Ecology and Evolution最新文献

Pacific sea turtle populations primarily inhabit subtropical and tropical waters, making sightings at the edge of their range in colder high-latitude regions of the Canadian Pacific particularly uncommon and even rare. This paper presents a comprehensive summary of known occurrences in British Columbia waters from 1931 to 2024, featuring demographics, spatiotemporal distribution, and pathological findings. The dataset contains 247 sea turtle records from four species including 77 previously unpublished records. Leatherback sea turtles (Dermochelys coriacea) were the most frequently sighted, followed by hard-shelled sea turtle species: 34 green (Chelonia mydas ), three loggerhead (Caretta caretta), the first five olive ridley reports (Lepidochelys olivacea), and 54 unidentified sea turtles. Leatherbacks were primarily observed free-swimming, whereas almost half of the hard-shelled sea turtles were found dead or cold-stunned. This difference may be attributed to the inability of hard-shelled sea turtles to thermoregulate in high latitude waters. Although leatherback sightings predominantly occurred July through October, hard-shelled sea turtle records were distributed widely across all months of the year. There were 16 records involving human interactions, of which 75% were attributed to entanglement in fishing gear. Given the rarity of these occurrences and the conservation status of most sea turtle populations, these records provide important insights into high-latitude habitat use and threats, informing future monitoring and recovery efforts for these at-risk species.

White sharks undergo pronounced ecological and dietary shifts across ontogeny, and their teeth play a central role in mediating these changes. Understanding the complexity within shark tooth and jaw mechanics, plus the fine-scale tooth morphology, can provide insights into how feeding strategies and, hence, dietary niches and ecological function evolve with age and size. These morphological changes underpin ontogenetic niche shifts, revealing how functional adaptations in dentition enable white sharks to exploit different prey resources throughout development. This study provides novel insights into the ontogenetic and positional variation in C. carcharias dentition, integrating both Elliptic Fourier Analysis (EFA) and traditional morphometric approaches. We reveal significant patterns of tooth morphology that vary with jaw position and ontogenetic stage, reflecting functional adaptations to changing dietary and biomechanical demands. A key ontogenetic shift was identified as teeth transitioned from narrow, cuspidate forms with accessory cusplets in juveniles to broader, serrated teeth in larger individuals. We found no significant differences in tooth morphology between sexes, aligning with known similarities in diet and body shape in the eastern Australian white shark population. Significant anterior-to-posterior variation in tooth form was observed within the jaw, with lateral teeth becoming more compressed and recurved, suggesting functional transitions in prey handling throughout the jaw. Additionally, we documented structural changes in jaw morphology at approximately 210 cm PCL, corresponding to broader teeth and increased bite capacity. These shifts likely reflect developmental milestones in feeding capability, supporting the transition from a solely piscivorous diet to the inclusion of marine mammal prey.

Artificial sulfur (S) and nitrogen (N) addition experiments often fail to accurately simulate acid deposition in terms of type, composition, intensity, frequency, and duration, potentially leading to biased estimates of deposition impact on plant diversity. Consequently, studying plant diversity patterns around acid emission sources provides a more reliable alternative. Yet, this approach remains understudied in field research, particularly in saline-alkaline regions where high soil buffering capacity may attenuate plant sensitivity to acid deposition. Therefore, we investigated plant functional diversity (PFD) and analyzed its influencing factors in a desert coal-mining region in northwestern China characterized by high pH, abundant CaCO₃ content in soils, and increasing acid deposition. The plant communities were characterized by high leaf thickness, low specific leaf area, and limited leaf total carbon (C) and N concentrations, indicating the preference of the plant communities for a slow investment-returning ecological strategy in the study region. In this context, leaf traits (e.g., thickness and total C and N concentrations), rather than PFD, played a major role in stabilizing plant communities. The intensity of S and N deposition had no effect on PFD. In contrast, exchangeable cation (BC) deposition directly reduced the functional richness, functional dispersion, and the Rao's indices, possibly by exacerbating soil salinity and alkalinity in the study region. Our findings indicate that PFD is mainly influenced by BC deposition in saline-alkaline coal-mining regions. Therefore, the potential risk of BC deposition, which accompanies acid deposition, posed on plant diversity should not be overlooked in these regions.

Monitoring the health of cetaceans is challenging as traditional approaches including vessel-based surveys and necropsies are often opportunistic and limited in their ability to detect subtle physiological changes. Infrared thermography (IRT) offers a non-invasive alternative by detecting surface temperature anomalies that may reflect localised physiological variation, including changes associated with inflammation, scarring, tissue disruption or thermoregulatory processes. Mounted on drones, IRT can enable remote thermal imaging of free-ranging individuals. This case study presented preliminary observations from the exploratory use of drone-IRT to detect localised thermal anomalies in the skin of bottlenose dolphins (Tursiops truncatus) under human care. A total of 14 adult dolphins were monitored across the Austral summer and winter, with two individuals exhibiting consistent thermal hotspots 3°C–5°C warmer than surrounding body surface temperatures. One individual exhibited a transient anomaly that resolved over time, whereas the other displayed persistent hotspots that became more pronounced. These anomalies corresponded with external markings, suggesting localised alterations in skin surface thermal patterns. This case study provided preliminary evidence that drone-IRT can detect localised thermal anomalies in a dolphin's skin and highlights the potential for drone-IRT as a non-invasive tool for monitoring health in both managed and wild dolphin populations. Further quantitative investigations with larger sample sizes and concurrent veterinary assessments may provide validation regarding such observations and to evaluate whether such anomalies are indicative of underlying health issues.

Accurate information underpins successful ecological science and management. Cryptic species, those that are difficult to differentiate, pose challenges to reliable collection of taxon-specific information. Blackbirds, including tricolored blackbirds (Agelaius tricolor), a cryptic species of high conservation concern, and red-winged blackbirds (Agelaius phoeniceus), an abundant congener, are sometimes killed by wind turbines. We used publicly available survey records to evaluate rates at which blackbirds were reported dead at wind energy facilities in California, USA. We then used genetic species identification of carcasses found to estimate true rates of discovery and of misidentification. Of 329 blackbird fatalities in survey records, most were identified as red-winged (n = 149), “unidentified” (n = 90), or Brewer's (Euphagus cyanocephalus; n = 70); only 13 were identified as tricolored. We also genetically analyzed samples from 40 blackbirds. Of 14 carcasses identified in the field to species, two, including one tricolored, were incorrectly called Brewer's blackbirds (14% misidentification rate). Of the 26 birds called “unidentified blackbird” in the field, 17 (65%) were tricolored, leading to a 19× underestimation of true fatality rate. The state-wide population of tricolored blackbirds is < 1% the size of that of red-winged blackbirds. A large proportion of blackbirds found dead were actually tricoloreds, indicating that fatality rates of this state threatened species may be substantially underestimated. The potential for misidentification or nonidentification may create perverse incentives that undermine conservation and have consequences for on-the-ground management, mitigation, and operations of high-priority infrastructure.

Guizhou Province, China, experienced two extreme drought events during the periods of autumn to spring 2009–2010 and spring to autumn 2011. These events, classified as “one-century drought,” led to severe water shortages, significant declines in crop yield, and substantial socioeconomic losses. Despite the evident impact, the heterogeneity of vegetation responses, measured using the Normalized Difference Vegetation Index (NDVI), across different vegetation types and landforms in this region remains insufficiently quantified. Therefore, this study investigates the spatiotemporal evolution of these two events and evaluates the differential NDVI responses of vegetation using multiple climatic datasets and remote sensing-derived vegetation indices. Results indicate that both drought events reached severe levels and persisted for approximately 8 months. The southwestern and western parts of Guizhou Province were hit the hardest. The 2009–2010 drought exerted a more pronounced inhibitory effect on vegetation growth, as evidenced by significantly greater reductions in NDVI during the spring season. Analysis across five major vegetation types showed universal declines in NDVI anomalies, with meadows experiencing the most severe suppression, followed by scrublands, broadleaf forests, and grasslands. Needleleaf forests exhibited the highest drought tolerance. In contrast, the 2011 drought had a comparatively milder impact on vegetation dynamics. Notably, certain vegetation types, particularly broadleaf forests, displayed sustained greening even under drought conditions. Furthermore, vegetation growing on karst landforms exhibited more pronounced declines in greenness compared to those on non-karst landforms, highlighting the influence of geological substrates on drought sensitivity. These findings suggest that under conditions of extreme drought severity, alterations in hydrothermal conditions significantly affect vegetation response patterns across both vegetation types and landform categories. This study provides important insights into the ecological impacts of drought in karst-dominated regions and offers a scientific basis for formulating drought risk management strategies and ecological conservation policies in Guizhou Province.

Maintaining subsistence species on hunting lands is essential to the food security and cultural preservation/flourishing of Indigenous peoples that rely on traditional foods. In northern North America, moose play a central role in subsistence, cultural, and stewardship practices but are declining in many parts of their range. Moose (Alces alces) in Minnesota are a threatened population that is integral to the lifeways of the Lake Superior Chippewa. This study, led by the Grand Portage Band, examines the shifting causes of adult moose mortality between 2010 and 2022 on the Grand Portage Indian Reservation and Voyageurs National Park. These efforts, rooted in principles of Indigenous sovereignty and co-stewardship, seek to sustain this vital species on ancestral lands. We observed that the relative importance of mortality causes varied over time, with Parelaphostrongylus tenuis and other health-related factors driving mortality during the initial decline period (2010–2014), while predation became a leading cause of mortality and quadrupled in probability during the stabilization period (2015–2022). Using a Bayesian framework, we integrated multiple contributing factors to accurately estimate cause-specific mortality probabilities and survival rates. The findings underscore the necessity for adaptive management strategies that address both parasitism and predation pressures to recover moose populations to pre-decline levels. Moreover, this study exemplifies how a long-term, Indigenous-led wildlife collaring and monitoring program is critical to capturing these dynamics and supporting the Grand Portage Band's ongoing stewardship. This research advances our understanding of moose mortality in a vulnerable population and reinforces the importance of Indigenous leadership in wildlife management and scientific co-production. By integrating traditional ecological knowledge found in Tribal-governmental planning documents with contemporary science led by their Natural Resources Management department, the Grand Portage Band is ensuring that moose remain a resilient and enduring part of their cultural and subsistence practices, thus contributing to the broader framework of Indigenous co-stewardship.

Campus green spaces are vital components of urban green infrastructure, providing crucial habitats for wildlife, especially birds, in fragmented urban environments. However, their role in supporting nocturnal bird habitats remains underexplored. This study investigates nocturnal bird roosting habitat selection in the green spaces of a university campus in western China. The seasonal surveys were conducted along fixed routes to track the distribution of birds' nocturnal roosts on campus. Infrared hotspots were detected using thermal imaging night-vision cameras. Roosting tree species were identified, and roosting point heights were estimated visually. The survey results identified eight nocturnal roosting sites and common campus vegetation, which were used for in-depth analysis of bird roosting habitat characteristics. The study found that: (1) Campus birds preferred Ficus concinna and Ficus virens (93% selection rate), especially those with dense foliage and high concealment. (2) Birds showed seasonal variations in their roosting positions. In summer, they were more dispersed, while in autumn and winter, they concentrated vertically. Horizontally, they preferred the outer ends of branches away from the trunk. (3) The number of infrared (thermal) hotspots corresponding to birds' nighttime roosts was significantly higher in summer than in the other seasons. Based on these findings, the paper proposes strategies to optimize campus green space management, including the targeted planting of tree species, adjustments to vegetation structure, and the reduction of excessive branching to enhance nocturnal roosting sites. This research offers valuable insights into the nocturnal behavior of urban birds and provides practical recommendations for urban planners and conservationists to promote biodiversity-friendly urban design and management policies.

The Mexican tetra (Astyanax mexicanus) has emerged as a leading model for evolutionary biology and the study of adaptation to extreme subterranean environments. The river-dwelling morph of the species is distributed in Mexico and Texas, while the blind and cave-adapted morph inhabits the karstic caves of the Sierra Madre Oriental in northeastern Mexico. The molecular, cellular, and genetic underpinnings of Astyanax cavefish evolution are increasingly studied, but our understanding of its habitat and environment is incomplete, limiting the interpretations of its morphological, physiological, and behavioral adaptations. Notably, knowledge on the physicochemical parameters of the water is dispersed, and the hydrological regimes to which cavefish are subjected are largely unexplored. From 2009 to 2025, we have recorded the physicochemical parameters of the water at localities hosting A. mexicanus cavefish and surface fish in the Sierra de El Abra and Sierra La Colmena regions of the states of San Luis Potosí and Tamaulipas, Mexico. We sampled 13 caves out of the 33 known Astyanax caves and 30 surface stations (rivers, springs, ponds). Data were collected using a variety of devices and probes, including both point measurements (at the end of winter) and longitudinal measurements (throughout the year). The comparison of epigean and hypogean waters showed strong signatures of these two macrohabitats. As compared to surface, on average cave water was cooler, much less conductive, and highly hypoxic. Moreover, a comparison between different caves (i.e., mesohabitat level) revealed significant differences in both specific water parameters and hydrological regimes. One- or two-year longitudinal recordings demonstrated that some caves exhibit relatively stable hydrological regimes, while others experience multiple, sudden, and significant fluctuations. Finally, distinct pools within a single cave showed notable differences, displaying a reproducible increasing gradient in water temperature as a function of distance from the cave entrance, and revealing specificities at the microhabitat level. We interpret our comprehensive dataset on cave water quality and hydrodynamics in the context of an integrated view of cave biology and the evolution of cave organisms.