The Subei Shoal is a special coastal area with complex physical oceanographic properties in the Yellow Sea.In the present study,the distribution of phytoplankton and its correlation with environmental factors were stu...The Subei Shoal is a special coastal area with complex physical oceanographic properties in the Yellow Sea.In the present study,the distribution of phytoplankton and its correlation with environmental factors were studied during spring and summer of 2012 in the Subei Shoal of the Yellow Sea.Phytoplankton species composition and abundance data were accomplished by Utermohl method.Diatoms represented the greatest cellular abundance during the study period.In spring,the phytoplankton cell abundance ranged from 1.59×10^3 to 269.78×10^3 cell/L with an average of 41.80×10^3 cell/L,and Skeletonema sp.and Paralia sulcata was the most dominant species.In summer,the average phytoplankton cell abundance was 72.59×10^3 cell/L with the range of 1.78×10^3 to 574.96×10^3 cell/L,and the main dominant species was Pseudo-nitzschia pungens,Skeletonema sp.,Dactyliosolen fragilissima and Chaetoceros curvisetus.The results of a redundancy analysis(RDA)showed that turbidity,temperature,salinity,pH,dissolved oxygen(DO),the ratio of dissolved inorganic nitrogen to silicate and SiO4-Si(DIN/SiO4-Si)were the most important environmental factors controlling phytoplankton assemblages in spring or summer in the Subei Shoal of the Yellow Sea.展开更多
Hyperspectral remote sensing offers an effective approach for frequent, synoptic water quality measurements over a large spatial extent. However, the optical complexity of case 2 water makes the water quality monitori...Hyperspectral remote sensing offers an effective approach for frequent, synoptic water quality measurements over a large spatial extent. However, the optical complexity of case 2 water makes the water quality monitoring by remote sensing in estuarine water a challenge. The prime objective of this study was to develop algorithms for hyperspectral remote sensing of water quality based on in situ spectral measurement of water reflectance. In this study, water reflectance spectra R(λ) were acquired by a pair of Ocean Optic 2000 spectroradiometers during the summers from 2008 to 2011 at Patuxent River, a tributary of Chesapeake Bay, USA. Simultaneously, concentrations of chlorophyll a and total suspended solids (TSS), as well as absorption of colored dissolved organic matter (CDOM) were measured. Empirical models that based on spectral features of water reflectance generally showed good correlations with water quality parameters. The retrieval model that using spectral bands at red/NIR showed a high correlation with chlorophyll a concentration (R2 = 0.81). The ratio of green to blue spectral bands is the best predictor for TSS (R2 = 0.75), and CDOM absorption is best correlated with spectral features at blue and NIR regions (R2 = 0.85). These empirical models were further applied to the ASIA Eagle hyperspectral aerial imagery to demonstrate the feasibility of hyperspectral remote sensing of water quality in the optical complex estuarine waters.展开更多
Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although m...Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although market chains of live bird trade have been studied through indirect means including interviews and questionnaires, direct methods have not been used to identify movements of individual poultry. To bridge the knowledge gap on quantitative movement and transportation of poultry, we introduced a novel approach for applying telemetry to document domestic duck movements from source farms at Poyang Lake, China. We deployed recently developed transmitters that record Global Positioning System （GPS） locations and send them through the Groupe Spécial Mobile （GSM） cellular telephone system. For the ifrst time, we were able to track individually marked ducks from 3 to 396 km from their origin to other farms, distribution facilities, or live bird markets. Our proof of concept test showed that the use of GPS-GSM transmitters may provide di-rect, quantitative information to document the movement of poultry and reveal their market chains. Our ifndings provide an initial indication of the complexity of source-market network connectivity and highlight the great potential for future telemetry studies in poultry network analyses.展开更多
Background: A number of conservation and societal issues require understanding how species are distributed on the landscape, yet ecologists are often faced with a lack of data to develop models at the resolution and e...Background: A number of conservation and societal issues require understanding how species are distributed on the landscape, yet ecologists are often faced with a lack of data to develop models at the resolution and extent desired, resulting in inefficient use of conservation resources.Such a situation presented itself in our attempt to develop waterfowl distribution models as part of a multi-disciplinary team targeting the control of the highly pathogenic H5N1 avian influenza virus in China.Methods: Faced with limited data, we built species distribution models using a habitat suitability approach for China's breeding and non-breeding(hereafter, wintering) waterfowl.An extensive review of the literature was used to determine model parameters for habitat modeling.Habitat relationships were implemented in GIS using land cover covariates.Wintering models were validated using waterfowl census data, while breeding models, though developed for many species, were only validated for the one species with sufficient telemetry data available.Results: We developed suitability models for 42 waterfowl species(30 breeding and 39 wintering) at 1 km resolution for the extent of China, along with cumulative and genus level species richness maps.Breeding season models showed highest waterfowl suitability in wetlands of the high-elevation west-central plateau and northeastern China.Wintering waterfowl suitability was highest in the lowland regions of southeastern China.Validation measures indicated strong performance in predicting species presence.Comparing our model outputs to China's protected areas indicated that breeding habitat was generally better covered than wintering habitat, and identified locations for which additional research and protection should be prioritized.Conclusions: These suitability models are the first available for many of China's waterfowl species, and have direct utility to conservation and habitat planning and prioritizing management of critically important areas, providing an example of how this approach may aid others faced with the challenge of addressing conservation issues with little data to inform decision making.展开更多
Background: For migrating birds, stopover requires spending time and energy that otherwise could be allocated to flying. Thus, birds optimally refuel their subsequent migratory flight by reducing stopover duration or ...Background: For migrating birds, stopover requires spending time and energy that otherwise could be allocated to flying. Thus, birds optimally refuel their subsequent migratory flight by reducing stopover duration or foraging activ-ity in food-rich environments. In coastal habitats, birds may forego refueling and take short stopovers irrespective of local food availability. Given the paucity of studies exploring how migrants adjust stopover behavior in response to temporal variation in food availability, especially in the Neotropics, we fixed radio tags to 51 Red-eyed Vireos(Vireo olivaceous) over two years at two sites on the coast of Mexico's Yucatan Peninsula.Methods: We applied VHF radio tags during the fall of 2016 and 2017, and tracked birds using automatic and manual receiving units. We estimated stopover duration and activity levels(one site only) for between six and fifteen birds,depending on site and year. We measured fruit availability weekly along the net lanes where we captured birds. We used a generalized linear model to estimate the relationships between stopover duration/activity level and fruit den-sity, bird body mass and year. We interpreted relationships for the model with the lowest AICc value.Results: We found that approximately half of the birds departed on the same day they were captured. For the birds that stayed longer, we could not discern whether they did so because they were light, or fruit density was high. On the other hand, lighter birds were more active than heavier birds but only in one of the two years.Conclusions: Given our results, it is unlikely that Red-eyed Vireos refuel along the Yucatan coast. However, they still likely need to recuperate from crossing the Gulf of Mexico, which may necessitate foraging more often if in poor body condition. If the birds then move inland then stopover should be thought of as a large-scale phenomenon, where habitats with different functions may be spread out over a broad landscape.展开更多
Background:While nest attentiveness plays a critical role in the reproductive success of avian species,nest attentiveness data with high temporal resolution is not available for many species.However,improvements in bo...Background:While nest attentiveness plays a critical role in the reproductive success of avian species,nest attentiveness data with high temporal resolution is not available for many species.However,improvements in both video monitoring and temperature logging devices present an opportunity to increase our understanding of this aspect of avian behavior.Methods:To investigate nest attentiveness behaviors and evaluate these technologies,we monitored 13 nests across two Common Tern(Sterna hirundo)breeding colonies with a paired video camera-temperature logger approach,while monitoring 63 additional nests with temperature loggers alone.Observations occurred from May to August of 2017 on Poplar(Chesapeake Bay,Maryland,USA)and Skimmer Islands(Isle of Wight Bay,Maryland,USA).We examined data respective to four times of day:Morning(civil dawn‒11:59),Peak(12:00‒16:00),Cooling(16:01‒civil dusk),and Night(civil dusk‒civil dawn).Results:While successful nests had mostly short duration off-bouts and maintained consistent nest attentiveness throughout the day,failed nests had dramatic reductions in nest attentiveness during the Cooling and Night periods(p<0.05)with one colony experiencing repeated nocturnal abandonment due to predation pressure from a Great Horned Owl(Bubo virginianus).Incubation appeared to ameliorate ambient temperatures during Night,as nests were significantly warmer during Night when birds were on versus off the nest(p<0.05).Meanwhile,off-bouts during the Peak period occurred during higher ambient temperatures,perhaps due to adults leaving the nest during the hottest periods to perform belly soaking.Unfortunately,temperature logger data alone had limited ability to predict nest attentiveness status during shorter bouts,with results highly dependent on time of day and bout duration.While our methods did not affect hatching success(p>0.05),video-monitored nests did have significantly lower clutch sizes(p<0.05).Conclusions:The paired use of iButtons and video cameras enabled a detailed description of the incubation behavior of COTE.However,while promising for future research,the logistical and potential biological complications involved in the use of these methods suggest that careful planning is needed before these devices are utilized to ensure data is collected in a safe and successful manner.展开更多
Environmentally heterogeneous mountains provide opportunities for rapid diversification and speciation.The family Prunellidae(accentors)is a group of birds comprising primarily mountain specialists that have recently ...Environmentally heterogeneous mountains provide opportunities for rapid diversification and speciation.The family Prunellidae(accentors)is a group of birds comprising primarily mountain specialists that have recently radiated across the Palearctic region.This rapid diversification poses challenges to resolving their phylogeny.Herein we sequenced the complete mitogenomes and estimated the phylogeny using all 12(including 28 individuals)currently recognized species of Prunellidae.We reconstructed the mitochondrial genome phylogeny using 13 protein-coding genes of 12 species and 2 Eurasian Tree Sparrows(Passer montanus).Phylogenetic relationships were estimated using a suite of analyses:maximum likelihood,maximum parsimony and the coalescent-based SVDquartets.Divergence times were estimated by implementing a Bayesian relaxed clock model in BEAST2.Based on the BEAST time-calibrated tree,we implemented an ancestral area reconstruction using RASP v.4.3.Our phylogenies based on the maximum likelihood,maximum parsimony and SVDquartets approaches support a clade of large-sized accentors(subgenus Laiscopus)to be sister to all other accentors with small size(subgenus Prunella).In addition,the trees also support the sister relationship of P.immaculata and P.rubeculoides+P.atrogularis with 100%bootstrap support,but the relationships among the remaining eight species in the Prunella clade are poorly resolved.These species cluster in different positions in the three phylogenetic trees and the nodes are often poorly supported.The five nodes separating the seven species diverged simultaneously within less than half million years(i.e.,between 2.71 and 3.15 million years ago),suggesting that the recent radiation is likely responsible for rampant incomplete lineage sorting and gene tree conflicts.Ancestral area reconstruction indicates a central Palearctic region origin for Prunellidae.Our study highlights that whole mitochondrial genome phylogeny can resolve major lineages within Prunellidae but is not sufficient to fully resolve the relationship among the species in the Prunella clade that almost simultaneously diversify during a short time period.Our results emphasize the challenge to reconstruct reliable phylogenetic relationship in a group of recently radiated species.展开更多
基金The Public Science and Technology Research Funds Projects of the Ocean under contract Nos 201205010 and201205009-5the National Science&Technology Pillar Program under contract No.2012BAC07B03+3 种基金the National Natural Science Foundation of China under contract No.41206111the Chinese Science and Technology Base Projects under contract No.2012FY112500the Shanghai Universities First-class Disciplines Project(Disapline name:Marine Science(0707))the Plateau Peak Disciplines Project of Shanghai Universities(Marine Science 0707)
文摘The Subei Shoal is a special coastal area with complex physical oceanographic properties in the Yellow Sea.In the present study,the distribution of phytoplankton and its correlation with environmental factors were studied during spring and summer of 2012 in the Subei Shoal of the Yellow Sea.Phytoplankton species composition and abundance data were accomplished by Utermohl method.Diatoms represented the greatest cellular abundance during the study period.In spring,the phytoplankton cell abundance ranged from 1.59×10^3 to 269.78×10^3 cell/L with an average of 41.80×10^3 cell/L,and Skeletonema sp.and Paralia sulcata was the most dominant species.In summer,the average phytoplankton cell abundance was 72.59×10^3 cell/L with the range of 1.78×10^3 to 574.96×10^3 cell/L,and the main dominant species was Pseudo-nitzschia pungens,Skeletonema sp.,Dactyliosolen fragilissima and Chaetoceros curvisetus.The results of a redundancy analysis(RDA)showed that turbidity,temperature,salinity,pH,dissolved oxygen(DO),the ratio of dissolved inorganic nitrogen to silicate and SiO4-Si(DIN/SiO4-Si)were the most important environmental factors controlling phytoplankton assemblages in spring or summer in the Subei Shoal of the Yellow Sea.
文摘Hyperspectral remote sensing offers an effective approach for frequent, synoptic water quality measurements over a large spatial extent. However, the optical complexity of case 2 water makes the water quality monitoring by remote sensing in estuarine water a challenge. The prime objective of this study was to develop algorithms for hyperspectral remote sensing of water quality based on in situ spectral measurement of water reflectance. In this study, water reflectance spectra R(λ) were acquired by a pair of Ocean Optic 2000 spectroradiometers during the summers from 2008 to 2011 at Patuxent River, a tributary of Chesapeake Bay, USA. Simultaneously, concentrations of chlorophyll a and total suspended solids (TSS), as well as absorption of colored dissolved organic matter (CDOM) were measured. Empirical models that based on spectral features of water reflectance generally showed good correlations with water quality parameters. The retrieval model that using spectral bands at red/NIR showed a high correlation with chlorophyll a concentration (R2 = 0.81). The ratio of green to blue spectral bands is the best predictor for TSS (R2 = 0.75), and CDOM absorption is best correlated with spectral features at blue and NIR regions (R2 = 0.85). These empirical models were further applied to the ASIA Eagle hyperspectral aerial imagery to demonstrate the feasibility of hyperspectral remote sensing of water quality in the optical complex estuarine waters.
基金supported by the grants from the National Institutes of Health(1R01AI101028-01A1)the Office of Health,Infectious Diseases and Nutrition in the Bureau for Global Health,U.S.Agency for International Development(GHA-G-00-06-00001)
文摘Agro-ecological conditions associated with the spread and persistence of highly pathogenic avian inlfuenza （HPAI） are not well understood, but the trade of live poultry is suspected to be a major pathway. Although market chains of live bird trade have been studied through indirect means including interviews and questionnaires, direct methods have not been used to identify movements of individual poultry. To bridge the knowledge gap on quantitative movement and transportation of poultry, we introduced a novel approach for applying telemetry to document domestic duck movements from source farms at Poyang Lake, China. We deployed recently developed transmitters that record Global Positioning System （GPS） locations and send them through the Groupe Spécial Mobile （GSM） cellular telephone system. For the ifrst time, we were able to track individually marked ducks from 3 to 396 km from their origin to other farms, distribution facilities, or live bird markets. Our proof of concept test showed that the use of GPS-GSM transmitters may provide di-rect, quantitative information to document the movement of poultry and reveal their market chains. Our ifndings provide an initial indication of the complexity of source-market network connectivity and highlight the great potential for future telemetry studies in poultry network analyses.
基金supported by the United States Geological Survey(Ecosystems Mission Area)the National Science Foundation Small Grants for Exploratory Research(No.0713027)Wetlands International
文摘Background: A number of conservation and societal issues require understanding how species are distributed on the landscape, yet ecologists are often faced with a lack of data to develop models at the resolution and extent desired, resulting in inefficient use of conservation resources.Such a situation presented itself in our attempt to develop waterfowl distribution models as part of a multi-disciplinary team targeting the control of the highly pathogenic H5N1 avian influenza virus in China.Methods: Faced with limited data, we built species distribution models using a habitat suitability approach for China's breeding and non-breeding(hereafter, wintering) waterfowl.An extensive review of the literature was used to determine model parameters for habitat modeling.Habitat relationships were implemented in GIS using land cover covariates.Wintering models were validated using waterfowl census data, while breeding models, though developed for many species, were only validated for the one species with sufficient telemetry data available.Results: We developed suitability models for 42 waterfowl species(30 breeding and 39 wintering) at 1 km resolution for the extent of China, along with cumulative and genus level species richness maps.Breeding season models showed highest waterfowl suitability in wetlands of the high-elevation west-central plateau and northeastern China.Wintering waterfowl suitability was highest in the lowland regions of southeastern China.Validation measures indicated strong performance in predicting species presence.Comparing our model outputs to China's protected areas indicated that breeding habitat was generally better covered than wintering habitat, and identified locations for which additional research and protection should be prioritized.Conclusions: These suitability models are the first available for many of China's waterfowl species, and have direct utility to conservation and habitat planning and prioritizing management of critically important areas, providing an example of how this approach may aid others faced with the challenge of addressing conservation issues with little data to inform decision making.
基金supported by a joint grant from the Secretaria de Medio Ambiente y Recursos Naturales of Mexico and the Consejo Nacional de Ciencia y Tecnología of Mexico (#262986)。
文摘Background: For migrating birds, stopover requires spending time and energy that otherwise could be allocated to flying. Thus, birds optimally refuel their subsequent migratory flight by reducing stopover duration or foraging activ-ity in food-rich environments. In coastal habitats, birds may forego refueling and take short stopovers irrespective of local food availability. Given the paucity of studies exploring how migrants adjust stopover behavior in response to temporal variation in food availability, especially in the Neotropics, we fixed radio tags to 51 Red-eyed Vireos(Vireo olivaceous) over two years at two sites on the coast of Mexico's Yucatan Peninsula.Methods: We applied VHF radio tags during the fall of 2016 and 2017, and tracked birds using automatic and manual receiving units. We estimated stopover duration and activity levels(one site only) for between six and fifteen birds,depending on site and year. We measured fruit availability weekly along the net lanes where we captured birds. We used a generalized linear model to estimate the relationships between stopover duration/activity level and fruit den-sity, bird body mass and year. We interpreted relationships for the model with the lowest AICc value.Results: We found that approximately half of the birds departed on the same day they were captured. For the birds that stayed longer, we could not discern whether they did so because they were light, or fruit density was high. On the other hand, lighter birds were more active than heavier birds but only in one of the two years.Conclusions: Given our results, it is unlikely that Red-eyed Vireos refuel along the Yucatan coast. However, they still likely need to recuperate from crossing the Gulf of Mexico, which may necessitate foraging more often if in poor body condition. If the birds then move inland then stopover should be thought of as a large-scale phenomenon, where habitats with different functions may be spread out over a broad landscape.
基金This work was supported by the U.S.Army Corps of Engineers(Baltimore District),U.S.Geological Survey(Patuxent Wildlife Research Center)the University of Maryland,the Maryland Department of Natural Resources(Wildlife and Heritage Program)the Maryland Environmental Service,and the Maryland Coastal Bays Program.
文摘Background:While nest attentiveness plays a critical role in the reproductive success of avian species,nest attentiveness data with high temporal resolution is not available for many species.However,improvements in both video monitoring and temperature logging devices present an opportunity to increase our understanding of this aspect of avian behavior.Methods:To investigate nest attentiveness behaviors and evaluate these technologies,we monitored 13 nests across two Common Tern(Sterna hirundo)breeding colonies with a paired video camera-temperature logger approach,while monitoring 63 additional nests with temperature loggers alone.Observations occurred from May to August of 2017 on Poplar(Chesapeake Bay,Maryland,USA)and Skimmer Islands(Isle of Wight Bay,Maryland,USA).We examined data respective to four times of day:Morning(civil dawn‒11:59),Peak(12:00‒16:00),Cooling(16:01‒civil dusk),and Night(civil dusk‒civil dawn).Results:While successful nests had mostly short duration off-bouts and maintained consistent nest attentiveness throughout the day,failed nests had dramatic reductions in nest attentiveness during the Cooling and Night periods(p<0.05)with one colony experiencing repeated nocturnal abandonment due to predation pressure from a Great Horned Owl(Bubo virginianus).Incubation appeared to ameliorate ambient temperatures during Night,as nests were significantly warmer during Night when birds were on versus off the nest(p<0.05).Meanwhile,off-bouts during the Peak period occurred during higher ambient temperatures,perhaps due to adults leaving the nest during the hottest periods to perform belly soaking.Unfortunately,temperature logger data alone had limited ability to predict nest attentiveness status during shorter bouts,with results highly dependent on time of day and bout duration.While our methods did not affect hatching success(p>0.05),video-monitored nests did have significantly lower clutch sizes(p<0.05).Conclusions:The paired use of iButtons and video cameras enabled a detailed description of the incubation behavior of COTE.However,while promising for future research,the logistical and potential biological complications involved in the use of these methods suggest that careful planning is needed before these devices are utilized to ensure data is collected in a safe and successful manner.
基金funded by the National Natural Science Foundation of China(NSFC32020103005)the Third Xinjiang Scientific Expedition and Research(XIKK)(2022xjkk0205)Second Tibetan Plateau Scientific Expedition and Research(2019QZKK0501)。
文摘Environmentally heterogeneous mountains provide opportunities for rapid diversification and speciation.The family Prunellidae(accentors)is a group of birds comprising primarily mountain specialists that have recently radiated across the Palearctic region.This rapid diversification poses challenges to resolving their phylogeny.Herein we sequenced the complete mitogenomes and estimated the phylogeny using all 12(including 28 individuals)currently recognized species of Prunellidae.We reconstructed the mitochondrial genome phylogeny using 13 protein-coding genes of 12 species and 2 Eurasian Tree Sparrows(Passer montanus).Phylogenetic relationships were estimated using a suite of analyses:maximum likelihood,maximum parsimony and the coalescent-based SVDquartets.Divergence times were estimated by implementing a Bayesian relaxed clock model in BEAST2.Based on the BEAST time-calibrated tree,we implemented an ancestral area reconstruction using RASP v.4.3.Our phylogenies based on the maximum likelihood,maximum parsimony and SVDquartets approaches support a clade of large-sized accentors(subgenus Laiscopus)to be sister to all other accentors with small size(subgenus Prunella).In addition,the trees also support the sister relationship of P.immaculata and P.rubeculoides+P.atrogularis with 100%bootstrap support,but the relationships among the remaining eight species in the Prunella clade are poorly resolved.These species cluster in different positions in the three phylogenetic trees and the nodes are often poorly supported.The five nodes separating the seven species diverged simultaneously within less than half million years(i.e.,between 2.71 and 3.15 million years ago),suggesting that the recent radiation is likely responsible for rampant incomplete lineage sorting and gene tree conflicts.Ancestral area reconstruction indicates a central Palearctic region origin for Prunellidae.Our study highlights that whole mitochondrial genome phylogeny can resolve major lineages within Prunellidae but is not sufficient to fully resolve the relationship among the species in the Prunella clade that almost simultaneously diversify during a short time period.Our results emphasize the challenge to reconstruct reliable phylogenetic relationship in a group of recently radiated species.
