Research Articles (Zoology and Entomology)

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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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Reproductive females of a cooperatively breeding rodent are in better body condition when living in large groups
Finn, K.T.; Janse van Vuuren, Andries Koch; Suess, Tobias; Hart, Daniel William; Bennett, Nigel Charles; Zottl, M. (Wiley, 2025-07)
Cooperation and group living have been suggested to facilitate survival in varying environments and under challenging conditions. However, group living may also be associated with costs, particularly in species where individuals within groups may compete for limited resources. The costs and benefits of cooperative group living on cooperatively breeding mammals in varying environments remain unclear. Here, we use data collected from wild, cooperatively breeding Natal mole-rats (Cryptomys hottentotus natalensis) inhabiting a seasonally varying environment to assess whether body condition changes between seasons and whether these changes are contingent upon group size. We demonstrate that the body condition of reproductive females improved with increasing helper number during both the benign summer and the harsher winter seasons. However, the body condition of other group members showed little dependency on group size or season. Only when including one extremely large group did the body condition of non-breeders weakly, albeit significantly, change depending on group size and seasonality. These results suggest that larger group sizes may yield some benefits for non-breeding group members during winter and may invoke some costs during summer. Group living in Natal mole-rats is likely promoted by a combination of collective foraging, thermoregulatory benefits, and potentially some indirect fitness benefits through improved body condition of the breeding female.
Fertility up in flames : reduced fertility indices as a consequence of a simulated heatwave on small African mammals
Jacobs, Paul Juan; Bennett, Nigel Charles; Du Plessis, L.; Hart, Daniel William (Wiley, 2025-03)
With the increasing frequency and intensity of heatwaves due to climate change, the survival and reproductive success of mammals could be under significant threat. However, the specific effects of these environmental stressors on mammalian reproductive fitness remain insufficiently explored. This study investigates the impact of a simulated heatwave on male fertility indices in two African rodent species: the mesic four-striped field mouse (Rhabdomys dilectus) and the Namaqua rock mouse (Micaelamys namaquensis) during the breeding season. We measured key indicators of male fertility, including testes mass, testes volume, seminiferous tubule diameter, the presence of sperm, and plasma testosterone levels. Our findings reveal that both species experienced significant effects on male fertility indices, with the smaller R. dilectus showing a decline in all fertility indices following a simulated heatwave. These results suggest that the projected increase in heatwave events may compromise the reproductive success of small mammals, potentially leading to population declines. Finally, this study highlights the need for focused studies on the effect of heatwaves on long-term reproductive success in both males and females.
Examining alterations in fGCM concentrations post-defaecation across three animal feeding classes (ruminants, hindgut fermenters and carnivores)
Osburn, Kayla Rae; Crossey, Bruce Gareth; Majelantle, Tshepiso Lesedi; Ganswindt, Andre (Wiley, 2025-05)
Quantification of faecal glucocorticoid metabolites (fGCMs) is a popular non-invasive technique for monitoring wildlife's response to stressors, demanding an understanding of the stability of fGCM concentrations post-defaecation to ensure comparability of determined fGCM values across samples. To provide species-specific recommendations for the duration within which sampling can take place, we measured the rate at which the fGCM concentrations of nine different species changed throughout a 7-day period post-defaecation. In this study, we explored the temporal dynamics of fGCM concentrations in nine species across three feeding classes (ruminants, hindgut fermenters and carnivores): impala (Aepyceros melampus), giraffe (Giraffa camelopardalis), blue wildebeest (Connochaetes taurinus), plains zebra (Equus quagga), African elephant (Loxodonta africana), white rhino (Ceratotherium simum), cheetah (Acinonyx jubatus), spotted hyena (Crocuta crocuta) and leopard (Panthera pardus). Utilizing enzyme immunoassays already established for each of the focal species, we identified broader feeding class-specific patterns. All herbivores exhibited a significant decrease in fGCM concentrations over time, starting from 6 h (impala) to 48 h (giraffe, blue wildebeest, white rhino and African elephant) post-defaecation. For carnivores, concentrations remained fairly comparable for 12–24 h, after which fGCM concentrations either decreased (spotted hyena), increased (leopard) or remained stable (cheetah), with notable variation in triplicate concentrations (cheetah and leopard). These findings offer insights into scheduling faecal sampling for endocrine monitoring, particularly from free-roaming wildlife, to ensure comparability of determined hormone metabolite concentrations. Furthermore, the species-specific variation in fGCM concentration post-defaecation demonstrated in this study underlines the necessity to investigate every new species to ensure accurate and comparable results. Future studies ought to investigate how the mass of collected material, sex and drying methodologies affect the measurement of fGCMs post-defaecation.
Endemic plants and animals are susceptible to extinction in an imperilled alpine hotspot in southern Africa
Taylor, Peter J.; Bredenhand, Emile; Monadjem, Ara; Armstrong, Adrian J.; Rakotoarivelo, Andrinajoro R.; Mdluli, Veli Monday; Howard, Alexandra; Modise, Serero; Motitsoe, Samuel N.; Ntloko, Pindiwe; Kirkaldy, Abigail P.; Kleynhans, Dewald J.; Jankielsohn, Astrid; Mosikidi, Toka; Oosthuizen, Maria Kathleen; Payne, Stephanie; Munyai, Thinandavha C.; Carbutt, Clinton; Ramoejane, Mpho; Bereng, Mosiuoa; Stiller, Michael; Haddad, Charles R.; Steenhuisen, Sandy-Lynn; Mlambo, Musa C.; Moyo, Sibusisiwe; Nyembe, Nthatisi I.; Mofokeng, Lehlohonolo; Van As, Johann; Malekana, Lesego; Daniel, Gimo M.; Gwate, Onalenna; Van As, Michelle; Harrison, James Du Guesclin; Thabethe, Nokubonga F.; Kheswa, Nozipho; Moloi, Karabo; Sishange, Nkanyiso; Clark, V. Ralph (South African National Biodiversity Institute, 2025-11)
BACKGROUND : As global temperatures rise, alpine species at the upper limit of their distribution are at risk of decline and extinction due to shrinking habitats downslope. The alpine (> 2 800 m a.s.l.) biodiversity of the Maloti-Drakensberg is poorly known but may be threatened by climate change. OBJECTIVES : Using expert BioBlitzes, we documented species richness and elevational patterns of distribution in 14 plant and animal higher taxa from alpine and upper-montane zones in an unexplored corner of the Maloti-Drakensberg. METHODS : Using standardised methods such as Sherman traps, acoustic monitoring, bird timed counts, pitfall traps, sweep nets, aquatic SASS5 kick-nets, timed searches and herbarium collections, we assessed elevational zonation of flowering plant and selected invertebrate and vertebrate diversity in the Witsieshoek Community Conservation Area (WCCA). RESULTS : GBIF records complemented expert BioBlitz data, together enumerating 1 216 plant, vertebrate and invertebrate species along an elevation gradient from 1 760 m to 3 145 m at WCCA. Birds, insects and plants showed concordant beta diversity patterns from BioBlitz and GBIF data: high turnover compared to nestedness in more sedentary insects and plants, and the opposite in more mobile birds (GBIF data not available for bats). Although identifications are ongoing, 17% of species or morphospecies were exclusively recorded in the alpine zone, including 82 species of plants and 92 of animals. CONCLUSION : Alpine endemics are vulnerable to the ‘escalator to extinction’ process due to climate change. Surveys of under-explored alpine hotspots should be prioritised, drawing on mountain tourism-based citizen science. We advocate an ecotourism- and community-centred, restoration and rewilding approach for this strategic and biodiverse community conservation area.
A South African perspective on the 2023 IPBES Thematic Assessment Report on Invasive Alien Species and their control
Wilson, John R.U.; Faulkner, Katelyn T.; Winzer, L. Fernandez; Mcculloch-Jones, E.J.; Van Wilgen, B.W.; Blanchard, R.; Carbutt, C.; Dechoum, M.S.; Foxfroft, L.C.; Greve, Michelle; Hui, C.; Ivey, P.; Kgope, B.; Kumschick, S.; Le Roux, Peter Christiaan; Masehela, T.S.; Measey, J.; Miza, S.; Mogapi, T.; Mpikanisi, F.; Mulaudzi, L.; Nelukalo, K.; Nnzeru, L.; Nsikani, M.M.; Pattison, Z.; Rahlao, S.J.; Richardson, D.M.; Robinson, T.B.; Shackleton, R.T.; Tererai, F.; Tshidada, N.; Tshikhudo, P.P.; Tshivhandekano, I.; Wanjau, K.; Ziller, S.R.; Zengeya, Tsungai Alfred (South African National Biodiversity Institute, 2025-11-06)
BACKGROUND : Biological invasions are a major threat to biodiversity and sustainable development. A global assessment of biological invasions released in 2023 by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), concluded that while invasions ‘…cause dramatic and, in some cases, irreversible changes…’ they can be ‘…overcome through a context-specific integrated governance approach’. AIM : Here we evaluate insights from the IPBES assessment in the context of South Africa and explore how these insights could inform the development of a national policy and strategy to address biological invasions. RESULTS : Trends and status of biological invasions in South Africa are similar to those seen globally, but there are some distinct local nuances. South Africa has: 1) a long history of invasions with negative impacts caused especially by invasive trees and freshwater fishes, whilst invasive marine invertebrates have transformed large parts of the coastline; 2) a long history of control (biological control was first implemented in 1913) with large-scale, state-run invasive species management programmes currently in place; 3) a comprehensive regulatory system (e.g., there is provision for beneficial invasive species to be used under permits); 4) relatively high levels of awareness and engagement (at least among some stakeholder groups); and 5) a well-connected community of practice. DISCUSSION : Efforts to limit introductions (intentional or unintentional) are difficult given South Africa’s extensive and porous borders and the pressing need to increase trade and travel. Regulatory and implementation efforts aimed at prevention are improving, with the newly established Border Management Authority aiming to integrate biosecurity interventions at ports of entry. Such integrated governance is, we argue, needed more broadly if affected sectors, society groups and stakeholders are to be effectively included in decision-making and management. A more systematic flow of information from observation to action is essential, as is better feedback between research, policy and implementation at all scales. Biological invasions will continue to pose threats, but many of these can be effectively mitigated through focussed interventions. Co-ordinating such interventions in the context of other cross-cutting global change challenges and initiatives is a cost-effective way of protecting and improving livelihoods, human health, quality of life and biodiversity.
The role of hyperthermia in avian tolerance of hot and humid conditions
Freeman, Marc Trevor; Coulson, Bianca; Ngcamphalala, Celiwe A.; Makola, Mathome Otto; McKechnie, Andrew E. (Elsevier, 2025-12)
Pronounced hyperthermia is thought to be important for thermoregulation during hot weather in animals inhabiting humid environments, where high atmospheric humidity constrains evaporative cooling. To assess the role of facultative, reversible hyperthermia in avian thermoregulation under hot, humid conditions, we examined how humidity influences thermoregulatory performance at air temperatures (Tair) exceeding normothermic body temperature (Tb) in red-billed queleas (Quelea quelea), a species capable of extreme hyperthermia (Tb > 48 °C). Using flow-through respirometry, we exposed queleas to Tair = 34 °C–50 °C at four experimental absolute humidities (6 g H2O m− 3, 13 g H2O m− 3, 19 g H2O m− 3, and 25 g H2O m−3). Across these humidity treatments, resting metabolic rate, evaporative water loss and maximum evaporative cooling efficiency responded similarly to increasing Tair, and maximum tolerable body temperature (Tbmax) remained consistent (48.60 ± 0.40 °C). Heat tolerance limits (HTL; environmental temperatures associated with thermoregulatory failure) averaged Tair = 48.41 ± 1.03 °C among humidity treatments. At Tair > ∼44.5 °C, evaporative cooling efficiency plateaued and queleas became poikilothermic, with Tb tracking Tair ≤ ∼48.4 °C. These findings demonstrate extreme hyperthermia tolerance can offset the constraints on evaporative cooling imposed by high humidity, allowing some birds to tolerate extreme combinations of heat and humidity. We propose a modification to an existing conceptual framework of the thermoregulatory roles of facultative hyperthermia to accommodate the effects of humidity on evaporative cooling and heat tolerance limits.
Parental heat stress has transgenerational physiological- but not ecological-progeny fitness advantage in the larger grain borer
Mlambo, Shaw; Machekano, Honest; Mvumi, Brighton Marimanzi; Nyamukondiwa, Casper (Emerald, 2026-03)
Climate change forecasts predict that global temperature and variability will continue rising owing to anthropogenic activities. This poses significant stress on ectotherms, whose bodily function depends on ambient temperatures. The ability of species to adapt within and/or across generations through phenotypic plasticity is thus a critical ecological topic. We investigated transgenerational thermal plasticity of the larger grain borer, Prostephanus truncatus, a devastating postharvest maize pest. Specifically, we tested the effects of parental exposure to sublethal heat stress (35 and 38 °C for 2 h; 80 % RH) on progeny thermal— and ecological—performance. Following acclimation, the colonies were separately maintained on shelled maize at optimum conditions of 32 °C at 65 ± 10 % RH. After 21 d, adult beetles were removed and the emerging progeny respectively labelled as F1 treatments (F1_35 °C and F1_38 °C). Subcultures from these 2 × F1 treatments were sampled in the same manner to obtain F2 (F2_35 °C and F2_38 °C) and subsequently F3 (F3_35 °C and F3_38 °C) generations which were then evaluated against parental (control) cultures maintained at optimal conditions 32 °C (P_32 °C). Our results showed that parental heat acclimation: (i) had transgenerational physiological— but not ecological-progeny fitness advantage; (ii) decreased critical thermal limit ranges; (iii) had cross-protection improvement in cold tolerance; and (iv) had transgenerational physiological responses that may last generations. Transgenerational plastic responses may help in understanding how species and ecosystems adapt to environmental temperature changes. This is the first report documenting transgenerational heat tolerance plasticity in P. truncatus. HIGHLIGHTS • Parental heat acclimation had transgenerational physiological- but not ecological-progeny fitness advantage. • Parental heat acclimation decreased progeny critical thermal limit ranges. • Parental heat acclimation had cross protective improvement in progeny cold tolerance. • Transgenerational physiological responses may last generations.
Using physiology to unravel the implications of heatwaves for big brown bats (Eptesicus fuscus)
De Mel, Ruvinda K.; Baloun, Dylan E.; Freeman, Marc Trevor; Probert, Anna F.; Cangemi, Taylor B.; Watters, Tina K.; Lausen, Cori L.; Kearney, Michael R.; Brigham, Mark; Czenze, Zenon J. (Company of Biologists, 2025-10)
Nocturnal endotherms are vulnerable to high ambient temperatures (Ta) during the day when sequestered in retreat sites. Artificial roost design must therefore account for the thermal sensitivity of target species and the potential roost temperatures during heatwave conditions at installation sites. We recorded physiological responses of big brown bats (Eptesicus fuscus) under naturally observed roost temperatures using flow-through respirometry. We used the resulting data to parameterise a biophysical model with which we calculated the evaporative cooling requirements as percent body mass during the hottest day of 2023 and a heatwave during 2021. Our data revealed that the evaporative cooling requirements of bats roosting in certain artificial roosts would have exceeded the lethal dehydration threshold for both females and males during the 2021 heatwave (>22.1% body mass). Regardless of the availability of freestanding water in the environment, bats roosting in artificial roosts prone to overheating are at risk of lethal dehydration during heatwaves, even in high latitude habitats. Therefore, conservation management of small nocturnal endotherms should incorporate both physiological data and roost microclimate data when designing and deploying artificial roosts.
Metabolic expenditure of submaximal locomotion in naked mole-rats (Heterocephalus glaber) and Damaraland mole-rats
Thirkell, Jack E.; Bennett, Nigel Charles; Hart, Daniel William; Faulkes, Chris G.; Daley, Monica A.; Portugal, Steven J. (Company of Biologists, 2025-06)
Despite extensive studies on the physiology of subterranean rodents, there is comparatively little work documenting the energetics specifically associated with their locomotory energetics. The energetic cost associated with burrowing is great and, in part, explains why subterranean species often maintain their burrows and tunnels across generations. Indeed, the digging metabolic rate of five African mole-rats has been determined to be between three and five times higher than their respective resting metabolic rate, yet the energetic cost of non-digging locomotion (i.e. walking) has not been recorded. Digging in most subterranean species tends to lead to specialisation of the forelimbs and teeth, which may significantly affect the energetic cost associated with non-digging locomotion. Unlike many comparably sized burrowing and tunnelling mammals, African mole-rats appear, superficially at least, to have almost identical forelimbs and hindlimbs. This study explored the locomotory energetics associated with sustained submaximal locomotion (i.e. fast walking; 10 cm s−1) in two African mole-rat species (Fukomys damarensis and Heterocephalus glaber), utilising open-flow respirometry and a small animal treadmill. The mean locomotory energetic rate for F. damarensis was a near 1-fold increase (91.4%) above resting metabolic rate and a 2-fold increase (203.2%) for H. glaber. Net cost of transport was higher overall for H. glaber (2.9±0.6 ml O2 kg−1 m−1) than for F. damarensis (2.4±0.5 ml O2 kg−1 m−1). A trade-off likely exists between limb specialisation for digging and economic locomotion, and thus for most obligately subterranean species, locomotion represents an energetic investment.
Microallopatric speciation in southern African dung beetle genus macroderes driven by miocene aridification and ancestral flight loss
Daniel, Gimo M.; Abdalla, Ishtiag H.; Scholtz, Clarke H.; Sole, Catherine L. (Wiley, 2025-12)
AIM : Southern Africa harbours a diverse array of dung beetles (Scarabaeidae: Scarabaeinae), with many species endemic to the region. Despite this diversity, the historical drivers of their evolution remain largely unexplored. This study investigates the evolutionary history of the flightless dung beetle genus Macroderes, testing its monophyly and assessing the role of environmental transitions in shaping its diversification. Location Southwestern Africa, particularly the Greater Cape Floristic Region. Taxon The dung beetle genus Macroderes (Scarabaeidae: Scarabaeinae). METHODS : We conducted molecular phylogenetic analyses across multiple Macroderes species to test monophyly. Using BIOGeoBEARS, we inferred its ancestral range. To explore its biogeographical history and assess how late Cenozoic aridification in southwestern Africa shaped present-day microallopatric speciation patterns, we performed ancestral character reconstruction analyses. These examined Macroderes' origins, environmental adaptations (semi-arid vs. moist habitats), and the emergence of flight-lessness as an adaptive trait, specifically investigating whether the genus descended from volant or flightless ancestors. Bayesian diversification models evaluated diversification dynamics. RESULTS : Our findings support Macroderes' monophyly, with its most recent common ancestor (MRCA) originating in the late Miocene (~8.44 mya; 95% CI: 9.74–7.06 mya). The MRCA was flightless and associated with a semi-arid environment resembling the present-day Succulent Karoo biome. Subsequent diversification involved multiple southward colonisation events into Fynbos, indicating repeated environmental transitions. MAIN CONCLUSIONS : The evolutionary history of Macroderes highlights how aridification and flightlessness have shaped its diversification. Flightlessness in Macroderes is closely linked to adaptation to semi-arid environments, restricting dispersal and contributing to the genus's short-range endemicity. Repeated southward movement highlights the dynamic evolutionary history of Macroderes and the significant role of environmental transitions in shaping its lineage. Our findings highlight the role of historical climatic changes in driving speciation within flightless dung beetles.
Diversification and biogeographic history of African dormice (genus Graphiurus) revealed by ultraconserved elements and mitochondrial data
Onditi, Kenneth Otieno; Demos, Terrence C.; Kerbis-Peterhans, Julian C.; Nicolas, Violaine; Mikula, Ondřej; Bryjová, Anna; Hounmavo, Amétépé; Monadjem, Ara; Bryja, Josef (Elsevier, 2026-04)
The sub-Saharan Africa endemic dormouse genus Graphiurus is a morphologically diverse group of rodents that has lacked a genus-wide genetic framework, hindering inference of their evolution and biogeography. Here, we assembled the first comprehensive, range-wide genomic dataset for Graphiurus, including ultraconserved elements and the cytochrome b gene. We used phylogenetic reconstruction, divergence-time estimation, and ancestral area reconstruction to clarify biogeographic histories and evaluate how historical range dynamics may have influenced lineage diversification. Graphiurus is the earliest-diverging lineage within Gliridae sister to all other extant genera. Within Graphiurus, we recovered 24 molecular operational taxonomic units (MOTUs) forming two reciprocally monophyletic, deeply divergent clades: a West African lineage comprising three MOTUs and a pan-sub-Saharan Africa lineage comprising 21 MOTUs. Genetic distances between these clades are equal to or greater than those used to distinguish genera. Diversification within Graphiurus started in the middle Miocene, peaking in a rapid radiation during the Plio-Pleistocene. These diversification events coincided with increased climatic instability that fragmented forests into isolated refugia. Ancestral-area reconstructions suggest a Graphiurus origin in the Upper Guinean rainforest, followed by jump dispersal across the Afrotropics, with most subsequent divergences occurring in East Africa. As the first comprehensive phylogenetic analysis of Graphiurus, our study underscores the urgent need for an integrated taxonomic revision of the genus that couples genomic data with detailed morphology and critical re-examination of type material to resolve species limits and formally describe the recovered MOTUs. Many MOTUs appear range restricted, underscoring vulnerability to ongoing habitat loss within montane refugia. HIGHLIGHTS • The first phylogenomic dataset clarifies evolutionary relationships and highlights diversity within Graphiurus. • 24 highly supported genetic lineages in two deeply divergent, reciprocally monophyletic clades at genera level identified. • Divergence started in early Miocene, but major diversification aligned with Pliocene–Pleistocene climatic fluctuations. • Long-term habitat refugia in the Eastern African highlands were critical for lineage persistence. • An integrative taxonomic revision of the genus is needed.
Strength in numbers : group size enhances individual survival and colony longevity in Damaraland mole-rats Fukomys damarensis
Jacobs, Paul Juan; Hart, Daniel William; Jarvis, Jennifer U.M.; Bennett, Nigel Charles (Elsevier, 2026-02)
Cooperative behaviour presents an evolutionary paradox because although dispersal may increase direct fitness, many individuals forego reproduction to assist others. In arid-dwelling subterranean mammals, the high energetic costs of underground foraging, together with scarce and patchily distributed food resources are thought to have favoured the evolution of group living and cooperative breeding. These social systems are believed to enhance foraging efficiency and improve the survival prospects of individuals and groups. Using a longitudinal dataset from a wild population of Damaraland mole-rats (Fukomys damarensis) in arid central Namibia, we examine how group size predicts survival and persistence at both the individual and group levels. Our findings show that larger groups confer significant apparent survival benefits, that is the probability that an individual survives and remains available for recapture or resighting, reflecting both true survival and site fidelity, and also enhance colony persistence relative to solitary animals or pairs. We further demonstrate that these very small social-unit states are inherently unstable as without increases in group size, they are unlikely to persist within the population for extended periods. Larger groups clearly enhance survival, making remaining in the natal colony more beneficial than dispersing in an arid environment where dispersal is highly risky. HIGHLIGHTS • Dispersal is risky for Damaraland mole-rats in arid environments. • Solitary individuals and pairs did not persist for an extended period in the same state. • Larger group sizes provide survival benefits for individuals and for colonies.
Large herbivores are linked to higher herbaceous plant diversity and functional redundancy across spatial scales
Trepel, Jonas; Atkinson, Joe; Le Roux, Elizabeth; Abraham, Andrew J.; Aucamp, Margerie; Greve, Michelle; Greyling, Marilize; Kalwij, Jesse M.; Khosa, Steven; Lindenthal, Lukas; Makofane, Caroline; Mokoena, Londiwe; Oosthuizen, Anika; Rech, Bent J.; Lundgren, Erick; Svenning, Jens-Christian; Buitenwerf, Robert (Wiley, 2026-01)
Large herbivores can strongly influence plant communities. However, these effects are highly variable, potentially depending on the herbivore regime, that is, herbivore diversity and density. However, the role of the herbivore regime has been challenging to evaluate across spatial scales due to widespread defaunation and a lack of data on herbivore communities and their densities. Here, we investigated the effects of large herbivores along a gradient of trophic complexity (low to high herbivore diversity) and herbivory intensity (estimated from herbivore biomass and visitation frequency) on plant taxonomic and functional diversity at different scales (plot [n = 250], site [n = 50] and landscape [n = 10]) in 10 reserves in the savanna biome in South Africa. We found higher total plant species richness, driven by higher herbaceous (but not woody) plant species richness, in areas with higher herbivory intensity across multiple scales. While herbivores had no significant relationship with plant functional richness, we observed higher functional redundancy at all scales in areas more frequently visited by herbivores. Overall, herbivore–vegetation relationships were largely consistent across scales, and the strongest effects emerged at the largest scale. Our results show a positive relationship between large herbivores and both herbaceous plant species richness and plant functional redundancy, the latter suggesting higher vegetation resilience (the capacity of ecosystems to quickly recover from disturbances as different species compensate for the loss or decline of others). These effects are largely consistent across scales, indicating that the impact of herbivore regimes on plant communities is predominantly scale-independent and that large herbivores drive vegetation dynamics at both local and large scales. However, the stronger effects observed at the landscape scale imply that herbivore impacts manifest most prominently at larger scales. Altogether, our results suggest that restoring large herbivore populations can be expected to promote herbaceous plant diversity and ecosystem resilience.
Breeding male mole-rats (Fukomys) use strong bites to defend reproductive monopoly
Sumbera, Radim; Kraus, Andrea; Mikula, Ondrej; Okrouhlik, Jan; Measey, John; Begall, Sabine; Bennett, Nigel Charles; Zottl, Markus; Herrel, Anthony; Lovy, Matej (Nature Research, 2026-01)
Bite force is a simple trait indicating an animal’s performance related to foraging, social dominance, and defence, all of which influence individual reproductive success. We examine the effect of breeding status on bite force in four social species of Fukomys, a genus of subterranean African rodents (Bathyergidae). These species are cooperative breeders, where reproduction is limited typically to a breeding pair. We collected in vivo bite force data, head width, and upper incisors width from 404 individuals from 75 families and tested whether breeders exhibit stronger bite force. We reveal that breeding males of all four species outperform non-breeders, with bite force in non-breeding males and females being 12% and 22% lower, respectively. In contrast, breeding females underperform relative to other categories, with bite force approximately 31% lower than in breeding males, and many are reluctant to bite. Head width and upper incisors width corroborate these findings. We propose that breeding males require a stronger bite force because of repeated competition with non-related males that may try to enter the family. In contrast, there is much less competition for the breeding position among females, as females rarely intrude into established families.
Top-down drivers of savanna ecosystems promote bird foraging : effects of fire and large mammals on granivorous and insectivorous birds
Caminho, Jónata; Monadjem, Ara; André, Arquimedes; Bendana, Isaías Simão; Félix Mundoza, Diolinda; Da Graça Elias, Clementina; Greedes Fernando Marcolino, Iolanda; Massad, Tara Joy (Wiley, 2026-01)
ENGLISH : Fire and large mammal herbivores play major roles in shaping plant communities in savannas. However, the interactive effects of these drivers on other components of savanna biodiversity are less well understood. This study, conducted in Gorongosa National Park, Mozambique, tested the effects of fire and large mammals on the abundance and richness of foraging granivorous and insectivorous birds. We manipulated the presence of large mammals and early and late dry season burns and measured multiple aspects of grasses and woody plants as well as bird foraging. We modeled the abundance and richness of foraging birds in response to tree basal area, shrub abundance, grass biomass, grass cover, and grass richness in plots with and without large mammals and fire in the wet season prior to experimental burns, in the dry season following the burns, and in the subsequent wet season. Early and late dry season burns increased granivorous bird foraging in the wet season following the fires. Foraging insectivores increased in plots with cold burns 4 months after fire. The exclusion of large mammals generally reduced bird foraging, although positive effects of large mammal exclosures were detected when resources were limited, and fire and large mammals indirectly affected foraging by changing vegetation and therefore seed and arthropod food resources. Foraging was higher for both guilds where tree cover was greater, and foraging of insectivores increased with shrub cover and grass biomass and richness. These results emphasize the importance of considering fire-herbivore interactions for the conservation of savanna biodiversity.
From beginning to end : the synecology of tree-killing bark beetles, fungi, and trees
Six, Diana L.; Hammerbacher, Almuth; Trowbridge, Amy; Bullington, Lorinda (Wiley, 2026-02)
Over a century of research has revealed an amazing complexity of behaviours and physiological adaptations that allow tiny bark beetles to overcome large trees, sometimes resulting in outbreaks that kill millions of trees. Turning a tree into a home and successfully raising offspring involves constant interactions among the beetles, the tree, its microbiome, and the beetles' associated microbes, all influenced by abiotic factors that can determine success or failure. While we have learned much about these systems, substantial knowledge gaps remain. This synthesis aims to clarify and integrate current understanding, identify gaps, challenge long-held assumptions, and address interpretative issues that impede progress toward a holistic understanding of these systems. We advocate for expanding perspectives using synecological approaches to understand these complex systems better. We encourage expanding research into how colonization by the bark beetle–fungi complex influences subsequent tree decay and forest carbon dynamics. An explicit goal is to provide a comprehensive resource for new researchers while encouraging them to question established hypotheses and to explore new avenues of enquiry.
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.

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