With the continued development of tracking technology and increasing interest in animal movement,our understanding of migration behavior has become more comprehensive.However,there are still many species that have not...With the continued development of tracking technology and increasing interest in animal movement,our understanding of migration behavior has become more comprehensive.However,there are still many species that have not been well studied,particularly sea birds.Here,we present the first year-round Global Positioning System(GPS)tracking data of the Black-tailed Gull(Larus crassirostris)at the population level.We used solar-powered GPS-Global System for Mobile communication(GSM)loggers to successfully track 30 individuals breeding at Xingrentuo Islet,Liaoning Province,China,for 1-3 years.Except for one individual who roamed in the far north of the Yellow Sea during non-breeding period,all others did a directed southward migration.Migration routes and wintering sites differed among migrating gulls and between years for the birds tracked for two or more years.Additionally,during wintering,the migrating gulls were more likely to travel over a large body of water and shift sites,and some trajectories were quite complex,which was probably closely related to what we observed in the field about their boat-chasing behavior.Compared to wintering movements,the post-breeding movements ranged over a smaller area.Specifically,almost all of them had a long post-breeding period near the breeding islet(≥120days,<220 km from the breeding islet),and 80%of the gulls who were tracked more than one year had at least one faithful post-breeding site.Compared to the post-breeding period,only approximately half of the migrating gulls had a pre-breeding period that was shorter(3-20 days)and closer to the breeding islet(≤80 km).Migration distance varied among migrating gulls(range 209-2405 km)and the gulls moved least distance during postbreeding period.Furthermore,we found that the southward movement of the migrating gulls occurred when the temperature near the breeding islet dropped;specifically,the gulls directly migrated southward away from the post-breeding site.Our results suggest that the Black-tailed Gull has a long post-breeding period but a short prebreeding period near the breeding islet and high diversity of their migrating patterns(in especial migration routes and wintering sites).展开更多
The Relict Gull(Larus relictus) is recognized as a vulnerable species,with a worldwide population of about 6,000 individuals.Always inhabiting the extreme arid regions of Central Asia,their migratory routes and winter...The Relict Gull(Larus relictus) is recognized as a vulnerable species,with a worldwide population of about 6,000 individuals.Always inhabiting the extreme arid regions of Central Asia,their migratory routes and winter grounds are unclear.This research focused on distribution sites,habitat,behavior,population size and seasonal changes of Relict Gull.Line transects and point counts in every month were used to investigate the gulls around the Ebinur Lake.The result showed Relict Gull was summer visitor to Xinjiang,Western China.Population curve with a single peak was obtained.This gull appeared in early April and was 63 individuals(1% of the global population).The number remained stable from May to July in 2009.The discovery of fledglings indi-cates that Relict Gull may breed here.They left Ebinur Lake in August.Relict Gull in Ebinur Lake should belong to the Central Asian subpopulation,which was the most westerly record in China.展开更多
In this paper, we perform the density functional theory （DFT） -based calculations by the first-principles pseudopo- tential method to investigate the physical properties of the newly discovered superconductor LaRu2A...In this paper, we perform the density functional theory （DFT） -based calculations by the first-principles pseudopo- tential method to investigate the physical properties of the newly discovered superconductor LaRu2As2 for the first time. The optimized structural parameters are in good agreement with the experimental results. The calculated independent elas- tic constants ensure the mechanical stability of the compound. The calculated Cauchy pressure, Pugh＇s ratio as well as Poisson＇s ratio indicate that LaRu2As2 should behave as a ductile material. Due to low Debye temperature, LaRu2As2 may be used as a thermal barrier coating （TBC） material. The new compound should exhibit metallic nature as its valence bands overlap considerably with the conduction bands. LaRu2As2 is expected to be a soft material and easily machinable because of its low hardness value of 6.8 GPa. The multi-band nature is observed in the calculated Fermi surface. A highly anisotropic combination of ionic, covalent and metallic interactions is expected to be in accordance with charge density calculation.展开更多
Information on the migratory pathways for birds is essential to the future citing of wind power facilities, particularly in off-shore waters. Yet, relatively little is known about the coastal or offshore migratory beh...Information on the migratory pathways for birds is essential to the future citing of wind power facilities, particularly in off-shore waters. Yet, relatively little is known about the coastal or offshore migratory behavior of most birds, including Franklin’s gulls (Larus pipixcan), a long-distant migrant. We report observations along the coast of Peru made in November 2008 to determine where birds concentrated. Wind facilities can not avoid regions of high avian activity without knowing where that activity occurs. Migrant flocks of 250 to 50,000 were observed on coastal farmfields, dumps and estuaries, on beaches and mudflats, and up to 45 km offshore. Bathing and foraging flocks ranged in size from 20 to 500 birds, and most flocks were monospecific, with occasional grey-headed (Larus cirrocephalus) and band-tailed (L. belcheri) on the periphery. While previous notes report Franklin’s gulls foraging coastally, we found flocks feeding up to 45 km offshore by diving for prey or feeding on the water. The relative percentage of birds of the year varied in migrant flocks from zero to 14%, with lower numbers of young foraging aerially on insects (only 1%). The percentage of young feeding over the ocean decreased with increasing distance from shore;no young of the year were recorded at 36-44 km offshore. While there were large flocks of Franklin’s gulls resting on the water inshore, the number of gulls foraging offshore did not decline up to 45 km offshore. The presence of foraging flocks of Franklin’s gulls out to 45 km offshore, and occupying space from 0 to 20 m above the water, suggests that they would be vulnerable to offshore anthropogenic activities, such as offshore drilling and wind facilities.展开更多
Here we report the discovery of superconductivity in the ternary LaRu2As2 compound. The polycrystalline LaRu2As2 samples were synthesized by the conventional solid state reaction method. Powder X-ray diffraction analy...Here we report the discovery of superconductivity in the ternary LaRu2As2 compound. The polycrystalline LaRu2As2 samples were synthesized by the conventional solid state reaction method. Powder X-ray diffraction analysis indicates that LaRu2As2 crystallizes in the ThCr2Si2-type crystal structure with the space group 14/ mmm （No. 139）, and the refined lattice parameters are a = 4.182（6）A and c = 10.590（3）A. The temperature dependent resistivity measurement shows a clear superconducting transition with the onset Tc （critical tempera- ture） at 7.8 K, and zero resistivity happens at 6.8 K. The upper critical field at zero temperature μ0Hc2（0） was estimated to be 1.6 T from the resistivity measurement. DC magnetic susceptibility measurement shows a bulk superconducting Meissner transition at 7.0 K, and the isothermal magnetization measurement indicates that LaRu2As2 is a type-II superconductor.展开更多
Parental effects occur whenever the phenotype of parents or the environment that they experience influences the phenotype and fitness of their offspring, In birds, parental effects are often mediated by the size and b...Parental effects occur whenever the phenotype of parents or the environment that they experience influences the phenotype and fitness of their offspring, In birds, parental effects are often mediated by the size and biochemical quality of the eggs in terms of maternally transferred components. Exogenous antioxidants are key egg components that accomplish crucial physiological functions during early life. Among these, vitamin E plays a vital role during prenatal development when the intense metabolism accompanying rapid embryo growth results in overproduction of pro-oxidant molecules. Studies of captive birds have demonstrated the positive effect of vitamin E supplementation on diverse phenotypic traits of hatchling and adult individuals, but its effects on embryo phenotype has never been investigated neither in captivity nor under a natural selection regime. In the present study, we experimentally tested the effect of the in ovo supplementation of vitamin E on morphological traits and oxidative status of yellow-legged gull （Larus michahellis） embryos. The supplementation of vitamin E promoted somatic growth in embryos soon before hatching, but did not affect their oxidative status. Our results suggest that maternally transferred vitamin E concentrations are optimized to prevent imbalances of oxidative status and the consequent raise of oxidative damage in yellow-legged gull embryos during prenatal development.展开更多
Il 12 gennaio 1992 mentre osservavo alcuni Svassi maggiori in un piccolo portonella parte bassa del lago d’Iseo, ho notato che in un gruppo di 5 Gabbiani realiin sosta, due individui avevano le zampe color rosa-carni...Il 12 gennaio 1992 mentre osservavo alcuni Svassi maggiori in un piccolo portonella parte bassa del lago d’Iseo, ho notato che in un gruppo di 5 Gabbiani realiin sosta, due individui avevano le zampe color rosa-carnicino, carattere distintivodelle popolazioni nordiche, attualmente considerate appartenenti ad una specie buo-na (Larus argentatus). I rimanenti tre erano tipici Gabbiani reali mediterranei (Laruscachinnans) con zampe gialle.展开更多
基金financially supported by the National Key Research and Development Program of China(Grant No.2022YFC2601601)the National Natural Science Foundation of China(Grant No.31727901)the China Scholarship Council(No.2019-13045 to H.X.)。
文摘With the continued development of tracking technology and increasing interest in animal movement,our understanding of migration behavior has become more comprehensive.However,there are still many species that have not been well studied,particularly sea birds.Here,we present the first year-round Global Positioning System(GPS)tracking data of the Black-tailed Gull(Larus crassirostris)at the population level.We used solar-powered GPS-Global System for Mobile communication(GSM)loggers to successfully track 30 individuals breeding at Xingrentuo Islet,Liaoning Province,China,for 1-3 years.Except for one individual who roamed in the far north of the Yellow Sea during non-breeding period,all others did a directed southward migration.Migration routes and wintering sites differed among migrating gulls and between years for the birds tracked for two or more years.Additionally,during wintering,the migrating gulls were more likely to travel over a large body of water and shift sites,and some trajectories were quite complex,which was probably closely related to what we observed in the field about their boat-chasing behavior.Compared to wintering movements,the post-breeding movements ranged over a smaller area.Specifically,almost all of them had a long post-breeding period near the breeding islet(≥120days,<220 km from the breeding islet),and 80%of the gulls who were tracked more than one year had at least one faithful post-breeding site.Compared to the post-breeding period,only approximately half of the migrating gulls had a pre-breeding period that was shorter(3-20 days)and closer to the breeding islet(≤80 km).Migration distance varied among migrating gulls(range 209-2405 km)and the gulls moved least distance during postbreeding period.Furthermore,we found that the southward movement of the migrating gulls occurred when the temperature near the breeding islet dropped;specifically,the gulls directly migrated southward away from the post-breeding site.Our results suggest that the Black-tailed Gull has a long post-breeding period but a short prebreeding period near the breeding islet and high diversity of their migrating patterns(in especial migration routes and wintering sites).
基金supported by Science Supporting Project of National Ministry of Science and Technology (2008BAC39B04)National Natural Science Foundation of China (30470262,30970340)
文摘The Relict Gull(Larus relictus) is recognized as a vulnerable species,with a worldwide population of about 6,000 individuals.Always inhabiting the extreme arid regions of Central Asia,their migratory routes and winter grounds are unclear.This research focused on distribution sites,habitat,behavior,population size and seasonal changes of Relict Gull.Line transects and point counts in every month were used to investigate the gulls around the Ebinur Lake.The result showed Relict Gull was summer visitor to Xinjiang,Western China.Population curve with a single peak was obtained.This gull appeared in early April and was 63 individuals(1% of the global population).The number remained stable from May to July in 2009.The discovery of fledglings indi-cates that Relict Gull may breed here.They left Ebinur Lake in August.Relict Gull in Ebinur Lake should belong to the Central Asian subpopulation,which was the most westerly record in China.
文摘In this paper, we perform the density functional theory （DFT） -based calculations by the first-principles pseudopo- tential method to investigate the physical properties of the newly discovered superconductor LaRu2As2 for the first time. The optimized structural parameters are in good agreement with the experimental results. The calculated independent elas- tic constants ensure the mechanical stability of the compound. The calculated Cauchy pressure, Pugh＇s ratio as well as Poisson＇s ratio indicate that LaRu2As2 should behave as a ductile material. Due to low Debye temperature, LaRu2As2 may be used as a thermal barrier coating （TBC） material. The new compound should exhibit metallic nature as its valence bands overlap considerably with the conduction bands. LaRu2As2 is expected to be a soft material and easily machinable because of its low hardness value of 6.8 GPa. The multi-band nature is observed in the calculated Fermi surface. A highly anisotropic combination of ionic, covalent and metallic interactions is expected to be in accordance with charge density calculation.
文摘Information on the migratory pathways for birds is essential to the future citing of wind power facilities, particularly in off-shore waters. Yet, relatively little is known about the coastal or offshore migratory behavior of most birds, including Franklin’s gulls (Larus pipixcan), a long-distant migrant. We report observations along the coast of Peru made in November 2008 to determine where birds concentrated. Wind facilities can not avoid regions of high avian activity without knowing where that activity occurs. Migrant flocks of 250 to 50,000 were observed on coastal farmfields, dumps and estuaries, on beaches and mudflats, and up to 45 km offshore. Bathing and foraging flocks ranged in size from 20 to 500 birds, and most flocks were monospecific, with occasional grey-headed (Larus cirrocephalus) and band-tailed (L. belcheri) on the periphery. While previous notes report Franklin’s gulls foraging coastally, we found flocks feeding up to 45 km offshore by diving for prey or feeding on the water. The relative percentage of birds of the year varied in migrant flocks from zero to 14%, with lower numbers of young foraging aerially on insects (only 1%). The percentage of young feeding over the ocean decreased with increasing distance from shore;no young of the year were recorded at 36-44 km offshore. While there were large flocks of Franklin’s gulls resting on the water inshore, the number of gulls foraging offshore did not decline up to 45 km offshore. The presence of foraging flocks of Franklin’s gulls out to 45 km offshore, and occupying space from 0 to 20 m above the water, suggests that they would be vulnerable to offshore anthropogenic activities, such as offshore drilling and wind facilities.
基金the financial supports from the National Natural Science Foundation of China (11474339)the National Basic Research Program of China (2010CB923000 and 2011CBA00100)the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB07020100)
文摘Here we report the discovery of superconductivity in the ternary LaRu2As2 compound. The polycrystalline LaRu2As2 samples were synthesized by the conventional solid state reaction method. Powder X-ray diffraction analysis indicates that LaRu2As2 crystallizes in the ThCr2Si2-type crystal structure with the space group 14/ mmm （No. 139）, and the refined lattice parameters are a = 4.182（6）A and c = 10.590（3）A. The temperature dependent resistivity measurement shows a clear superconducting transition with the onset Tc （critical tempera- ture） at 7.8 K, and zero resistivity happens at 6.8 K. The upper critical field at zero temperature μ0Hc2（0） was estimated to be 1.6 T from the resistivity measurement. DC magnetic susceptibility measurement shows a bulk superconducting Meissner transition at 7.0 K, and the isothermal magnetization measurement indicates that LaRu2As2 is a type-II superconductor.
文摘Parental effects occur whenever the phenotype of parents or the environment that they experience influences the phenotype and fitness of their offspring, In birds, parental effects are often mediated by the size and biochemical quality of the eggs in terms of maternally transferred components. Exogenous antioxidants are key egg components that accomplish crucial physiological functions during early life. Among these, vitamin E plays a vital role during prenatal development when the intense metabolism accompanying rapid embryo growth results in overproduction of pro-oxidant molecules. Studies of captive birds have demonstrated the positive effect of vitamin E supplementation on diverse phenotypic traits of hatchling and adult individuals, but its effects on embryo phenotype has never been investigated neither in captivity nor under a natural selection regime. In the present study, we experimentally tested the effect of the in ovo supplementation of vitamin E on morphological traits and oxidative status of yellow-legged gull （Larus michahellis） embryos. The supplementation of vitamin E promoted somatic growth in embryos soon before hatching, but did not affect their oxidative status. Our results suggest that maternally transferred vitamin E concentrations are optimized to prevent imbalances of oxidative status and the consequent raise of oxidative damage in yellow-legged gull embryos during prenatal development.
文摘Il 12 gennaio 1992 mentre osservavo alcuni Svassi maggiori in un piccolo portonella parte bassa del lago d’Iseo, ho notato che in un gruppo di 5 Gabbiani realiin sosta, due individui avevano le zampe color rosa-carnicino, carattere distintivodelle popolazioni nordiche, attualmente considerate appartenenti ad una specie buo-na (Larus argentatus). I rimanenti tre erano tipici Gabbiani reali mediterranei (Laruscachinnans) con zampe gialle.
