presented, and the likely arrival of a further three vagrant seal species is speculated upon. The setting up and/or expansion of a recording system underpinned by an appropriate sighting protocol for vagrant seals in which citizen scientists can participate is advanced. Determination of whether range contractions/expansions of seals in the South Atlantic are taking place reflects on the status of the source population(s). Seal vagrancy may conceivably also be involved in the spread of viral diseases such as highly pathogenic avian influenza and rabies. Insights gained through extra-limital sightings of seals may assist with the establishment of conservation strategies.
Smallholder farmers’ knowledge, perception and management of Spodoptera frugiperda (Lepidoptera: Noctuidae) on Zea mays at irrigation schemes in Limpopo province, South Africa
Nethononda, Phophi D.; Hurley, Brett Phillip; Slippers, Bernard; Makhura, Moraka Nakedi (Elsevier, 2026-03)
The fall armyworm (Spodoptera frugiperda) was first detected in Limpopo province, South Africa, during the 2016/2017 cropping season and continues to cause significant damage to maize production in the region. Despite the significant damage caused by S. frugiperda to maize, there is a lack of documented information on smallholder farmers' responses and control practices in South Africa. This study investigated smallholder farmers' knowledge, perceptions, and management practices of S. frugiperda at the Dzindi and the Tshiombo irrigation schemes in Limpopo province, South Africa. In this study, an irrigation scheme refers to a communal water distribution system that channels water from a river to multiple plots under smallholder cultivation through furrows or canals. Data were collected through 16 focus group discussions with farmers from the two irrigation schemes. A total of 118 farmers participated in the interviews. Each was assigned a unique identifier, which allowed for the recording and analysis of individual responses where applicable. Thematic analysis was used to identify and summarize common themes from participants’ responses, while descriptive analysis using frequencies and percentages was employed to present the responses quantitively. Farmers perceived S. frugiperda as the most destructive insect pest, yet lacked knowledge of its biology, being unable to identify its eggs, pupae, or adult moths. Control was largely through insecticide use. At the Dzindi irrigation scheme, farmers adopted Bt maize but did not comply with resistance management practices. The findings underscore the urgent need for farmer education on insect biology, responsible pesticide use, and proper implementation of Bt maize. The study also highlights the importance of collective rather than individual efforts in managing S. frugiperda, as the consequences of mismanagement can affect all farmers. These findings reveal major gaps in Integrated Pest Management (IPM) practices among smallholder farmers in Limpopo province, South Africa. HIGHLIGHTS • First detection of Spodoptera frugiperda in Limpopo Province, South Africa, occurred during the 2016/2017 cropping season. • Smallholder farmers lack knowledge of the pest's biology, relying on insecticides for its management. • Concurrent use of insecticides and Bt maize raises concerns over the potential evolution of S. frugiperda resistance in the region.
Honey bees of Ethiopia : their lineages and subspecies based on morphometrics, mitochondrial DNA, and mandibular gland pheromone analyses
Wanore, Walellign Wotro; Pirk, Christian Walter Werner; Yusuf, Abdullahi Ahmed; Baleba, Steve B.S.; Chege, Mary; Ndungu, Nelly N.; Wubie, Abebe J.; Ayalew, Workneh; Nganso, Beatrice T. (Public Library of Science, 2025-11-07)
Apiculture is a vital economic sector in Ethiopia, providing income and employment for over two million people. However, the classification of the honey bee subspecies in Ethiopia remains debatable. To shed light on this, we analysed wing geometric and classical morphometrics, mandibular gland pheromones, and COI–COII mitochondrial DNA sequences from worker honey bees collected across high, mid and low elevation gradients within Oromia, Amhara, and Southern Nations Nationalities and Peoples’ (SNNP) regions. Our results revealed significant regional morphological and pheromonal variation driven by elevation. Wing size increased with altitude, suggesting adaptive responses to elevation. Classical morphometrics supported this trend, with bees at higher elevation exhibiting larger flight structures. Regional differences in mandibular gland pheromone secretion were also observed, with workers from Amhara secreting the least quantities of these compounds, including the queen substance 9-oxo-2(E)-decenoic acid (9-ODA) and its precursor 9-hydroxy-2(E)-decenoic acid (9-HDA), as well as the worker component 10-hydroxy-2 (E)-decenoic acid (10-HDA) and its precursor 10-hydroxy-decanoic acid (10-HDAA). Furthermore, the secretion of 9-HDA and the total amount of mandibular gland pheromone significantly and negatively correlated with elevation. For mtDNA analysis, all samples from Ethiopia clustered with the Y lineage (Apis mellifera simensis) and separated from neighbouring honey bee populations of the A lineage (A. m. scutellata and A. m. monticala). Overall, our results reveal the significant influence of elevation on adaptive traits of Ethiopian honey bees, which are of the same subspecies.
Development of an 11-oxoetiocholanolone mini-kit for the quantification of faecal glucocorticoid metabolites in various wildlife species
Edwards, KatieL.; Wheaton, Catharine J.; Brown, Janine L.; Dimovski, Alicia M.; Fanson, Kerry V.; Ganswindt, Andre; Ganswindt, Stefanie Birgit; Hagenah, Nicole; Keeley6, Tamara; Möstl, Erich; O’Hara, Bobbi; Penfold, LindaM.; Shablin, Samantha A.; Palme, Rupert (Oxford University Press, 2025-10)
As part of its mission to advance the field of wildlife endocrinology, the International Society of Wildlife Endocrinology aims to develop cost-effective antibodies and enzyme immunoassay kits that support research across a diverse range of species and sample matrices. To provide additional options for the quantification of faecal glucocorticoid metabolites (fGCMs), an antibody against 11-oxoetiocholanolone-17-carboxymethyl oxime (CMO) was generated in rabbits, and an enzyme immunoassay incorporating a horseradish peroxidase-conjugated label and 11-oxoetiocholanolone standard has been developed, designed for use with anti-rabbit IgG secondary antibody coated plates. This mini-kit was used to quantify glucocorticoid metabolites with a 5β-3α-ol-11-one structure in faecal extracts from 23 species: African and Asian elephants, Alpine chamois, American bison, Bengal tiger, blue wildebeest, blue-and-yellow macaw, brushtail possum, cape buffalo, fat-tailed dunnart, Florida manatee, ghost bat, giraffe, golden langur, Gould’s wattled bat, hippopotamus, Leadbeater’s possum, mandrill, okapi, roan antelope, samango monkey, short-beaked echidna, and western lowland gorilla. Pharmacological (adrenocorticotropic hormone challenge) and biological (inter-zoo translocation, wild capture, social disruption, illness/injury and veterinary intervention) challenges resulted in expected increases in fGCM concentrations, and in a subset of species, closely paralleled results from a previously established immunoassay against 11-oxoetiocholanolone-17-CMO. Two additional species tested, Krefft’s glider, which showed contradictory results on this assay compared to a previously validated enzyme immunoassay (EIA) and Ankole cow, where the magnitude increase post-event did not quite reach the 2-fold change criteria, highlight that differences in excreted faecal metabolites across species mean that no EIA will be suitable for all species. This assay provides a valuable new option for assessing adrenal activity across taxa using a group-specific antibody. Future studies should put similar emphasis on validation to determine optimal assay choice for measuring fGCMs in a variety of species.
Improvement of colony management in insect mass-rearing for sterile insect technique applications
Abd-Alla, Adly M.M.; Geiger, Anne; Haymer, David; Herrero, Salvador; Jehle, Johannes A.; Khamis, Fathiya Mbarak; Liedo, Pablo; Malacrida, Anna R.; Njiokou, Flobert; Mastrangelo, Thiago; Pagabeleguem, Soumaila; Ramirez-Santos, Edwin M.; Ros, Vera I.D.; Segura, Diego F.; Tsiamis, George; Weiss, Brian L. (Wiley, 2025-10)
Sterile Insect Technique (SIT) applications against major insect pests and disease vectors rely on the cost-effective production of high-quality sterile males. This largely depends on the optimal management of target pest colonies by maximizing the benefits provided by a genetically rich and pathogen-free mother colony, the presence of symbiotic microorganisms, and efficient domestication, mass-rearing, irradiation, and release processes. At the same time microbial (bacteria, fungi, microsporidia, and viruses) pathogen outbreaks should be minimized or eliminated, and the use of hazardous chemicals restricted. The optimization of the colony management strategies for different SIT target insects will ensure a standardized high-quality mass-rearing process and the cost-effective production of sterile males with enhanced field performance and male mating competitiveness. The aims of the Coordinated Research Project (CRP) were to develop best practices for insect colony management for the cost-effective production of high-quality sterile males for SIT applications against major insect pests and disease vectors through a multidisciplinary approach involving entomologists, geneticists, ecologists, microbiologists, pathologists, virologists, and mass-rearing experts.
Prostephanus truncatus outcompetes Sitophilus zeamais under varying temperatures and introduction sequence on stored maize grain
Mlambo, Shaw; Mvumi, Brighton M.; Machekano, Honest; Nyamukondiwa, Casper (Elsevier, 2026-01)
Coexistence of insect pests can result in facultative or antagonistic interactions. For sympatric pest species, explaining coexistence is crucial for understanding their combined impact, resource competition, and may inform management strategies. Prostephanus truncatus and Sitophilus zeamais commonly coexist as primary colonisers in stored maize grain. To determine how these species interact, two experiments mimicking competition scenarios on stored grain were conducted at 25, 30 and 35 °C (65 % RH). In Experiment 1, P. truncatus and S. zeamais were introduced simultaneously (interspecific) and in singular (intraspecific) populations at low (20), medium (40), and high (80) parental densities. In Experiment 2, we used similar temperatures and parental densities. However, one species was introduced 10 days after the other, and vice versa. Mini-polypropylene bags, each loaded with 65 ± 5g of dried orange maize grain, were used for both experiments. Progeny production, grain damage, grain weight loss, insect feeding dust and holes on bags bored by beetles, were recorded after 65 days of storage. Results showed that (i) P. truncatus outcompeted S. zeamais in interspecific interactions at 25 and 30 °C across parental densities, (ii) both species’ ecological performances were suppressed at 35 °C, (iii) P. truncatus caused higher grain damage regardless of the introduction sequence with S. zeamais and (iv) P. truncatus dispersed by tunnelling through polypropylene bags to avoid competition. Understanding interactions among sympatric pest species is essential for accurately predicting infestation outcomes and developing effective pest management under increasingly warming environments. HIGHLIGHTS • P. truncatus outcompeted S. zeamais across different temperatures and parental densities. • Ecological performance was suppressed at 35 °C for both P. truncatus and S. zeamais. • Sequence of introduction did not reduce P. truncatus competitive advantage over S. zeamais. • Tunneling was competition-induced and could trigger P. truncatus dispersal.
Staying alive : individual behavioral variation influences survival, but not reproductive success, in female group-living ground squirrels
Warrington, Miyako H.; Van der Marel, Annemarie; Sojka, Jennifer; Shofstall, Krista J.; Waterman, Jane M. (Wiley, 2025-07)
Animals living in harsh or unpredictable environments adopt adaptive strategies to improve their fitness, with behavioral variation playing a key role in shaping individual outcomes. We examined whether between-individual variation in behavioral traits (personality) was associated with reproductive success and survival in female Cape ground squirrels (Xerus inauris). Using a 10-year dataset (2011–2021), we quantified behavioral expressions of the animal's response to trapping and handling (trap response, as a proxy for docility), trapping rate (trappability, for boldness) and the number of different trapping locations an animal was trapped at (trap diversity, for exploration) and examined their associations with (1) annual reproductive success, (2) lifetime reproductive success, (3) annual survival, and (4) on-site persistence (a proxy for lifespan). Response measures taken during transfer from the cage, handling by a human observer, and whether individuals ran or walked after release were moderately repeatable. Trappability was also repeatable, while trap diversity was not. Trap response and trappability were positively correlated with survival, but not reproductive success. Females that easily transferred from the trap to the handling bag (more docile) had higher annual survival, while those that ran after release had longer lifespans. Individuals trapped at a higher rate (bolder) had higher annual survival. The absence of a relationship between behavioral traits and reproductive success in females suggests that other factors, such as group dynamics, social interactions, and maternal effects, may be more influential in explaining the high reproductive skew in female reproductive success. Overall, our findings highlight the role of individual behavioral variation in shaping survival outcomes while emphasizing the need for further research into the mechanisms driving reproductive success in this species.
Monthly and diel acoustic occurrence of four Baleen whale species in South African waters
Shabangu, Fannie Welcome; Hlati, Kuhle; Van den Berg, Marcel A.; Lamont, Tarron; Kirkman, Stephen P. (Wiley, 2025-08)
Understanding of the spatio-temporal occurrence of cetaceans post the whaling era is essential for protecting and improving management strategies of these marine mammals. To determine the monthly and diel acoustic occurrence of four baleen whale species relative to environmental conditions off the west coast of South Africa, we collected passive acoustic monitoring data within Child's Bank marine protected area in January and May through October 2024 at various water depths. Burst tonal calls of the southern African Bryde's whale offshore population were detected in January and May through July with the highest occurrence in January. Humpback whale songs and southern right whale gunshot sounds were detected from May through October with high occurrence in September and with smaller modes in other months. Antarctic minke whale bioduck calls were also found in June through October, showing high occurrence in August through October. Calls from an unknown source with similar characteristics to Antarctic minke whale bioduck calls were present in May, July, and August with the highest occurrence in August. Diel acoustic occurrence of Bryde's, southern right, Antarctic minke, and minke-like whale calls indicated that these animals vocalised more during the day while humpback whales were more vocally active at night. Sea surface height and sea surface temperature, either separately or in combination, were the most important predictors of whale acoustic occurrence, highlighting the influence of environmental conditions on the distribution, habitat selection, and ecology of these whales. Overall, this study advances our understanding of the movement, occurrence, and behavioural patterns of several baleen whales relative to environmental conditions. It also provides the first description of the southern African Bryde's whale offshore population's call characteristics, which will be useful at guiding future studies to acoustically differentiate between it and the inshore population.
Interspecies haptic sociality : an observation of grooming between two mongoose species
Smith, Kyle; Hepplewhite, Malcolm; San, Emmanuel Do Linh; Somers, Michael J. (Wiley, 2025-06)
Meerkats (Suricata suricatta) and yellow mongooses (Cynictis penicillata) share many behavioural characteristics and are known to, on rare occasions, live in close association through displayed cooperative vigilance and shared burrow use. Here, we describe the first visual observation of tactile social behaviour through grooming between a meerkat and a yellow mongoose in the Rietvlei Nature Reserve, South Africa. We hypothesise that the close relationship between the two species in the reserve may be a response to a combination of phylogenetic ties, shared behavioural traits, and the population collapse of meerkats in the reserve that exposed a vacant social niche. This observation of interspecific sociality further extends our knowledge of cooperation and group augmentation among meerkats, yellow mongooses and carnivores in general.
Despite potential risks African elephants do not always avoid mountaineering
Teixeira, Justine M.; Van der Westhuizen, Rickert; Shrader, A.M. (Adrian) (Wiley, 2025-07)
As herbivores forage, they move across a wide range of topographical features. Yet, they tend to avoid terrain such as steep slopes where energetic costs of movement are high and there is a greater risk of falls and tumbles. Recent studies suggest that African elephants (Loxodonta africana) avoid steep slopes (e.g., > 15°). However, in reserves with undulating topography, elephants may have to use steep slopes to obtain food, especially when availability is limited in more gradual areas. To explore this, we investigated slope use by elephants in the Ithala Game Reserve, South Africa, where the topography varies greatly and ranges between 400 to 1400 masl. Using 8.5 years of positional data, we examined how slope use varied between herd types (14 breeding herds and 13 males), habitat type and season (wet vs. dry). Elephants were found primarily on slopes < 30° (i.e., 95% of the locations), while 67% of the locations were on slopes < 15°, and 52% on slopes < 10°. Breeding herds used steeper slopes (mean = 12.6° ± 0.08 SE) than bulls (mean = 12.0° ± 0.8 SE). In addition, habitat influenced slope use, with the steepest slopes used in woodlands and the most gradual used in built-up areas and grasslands. However, these slope use differences were very small (i.e., 0.6° to 9.7°) and thus unlikely to be biologically meaningful. Rather, the ability to detect these slight differences was likely an artefact of our large sample size (N = 23,837 locations). Moreover, slope use did not vary between the wet and dry seasons. Nevertheless, 5% of all the elephant locations occurred on very steep slopes (i.e., > 30°) and 33% were on slopes > 15°, indicating that although they may prefer flat terrain, when required, elephants will mountaineer.

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