Following a series of surveys since 2003, a full-seasonal raptor count was undertaken at Baiwangshan, a mountain in the vicinity of Beijing, from 6 March to 22 May 2009, when 3802 individual birds of 23 species were r...Following a series of surveys since 2003, a full-seasonal raptor count was undertaken at Baiwangshan, a mountain in the vicinity of Beijing, from 6 March to 22 May 2009, when 3802 individual birds of 23 species were recorded. Four species, i.e., Oriental Honey Buzzard(Pernis ptilorhynchus), Common Buzzard(Buteo buteo), Eurasian Sparrow Hawk(Accipiter nisus) and Gray-faced Buzzard(Butastur indicus) together accounted for up 90% of the total and P. ptilorhynchus alone for 70%. Raptor passage of such magnitude and diversity at an inland site in China was unheard of up to then. As well, 113 other migrants were recorded at the site during this period, including 24 water birds, 74 passerines and 15 others(cuckoos, owls and other migrants).展开更多
Many Chinese people leave big cities for family reunions during the Chinese New Year （CNY）, which is the most important public holiday in China. However, how modem mass human migration during the CNY holiday affects...Many Chinese people leave big cities for family reunions during the Chinese New Year （CNY）, which is the most important public holiday in China. However, how modem mass human migration during the CNY holiday affects the urban heat island （UHI） is still un- known. Here, the authors investigate the role of modem human migration for the UHI effects during the CNY holiday for the period of 1992-2006 in Harbin City, Northeast China. The results show that during the CNY week, the UHI effects expressed as daily mean, maxi- mum, and minimum temperature differences between urban and rural stations averaged over the period of 1992-2006 are 0.65℃ （43%）, 0.31℃ （48%）, and 1.14℃ （71%） lower than during the background period （four weeks before and four weeks after the CNY week）, re- spectively. Our findings identify previously unknown impacts of modem mass human migration on the UHI effects based on a case study in Harbin City.展开更多
Population movements around the Chinese New Year （CNY）, which are much larger in recent years than before, are the largest annual human migration in the world. However, it is still largely unknown how or to what ext...Population movements around the Chinese New Year （CNY）, which are much larger in recent years than before, are the largest annual human migration in the world. However, it is still largely unknown how or to what extent such mass human migration affects urban climate. Here, we investigate the role of mass human migration in influencing Beijing＇s urban heat island （UHI） during the CNY holiday for the period of 2004-2013. We find that the UHI effects expressed as daily mean （ATmean）, maximum （ATmax）, and minimum （ATmin） temperature differences between urban and rural areas show a weakening trend during the CNY week relative to the background period （4 weeks including 2-3 weeks before and 2-3 weeks after the CNY week）. In particular, large reductions occurred during the CNY week for the period of 2009-2013, when nearly half of population left the city before the CNY holiday. △Tmean, △Tmax, and △Tmin averaged over the period of 2009-2013 during the CNY week were 0.64, 0.45, and 0.83 ℃ lower than during the background period, representing relative reductions of 35 %, 66 %, and 27 %, respectively. Our findings highlight the important role of modem mass human migration for urban climate based on a case study in Beijing.展开更多
Migratory birds rely on fueling prior to migratory flights. Fueling in migrants is controlled by intrinsic as well as ex- trinsic factors. From captive studies we have started understanding the internal mechanisms con...Migratory birds rely on fueling prior to migratory flights. Fueling in migrants is controlled by intrinsic as well as ex- trinsic factors. From captive studies we have started understanding the internal mechanisms controlling bird migration. Field studies have demonstrated the effects of external factors, such as food availability, weather, competitors, parasites or diseases, on the stopover behavior of migrants. However, an integrated approach is still missing to study coherently how the innate migration program interacts with the varying environmental cues and to estimate the contribution of the innate migration program and the environment to realized migration. The northern wheatear Oenanthe oenanthe offers a unique opportunity for integrated studies. It breeds across almost the whole Holarctic with just a ＂gap＂ between eastern Canada and Alaska. All breeding populations over- winter in sub-Saharan Africa which makes the northern wheatear one of the most long-distant migratory songbirds with extraor- dinary long non-stop flights across oceans. It is a nocturnal migrant which travels without parental or social aid/guidance. Thus, young birds rely entirely on endogenous mechanisms of timing, route selection and fueling on their first outbound migration. By establishing indoor housing under controlled conditions the endogenous control mechanisms of northern wheatear migration could be revealed. At the same time, environmental factors controlling fueling could be investigated in the field. On migration wheatears occur in a variety of habitats with sparse vegetation where their stopover behavior could be quantitatively studied in the light of ＂optimal migration＂ theory by the use of remote balances, radio-tagging and even experimentally manipulated food availability. The present paper summarizes our approach to understand the control of migration in northern wheatears by combin- ing field and laboratory studies at various spatial and temporal scales, and linking various sub-disciplines .展开更多
文摘Following a series of surveys since 2003, a full-seasonal raptor count was undertaken at Baiwangshan, a mountain in the vicinity of Beijing, from 6 March to 22 May 2009, when 3802 individual birds of 23 species were recorded. Four species, i.e., Oriental Honey Buzzard(Pernis ptilorhynchus), Common Buzzard(Buteo buteo), Eurasian Sparrow Hawk(Accipiter nisus) and Gray-faced Buzzard(Butastur indicus) together accounted for up 90% of the total and P. ptilorhynchus alone for 70%. Raptor passage of such magnitude and diversity at an inland site in China was unheard of up to then. As well, 113 other migrants were recorded at the site during this period, including 24 water birds, 74 passerines and 15 others(cuckoos, owls and other migrants).
基金supported by the National Natural Science Foundation of China(Grant Nos.41275089 and 41305071)the National Basic Research Program of China(Grant No.2012CB955604)Jingyong ZHANG was supported by the Jiangsu Collaborative Innovation Center for Climate Change
文摘Many Chinese people leave big cities for family reunions during the Chinese New Year （CNY）, which is the most important public holiday in China. However, how modem mass human migration during the CNY holiday affects the urban heat island （UHI） is still un- known. Here, the authors investigate the role of modem human migration for the UHI effects during the CNY holiday for the period of 1992-2006 in Harbin City, Northeast China. The results show that during the CNY week, the UHI effects expressed as daily mean, maxi- mum, and minimum temperature differences between urban and rural stations averaged over the period of 1992-2006 are 0.65℃ （43%）, 0.31℃ （48%）, and 1.14℃ （71%） lower than during the background period （four weeks before and four weeks after the CNY week）, re- spectively. Our findings identify previously unknown impacts of modem mass human migration on the UHI effects based on a case study in Harbin City.
基金supported by the National Natural Science Foundation of China(41275089 and 41305071)the National Basic Research Program of China(2012CB955604)
文摘Population movements around the Chinese New Year （CNY）, which are much larger in recent years than before, are the largest annual human migration in the world. However, it is still largely unknown how or to what extent such mass human migration affects urban climate. Here, we investigate the role of mass human migration in influencing Beijing＇s urban heat island （UHI） during the CNY holiday for the period of 2004-2013. We find that the UHI effects expressed as daily mean （ATmean）, maximum （ATmax）, and minimum （ATmin） temperature differences between urban and rural areas show a weakening trend during the CNY week relative to the background period （4 weeks including 2-3 weeks before and 2-3 weeks after the CNY week）. In particular, large reductions occurred during the CNY week for the period of 2009-2013, when nearly half of population left the city before the CNY holiday. △Tmean, △Tmax, and △Tmin averaged over the period of 2009-2013 during the CNY week were 0.64, 0.45, and 0.83 ℃ lower than during the background period, representing relative reductions of 35 %, 66 %, and 27 %, respectively. Our findings highlight the important role of modem mass human migration for urban climate based on a case study in Beijing.
文摘Migratory birds rely on fueling prior to migratory flights. Fueling in migrants is controlled by intrinsic as well as ex- trinsic factors. From captive studies we have started understanding the internal mechanisms controlling bird migration. Field studies have demonstrated the effects of external factors, such as food availability, weather, competitors, parasites or diseases, on the stopover behavior of migrants. However, an integrated approach is still missing to study coherently how the innate migration program interacts with the varying environmental cues and to estimate the contribution of the innate migration program and the environment to realized migration. The northern wheatear Oenanthe oenanthe offers a unique opportunity for integrated studies. It breeds across almost the whole Holarctic with just a ＂gap＂ between eastern Canada and Alaska. All breeding populations over- winter in sub-Saharan Africa which makes the northern wheatear one of the most long-distant migratory songbirds with extraor- dinary long non-stop flights across oceans. It is a nocturnal migrant which travels without parental or social aid/guidance. Thus, young birds rely entirely on endogenous mechanisms of timing, route selection and fueling on their first outbound migration. By establishing indoor housing under controlled conditions the endogenous control mechanisms of northern wheatear migration could be revealed. At the same time, environmental factors controlling fueling could be investigated in the field. On migration wheatears occur in a variety of habitats with sparse vegetation where their stopover behavior could be quantitatively studied in the light of ＂optimal migration＂ theory by the use of remote balances, radio-tagging and even experimentally manipulated food availability. The present paper summarizes our approach to understand the control of migration in northern wheatears by combin- ing field and laboratory studies at various spatial and temporal scales, and linking various sub-disciplines .
