Research Articles (Biodiversity and Conservation Biology)

Permanent URI for this collectionhttps://hdl.handle.net/10566/35

Browse

Now showing 1 - 20 of 298

Distribution and status of reptile species in south-eastern Zimbabwe
(Taylor and Francis Ltd., 2025) van Wyk, Kurt; Maritz, Bryan; Clegg, Bruce William
While the loss of biodiversity in response to anthropogenic drivers is well documented, reptiles are rarely prioritised in global conservation efforts. Although more than 20% of all reptile species are currently listed as threatened, and a growing body of evidence highlights the sensitivity of reptiles to habitat change, basic information on the distribution, natural history, and regional conservation status of African reptiles remains sparse. Habitat loss through agricultural land-use change is regarded as the primary threat to global biodiversity and to southern African reptiles in particular. Arid and semi-arid ecoregions in southern Africa have been identified as areas of global conservation priority for reptiles. However, the status of Zimbabwe’s reptiles remains largely unknown. Limited resources and more urgent concerns have hampered what Zimbabwe has been able to achieve with respect to international conservation initiatives. Furthermore, the ecological impacts of recent, wide-scale land-use change in the country have received little attention. As legacies of historical land-use change are acknowledged as determinants of current landscape ecology, addressing the long-term effects of land-use change on Zimbabwe’s reptiles is crucial for effective conservation and management. Here we provide a complete account of the reptile taxa recorded in south-eastern Zimbabwe. We discuss sources of spatial and temporal bias in the occurrence dataset and highlight the importance of the region’s protected area network for conserving reptile diversity. Our study increases the number of published reptile occurrence records from the region by an estimated 285%
Vulnerability of marine megafauna to global at-sea anthropogenic threats
(John Wiley and Sons Inc, 2026) Waller, Lauren; VanCompernolle, Michelle; Morris, Juliet
Marine megafauna species are affected by a wide range of anthropogenic threats. To evaluate the risk of such threats, species’ vulnerability to each threat must first be determined. We build on the existing threats classification scheme and ranking system of the International Union for Conservation of Nature (IUCN) Red List of Threatened Species by assessing the vulnerability of 256 marine megafauna species to 23 at-sea threats. The threats we considered included individual fishing gear types, climate-change-related subthreats not previously assessed, and threats associated with coastal impacts and maritime disturbances. Our ratings resulted in 70 species having high vulnerability (v > 0.778 out of 1) to at least 1 threat, primarily drifting longlines, temperature extremes, or fixed gear. These 3 threats were also considered to have the most severe effects (i.e., steepest population declines). Overall, temperature extremes and plastics and other solid waste were rated as affecting the largest proportion of populations. Penguins, pinnipeds, and polar bears had the highest vulnerability to temperature extremes. Bony fishes had the highest vulnerability to drifting longlines and plastics and other solid waste; pelagic cetaceans to 4 maritime disturbance threats; elasmobranchs to 5 fishing threats; and flying birds to drifting longlines and 2 maritime disturbance threats. Sirenians and turtles had the highest vulnerability to at least one threat from all 4 categories. Despite not necessarily having severe effects for most taxonomic groups, temperature extremes were rated among the top threats for all taxa except bony fishes. The vulnerability scores we provide are an important first step in estimating the risk of threats to marine megafauna. Importantly, they help differentiate scope from severity, which is key to identifying threats that should be prioritized for mitigation.
Editorial expression of concern: PICSI vs. MACS for abnormal sperm DNA fragmentation ICSI cases: a prospective randomized trial
(Springer, 2025) Henkel, Ralf; Hasanen, Eman; Elqusi, Khaled
The Editor-in-Chief is issuing this Editorial Expression of Concern to alert readers that concerns have been raised about the data presented in this article. Specifically, Table 1 presents the demographic information about the PICSI arm of this study as a decimal percentage, even though such percentages are not possible for a cohort of 200. The authors have stated that the reason for this is that not all participants provide full information about all demographic characteristics, so in each case the values are a percentage of a number that is less than 200. However, the authors have not been able to provide patient-level data due to the confidentiality statement that was signed by participants included in this study, and so the Editor-in-Chief has not been able to confirm this explanation or to verify the number of participants who failed to return information for each demographic characteristic. Readers are advised to interpret the data presented in this article with caution
Identifying essential chemical descriptors for auxins, cytokinins, and gibberellins using principal component analysis
(Springer, 2025) Sershen Naidoo; Quintana‑Zaez Julio César; Gómez Daviel
Auxins, cytokinins, and gibberellins are plant growth regulators (PGRs) that significantly influence plant growth and development. Investigating their molecular descriptors is vital for understanding how these PGRs work in intricate networks, influencing each other’s activity and responding to environmental cues, but this can be challenging given that PGRs often mimic or interact with naturally occurring plant growth regulators, which are themselves a complex group of chemicals with diverse structures and functions. This motivated the present study, which evaluated the effectiveness of principal component analysis (PCA), a statistical method renowned for reducing the dimensionality of intricate datasets, in identifying the key molecular descriptors that distinguish these three plant growth regulators. A total of 212 molecular descriptors were previously determined. Using PCA, the study identified critical chemical descriptors for auxins, cytokinins, and gibberellins, including ring count, presence of secondary alcohols, and terminal primary C (sp2) structures. Importantly, the study also confirmed the value of PCA in identifying key molecular descriptors for PGRs in studies focused on understanding their mechanism(s) of action. This paper introduced a novel methodological approach that contributes meaningfully to the understanding of PGRs.
Evaluation of risks of oil contamination in endangered seabirds in Algoa Bay, South Africa, linked to ship-to-ship bunkering and anthropogenic maritime activities
(Elsevier Ltd, 2026) Ludynia, Katrin; Stassen, Monica; Fearon, Giles
This study evaluates the ecological risks of oil contamination to endangered seabirds in Algoa Bay, South Africa, linked to ship-to-ship (STS) bunkering activities and other anthropogenic maritime activities. Between 2016 and 2024, 378 oiled seabirds—primarily African penguins and Cape gannets—were admitted to rehabilitation centres, with over half linked to STS-related spills. An established modelling system was used to model the trajectory of oil from the MV Chrysanthi S spill in 2019 (400 L of Heavy Fuel Oil), using the simulated environmental conditions at the time of the spill. The model predicted that core foraging areas would have remained exposed to oil for about a week after the spill and that birds would have been found and rescued days after their contamination. Probabilistic modelling of 200 spill scenarios revealed high likelihoods of shoreline oiling and persistent surface contamination, especially during austral winter, when oil is more likely to reach Bird Island's seabird foraging areas. Spills from the offshore extent of anchorage area 2 are more likely to result in impacts on the seabird foraging areas. The model indicates that a high degree of conservatism is required when selecting ecological thresholds for impacts on African penguins, given the relatively high observed impacts despite low modelled surface thicknesses from a 400 L spill. These findings underscore the urgent need for stricter regulation of offshore bunkering in ecologically sensitive areas and improved preparedness for wildlife rescue and rehabilitation, especially in an area of such high biodiversity as Algoa Bay.
A place-based assessment of biodiversity intactness in sub-Saharan Africa
(Nature Research, 2025) Maritz, Bryan; Clements, Hayley S; Biggs, Reinette
Maintaining biodiversity is central to the sustainable development agenda1. However, a lack of context-specific biodiversity information at policy-relevant scales has posed major limitations to decision-makers2,3. To address this challenge, we undertook a comprehensive assessment of the biodiversity intactness of sub-Saharan Africa4 using place-based knowledge of 200 African biodiversity experts5. We estimate that the region has on average lost 24% of its pre-colonial and pre-industrial faunal and floral population abundances, ranging from losses of <20% for disturbance-adapted herbaceous plants to 80% for some large mammals. Rwanda and Nigeria are the least intact (<55%), whereas Namibia and Botswana are the most intact (>85%). Notably, most remaining organisms occur in unprotected, relatively untransformed rangelands and natural forests. Losses in biodiversity intactness in the worst-affected biomes are driven by land transformation into cropland in grasslands and fynbos (Mediterranean-type ecosystems), by non-agricultural degradation in forests and by a combination of the two drivers in savannas. This assessment provides decision-makers with multifaceted, contextually appropriate and policy-relevant information on the state of biodiversity in an understudied region of the world. Our approach could be used in other regions, including better-studied localities, to integrate contextual, place-based knowledge into multiscale assessments of biodiversity status and impacts.
Revealing hidden diversity: new Latrunculia and Iophon species (Porifera, Demospongiae, Poecilosclerida) from the continental shelf of the Namaqua ecoregion (Benguela ecosystem), along with a range extension of Latrunculia (Aciculatrunculia) biformis
(Cambridge University Press, 2026) Samaai, Toufiek; Payne, Robyn Pauline; Kamwi, Blessing
Four new species of Poecilosclerida (Porifera, Demospongiae) assigned to the genera Latrunculia and Iophon are described from South Africa and Namibia, located in the Namaqua ecoregion. The Porifera occurring along the continental shelf within this ecoregion are relatively well-known, with 76 species formally described in previous literature. Of these, 35 species belong to the Order Poecilosclerida. Additionally, Latrunculia (Aciculatrunculia) biformis is reported from the continental shelf on the west coast of South Africa, extending its range further northwards into the South Atlantic. DNA barcoding and molecular phylogenetic analyses were employed to ensure accurate taxonomic assignment and designation of new species.
The grazer Cymbula oculus (Patellogastropoda: Patellidae) serves as an important settlement substrate for several of its macroalgal prey
(National Inquiry Services Centre Ltd, 2025) Moosa, Waqeefah; Phillips, Jesse; Maneveldt, Gavin
Intertidal communities are predictably affected by both physical and biological factors, with herbivory as a particularly important factor. Instead of dense beds of macroalgae, which typically characterise the mid-eulittoral zone along the south coast of South Africa, at Kalk Bay this zone is dominated by a generalist grazer, the goat’s eye limpet Cymbula oculus. Despite its voracious grazing behaviour, this species of true limpet (family Patellidae) appears to positively influence macroalgal richness through epibiotic interactions. This study aimed to determine the role of C. oculus as an alternative settlement substrate for several macroalgal species that would otherwise be consumed by this grazer. Additionally, we wanted to determine whether the limpet’s density was on the increase, and, if so, what such an increase might mean for a future scenario at the site. Data collection and sampling took place within quadrats along transect lines. The quadrats were photographed to determine macroalgal cover on the limpet shells and on the surrounding primary rocky substrate, and analysed using ImageJ software. Additionally, C. oculus density was estimated, as well as macroalgal biomass on both the limpet shells and the primary rocky substrate. It was found that C. oculus shells are an important secondary substrate for macroalgae, and that species of foliose and turfy macroalgae benefit more than encrusting macroalgal species. The mean density of C. oculus, at 20 (SE 2.22) ind. m−2, was significantly greater than that reported two decades ago. The potential exists for increased cover abundance of chemically and morphologically defended macroalgae on the primary rocky substrate, a future scenario that seems increasingly possible given the increased C. oculus densities.
The influence of physicochemical variables on plant species richness and distribution in the coastal salt marshes of the Berg River Estuary, South Africa
(Elsevier B.V, 2025) Mngomezulu, Nomcebo T.; Rajkaran, Anusha; Veldkornet, Dimitri A.
The continuous distribution of coastal salt marsh habitats along an elevation gradient can be disrupted by tidal creeks running through them. Tidal creeks wind through salt marshes and create different environmental conditions for adjacent habitats. While studies have emphasized the importance of tidal creeks as links facilitating interactions in salt marshes, few have studied plant communities and physiochemical conditions associated with tidal creeks. This study determined the influence of creek physicochemical variables on the diversity and distribution of coastal salt marsh plants. Six transects in the lower reaches of the Berg River Estuary, South Africa were sampled over two seasons at sites with either the presence or absence of creeks. Species composition and abundance were analysed by replicate quadrats and paired with physicochemical variables (groundwater and sediment). The k-means of 20 species in 334 quadrats revealed four distinct clusters of salt marsh habitats, creeks, intertidal salt marsh, supratidal salt marsh and reeds. Species richness was higher along transects with creeks (16) compared to those with no creeks (5). The physiochemical variables, groundwater temperature, pH, dissolved oxygen, conductivity, and sediment variables (redox potential, organic content, percentage silt and percentage sand), significantly influenced the abundance of creek species. This study highlights the importance of tidal creeks in forming unique vegetation communities in salt marshes, where they act as refugia for intertidal species. It is suggested that tidal creek communities should be included in salt marsh vegetation descriptions and monitored in association with physicochemical variables in response to climate change.
Germination and establishment of Teramnus labialis (l.f.) sprenG plants are affected by scarification treatment used
(Sociedad Botanica de Mexico, A.C, 2025) Naidoo, Sershen; Acosta, Yanier; Sánchez, Jorge A.
Background: Some of the species that make up the legume family are used as animal feed and to improve soil fertility. However, their use is limited due to low seed availability and low germination rates. Questions: Which scarification treatment is most effective in increasing germination? What is the response of plants to growth under field conditions? Studied specie: Teramnus labialis (L.f.) Spreng. Study site and date: Ciego de Ávila, Cuba, 2019 year. Methods: Four scarification treatments (sanding, sulfuric acid, hot water, and liquid nitrogen (LN)) were evaluated under controlled laboratory and field conditions. Seed coat structures, imbibition capacity, electrolyte loss, and germination were studied under controlled laboratory conditions. Under field conditions, plant morphological traits were evaluated during the vegetative and reproductive phases. Results: Scarification with LN caused multiple cracks in the seed coat, while sulfuric acid caused wear and detachment of the seed coat. With the use of LN, seed imbibition and germination were improved. In addition, 78 % of plants emerged with this treatment and crop establishment was achieved 120 days after sowing. Conclusions: Scarification with LN of T. labialis seeds was the most effective treatment to improve germination and reduce the time to establishment of the species. © 2025 Sociedad Botanica de Mexico, A.C.
A decade of implementing the Biodiversity management plan for African penguins – successes, failures and lessons learnt
(Elsevier GmbH, 2025) Barham, Peter; Ludynia, Katta; Sherley, Richard; Waller, Lauren
The rapid decline of the African penguin Spheniscus demersus in the early 2000 s triggered the drafting of the first African Penguin Biodiversity Management Plan (BMP) published in 2013, to “halt the decline of the African penguin population”. Working Groups (WGs) were created with stakeholders involved in penguin conservation to facilitate the implementation of the BMP. This study reviews the execution of the plan (1) from aide memoires and reports circulated within these WGs between 2013 and 2022; (2) by interviewing (in 2023) some of the stakeholders involved to assess their perceptions of the BMP 10 years post-implementation; and (3) by assessing the effectiveness of some actions using available scientific data. Interviewees unanimously agreed that the plan improved the species's management and facilitated collaboration across institutions involved. Conservation actions identified as the most effective were 1) the rehabilitation of adults and chicks; 2) predator management and 3) habitat improvement with the provision of artificial nests. Scientific reviews of these actions validated their success. For example, rehabilitation effort may have increased the 2023 penguin breeding population by ca 7 %. Nevertheless, African penguin numbers continued decreasing and the species is now “Critically Endangered” on the IUCN Red List. Measures are still lacking in effectively increasing prey availability despite intensive engagement. Dedicated funding, trained capacity and accountability by relevant institutions undertaking their actions and deliverables were identified as essential for a more successful implementation of the BMP. Lessons learnt may pave the way for stronger conservation actions for African penguins and other threatened seabirds.
The first record of Cape Clawless Otters Aonyx capensis predating on African Penguins Spheniscus demersus
(Taylor and Francis Ltd, 2025) Ludynia, Katrin; Snyman, Albert; Purves, Arne
The African Penguin Spheniscus demersus, a critically endangered seabird endemic to southern Africa, faces substantial threats from terrestrial predators at its mainland colonies. Correct identification of the predator species is essential for effective conservation management. This study provides the first documented evidence of Cape Clawless Otter Aonyx capensis predation on African Penguins. We describe characteristic lesion patterns distinguishing otter predation from other predators, such as Caracal Caracal caracal. These findings underscore the importance of accurate predator identification to guide targeted mitigation strategies and highlight the need for adaptive management to protect vulnerable mainland African Penguin colonies from emerging predation pressures.
The agony of choice: comparing abundance estimates from multiple N-mixture model variants fitted to a reptile community dataset
(Society for the Study of Amphibians and Reptiles, 2025) van Wyk, Kurt; Maritz, Bryan
Ecological surveys rarely achieve perfect detection of target species, and failure to account for imperfect detection produces erroneous estimates of abundance. N-mixture models account for variation in detectability by separating the observation process from the ecological process that determines true site-level abundance, making these models theoretically well suited to studies of inconspicuous species, such as reptiles. Multiple N-mixture model variants have been published in different fields of ecology, but little is known about their ability to provide ecologically realistic abundance estimates from real-world observation data, especially for reptiles, which routinely have very low detection probabilities. Using a dataset of reptile observations from southeastern Zimbabwe, we compared estimates of five N-mixture model variants. For each species, we assessed the goodness-of-fit of each variant, proximity of each variant’s site-level abundance estimates to an ecologically realistic range of values, and congruence between these estimates. We were able to fit acceptable models only for the most frequently detected species in our dataset (9 of 25 species). We found that model fit varied significantly according to model variant as well as species occupancy and detection probability, and that model variant pairs were rarely congruent in their abundance estimates. Importantly, our results demonstrate that fitting a single N-mixture model variant to data sampled from an ecologically diverse community can yield artifactual variation in abundance estimates. Further case studies in reptile spatial ecology will help to identify circumstances in which a priori matching of species and method of abundance estimation may be possible. Until then, rigorous but adaptive survey design may be a more reliable means of avoiding bias than accounting for it statistically. We provide a framework for application of multiple N-mixture model variants in faunal ecology to guide analytical decision-making.
The impact of weather variation on the body condition of cape cobras (Naja nivea) in the Kalahari — implications for climate change
(Academic Press, 2025) Scholtz, Kim J.; Maritz, Robin A.; Maritz, Bryan
Hot and dry weather conditions are known to impact the body condition and the fitness of many organisms. However, this relationship has not been extensively studied in snakes. We examined the impact of variation in rainfall and temperature on body condition for a population of cape cobras (Naja nivea) at Tswalu Kalahari Reserve (Northern Cape Province, South Africa) over a period of five years during which time environmental conditions fluctuated substantially. We measured the mass and body length of 105 cobras, 58 from which we collected repeat measures, and calculated a body condition index (BCI) for each observation. We tested whether BCI was impacted by season, sex, and/or differences from expected mean monthly rainfall (during the preceding four-, 12-, and 24-week periods) and mean daily maximum temperature (during the preceding four-, 12-, and 24-week periods). Secondly, we tested whether BCI measures of cobras during the mating-season (September–November) were different between sexes and impacted by an index of environmental conditions (PC1 of rainfall and temperature) in the preceding summer. For our initial analysis, we found that the best-fitting model included season, sex, the relative amount of rain in the preceding twelve weeks (positive relationship), and the temperature in the preceding twelve weeks (negative relationship). Moreover, the BCI of cobras during the mating season was correlated with environmental conditions during the previous summer, with mating cobras exhibiting lower BCI measures following hot and dry summers. Our study reveals detrimental impacts of hot and dry conditions on cape cobra body condition, including measurable effects on body condition of mate-searching animals, following hot and dry summers. Taken together, we predict that prolonged hot dry periods, or increased frequency of hot dry periods in the future, might have detrimental effects on cape cobra populations in the Kalahari.
Premna sebrabergensis (Lamiaceae, Premnoideae), a new species from Angola and Namibia
(Magnolia Press, 2025) van Jaarsveld, Ernst Jacobus; Swanepoel, Wessel; Becker, Rolf W
Premna sebrabergensis, hitherto misidentified in herbaria as Volkameria glabra (= Clerodendrum glabrum), is here described as a new species. It is a range-restricted species, only known from the Zebra Mountains in the Kaokoveld Centre of Endemism, in northwestern Namibia and southwestern Angola. It grows primarily in soils derived from anorthosite and gabbro of the Kunene Igneous Complex. Diagnostic characters for P. sebrabergensis include the pale green or yellow-green appearance of the plants, vegetative parts with an indumentum of simple antrorse-directed white trichomes and yellow glandular peltate scales, leaves usually ovate, often with elongated acuminate apex and flowers in paniculately arranged cymes. Based on IUCN Red List criteria, a provisional conservation assessment of Endangered (EN) is recommended for the new species.
Community- and species-level responses of reptiles to an avian ecosystem engineer
(John Wiley and Sons Inc, 2025) Buckley, Emma E.; Maritz, Bryan
Ecosystem engineers can alter the distribution and abundance of resources in a landscape, thereby impacting the distribution of other species that use those resources. Although reptiles are known to respond to the ecosystem engineering of birds, case studies are surprisingly rare. Here, we sampled reptile abundance and diversity underneath pairs of trees that do, or do not, contain the thatched colonies of sociable weavers (Philetairus socius) in the Kalahari. We conducted our systematic sampling both when the weavers were breeding, and again at the beginning of summer before the onset of breeding. We test the hypotheses that (1) reptile species richness and (2) overall abundance are higher under trees with weaver colonies, and whether differences in those measures vary with season. We additionally explicitly test whether colony trees hosted greater abundances of (3) Kalahari tree skinks (Trachylepis spilogaster), and (4) cape thick-toed geckos (Pachydactylus capensis)—the two most frequently detected species in our study. We find robust support for all four hypotheses. Trees with colonies had approximately twice the richness of trees without colonies when weavers were breeding but showed no difference in richness outside of the breeding period. Trees with colonies also yielded approximately twice the number of captures (from all reptile species) than did trees without colonies, but this effect was present in both seasons. We found strong support for trees with colonies hosting larger populations of Kalahari tree skinks than noncolony trees in both seasons. We also found strong support for cape thick-toed geckos occurring at higher abundances under colony trees. Taken together, our results indicate that multiple species of reptiles are responding to the presence of sociable weaver colonies in the Kalahari, and that those species effects are summing up to detectable community-wide effects.
Target-enriched multilocus assay on poriferan museum collections unsettles tethyid classification.
(Academic Press Inc., 2025) Samaai, Toufiek; Erpenbeck, Dirk; Deister, Fabian
Marine biodiversity collections are critical resources for understanding biodiversity and evolutionary patterns. However, their taxonomic utility is limited due to challenges in morphological identification and cryptic speciation, particularly in sponges (Porifera). This study applied a novel target-enriched multilocus assay to a decades-old unidentified collection of Tethyidae from the Queensland Museum. Target-specific baits were designed based on Tethya genome data, enabling the sequencing of nuclear ultraconserved elements (UCEs) and mitochondrial genomes, even from degraded samples. In the study, 40 specimens were sequenced, and we found up to 4,440 UCEs per sample. The phylogenies were based on up to 2,788 loci and demonstrated overall high bootstrap support. Results include robust support for earlier findings on the non-monophyly of Tethya, with lineages linking to other genera (e.g., Stellitethya, Tethycometes), suggesting that Tethya is a paraphyletic group foundational to Tethyidae. Morphological subgroupings, previously hypothesized, were validated genetically, though several novel relationships emerged. This approach highlights the suitability of target-enriched multilocus assays for archival collections, enabling detailed biodiversity assessments using collection material initially not sampled for molecular work. Our Tethya case study underlines that this methodology provides a framework for broader applications in marine biodiversity conservation, facilitating the understanding and preservation of past and present biodiversity to guide future efforts.
Rangeland conditions and grazing capacities on livestock farms during and after drought in three biomes in South Africa
(Multidisciplinary Digital Publishing Institute (MDPI), 2025) Letsoalo, Ngoako L.; Samuels, Igshaan M.; Engelbrecht, Adriaan; Cupido, Clement F.
Climate change has intensified extreme weather events worldwide, such as droughts, which have severely affected South Africa’s rangelands by reducing productivity and increasing livestock mortality. This study aimed to investigate variability in grazing capacities and stocking rates with respect to land tenure, long-term grazing capacity norms, field surveys, and farmer perceptions during and post-drought conditions in the three biomes in South Africa. In-person interviews and field surveys were conducted with 85 farmers from the Grassland (n = 25), Savanna (n = 35), and Nama-Karoo (n = 30) biomes and vegetation condition was surveyed during or after the drought. Grazing capacity did not differ significantly across land tenure systems in the Savanna biomes (p > 0.05), but significant differences were found in the Grassland and Nama-Karoo biomes (p< 0.05). Over > 60% of farmers in the Nama-Karoo biome rated their rangeland condition as poor because of the drought, and field surveys showed that grazing capacities were four times lower than the national recommended grazing capacity norm. Considering the high inter-annual variability in vegetation productivity and differences in farmers’ perceptions based on local knowledge, it is recommended that the Department of Agriculture adopt flexible grazing capacity ranges in the regulations of the Conservation of Agricultural Resource Act 43 of 1983.
Methane emissions from indigenous nitrogen-efficient bovidae are overestimated
(Nature Publishing Group, 2025) Samuels, Igshaan; Ma, Zhiyuan; Mi, Jiandui
Livestock are vital for global food security, but are a significant source of methane, a greenhouse gas. Breeding for highly efficient nitrogen utilization and lower emissions is therefore a key goal for sustainable agriculture. Here we compared these traits across wild, indigenous, crossbred, and improved bovines via an extensive meta-analysis, supplemented with measurements of 150 yaks. Our results revealed that indigenous bovine produce less methane and have lower urinary nitrogen loss than improved breeds, indicating superior feed conversion and nitrogen efficiency. Notably, crossbreeds also produce significantly less methane, revealing a hybrid advantage for sustainable breeding. Furthermore, our direct measurements showed that methane emissions from yaks were 39% lower than predicted by Intergovernmental Panel on Climate Change Tier2 models, a pattern of overestimation also evident in other indigenous bovines. These findings reveal that well-adapted indigenous breeds are crucial genetic resources, highlighting the need for breed-specific data to guide global mitigation efforts. (Figure presented.)
Genome divergence between European anchovy ecotypes fuelled by structural variants originating from trans-equatorial admixture
(Royal Society Publishing, 2025) Van der Lingen, Carl; Meyer, Laura; Barry, Pierre
The formation of ecotypes is driven by evolutionary mechanisms that reduce gene flow through complex interactions among ecological, historical and genomic factors. In the European anchovy (Engraulis encrasicolus), marine and coastal ecotypes have been identified in the northeast Atlantic and the Mediterranean Sea, yet the genomic basis of their divergence remains unclear. Here, we present the first genome-scale analysis of this species complex, integrating whole-genome sequencing (WGS) and RAD-seq data from populations spanning its distribution range. In addition to the known marine and coastal ecotypes, we identify a previously undetected lineage extending from southern Morocco, through the Canary Islands, to South Africa. This southern Atlantic lineage exhibits a gradient of admixture with northern populations near the Atlantic–Mediterranean transition zone. Genomic differentiation landscapes reveal large regions of high linkage disequilibrium, probably corresponding to 13 structural variants (SVs) segregating within or between lineages. Notably, three of the six SVs contributing to the gene flow barrier between northern ecotypes originated in the southern lineage, supporting a partially shared evolutionary history between the coastal ecotype and the southern lineage. This study highlights how SVs that arose in geographically isolated lineages can act as key genetic elements in ecotype formation, reinforcing reproductive isolation through distinct evolutionary pathways.

Browse

Recent Submissions