Ecology and Evolution最新文献

Alternanthera pungens Kunth is considered to be less invasive compared to its exotic congener A. philoxeroides (Mart.) Griseb. However, in recent 10 years, it has spread rapidly in Yunnan Province, China. To better understand the species' invasion and distribution, we simulated the potential distribution of A. pungens in China using a MaxEnt model under the current climate scenario and several future climate scenarios, with varying emissions and time frames. The model achieved excellent prediction performance, with A. pungens having an area under the curve value and true skill statistics value of 0.979 and 0.910, respectively. Temperature seasonality and mean temperature of coldest quarter were the greatest predictive environmental variables, with a cumulative contribution of more than 85.3% and a cumulative permutation importance of more than 89.8%. The suitable geographic region of A. pungens is concentrated in southern China. Under the current climate scenarios, projected areas ranked as highly and moderately suitable for A. pungens accounted for 0.31% and 1.03% of the Chinese mainland area, respectively. Under future climate scenarios, the suitable areas for A. pungens in China will expand northwards, with a maximum projected growth rate of 41.4% in the 2070s. This study was the first to show that A. pungens is predicted to expand its range in China in the future. Early warning and monitoring of A. pungens should be pursued, with greater vigilance in southern China to prevent its further spread and invasion.

The occurrence of climate change-induced hypoxia, that is, low dissolved oxygen levels in water, is increasing at an unprecedented rate. When organisms cannot escape, they must cope through plasticity, within or across generations, or even locally adapt. Documenting all these responses is essential to better understand the populations' capacity to persist in changing environments over generations. Therefore, two populations of sticklebacks (Gasterosteus aculeatus), one exposed to frequent hypoxia in the wild and one not, were bred for two generations, exposing offspring to either normoxia or daily fluctuating hypoxia (35% DO at night). When exposed to hypoxia within a generation, fish were less social and took fewer risks. However, fish from the population previously exposed to hypoxia in the wild were, on the contrary, more social and took more risks while also decreasing standard metabolic rate and growth, showing signs of adaptation. Fish also showed adaptation of their plasticity by losing plasticity for their hypoxia tolerance thresholds. No intergenerational plasticity was revealed. Overall, our study revealed that fish were able to cope with hypoxia within and across generations mainly through within-generation plasticity on behaviour, potentially giving time before adaptation could take place.

Bones of dead animals are consumed by many species, yet the partitioning of this resource, and the associated ecological and evolutionary implications, remains poorly understood. Using bone modification features found on shed female caribou (Rangifer tarandus) antlers and skeletal bones lying on caribou calving grounds of the Arctic National Wildlife Refuge (Alaska), we evaluated resource partitioning by co-occurring ungulates, carnivorans, and rodents. We found that 86.4% of shed antlers were modified by animals and that caribou were the dominant modifiers (99%); rodent (3.5%) and carnivoran (0%) modifications were rarely observed. Conversely, 44.2% of skeletal bones showed modifications, most of which were attributable to carnivorans (91.9%), and only rarely to caribou (12.1%) and rodents (1%). Carnivoran preferences for skeletal bones over shed antlers are consistent with their proclivity for the bones of recently dead animals, which are rich in fats and associated soft tissues. Ubiquitous ingestion by caribou of their population's shed antlers indicates the importance of a rarely recognized nutrient resource during the calving and post-calving intervals and offers new insights into the biological benefits of female caribou antlers. Caribou are the only cervid for which females grow antlers. In migratory populations, females shed their antlers after reaching their calving grounds and within only days of birthing their young. Pervasive antler consumption by caribou suggests that synchroneity between birthing and antler shedding evinces the importance of nutrient (Ca, P) transport for supporting calf survival and that osteophagy may have contributed to the evolution and maintenance of antlers in female caribou, along with their peculiar shedding schedules. Antler accumulations may also contribute to calving ground fidelity by establishing a predictable mineral reservoir in nutrient-poor settings.

Arthropod DNA barcode reference libraries have advanced ecological research but remain incomplete in many areas, including the western United States. To improve coverage in the Northern Rocky Mountains, we developed the MPG Ranch Arthropod Library (MPG-AL), a cytochrome oxidase I (COI) DNA barcode reference library for local arthropods in west-central Montana. From 2017 to 2019, we collected 86,533 specimens from various habitats, generating 52,270 DNA barcodes for arthropod taxa from 38 orders, 389 families, 1668 genera, and 1793 species. A comparison of the MPG-AL taxonomic coverage with a combined dataset of publicly accessible Montana arthropod DNA barcodes in the Barcode of Life Database (BOLD) and Montana Natural Heritage Program occurrence records revealed that the MPG-AL added references representing 5154 Barcode Index Numbers (BINs) to BOLD. These additions mark a 280% increase for Montana arthropod DNA barcodes, including 1140 new BINs for taxa previously lacking reference barcode sequences in BOLD. The MPG-AL provides a substantial foundation for establishing a comprehensive arthropod DNA barcode database in the Northern Rocky Mountain ecoregion. However, many taxa still lack reference barcode sequences, particularly in large, diverse insect orders. Future barcoding efforts are encouraged to expand regional taxonomic coverage through targeted sampling and collaborations with regional entomological collections. A comprehensive regional arthropod DNA barcode library will enhance our understanding of arthropod population trends and trophic relationships in the western United States amid persistent threats such as climate change, habitat loss, pesticides, and invasive species.

Bull Sharks are circumtropical top predators able to tolerate a wide range of salinity conditions that include freshwater. In several areas of Central America this species is known to migrate upstream in rivers and is commonly found in freshwater. The Panama Canal, an engineered system critical for global shipping, has experienced repeated marine fish incursions into Lake Gatun, the freshwater portion of the system, since it opened over 100 years ago. With increased numbers of species and abundance of these marine migrants into the system it is surprising that no credible reports of Bull Sharks have been made to date. Here we present the first confirmed report of a Bull Shark captured in Lake Gatun, 30 km from the Pacific entrance of the Canal. Analyzing its DNA barcode and vertebral morphometrics and chemistry, we were able to infer the origin (Pacific Ocean), the total length and age (120-150 cm, 2-3 year old) and likely pupping of this shark in low salinity areas adjacent to the Canal. The recent capture of more bull sharks by the artisanal fisher who collected the study shark and a video of sharks at the seaward entrance to the new Pacific locks indicates that there is the potential for increased contact between Pacific and Atlantic Bull Shark populations through the Panama Canal.

[This corrects the article DOI: 10.1002/ece3.5802.].

[This corrects the article DOI: 10.1002/ece3.72578.].

Ticks (Ixodida) are ecologically and epidemiologically important parasites, yet their diversity, host associations, and environmental drivers remain poorly resolved in many parts of the world, including subtropical and urban Hong Kong. Here, we combined wet-season spatial surveys (23 sites in 2023) with monthly temporal sampling (four sites across 11 months in 2024) to characterize the spatiotemporal dynamics of ticks in Hong Kong. Ticks were collected using standardized drags, CO² traps, and opportunistic sampling; adults were identified morphologically and validated via COI barcoding. Vertebrate host use was inferred through iDNA metabarcoding of tick abdomens. Our findings provide the first documented widespread occurrence of Haemaphysalis hystricis and Haemaphysalis formosensis in Hong Kong. Additionally, we provide initial insights into local life stage-specific seasonality dynamics, whereby adult peaks in late winter-spring, nymphs are elevated in the cool dry months, and larvae noticeably surge during the wet season. In assessing the potential environmental drivers, adult abundance was most strongly associated with moisture (relative humidity and dew point). Presence-only models suggested additional contributions from porcupine (Hystrix spp.) occurrence and temperature. iDNA analysis suggests primarily mammalian host feeding (73.7%), specficially wild boar (Sus spp.) and porcupines being the most frequent (43.4%), with additional detections of civets, dogs, cattle, and several bird families. In general, H. hystricis exhibited a broader host spectrum than H. formosensis. Overall, these results indicate that moisture availability and mammal host communities influence Haemaphysalis tick distributions across Hong Kong's mosaic landscape. Future consideration should be made for expanding spatial and temporal surveillance, integrating microhabitat moisture and host density data, and coupling ecological surveys with pathogen screening to inform One Health surveillance and management.

The leatherback turtle (Dermochelys coriacea) undertakes extensive migrations between nesting and foraging areas, where it is exposed to threats such as fisheries bycatch, coastal development, and pollution. Although classified globally as Vulnerable by the IUCN, the Southwest Atlantic subpopulation is considered Critically Endangered, with nesting restricted to Brazil. While satellite telemetry and previous mitochondrial DNA (mtDNA) Genetic Mixed Stock Analysis (MSA) studies have indicated that leatherbacks from West African rookeries migrate to foraging grounds off Argentina and Uruguay, the potential for connectivity with rookeries from other regions remains an open question. Genetic Stock Identification (GSI) using 15 nuclear DNA (nDNA) microsatellite markers was conducted on 78 stranded or incidentally caught leatherbacks from feeding grounds off the coasts of Argentina and Uruguay. Assignment analysis results demonstrated that 92% of the foraging leatherbacks originated from Ghana and Gabon in the Southeast Atlantic (SEA), with lesser contributions from the rookeries in the Northwest Atlantic (NEA; 6%) and the Southwest Indian Ocean (SWI; 1%) rookery in South Africa, all with assignment probabilities (AP) exceeding 95%. Our findings corroborate and extend previous mtDNA studies by enhancing the precision of GSI for individuals possessing common haplotypes and by clarifying the unknown origin of individuals with 'orphan' mtDNA haplotypes, such as Dc7.1, which were assigned to the SEA rookeries (AP = 99%). Furthermore, we directly assigned one individual, previously of uncertain mtDNA origin (Dc9.1), to the South Africa rookery (AP = 97%), highlighting the need to consider the extension of the SWI Regional Management Unit (RMU) boundaries to Southwest Atlantic waters in future assessments. The absence of detected connectivity with Brazilian nesting populations underscores the necessity for increased sample sizes and the application of advanced molecular markers. These results advance the understanding of population connectivity across oceanic scales and emphasize the crucial role of international collaboration in conservation endeavors.

[This corrects the article DOI: 10.1002/ece3.72962.].