Abstract

The worldwide extinction of megafauna during the Late Pleistocene and Early Holocene is evident from the fossil record, with dominant theories suggesting a climate, human or combined impact cause. Consequently, two disparate scenarios are possible for the surviving megafauna during this time period - they could have declined due to similar pressures, or increased in population size due to reductions in competition or other biotic pressures. We therefore infer population histories of 139 extant megafauna species using genomic data which reveal population declines in 91% of species throughout the Quaternary period, with larger species experiencing the strongest decreases. Declines become ubiquitous 32–76 kya across all landmasses, a pattern better explained by worldwide Homo sapiens expansion than by changes in climate. We estimate that, in consequence, total megafauna abundance, biomass, and energy turnover decreased by 92–95% over the past 50,000 years, implying major human-driven ecosystem restructuring at a global scale.

Link: https://www.nature.com/articles/s41467-023-43426-5?fromPaywallRec=false

a Each step line represents changes in Ne with respect to time for a single megafauna species, coloured by a gradient based on average adult mass. The dashed line represents the fit of the piecewise linear model, as determined by breakpoint analysis. The grey-shaded area represents the 95% confidence interval of the linear model prediction. The blue rectangle represents the timespan of realm-specific breakpoints (Supplementary Fig. 2). Both axes are log10-transformed. Credit information for photographs of Antilocapra americana, Elephas maximus, Ursus arctos, Macropus giganteus and Giraffa tippelskirschi are available in Supplementary Table 2. All photographs are under CC-BY copyright (https://creativecommons.org/licenses/by/4.0/) and adapted for the purpose of the figure. b Relationship between species’ adult mass and the rate of population size change (slope). The x-axis is log10-transformed. Points are median slope values with 95% HPDI ranges indicated by bars (each distribution is derived using n = 1000 posterior samples). c Distribution of species’ decline severity. Source Data for this figure are in Source Data 1–4.

Abstract

The timing and causes of the extinction of Pleistocene megafauna are unresolved issues in the natural history of Australia and New Guinea (Sahul). In Australia, megafauna are believed to have become extinct by c. 41ka, but in the Highlands of New Guinea some species persisted until the Last Glacial Maximum (LGM), as late as c. 22ka. Here, we present the first evidence that one of these taxa survived beyond even this timeframe. We describe a manual phalanx from a megafaunal macropodid, probably referable to a quadrupedal, forest-dwelling member of the genus Protemnodon recovered from the Middle Holocene (6.8 - 5.3ka) archaeological deposit of Taora, a coastal rockshelter located west of Vanimo, Papua New Guinea. This late local persistence is likely a consequence of low human populations and a relatively small body size. Its disappearance from the region is coincident with broader decline in local mammalian diversity following post-glacial environmental change. Taora provides the first indication that any of Sahul’s megafauna survived beyond the end of the LGM and highlights geographic and chronological variability in this diverse group’s extinction history.

LINK: https://www.nature.com/articles/s44185-026-00146-5

Abstract

The adaptive strategies of Early Paleoindians associated with the rapid and continent-wide expansions of Clovis and related Fishtail Projectile Point (FPP) complexes in the Americas have been subject to differing interpretations. Were Early Paleoindians megafauna specialists or dietary generalists? These alternative models offer profoundly different implications for Early Paleoindian prey choice, mobility, and technology. We synthesize and evaluate the zooarchaeological records of the earliest widespread cultural manifestations in Eastern Beringia [~14,000 to 13,300 calibrated years before the present (cal B.P.)], North America (Clovis complex, ~13,400/13,050 to 12,800 cal B.P.), and South America (FPP complex, ~12,900 to 11,600 cal B.P.) and summarize their adaptive strategies. Zooarchaeological, technological, and mobility data strongly support the megafauna specialization model. All three groups obtained most of their food from megaherbivores (>1000 kg): woolly mammoth in Beringia, Columbian mammoth in North America, and giant ground sloths and gomphotheres in South America. Focus on megaherbivores facilitated rapid human expansion into different ecosystems before the time-transgressive extinction of megafauna led to regional diversification through adaptations to locally available resources.

LINK: https://www.science.org/doi/10.1126/sciadv.aef9628?__cf_chl_f_tk=9VepWN.9S7rwQLuSxVzXLwdtsZH85OInxUeSWrM05.8-1783018485-1.0.1.1-T5UvMvT69SUWkE6Y9pdDSqDq8EeyrrxdZfkqFGvK_qs

Faunal sample locations for Beringia, North and South America, and Clovis and Fishtail Projectile Point–related distributions.Point geolocations from (50, 75, 88, 204). Insets: faunal abundance proportions, MNI and total edible biomass (ΣMNI × edible biomass) for each taxon and size class. Clovis and Fishtail Fluted Point habitat derived from Habitat Suitability analyses (205), ranging from 1 to 0 (see section S3 for details). Sites: 1, Broken Mammoth; 2 and 3 Holzman South C5a and C5b; 4, Keystone Dune; 5, Little John; 6, Shég’ Xdaltth’í’; 7, Mead; 8, Swan Point; 9, Wally’s Beach; 10, Colby; 11, Lange-Ferguson; 12, La Prele; 13, Dent; 14, Boaz Mastodon; 15, Hiscock; 16, Martins Creek; 17, Kimmswick; 18, Jake Bluff; 19, Domebo; 20, Aubrey; 21, Lewisville; 22, Gault; 23, Kincaid Shelter; 24, Miami; 25, McLean; 26, Blackwater Draw; 27, Lubbock Lake; 28, Murray Springs; 29, Escapule; 30, Lehner; 31, Leikem; 32, Naco; 33, Fin Del Mundo; 34, Quebrada Santa Julia; 35 to 37, Tagua Tagua 1, 2, and 3; 38, Pay Paso; 39, Campo Laborde; 40, Cueva Tixi; 41, Cerro La China; 42, Paso Otero; 43, Piedra Museo; 44, Cerro Tres Tetas; 45, Cueva Tunel; 46, Casa Del Minero; 47, Cueva Lago Sofia; 48, Cueva del Medio; 49, Fell Cave; and 50, Tres Arroyos. Exposed Pleistocene land areas (at 77 m below sea level) from (206), and glacial ice (at 13,500 cal B.P.) from (207). South American glaciers (at 13,000 cal B.P.) from (208).

Abstract

1. The global decline of apex predator populations risks the loss of their crucial ecological functions. This raises a pressing yet contentious question: can human hunters, often termed ‘super-predators’, functionally substitute for the complex regulation once provided by their natural counterparts?
2. To investigate this question, we analysed 30,778 camera-trap records from 400 sites in southwestern China (2017–2021). Using propensity score matching (PSM) to control for environmental heterogeneity, we compared wildlife communities across hunter-dominated, apex predator-dominated, and predator-absent sites.
3. Our results showed that hunters fail to replicate the collective and individual ecological functions of natural apex predators (dhole, Asian golden cat, and clouded leopard). Apex predator sites supported the highest species richness and abundance, with 33.0% and 32.5% more species and 49.8% and 44.8% greater abundance than hunter-dominated and predator-absent sites, respectively. The prey species–site network was the most robust at apex predator sites and the weakest at hunter-dominated sites, indicating that hunting increases prey vulnerability to cascading extirpations following habitat loss.
4. Compared with hunter-dominated sites, sites dominated by single-apex predators had distinct species compositions and dominant prey. Prey exhibited prolonged avoidance (up to 2.6 times longer) of hunters compared with any apex predator, coinciding with the weakest network robustness at hunter-dominated sites.
5. Collectively, our findings provide compelling evidence that human hunters cannot replace apex predators in sustaining biodiversity and promoting stable spatial patterns. Our work therefore strongly supports the conservation of natural apex predators and offers crucial insights for regulating human hunting in ecosystem management.

LINK: https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2656.70306

Highlights

• • Individual anthropogenic threats differ in their severity across functional groups.
• • Crops and livestock most affected bird and mammal vertivores.
• • Pollution and climate change most affected bird and mammal aquatic predators.
• • Logging most affected bird frugivores and mammal frugivore/granivore/nectarivores.
• • Specific threats must be targeted to conserve specific ecosystem functions.

Abstract

Anthropogenic threats vary in how they affect individual species, functional diversity, and consequently, ecosystems as a whole. However, which groups of species are most affected by specific threats remains poorly understood. To evaluate which bird and mammal functional groups are most affected by specific threats, we use data aggregated by the International Union for Conservation of Nature (IUCN) to calculate the extent to which diet functional groups and body size explain the global impacts of the most common anthropogenic threats. For both birds and mammals, we found that terrestrial vertivores, aquatic predators, and frugivores (including mammalian nectivores and granivores) are most negatively impacted by anthropogenic threats, with crops and livestock as the top threats to vertivores, climate change and pollution for aquatic predators, and logging for the frugivores. Threats associated with plantations and recreation/work affect less than 5% of species across functional groups. Body mass is positively correlated with the impact of anthropogenic threats especially for hunting, such that larger species are substantially more threatened by hunting than smaller species. Our results reveal that bird and mammal vulnerabilities vary by diet functional group, body mass, and the type of anthropogenic threat. Given our findings that functionally important groups (i.e., predators and frugivores) are disproportionately impacted by multiple anthropogenic threats, and that individual threats differ in their severity across functional groups, we recommend targeting conservation actions to mitigate threats in a manner that will preserve critical ecosystem functions.

Link: https://www.sciencedirect.com/science/article/pii/S2351989426002416

Percent of birds (top) and mammals (bottom) negatively impacted by each anthropogenic threat with medium and high impact scores. Threats are arranged on the x-axis from least to most species impacted.

Probability that a mammal species in each functional group is negatively impacted by each anthropogenic threat. Mean probability is shown with 95% credible intervals in brackets. Functional groups in the legend (black silhouettes) are arranged left to right from lowest to highest mean body mass. A dash indicates that no species in the functional group were affected by the threat. Silhouettes were obtained from Phylopic (www.phylopic.org).

Probability that a bird species in each functional group is negatively impacted by each anthropogenic threat. Mean probability is shown with 95% credible intervals in brackets. Functional groups in the legend (black silhouettes) are arranged left to right from smallest to largest mean body mass. A dash indicates that no species in the functional group was affected by the threat. Silhouettes were obtained from Phylopic (www.phylopic.org).

Abstract

Grazing represents one of the most widespread land-use practices, and impacts plant diversity in grassland. In this study, we aim to examine its impacts on plant diversity and underlying regulatory mechanisms. We conduct a comprehensive meta-analysis of 1160 paired observations from 112 studies to synthesize grazing effects on plant diversity, and its environmental dependence in grassland ecosystems. Grazing decreased plant species richness by 3.99% while increasing functional diversity (Rao's quadratic entropy) by 18.20%. Grazing significantly altered community-weighted mean (CWM) trait values, reducing plant stature by 27.87% and leaf dry matter content by 5.86%, but increasing specific leaf area by 14.99%. Crucially, we found that the magnitude and direction (positive or negative) of grazing effects were strongly moderated by environmental context: prolonged grazing duration and small-bodied livestock exacerbated richness loss, particularly under low mean annual precipitation (<400 mm) and temperature (<5 °C) conditions. Elevation emerged as a key moderating variable, exhibiting distinct moderating patterns from climatic factors. Notably, mean annual precipitation (MAP) fundamentally altered the direction of grazing duration effects on both specific leaf area and leaf dry matter content. These results demonstrate that grazing effects on grassland plant communities are fundamentally context-dependent, varying across biodiversity dimensions and environmental gradients. Our findings provide critical insights for developing spatially explicit, sustainable grassland management strategies that account for these complex interacting factors in the face of environmental change.

Link: https://www.sciencedirect.com/science/article/pii/S1470160X26003687

Abstract

Seed-dispersing mammals play essential roles in forest regeneration, landscape connectivity, and the maintenance of plant diversity. Understanding the impacts of climate change on these species is critical, particularly in highly threatened ecosystems such as tropical seasonally dry forests. Here, we assessed how projected climate change could affect the distribution of 87 seed-dispersing mammal species within the Mesoamerican seasonally dry forests and estimated their vulnerability by integrating multiple metrics of climatic exposure and range-shift capacity. Potential distributions were modeled under current and future climates (2040s–2080s), considering two socio-economic pathways (SSP3-7.0 and SSP5-8.5). We quantified losses, gains, and stable areas under assumptions of species dispersal (contiguous or non-dispersal). Additionally, we applied a synthetic risk syndrome approach based on exposure and predictive traits and evaluated whether projected percentage changes in species distributions were associated with threat category and geographic range size. Our models indicate that many seed-dispersing mammals may experience range contractions: on average, 75 species’ ranges contracted, while 12 remained stable or expanded. Around 30% of species, most of them endozoochorous, were found to be highly vulnerable due to high climatic exposure and low range-shift capacity. Notably, even species currently classified as Least Concern and those with broad distributions may be negatively affected by climate change. Two species (Peromyscus aztecus and Sciurus aberti) showed consistent signals of potential local extirpation. These findings underscore the urgent need to incorporate climate change considerations into conservation and restoration strategies for Mesoamerican seasonally dry forests to safeguard key ecosystem functions.

Link: https://link.springer.com/article/10.1007/s10113-026-02595-x

Summary of risk syndrome categories for the 87 seed-dispersing mammal species associated with Mesoamerican seasonally dry forests. Seed dispersal modes (endozoochorous and scatter-hoarding species) and taxonomic families for each species are indicated with square brackets on both sides of the figure

Significance

The loss of frugivores and their seed dispersal abilities can have detrimental effects for plant communities that depend on them, especially on islands where functional diversity is low. Here, we use a combination of field observations and a dataset of fruit–frugivore functional traits in the Caribbean islands to evaluate the current and future status of seed dispersal interactions if currently threatened large frugivores become functionally extinct. We demonstrate that size traits are significantly related to extinction threat in frugivores and plants. Furthermore, based on empirical and trait-based projections using fruit–gape size matching, we show that large-fruited plants experience severe dispersal limitations, and demonstrate that loss of frugivores is associated with a fourfold increase in extinction risk of large-fruited plant species.

Link: https://www.pnas.org/doi/abs/10.1073/pnas.2535192123

Abstract

Interactions between humans and megafauna have long been central to debates on late Quaternary extinctions, but how these interactions have been documented across the literature remains poorly synthesized. Here, we present the first global scientometric and systematic review of empirical records of human–megafauna interactions. Using the Web of Science (WoS) database, publications identified through backward and forward citation chasing, and an extensive search of grey literature in multiple languages, we identified 537 publications containing empirical evidence: 152 killed/butchered or scavenged sites (KBSS), six rock art records, and two trackways. Over the past 70 years, studies on KBSSs have increased steadily, whereas rock art and trackway publications have remained limited to the years of their discovery. Research output is heavily concentrated in economically developed countries, particularly the USA (174 publications), Russia (42), and Germany (40), with limited contributions from Africa, Asia, and parts of South America. These patterns reveal substantial publication, geographic, and economic asymmetries shaping how human–megafauna interactions are documented. The database compiled here provides the first global empirical baseline for these interactions and offers a robust tool for investigating their spatial, temporal, and behavioral patterns in the late Quaternary.

Link: https://www.sciencedirect.com/science/article/abs/pii/S2352409X26002865

Editor’s summary

Large mammalian herbivores play key roles in ecosystems and are vulnerable to extinction from hunting and global environmental change. Loss of such species is expected to cause further extinctions, but this pattern has mainly been shown through simulations. Gijsman et al. combined simulations with experimental evidence to show that loss of elephants would lead to coextinctions of dung beetles and decreases in the dung decomposition and secondary seed dispersal that beetles provide (see the Perspective by Lewis and Slade). In the field, excluding elephants reduced dung beetle abundance and diversity, whereas excluding other mammalian herbivores had little additional effect. These results aligned with the central role of elephants in an empirically derived ecological network and support the designation of elephants as a keystone species in African savannas. —Bianca Lopez

Link: https://www.science.org/doi/10.1126/science.aeb7062

Elephant (Loxodonta africana) dung is disproportionately used by dung beetles, making elephants a central node in the mammal–dung beetle network. Experimental plots selectively excluded herbivore species by size, showing that elephants’ centrality predicts the outsized impact of their loss, including steep declines of dung beetle abundance, diversity, and ecosystem services. [Credit to Phylopic for the herbivore and beetle silhouettes]

https://eprints.whiterose.ac.uk/id/eprint/240972/1/Conservation%20Biology%20-%202026%20-%20Trepel%20-%20Reevaluating%20introduced%20herbivores%20in%20conservation.pdf

Highlights

• • Diet composition differed among fragmented Atlantic Forest landscapes.
• • Anthropized landscapes showed broader realized trophic interaction profiles.
• • Native fruits and small mammals dominated the less disturbed landscape.
• • Diet shifts reveal trophic plasticity in Atlantic Forest food webs.

Abstract

Omnivorous carnivores can alter their trophic role across human-modified landscapes by shifting the diversity and composition of resources they consume. Such changes may influence how these consumers are embedded in local food webs, particularly in fragmented tropical ecosystems where resource availability is strongly shaped by landscape structure. We investigated diet composition of the maned wolf (Chrysocyon brachyurus) across three Atlantic Forest landscapes in southeastern Brazil that differed in forest cover, fragmentation, and anthropogenic disturbance. A total of 77 fecal samples were collected from latrine sites between May and December 2025, and food items were identified to the lowest possible taxonomic level. We tested whether diet composition differed among landscapes and evaluated how trophic links varied along with the disturbance gradient. Diet composition differed significantly among landscapes and was dominated overall by fruits and small mammals. However, more anthropized landscapes showed a broader set of consumed resources, including insects, exotic fruits, and disturbance-tolerant plant species, whereas the less disturbed landscape was characterized by stronger use of native fruits and vertebrate prey. These results suggest that landscape anthropization can modify the trophic role of a generalist carnivore by expanding or concentrating on the set of trophic interactions it establishes. In fragmented Atlantic Forest mosaics, the maned wolf may function as a flexible trophic connector, linking native and anthropogenic resources across landscapes. Our findings highlight how landscape context can reshape trophic interaction patterns of a mobile omnivore, with implications for seed dispersal and predator–prey dynamics in human-modified food webs.

LINK: https://www.sciencedirect.com/science/article/abs/pii/S2352249626000170

Abstract

1. Although animal reintroductions are a cornerstone of conservation practice, the effectiveness of distinct release strategies remains debated. Soft-release, involving pre-release acclimatisation in enclosures, is often assumed to improve outcomes over hard-release, but evidence is inconsistent.
2. We propose that variation in acclimatisation duration, rather than release type alone, may explain these discrepancies. Using GPS telemetry data from the extensive Iberian lynx (Lynx pardinus) reintroduction programme—spanning multiple sites across its distribution range and individuals of varying ages, sexes and origins—we evaluated how acclimatisation period length and release strategy influence post-release movement and settlement.
3. We found that prolonged acclimatisation significantly reduced long exploratory movements and increased the probability of settling within the targeted area, while release type alone had no significant effect. This demonstrates that time spent in the enclosure, rather than the use of soft-release per se, drives early-stage reintroduction effectiveness.
4. The greatest benefits were achieved after approximately 6 weeks of acclimatisation, marking the point at which settlement probability exceeded 50% for all groups. Beyond this threshold, additional time in the enclosure provided diminishing returns, offering a practical benchmark for future releases.
5. Synthesis and applications. Our study highlights that when acclimatisation periods are too short, the substantial economic and logistical investment in soft-release protocols may fail to deliver the expected conservation gains. Therefore, defining evidence-based acclimatisation periods that are long enough to promote settlement, yet compatible with logistical constraints, may provide valuable guidance for reintroduction planning. More broadly, our findings identify acclimatisation duration as a promising factor to evaluate in other carnivore reintroduction programmes, which may likewise benefit from incorporating such assessments into their planning and design.

LINK: https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2664.70402

Abstract

We present the first detailed neuroanatomical study of Megantereon cultridens, a key member of the sabertoothed tribe Smilodontini, based on digital endocasts obtained via computed tomography of three fossil skulls from Spain, Italy, and France. Through qualitative anatomical description, regional brain volume estimation, and 3D geometric morphometrics, we assess the neuroanatomy of this extinct felid in comparison with extant pantherine and feline species. In comparison to modern felids, the endocranial morphology of M. cultridens reveals a rostrocaudally compressed cerebrum, a relatively enlarged frontal lobe, short olfactory tracts, and a diverging sulcal pattern, particularly in the configuration of the sulcus ectosylvius. While the absence of a distinct gyrus intersylvius suggests a reduced auditory cortex, the expanded occipital cortex may indicate enhanced visual processing. The expanded cerebellum indicates a preference for closed environments and scansorial abilities for this genus. Finally, all performed analyses place M. cultridens in an intermediate position between Felinae and Pantherinae in brain shape morphospace, with closest affinities to ecologically flexible extant species such as Puma concolor and Panthera onca. Our findings support the hypothesis that M. cultridens possessed a generalized neuroanatomical profile, likely associated with behavioral plasticity and ecological versatility in the Early Pleistocene European ecosystems characterized by a high degree of intraguild competition and an especially high diversity of medium to large felids.

Link: https://anatomypubs.onlinelibrary.wiley.com/doi/10.1002/ar.70213