Eyespots have been shown to perform an anti-predator function by intimidating predators.However,whether predators are deterred by the eyespots’mimicking eyes of higher-order predators,or by the conspicuousness of the...Eyespots have been shown to perform an anti-predator function by intimidating predators.However,whether predators are deterred by the eyespots’mimicking eyes of higher-order predators,or by the conspicuousness of the spots,is still being debated.The anti-predator mechanism of eyespots,which involves the predator’s visual perception and cognition,urges to be examined.To explore the“eye mimicry hypothesis”and“conspicuous signal hypothesis,”we designed prey with deceptive eyespots eliciting 2-dimensional(2D)or 3-dimensional(3D)visual illusions for domestic chicks(as predators).For 2D visual illusion,we provided prey with occluded eyespots for chicks.Chicks can“complete”the occluded eyespots into a full 2D concentric circle by the amodal completion mechanism,that is,one of visual illusion.For 3D visual illusion,we created the crescent-shaped sparkles on the eyespots to simulate a visually 3D eye.Our result indicated that(1)2D:chicks hesitated more when facing preys with occluded eyespots than facing preys with broken eyespots and(2)3D:compared to prey with no-sparkle eyespots,chicks spent more time approaching prey with sparkle eyespots and were more likely to approach them tangentially.Thus,the visual illusion perceived by chicks would impact the anti-predation effectiveness of eyespots.Eyespots that more closely resemble the real eyes,especially those with 3-dimensionality,provided more effective protection.Our study supported the eye mimicry hypothesis from the perspective of visual illusion.展开更多
The life-history strategies of organisms are shaped by trade-offs among traits that influence survival,development,reproduction,and ultimately fitness.However,the specific physiological and environmental mechanisms dr...The life-history strategies of organisms are shaped by trade-offs among traits that influence survival,development,reproduction,and ultimately fitness.However,the specific physiological and environmental mechanisms driving population-level variation in phenotypic traits,particularly in relation to migratory adaptations,remain poorly understood.Elevational migration represents an adaptive behavior for mountain birds that offers a unique model to investigate adaptive phenotypes because of the diverse migratory strategies that have been observed within and between species.Flight muscles,as multifunctional organs,exhibit phenotypic variation that aligns with locomotor and thermoregulatory demands.Linking flight muscle phenotypes to migratory strategies can provide insights into inter-and intraspecific variation in migratory adaptations.In this study,we examined spring arrival dates at high-altitude breeding sites for three closely related high-altitude breeding birds in the mountains of Asia:Blue-fronted Redstart(Phoenicurus frontalis),Himalayan Bluetail(Tarsiger rufilatus),and Rufous-gorgeted Flycatcher(Ficedula strophiata).We analyzed relationships between arrival dates and phenotypic traits,including flight muscle physiology,morphology,and internal organ mass,alongside environmental effects on these traits.Our findings indicate that species arriving earlier encountered lower temperatures and exhibited reduced fiber cross-sectional areas coupled with higher fast oxidative glycolytic(FOG)fibers densities.Males displayed pronounced protandry and higher fast glycolytic(FG)fibers densities.Ambient temperature significantly influenced flight muscle phenotypes,highlighting intraspecific variation and the potential plasticity of flight muscle fibers as crucial mechanisms for adapting to migration strategies and environmental conditions.Additionally,this study underscores the potential role of sexual selection in shaping functional phenotypic variation,further advancing our understanding of adaptive strategies in high-altitude migratory birds.展开更多
Currently,single atom(SA),quantum dots(QDs)and heterogeneous interfaces have been extensively em-ployed for the design of nov-el catalysts for overall water splitting.However,there are still few literatures about the ...Currently,single atom(SA),quantum dots(QDs)and heterogeneous interfaces have been extensively em-ployed for the design of nov-el catalysts for overall water splitting.However,there are still few literatures about the hydrogen(HER)and oxygen(OER)evolution perfor-mances for three different morphologies of the same metal loaded on MXenes substrates.Herein,the HER and OER per-formances of Mo_(2)CO_(2)modified by transition metals(TM,TM=Fe,Co,and Ni)with differ-ent SA loading(STM/Mo_(2)CO_(2)),QDs(QTM/Mo_(2)CO_(2))and heterogeneous interface(ITM/Mo_(2)CO_(2)),and TM loading and N3(TMN_(3)/Mo_(2)CO_(2))or N4 doping co-modification(TMN4/Mo_(2)CO_(2))are investigated by density functional theory(DFT)calculations.The re-sults show that the HER and OER performances of STM/Mo_(2)CO_(2)are better than those of ITM/Mo_(2)CO_(2)and QTM/Mo_(2)CO_(2).Especially,SNi/Mo_(2)CO_(2)exhibits the best HER and OER properties among the studied structures,with the correspondingΔGH*andηOER of−0.04 eV and 0.53 V,respectively.It is noteworthy that theΔGH*absolute value,ηOER,work function(Φ)and TM valence charges are significantly correlated,whereΔGH*absolute value,ηOER,andΦall present an increase trend following the order of STM/Mo_(2)CO_(2),ITM/Mo_(2)CO_(2),and QTM/Mo_(2)CO_(2),whereas TM valence charges exhibit a decrease trend with the above order.Furthermore,integral crystal orbital Hamilton population(ICOHP)results indicate that the more negative the ICOHP,the stronger bonding strength between TM and H atoms,and the better the corresponding HER performance in STM/Mo_(2)CO_(2).Campared with SNi/Mo_(2)CO_(2),Ni loading and N3 doping co-modification Mo_(2)CO_(2)(NiN_(3)/Mo_(2)CO_(2))shows better HER(ΔGH*=−0.01 eV)and OER catalytic activities(ηOER=0.36 V).Molecular dynamics simula-tions results indicate that most of the modified systems are stable at reaction temperature.In summary,NiN_(3)/Mo_(2)CO_(2)can be used as an efficient electrocatalyst for overall water splitting.展开更多
Covalent organic frameworks(COFs)are promising materials for mitigating polysulfide shuttling in lithium-sulfur(Li-S)batteries,but enhancing their ability to convert polysulfides across a wide temperature range remain...Covalent organic frameworks(COFs)are promising materials for mitigating polysulfide shuttling in lithium-sulfur(Li-S)batteries,but enhancing their ability to convert polysulfides across a wide temperature range remains a challenge,Herein,we introduce a redox-active COF(RaCOF)that functions as both a physical barrier and a kinetic enhancer to improve the temperature adaptability of Li-S batteries,The RaCOF constructed from redox-active anthraquinone units accelerates polysulfide conversion kinetics through reversible C=O/C-OLi transformations within a voltage range of 1,7 to 2.8 V(vs.Li^(+)/Li),optimizing sulfur redox reactions in ether-based electrolytes.Unlike conventional COFs,RaCOF provides bidentate trapping of polysulfides,increasing binding energy and facilitating more effective polysulfide management.In-situ XRD and ToF-SIMS analyses confirm that RaCOF enhances polysulfide adsorption and promotes the transformation of lithium sulfide(Li_(2)S),leading to better sulfur cathode reutilization.Consequently,RaCOF-modified Li-S batteries demonstrate low self-discharge(4.0%decay over a 7-day rest),excellent wide-temperature performance(stable from-10 to+60℃),and high-rate cycling stability(94%capacity retention over 500 cycles at 5.0 C).This work offers valuable insights for designing COF structures aimed at achieving temperature-adaptive performance in rechargeable batteries.展开更多
Altitudinal bird migration involves seasonal shifts up and down the altitude gradient annually.Asia as the place with the largest number of altitudinal migrants,has quite few related studies,especially for montane and...Altitudinal bird migration involves seasonal shifts up and down the altitude gradient annually.Asia as the place with the largest number of altitudinal migrants,has quite few related studies,especially for montane and temperate avifaunas.To explore the potential drivers of seasonal altitudinal migration for birds in the middle of Hengduan Mountains,we conducted a three-year investigation on breeding and non-breeding season bird communities at eight elevational bands(1200–4200 m)in the Gongga Mountains.We examined the altitudinal migration patterns and relationships between seasonal distribution shifts and species'traits of 50 species with sufficient data recorded in both seasons.We found that a large proportion of breeding birds underwent altitudinal migration and showed three migration patterns(downslope shift,upslope shift,no shift).Seasonal distribution shifts were mainly correlated with certain ecological traits.Species breeding at high and mid-elevations,nesting in scrub and being omnivorous are more likely to show downslope movements during the non-breeding season.In addition,territorially weaker species exhibited more diverse migration patterns.Notably,we found the hand-wing index(HWI)was actually more convincing than body mass in explaining altitudinal migration.These results consolidate the studies of seasonal altitudinal migration in montane birds.Our study could be used to bridge existing knowledge gaps that currently impeding effective conservation for montane avifaunas in the Hengduan Mountains.展开更多
Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting a...Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting alpine toad Scutiger chintingensis is a rare mountain amphibian endemic to the eastern margin of the Qinghai-Xizang Plateau in China.Within its whole distribution range,only three known populations(Wolong,Emei,and Wawu)exist and no recent population status report has been documented for this species over the past two decades.From 2020 to 2023,we investigated the species distribution,and assessed the risk factors for the main populations.We recorded this species in all distribution areas,and updated a new distribution site with a lower elevation limit.The relative population density was 0.024±0.012 ind./m^(2)on Mount Emei,whereas only 0.008±0.017 ind./m^(2)on Mount Wawu.No significant difference was observed in the number of individuals between the two populations;however,the relative population density was significantly different.Sewage and waste discharge resulting from the construction of scenic areas,as well as disturbances from tourism,were the primary anthropogenic factors that influenced the survival of this species.Our results provide the updated information on the distribution and population status of the Chinting alpine toad,and suggest that unrecorded populations,as well as a wider elevation range,may exist for this species.Our findings emphasise the importance of timely updates of species distribution and population information and offer a basis for the future conservation of endangered amphibians.展开更多
Gut microbiota and host interactions co-evolve and develop into stably adapted microbial communities and play vital roles in maintaining the health of organisms.Diet is supposed to be an important driver of difference...Gut microbiota and host interactions co-evolve and develop into stably adapted microbial communities and play vital roles in maintaining the health of organisms.Diet is supposed to be an important driver of differences in gut microbiota,but previous studies would commonly use literature depictions,which are essential but inaccurate,to explain the effects of diet on the gut microbiota of wild birds.In this study,we collected intestinal samples from five sympatric flycatchers to compare the gut microbial differences using bacterial 16S rRNA genes from Illumina MiSeq platform.Over 1,642,482 quality-filtered sequences from 1816S rRNA libraries were obtained and distinct compositions and diversities of gut microbiota were found in five flycatchers.Their gut microbiota is mainly from the four bacterial phyla of Proteobacteria,Firmicutes,Actinomycetes,and Bacteroidetes,but at the genus level showed a significant difference.Functional predictions revealed that the metabolic capacity of the gut microbiota of five flycatchers is greatly distinguished at KEGG level 3.And multiple food fragments showed a significant correlation with gut microbiota.Besides,the significant differences in the specific composition of the diets of the five insectivorous flycatchers indicated the differentiation of dietary niches.The study of the gut microbiota and feeding habits of sympatric flycatchers would increase the understanding of the gut microbial diversity of wild birds,and also improve our cognition of the co-evolution and co-adaptation within the host gut microbiota relations.展开更多
Many bird species in montane regions exhibit altitudinal migration behavior;however,altitudinal migration of birds is still understudied,especially in Asia.Mt.Gongga(7556 m) is the highest peak of the Hengduan Mountai...Many bird species in montane regions exhibit altitudinal migration behavior;however,altitudinal migration of birds is still understudied,especially in Asia.Mt.Gongga(7556 m) is the highest peak of the Hengduan Mountains in Southwest China.The steep elevation gradient and the high bird diversity make the eastern slope of Mt.Gongga(Hailuo Valley) an ideal place for studying the altitudinal migration behavior patterns of birds.We synchronously recorded the local bird diversity,temperature and humidity at two sites(1800 and 3000 m a.s.l.) during three migration seasons from September 2020 to June 2021 to identify birds exhibiting altitudinal migration behavior.During our surveys,we recorded 146 bird species in total and 20 passerine bird species were altitudinal migrants according to our altitudinal migration formula.Among those 20 altitudinal migrant species,eight bird species displayed a typical altitudinal migration pattern(upward migration during the breeding season and downward migration during the non-breeding season).Moreover,temperature was correlated with the daily number of individuals(DNI) at each study site.Therefore,increasing temperatures possibly caused upward migration of birds(DNI decreased at 1800 m and increased at 3000 m) and vice versa.To further elaborate,the Rufousgorgeted Flycatcher(Ficedula strophiata),the species with the most prominent altitudinal migration behavior,initiated upward migration at a temperature of 11-12℃ at 1800 m and initiated downward migration at a temperature of 12-13℃ at 3000 m.Besides,humidity was positively correlated with the DNI.Therefore,increasing humidity(equals to increasing rainfall or snow) possibly caused downward migration of birds(DNI increased) and vice versa.Furthermore,bird species exhibiting a typical altitudinal migration behavior pattern are feeding on insects.Thus,the spatial and temporal changes of the invertebrate biomass might be an important ecological driver for the altitudinal migration of invertivorous(birds eating invertebrates) birds.This study provides fundamental data for the altitudinal migration of birds in the Hengduan Mountains and shows how altitudinal migration is seasonally dynamic across an elevational gradient in a subtropical mountain region.展开更多
Artificial light at night(ALAN),as an emerging pollutant,disrupts wild animals'nocturnal behaviours and physiological processes.Recent evidence indicates that ALAN can also impair diurnal cognition,especially in h...Artificial light at night(ALAN),as an emerging pollutant,disrupts wild animals'nocturnal behaviours and physiological processes.Recent evidence indicates that ALAN can also impair diurnal cognition,especially in highly developed vertebrates.However,previous research has rendered mixed results across taxa and task types,with the parameters of the light source also scattered.That limits conclusion generalizability.Here we examined cognitive impacts of ALAN in housed Java Sparrows(Lonchura oryzivora),focusing on two questions:(1)whether ALAN uniformly impairs diverse cognitive traits and(2)how correlated colour temperatures(CCTs)modulate these effects.Sparrows were exposed to amber light(low CCT),neutral-white light(medium CCT),blue light(high CCT),or a no-light control.We then compared individual performance in three cognitive paradigms which were used to assess the animals'capacities of discrimination learning,reversal learning,and inhibitory control.Results showed no significant effects of ALAN on discrimination learning,but ALAN-exposed birds required fewer trials in reversal learning.Lower CCT(amber light)led to more failures in detour-reaching.These findings indicate that cognitive impacts of ALAN are not uniformly negative but depend on cognitive function and CCT.Our study highlights context-dependent effects of ALAN,providing insights for optimizing urban lighting policies to balance ecological and human needs.展开更多
Although promising strategies have been developed to resolve the critical drawbacks of lithium-sulfur(Li-S)batteries,the intractable issues including undesirable shuttling of polysulfides and sluggish redox reaction k...Although promising strategies have been developed to resolve the critical drawbacks of lithium-sulfur(Li-S)batteries,the intractable issues including undesirable shuttling of polysulfides and sluggish redox reaction kinetics have still been unresolved thoroughly.Herein,a cobalt single-atom(CoSA)catalyst comprising of atomic Co distributed homogeneously within nitrogen(N)-doped porous carbon(Co-NPC)nanosphere is constructed and utilized as a separator coating in Li-S batteries.The Co-NPC exposes abundant active sites participating in sulfur redox reactions,and remarkable catalytic activity boosting the rapid polysulfide conversions.As a result,Li-S batteries with Co-NPC coating layer realize significantly enhanced specific capacity(1295 mAh·g^(-1)at 0.2 C),rate capability(753 mAh·g^(-1)at 3.0 C),and long-life cyclic stability(601 mAh·g^(-1)after 500 cycles at 1.0 C).Increasing the areal sulfur loading to 6.2 mg·cm^(-2),an extremely high areal capacity of 7.92 mAh·cm^(-2)is achieved.Further in situ X-ray diffraction,density functional theory calculations,and secondary ion mass spectrometry confirm the high catalytic capability of CoSA towards reversible polysulfide conversion.This study supplies new insights for adopting single-atom catalyst to upgrade the electrochemical performance of Li-S batteries.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.32471564)。
文摘Eyespots have been shown to perform an anti-predator function by intimidating predators.However,whether predators are deterred by the eyespots’mimicking eyes of higher-order predators,or by the conspicuousness of the spots,is still being debated.The anti-predator mechanism of eyespots,which involves the predator’s visual perception and cognition,urges to be examined.To explore the“eye mimicry hypothesis”and“conspicuous signal hypothesis,”we designed prey with deceptive eyespots eliciting 2-dimensional(2D)or 3-dimensional(3D)visual illusions for domestic chicks(as predators).For 2D visual illusion,we provided prey with occluded eyespots for chicks.Chicks can“complete”the occluded eyespots into a full 2D concentric circle by the amodal completion mechanism,that is,one of visual illusion.For 3D visual illusion,we created the crescent-shaped sparkles on the eyespots to simulate a visually 3D eye.Our result indicated that(1)2D:chicks hesitated more when facing preys with occluded eyespots than facing preys with broken eyespots and(2)3D:compared to prey with no-sparkle eyespots,chicks spent more time approaching prey with sparkle eyespots and were more likely to approach them tangentially.Thus,the visual illusion perceived by chicks would impact the anti-predation effectiveness of eyespots.Eyespots that more closely resemble the real eyes,especially those with 3-dimensionality,provided more effective protection.Our study supported the eye mimicry hypothesis from the perspective of visual illusion.
基金financially supported by the National Natural Science Foundation of China (No.32270454)by the Survey of Wildlife Resources in Key Areas of Tibet (ZL202203601)。
文摘The life-history strategies of organisms are shaped by trade-offs among traits that influence survival,development,reproduction,and ultimately fitness.However,the specific physiological and environmental mechanisms driving population-level variation in phenotypic traits,particularly in relation to migratory adaptations,remain poorly understood.Elevational migration represents an adaptive behavior for mountain birds that offers a unique model to investigate adaptive phenotypes because of the diverse migratory strategies that have been observed within and between species.Flight muscles,as multifunctional organs,exhibit phenotypic variation that aligns with locomotor and thermoregulatory demands.Linking flight muscle phenotypes to migratory strategies can provide insights into inter-and intraspecific variation in migratory adaptations.In this study,we examined spring arrival dates at high-altitude breeding sites for three closely related high-altitude breeding birds in the mountains of Asia:Blue-fronted Redstart(Phoenicurus frontalis),Himalayan Bluetail(Tarsiger rufilatus),and Rufous-gorgeted Flycatcher(Ficedula strophiata).We analyzed relationships between arrival dates and phenotypic traits,including flight muscle physiology,morphology,and internal organ mass,alongside environmental effects on these traits.Our findings indicate that species arriving earlier encountered lower temperatures and exhibited reduced fiber cross-sectional areas coupled with higher fast oxidative glycolytic(FOG)fibers densities.Males displayed pronounced protandry and higher fast glycolytic(FG)fibers densities.Ambient temperature significantly influenced flight muscle phenotypes,highlighting intraspecific variation and the potential plasticity of flight muscle fibers as crucial mechanisms for adapting to migration strategies and environmental conditions.Additionally,this study underscores the potential role of sexual selection in shaping functional phenotypic variation,further advancing our understanding of adaptive strategies in high-altitude migratory birds.
基金financially supported by the National Natural Science Foundation of China(No.51971002)National Natural Science Foundation of Anhui,China(No.2108085QE188)Natural Science Foundation of Anhui Provincial Education Department(No.KJ2021A0361)。
文摘Currently,single atom(SA),quantum dots(QDs)and heterogeneous interfaces have been extensively em-ployed for the design of nov-el catalysts for overall water splitting.However,there are still few literatures about the hydrogen(HER)and oxygen(OER)evolution perfor-mances for three different morphologies of the same metal loaded on MXenes substrates.Herein,the HER and OER per-formances of Mo_(2)CO_(2)modified by transition metals(TM,TM=Fe,Co,and Ni)with differ-ent SA loading(STM/Mo_(2)CO_(2)),QDs(QTM/Mo_(2)CO_(2))and heterogeneous interface(ITM/Mo_(2)CO_(2)),and TM loading and N3(TMN_(3)/Mo_(2)CO_(2))or N4 doping co-modification(TMN4/Mo_(2)CO_(2))are investigated by density functional theory(DFT)calculations.The re-sults show that the HER and OER performances of STM/Mo_(2)CO_(2)are better than those of ITM/Mo_(2)CO_(2)and QTM/Mo_(2)CO_(2).Especially,SNi/Mo_(2)CO_(2)exhibits the best HER and OER properties among the studied structures,with the correspondingΔGH*andηOER of−0.04 eV and 0.53 V,respectively.It is noteworthy that theΔGH*absolute value,ηOER,work function(Φ)and TM valence charges are significantly correlated,whereΔGH*absolute value,ηOER,andΦall present an increase trend following the order of STM/Mo_(2)CO_(2),ITM/Mo_(2)CO_(2),and QTM/Mo_(2)CO_(2),whereas TM valence charges exhibit a decrease trend with the above order.Furthermore,integral crystal orbital Hamilton population(ICOHP)results indicate that the more negative the ICOHP,the stronger bonding strength between TM and H atoms,and the better the corresponding HER performance in STM/Mo_(2)CO_(2).Campared with SNi/Mo_(2)CO_(2),Ni loading and N3 doping co-modification Mo_(2)CO_(2)(NiN_(3)/Mo_(2)CO_(2))shows better HER(ΔGH*=−0.01 eV)and OER catalytic activities(ηOER=0.36 V).Molecular dynamics simula-tions results indicate that most of the modified systems are stable at reaction temperature.In summary,NiN_(3)/Mo_(2)CO_(2)can be used as an efficient electrocatalyst for overall water splitting.
基金funding supporting from the National Natural Science Foundation of China(22309003,22379001)the Natural Science Research Project of Anhui Province Education Department(2023AH051119)+3 种基金the open project funding from Shanghai Key Laboratory of Multi phase Materials Chemical Engineering(MMCE2024001)the National Key Research and Development Program of China(2022YFB2402201)the Shanghai Pilot Program for Basic Research-Fudan University 21TQ1400100(21TQ009)the Fundamental Research Funds for the Central Universities(20720220010).
文摘Covalent organic frameworks(COFs)are promising materials for mitigating polysulfide shuttling in lithium-sulfur(Li-S)batteries,but enhancing their ability to convert polysulfides across a wide temperature range remains a challenge,Herein,we introduce a redox-active COF(RaCOF)that functions as both a physical barrier and a kinetic enhancer to improve the temperature adaptability of Li-S batteries,The RaCOF constructed from redox-active anthraquinone units accelerates polysulfide conversion kinetics through reversible C=O/C-OLi transformations within a voltage range of 1,7 to 2.8 V(vs.Li^(+)/Li),optimizing sulfur redox reactions in ether-based electrolytes.Unlike conventional COFs,RaCOF provides bidentate trapping of polysulfides,increasing binding energy and facilitating more effective polysulfide management.In-situ XRD and ToF-SIMS analyses confirm that RaCOF enhances polysulfide adsorption and promotes the transformation of lithium sulfide(Li_(2)S),leading to better sulfur cathode reutilization.Consequently,RaCOF-modified Li-S batteries demonstrate low self-discharge(4.0%decay over a 7-day rest),excellent wide-temperature performance(stable from-10 to+60℃),and high-rate cycling stability(94%capacity retention over 500 cycles at 5.0 C).This work offers valuable insights for designing COF structures aimed at achieving temperature-adaptive performance in rechargeable batteries.
基金The Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0501)National Natural Science Foundation of China(No.31772478,31501851).
文摘Altitudinal bird migration involves seasonal shifts up and down the altitude gradient annually.Asia as the place with the largest number of altitudinal migrants,has quite few related studies,especially for montane and temperate avifaunas.To explore the potential drivers of seasonal altitudinal migration for birds in the middle of Hengduan Mountains,we conducted a three-year investigation on breeding and non-breeding season bird communities at eight elevational bands(1200–4200 m)in the Gongga Mountains.We examined the altitudinal migration patterns and relationships between seasonal distribution shifts and species'traits of 50 species with sufficient data recorded in both seasons.We found that a large proportion of breeding birds underwent altitudinal migration and showed three migration patterns(downslope shift,upslope shift,no shift).Seasonal distribution shifts were mainly correlated with certain ecological traits.Species breeding at high and mid-elevations,nesting in scrub and being omnivorous are more likely to show downslope movements during the non-breeding season.In addition,territorially weaker species exhibited more diverse migration patterns.Notably,we found the hand-wing index(HWI)was actually more convincing than body mass in explaining altitudinal migration.These results consolidate the studies of seasonal altitudinal migration in montane birds.Our study could be used to bridge existing knowledge gaps that currently impeding effective conservation for montane avifaunas in the Hengduan Mountains.
基金supported by the National Natural Science Foundation of China(32271737,32071544)the Interdisciplinary Innovation Team of the Chinese Academy of Sciences(CAS)“Light of West China”Program(xbzg-zdsys-202207)+1 种基金the Shenzhen Zhilan Foundation(2021070451A)Nature Science Foundation of Sichuan Province(2022NSFSC0125).
文摘Considering the increased anthropogenic impacts,species with a limited range and low detectability often lack fundamental information and conservation actions,placing them at a high risk of endangerment.The Chinting alpine toad Scutiger chintingensis is a rare mountain amphibian endemic to the eastern margin of the Qinghai-Xizang Plateau in China.Within its whole distribution range,only three known populations(Wolong,Emei,and Wawu)exist and no recent population status report has been documented for this species over the past two decades.From 2020 to 2023,we investigated the species distribution,and assessed the risk factors for the main populations.We recorded this species in all distribution areas,and updated a new distribution site with a lower elevation limit.The relative population density was 0.024±0.012 ind./m^(2)on Mount Emei,whereas only 0.008±0.017 ind./m^(2)on Mount Wawu.No significant difference was observed in the number of individuals between the two populations;however,the relative population density was significantly different.Sewage and waste discharge resulting from the construction of scenic areas,as well as disturbances from tourism,were the primary anthropogenic factors that influenced the survival of this species.Our results provide the updated information on the distribution and population status of the Chinting alpine toad,and suggest that unrecorded populations,as well as a wider elevation range,may exist for this species.Our findings emphasise the importance of timely updates of species distribution and population information and offer a basis for the future conservation of endangered amphibians.
基金financially supported by The Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0501)National Natural Science Foundation of China(No.31772478,31501851)。
文摘Gut microbiota and host interactions co-evolve and develop into stably adapted microbial communities and play vital roles in maintaining the health of organisms.Diet is supposed to be an important driver of differences in gut microbiota,but previous studies would commonly use literature depictions,which are essential but inaccurate,to explain the effects of diet on the gut microbiota of wild birds.In this study,we collected intestinal samples from five sympatric flycatchers to compare the gut microbial differences using bacterial 16S rRNA genes from Illumina MiSeq platform.Over 1,642,482 quality-filtered sequences from 1816S rRNA libraries were obtained and distinct compositions and diversities of gut microbiota were found in five flycatchers.Their gut microbiota is mainly from the four bacterial phyla of Proteobacteria,Firmicutes,Actinomycetes,and Bacteroidetes,but at the genus level showed a significant difference.Functional predictions revealed that the metabolic capacity of the gut microbiota of five flycatchers is greatly distinguished at KEGG level 3.And multiple food fragments showed a significant correlation with gut microbiota.Besides,the significant differences in the specific composition of the diets of the five insectivorous flycatchers indicated the differentiation of dietary niches.The study of the gut microbiota and feeding habits of sympatric flycatchers would increase the understanding of the gut microbial diversity of wild birds,and also improve our cognition of the co-evolution and co-adaptation within the host gut microbiota relations.
基金the National Natural Science Foundation of China(No.32270454)the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0501).
文摘Many bird species in montane regions exhibit altitudinal migration behavior;however,altitudinal migration of birds is still understudied,especially in Asia.Mt.Gongga(7556 m) is the highest peak of the Hengduan Mountains in Southwest China.The steep elevation gradient and the high bird diversity make the eastern slope of Mt.Gongga(Hailuo Valley) an ideal place for studying the altitudinal migration behavior patterns of birds.We synchronously recorded the local bird diversity,temperature and humidity at two sites(1800 and 3000 m a.s.l.) during three migration seasons from September 2020 to June 2021 to identify birds exhibiting altitudinal migration behavior.During our surveys,we recorded 146 bird species in total and 20 passerine bird species were altitudinal migrants according to our altitudinal migration formula.Among those 20 altitudinal migrant species,eight bird species displayed a typical altitudinal migration pattern(upward migration during the breeding season and downward migration during the non-breeding season).Moreover,temperature was correlated with the daily number of individuals(DNI) at each study site.Therefore,increasing temperatures possibly caused upward migration of birds(DNI decreased at 1800 m and increased at 3000 m) and vice versa.To further elaborate,the Rufousgorgeted Flycatcher(Ficedula strophiata),the species with the most prominent altitudinal migration behavior,initiated upward migration at a temperature of 11-12℃ at 1800 m and initiated downward migration at a temperature of 12-13℃ at 3000 m.Besides,humidity was positively correlated with the DNI.Therefore,increasing humidity(equals to increasing rainfall or snow) possibly caused downward migration of birds(DNI increased) and vice versa.Furthermore,bird species exhibiting a typical altitudinal migration behavior pattern are feeding on insects.Thus,the spatial and temporal changes of the invertebrate biomass might be an important ecological driver for the altitudinal migration of invertivorous(birds eating invertebrates) birds.This study provides fundamental data for the altitudinal migration of birds in the Hengduan Mountains and shows how altitudinal migration is seasonally dynamic across an elevational gradient in a subtropical mountain region.
基金supported by National Key Research and Development Project(2022YFC3202104)Tencent Foundation’s Biodiversity Conservation Funding Project for Universities。
文摘Artificial light at night(ALAN),as an emerging pollutant,disrupts wild animals'nocturnal behaviours and physiological processes.Recent evidence indicates that ALAN can also impair diurnal cognition,especially in highly developed vertebrates.However,previous research has rendered mixed results across taxa and task types,with the parameters of the light source also scattered.That limits conclusion generalizability.Here we examined cognitive impacts of ALAN in housed Java Sparrows(Lonchura oryzivora),focusing on two questions:(1)whether ALAN uniformly impairs diverse cognitive traits and(2)how correlated colour temperatures(CCTs)modulate these effects.Sparrows were exposed to amber light(low CCT),neutral-white light(medium CCT),blue light(high CCT),or a no-light control.We then compared individual performance in three cognitive paradigms which were used to assess the animals'capacities of discrimination learning,reversal learning,and inhibitory control.Results showed no significant effects of ALAN on discrimination learning,but ALAN-exposed birds required fewer trials in reversal learning.Lower CCT(amber light)led to more failures in detour-reaching.These findings indicate that cognitive impacts of ALAN are not uniformly negative but depend on cognitive function and CCT.Our study highlights context-dependent effects of ALAN,providing insights for optimizing urban lighting policies to balance ecological and human needs.
基金financially supported by the National Natural Science Foundation of China(No.22005003)the Natural Science Research Project of Anhui Province Education Department(Nos.2022AH030046 and 2022AH050334)+2 种基金the Yong Scientific Foundation of Anhui University of Technology for Top Talent(No.DT2100000947)the Scientific Research Foundation of Anhui University of Technology for Talent Introduction(No.DT19100069)The theoretical simulations were carried out at Shanxi Supercomputing Center of China,and performed on TianHe-2.
文摘Although promising strategies have been developed to resolve the critical drawbacks of lithium-sulfur(Li-S)batteries,the intractable issues including undesirable shuttling of polysulfides and sluggish redox reaction kinetics have still been unresolved thoroughly.Herein,a cobalt single-atom(CoSA)catalyst comprising of atomic Co distributed homogeneously within nitrogen(N)-doped porous carbon(Co-NPC)nanosphere is constructed and utilized as a separator coating in Li-S batteries.The Co-NPC exposes abundant active sites participating in sulfur redox reactions,and remarkable catalytic activity boosting the rapid polysulfide conversions.As a result,Li-S batteries with Co-NPC coating layer realize significantly enhanced specific capacity(1295 mAh·g^(-1)at 0.2 C),rate capability(753 mAh·g^(-1)at 3.0 C),and long-life cyclic stability(601 mAh·g^(-1)after 500 cycles at 1.0 C).Increasing the areal sulfur loading to 6.2 mg·cm^(-2),an extremely high areal capacity of 7.92 mAh·cm^(-2)is achieved.Further in situ X-ray diffraction,density functional theory calculations,and secondary ion mass spectrometry confirm the high catalytic capability of CoSA towards reversible polysulfide conversion.This study supplies new insights for adopting single-atom catalyst to upgrade the electrochemical performance of Li-S batteries.
