Research Articles (Mammal Research Institute)

Permanent URI for this collectionhttp://hdl.handle.net/2263/5233

A collection containing some of the full text peer-reviewed/ refereed articles published by researchers from the Mammal Research Institute

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Diet and traffic : anthropogenic factors that influence stress-related hormone levels in African clawless otters
Burger, Marli; Ganswindt, Andre; Webster, Andrea B.; Scheun, Juan; Majelantle, Tshepiso L. (Oxford University Press, 2025-12)
Environmental and anthropogenic factors significantly drive adrenocortical activity of animals, affecting their behaviour, distribution and survival. Understanding how animals respond to such drivers is essential for effective conservation. Spraint samples from free-ranging African clawless otters (Aonyx capensis) and camera trap data were collected from study sites categorized as natural or artificially transformed based on differences in anthropogenic disturbance levels. To determine if there were significant differences in faecal glucocorticoid metabolite (fGCM) concentrations between the Natural (Kalkfontein Nature Reserve) and Transformed (Millstream Farm) sites, we ran a linear model that included sex, season, habitat type and their interaction. fGCM concentrations differed significantly between the sexes (df = 1; F1,106 = 11.180; P = 0.001); with males (n = 32; 0.608 ± 0.367 μg/g DW) having significantly higher fGCM concentrations compared to females (n = 79; 0.414 ± 0.399 μg/g DW, P = 0.006). The fGCM concentrations differed significantly between seasons (df = 1; F1,106 = 45.268; P < 0.001), with those in the dry winter season significantly higher (n = 66; 0.631 ± 0.420 μg/g DW), compared to the wet summer season (n = 45; 0.234 ± 0.199 μg/g DW). The fGCM concentrations differed significantly between habitat type (df = 1; F1,106 = 6.026; P = 0.016) with fGCM concentrations of individuals from the KNR natural site (n = 34; 0.285 ± 0.199 μg/g DW) being significantly lower compared to those measured in individuals at the MF transformed site (n = 77; 0.552 ± 0.436 μg/g DW). Finally, the difference in fGCM concentrations between locations however were not dependent on season (df = 1; F1,106 = 0.369; P = 0.544). Anthropogenic disturbance and alterations to the natural and varied prey-base of African clawless otters in an anthropogenically transformed site significantly affect their adrenocortical activity. Future research should focus on how these animals respond to anthropogenic disturbance, and what effects disturbance has on their behaviour, distribution and fitness. Mitigating human–otter conflict requires incorporating such behavioural responses into management strategies.
Light sensitivity and diel activity rhythms in the Angoni vlei rat (Otomys angoniensis) under natural and artificial conditions
Oosthuizen, Tasha; Pillay, Neville; Oosthuizen, Maria Kathleen (Taylor and Francis, 2025-10-16)
Artificial light at night (ALAN) can disrupt daily rhythms of wildlife, yet little is known about its effects on African rodents. We investigated the diel activity rhythms of the Angoni vlei rat (Otomys angoniensis), a species with an inconclusive temporal niche. We exposed wild-caught vlei rats to three treatments: (1) standard laboratory light–dark cycle; (2) laboratory light–dark cycle with low-intensity ALAN (2 Lux); and (3) natural ambient light and temperature fluctuations. Activity was recorded via infrared sensors, and the activity rhythm was quantified using Cosinor analysis. Activity was predominantly nocturnal across all treatments. However, rhythm amplitude, MESOR and robustness were nearly three-times higher under natural conditions than in both laboratory treatments. ALAN did not significantly suppress activity, suggesting minimal masking effects (unlike strictly nocturnal animals) and possible flexibility in the temporal niche. In nature, O. angoniensis occupies dense grass habitats, and therefore, its predominantly nocturnal activity in captivity could be due to the lack of adequate cover during experiments. Moreover, the greater activity under natural conditions could be a consequence of brighter daytime light and natural temperature cycles. We suggest that although O. angoniensis displays nocturnal activity in the laboratory, it may be more diurnal in its natural habitat. Our findings demonstrate that the temporal activity of O. angoniensis is shaped by environmental context, with implications for contextualising circadian flexibility in species inhabiting human-altered landscapes.
Reflections on editorial leadership : looking back…moving forward
Den Hond, Frank; Painter, Mollie (Cambridge University Press, 2025-10)
We take the opportunity in this editorial that marks the end of our tenure, to offer some reflections on our experiences. It is an occasion for looking back, for reflection on the scholarship and practice of business ethics, and for celebrating some of the outstanding work that is being done in and for the journal.
Hyaena-mediated landscapes of fear : the influence of active spotted hyaena (Crocuta crocuta) den sites on the detection probability and occupancy probability of a mammal community
Jansen Van Vuuren, Amauree; Curveira-Santos, Gonçalo; Swanepoel, Lourens; Valeix, Marion; Fritz, Herve; Venter, Jan A. (Southern African Wildlife Management Association, 2025-11)
African ecosystems support a diverse variety of predator species and have the highest diversity of large carnivores on earth. Apex predators play a crucial role in these ecosystems. Through hunting and creating a landscape of fear, apex predators influence the populations and behaviours of smaller predators and prey. According to the mesopredator release hypothesis, the absence of an apex predator leads to an increase in mesopredator populations, resulting in higher predation pressure on their prey and a subsequent decline in prey populations. The spotted hyaena (Crocuta crocuta) is a key apex predator with several activity hotspots, the largest being the den, where landscapes of fear may be most pronounced. While there is substantial literature on factors influencing hyaena den site selection, the impact of these dens on the presence of potential prey and competitively inferior species remains underexplored. This study aimed to examine the influence of perceived risk associated with hyaena dens on the occupancy and detection probabilities of prey species within the ecosystem. We used camera traps set up around dens to assess these probabilities, providing a detailed analysis of mesopredator and prey species' responses to hyaena activity. Our results indicate a correlation between increased hyaena activity and reduced occupancy and detection probabilities in mesopredator and prey species. These findings suggest that hyaena dens create landscapes of fear, influencing mesopredator and prey species' distribution and behaviour.
Efficient statistical inference of turning points in animal movement data
Alharbi, Abdulmajeed F.; Blackwell, Paul G.; Alagaili, Abdulaziz; Bennett, Nigel Charles; Scantlebury, David Michael; Potts, Jonathan R. (Wiley, 2026)
Recent years have seen a proliferation of high-frequency animal movement data, often at greater than 1 Hz, allowing us to gain much greater insight into behaviour than with lower frequency data. In particular, it is becoming possible to detect the precise points at which animals are making decisions to turn, thus placing the idea that the animals move in ‘steps and turns’ onto rigorous grounding. 2. Despite this, current efforts to ascertain the points at which animals turn tend to rely on the user making pre-determined choices of certain model parameter values. Furthermore, whilst they may give good results, there is often no theory explaining why the inferred turning points are most likely to be correct, for example by maximising a likelihood function. 3. Here, we propose a theoretically grounded statistical technique to find turning points in high-frequency movement data that does not require any a priori choices of parameter values. By testing our algorithm on simulated data, we show that our technique is both fast (e.g. 3 s to parse data points) and accurate. For example, when the standard deviation of the noise is less than around radians then our algorithm correctly identifies nearly of the turning points, providing the noise is not heavily autocorrelated. Additionally, we demonstrate the effectiveness of our technique on magnetometer data from free-ranging Arabian oryx (Oryx leucoryx). 4. Overall, our work gives a fast, accurate and statistically grounded algorithm for turning point detection in high-frequency data. The resulting model of straight-line steps and turns provides a biologically meaningful summary of the animal's movement behaviour, which has potential to be used as an input to the wide range of step-and-turn techniques used in movement ecology, such as step selection analysis and hidden Markov models of behavioural states.
A systematic revision of Equatorial Guinea's bats confirms a biodiversity hotspot in Central Africa
Torrent, Laura; Garin, Inazio; Aihartza, Joxerra; Nguema Alene, Esther Abeme; Monadjem, Ara; Juste, Javier (Oxford University Press, 2025-12)
The bat fauna of Equatorial Guinea (EG), on the western edge of the Lower Guinea rainforest, a predicted African bat diversity hotspot, remained poorly documented. We collated data from literature, natural history collections and recent fieldwork to compile a comprehensive biodiversity assessment of the bats of mainland EG. This yielded 58 taxa from 29 genera and eight families: 11 species within Pteropodidae, three within Emballonuridae, two within Rhinolophidae, six within Hipposideridae, eight within Molossidae, one within Miniopteridae, five within Nycteridae, and 22 within Vespertilionidae. We report 33 new national records and three additional taxa that require further taxonomic confirmation. Notable additions include Casinycteris campomaanensis, Coleura afra, Glauconycteris superba, Hipposideros curtus and Mops petersoni. This study provides the first detailed documentation of bat diversity for mainland EG, enhancing our understanding of species richness and distributions in this biodiversity hotspot, and offering insights to guide future ecological research and conservation efforts. The bat species richness documented in our study exceeds that of any other forest site in tropical Africa with comparable size and habitat, with additional forest-dwelling species likely yet to be found. This biodiversity assessment highlights the importance of protecting bat assemblages in EG and the broader Lower Guinea rainforest region.
Low genetic diversity and regional isolation of South Africa’s inshore Bryde’s whales
Paynee, Dominique Kelsi; Vermeulen, Els; Penry, Gwenith S.; Elwen, Simon; Matthee, Conrad; Andreotti, Sara; Bloomer, Paulette (Springer, 2026-02-03)
Effective conservation of cryptic marine species depends on a sound understanding of genetic diversity, population structure and connectivity. These data allow for the delineation of conservation units and assessment of extinction risk and are especially valuable for species with fragmented distributions or suspected regional endemism. The Bryde’s whale (Balaenoptera edeni) exemplifies a challenge, being a poorly understood baleen whale species globally, with a complex of resident inshore and migratory offshore populations across temperate and sub-tropical waters. One such is the inshore population that inhabits South African coastal waters, where it is classified nationally as Vulnerable (D1) due to its small population size. This study uses a panel of 14 microsatellite markers and mitochondrial DNA control region sequences to advance our understanding of the genetic isolation and extinction risk of this population, informing the delineation of conservation units and guiding population-specific management actions. Results indicate that this population is characterized by moderate nuclear microsatellite and low mitochondrial DNA diversity and preliminarily indicate genetic differentiation between populations in the southern African region. On a global scale the findings show differentiation between broad ocean regions and the SAi while supporting the difference in evolutionary origin of SAi and SEA. These findings underscore the need for active conservation management for this isolated coastal population since they provide genetic evidence for the recognition of a discrete management unit. It is recommended that further refinement in understanding of the population’s evolutionary distinctiveness will strengthen conservation assessments, support listing decisions, and guide targeted management interventions.
An update on the occurrence of humpback whale (Megaptera novaeangliae) super-groups on the West Coast of South Africa
Seyboth, Elisa; Findlay, Ken; Vogel, Alex; Abras, Daniela; Hurwitz, David; Vermeulen, Els; Tresfon, Jean; Gridley, Tess; Elwen, Simon (Wiley, 2025-10)
Humpback whale (Megaptera novaeangliae) super-groups, comprising 20+, tightly aggregated, feeding individuals, form during the austral summer in the southern Benguela ecosystem off the west coast of South Africa. This phenomenon, observed since 2011, is thought to be linked to increased productivity from positive chlorophyll-a anomalies associated with reduced water export in the area, and possible changes in associated trophic structures. Oceanographic conditions vary over time and space, so that super-groups occurrence can also be highly spatially variable. In this study, we investigate the spatiotemporal patterns of super-groups by compiling records from scientific surveys, whale-watching operators, and citizen science reports between July 2015 and June 2022. In total, sightings of 239 humpback whale super-groups were collated for this period, considering sighting with best estimate group size of 20 individuals or more. Super-groups appeared from August to April, peaking between October and January, and the seasonality of their occurrence seems to have expanded in comparison to previously published data. Although the effect of inconsistent effort throughout the study is unknown, results identify the overall regularity and spatiotemporal patterns of super-group formations, while highlighting the need for improved, collaborative and systematic data collection to gain deeper insights into this mid-latitude feeding phenomenon.
Unlocking opportunities for meaningful participation of land reform beneficiaries in the wildlife economy
Shwababa, Siviwe; Child, Matthew F.; De Vos, Alta; Mneno, Naledi; Clements, Hayley S. (Elsevier, 2025-07)
Land reform is a key social justice movement across the world, typically focused on agricultural land uses. However, in many parts of the world, land reform properties exist in regions that have high biodiversity value, where options exist for integrating land reform with wildlife-based land uses to promote both conservation and socio-economic development. To effectively design and implement policies aimed at unlocking this under-explored pathway towards inclusive wildlife economies, we need information on the opportunities and barriers confronting the establishment and operation of viable wildlife enterprises on redistributed land. We conducted a survey of 19 landholders awarded land through reform in the Eastern Cape Province of South Africa. We aimed to understand the state of wildlife economy development and assess investment needs for these market entrants. Their characteristics were contrasted with data on 74 established wildlife ranches and 21 conventional livestock farms. Despite all land reform properties listing wildlife-based economic activities in their business plans and most (84 %) having wildlife, only 42 % were generating (very limited) income from their wildlife. Common barriers to upscaling revenues from wildlife were a lack of infrastructure (particularly fencing, water, accommodation) and wildlife stocks. Engagement in the wildlife economy is further hindered by lack of decision-support on viable wildlife business models and subsequent lack of access to skills development and market information. Our results show mismatches between activities that are supported by government and property business plans, and those that are context-appropriate and viable. We suggest that South Africa’s land reform programmes need to develop targeted infrastructure and skills development that consider the most appropriate business model for a given site. The barriers and opportunities outlined here could inform strategies that leverage state and private investment to more effectively create viable wildlife-based business models and achieve the dual goals of social justice and biodiversity conservation in South Africa.
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.
Exploring emotional attachment to non-traditional pets using the Lexington Attachment to Pets Scale (LAPS)
Sturgeon, Diane J.E.; Steele, Zachary T.; Pienaar, Elizabeth Frances (Routledge, 2026)
The growing popularity of non-traditional pets, including reptiles, amphibians, fish, insects, and arachnids, raises important questions about owner attachment and animal welfare. We assessed emotional attachment among US non-traditional pet owners using the Lexington Attachment to Pets Scale (LAPS). An online survey of 1,218 adult pet owners was conducted between 2018 and 2021 through both targeted recruitment (rescue groups, permit holders, herpetological societies) and general population sampling. The LAPS demonstrated excellent internal consistency when applied to non-traditional pets, supporting its cross-taxon validity. Owners of multiple taxa of pets reported significantly higher attachment scores than owners of a single taxon. Linear regression models revealed higher attachment among female respondents and those who personally chose to acquire their pets. Conversely, attachment was lower among older respondents, those with higher incomes, and single-taxon owners who exclusively owned non-traditional pets. Our results underscore the importance of considering owner demographics and motivations for acquiring pets when designing pet welfare interventions and targeted education for non-traditional pet owners.
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.
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.
Does the public value ecosystem services secured by pine savanna restoration and bobwhite management on private lands?
Nimlos, Nicole M.; Pienaar, Elizabeth Frances; Martin, James A. (Elsevier, 2026-03)
Private land stewardship in the southeastern United States is crucial to attain pine savanna restoration and conservation of the threatened northern bobwhite (Colinus virginianus). Both government and privately funded conservation efforts secure numerous ecosystem services, including groundwater recharge, scenic open spaces, and biodiversity. Yet, we have incomplete information on whether the public values these ecosystem services. From June 15th to July 19th, 2022, we administered stated preference choice experiment surveys to 770 members of the public in Alabama, Georgia, Florida, and South Carolina to ascertain if the public values ecosystem services provided by pine savanna and bobwhite conservation. We analyzed data using hybrid mixed logit models. Respondents positively valued recovery of threatened bobwhite and gopher tortoise populations and high levels of groundwater recharge and scenic open space. Respondents with higher moral obligations to prevent land use conversion (personal norms, awareness of consequences, and ascription of responsibility related to conservation) were more likely to support allocation of taxes to pine savanna restoration on private lands. Respondents' moral obligation to prevent land use conversion was positively correlated with their engagement in outdoor recreational activities. Our findings indicate that the public values pine savanna and bobwhite conservation efforts on private lands in the Southeast, and that outreach related to pine savanna restoration efforts should appeal to people's moral obligation to support conservation of biodiversity, habitat restoration, and the provision of ecosystem services. HIGHLIGHTS • We use hybrid mixed logit models to analyze preferences for pine savanna restoration. • Moral obligation to prevent land use conversion depends on political orientation. • Recreational activities and moral obligation influence support for restoration programs. • Respondents placed greatest value on bobwhite recovery and high groundwater recharge.
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.

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