The population dynamics and breeding behaviors of Black-crowned Night Herons （ Nycticorax nycticorax ）, Egrets （Egtetta garzetta）, Chinese Pond Herons （Ardeola bacchus） and Great Egrets （Casmerodius albus） wer...The population dynamics and breeding behaviors of Black-crowned Night Herons （ Nycticorax nycticorax ）, Egrets （Egtetta garzetta）, Chinese Pond Herons （Ardeola bacchus） and Great Egrets （Casmerodius albus） were observed in Tanghai Wetlands, Hebei Province from August 2004 to July 2005. Further, we studied the relationship of nest space distribution and directly calculated the nest density of vertical and horizontal levels, the niche overlapping index and the niche breadth. The results showed that there were two breeding areas, named Area Ⅰ and Area Ⅱ . The maximum population occurred in the period from April to September and was approximately 5800 individuals. Area Ⅰ was occupied earlier than Area Ⅱ by approximately half a month. In the breeding period, Black-crowned Night Herons were dominant in numbers and most occupied the upper nests of the core areas. Great Egrets also took the upper nests but they have the smallest population. Most Egrets took the middle nests of the edges of the area. Chinese Pond Herons, with a smaller population than the Egret, mostly nested in the edges, but some of them also took the lower nests of the core area. On the whole, the vertical niche of Egrets is the widest, the horizontal niche of Black-crowned Night Herons is the widest and the niche breadth of Chinese Pond Herons is the largest. The nest distribution pattern is the most similar between Chinese Pond Herons and Black-crowned Night Herons, and the niche overlapping index of Chinese Pond Herons and Egrets is the largest. Black-crowned Night Herons and Great Egrets control Egrets and Chinese Pond Herons in competition. Rich food and the optimal ecological environments lead to plenty of herons in the wetlands. In addition, it is a distinguishing feature of the four species that nests are built in poplar trees over 22 m tall.展开更多
The White-eared Night Heron (Gorsachius magnificus) is a Class II protected species in China. It is difficult to observe in the field and its population is small. The present study reports a new distribution site in N...The White-eared Night Heron (Gorsachius magnificus) is a Class II protected species in China. It is difficult to observe in the field and its population is small. The present study reports a new distribution site in Nanxiong County, in northern Guangdong Province, where observations of an active nest were made from 4 May to 14 July 2012, the first time consecutive observations have been made for a period of more than two months. The adults flew away from the nest at night, with a peak at 19:00-20:00 and returned in the mornings with a peak at 04:30-05:30. The peak time for feeding young was at 05:00-05:30, accounting for 26.5%of total feeding activities. No feeding occurred from 10:00 to 16:00. The results of our study of its behavior explain why the White-eared Night Heron is usually observed in the evening just before dark, or in the morning before sunrise, at least during the breeding season. There were about 67 days from hatching to fledging, longer than the fledging time of most heron species. This study is the first to cover the entire period of parental care and fills a gap in previous knowledge.展开更多
Once,in 2007,the authors had written:regarding to the endangerment of the White-eared Night Heron (Gorsachius magnificus),it would be evidentially to say that no longer the status of the bird is to meet the Criteria E...Once,in 2007,the authors had written:regarding to the endangerment of the White-eared Night Heron (Gorsachius magnificus),it would be evidentially to say that no longer the status of the bird is to meet the Criteria EN C1 but more likely still marginally meet EN C2a(i),and hence the bird might be currently remained amongst those Endangered (EN),with caveats that,if any bird could have been found in an area outside the range of any known subpopulation,it will then warrant a lower threat status.Now,it is time for due consideration.展开更多
A survey of Ardeid nesting colonies in central Guizhou,southwestern China in May 2006,which covered about one-third of the area of this province,recorded a total of 1587 nests of five species,i.e.,Little Egret (Egrett...A survey of Ardeid nesting colonies in central Guizhou,southwestern China in May 2006,which covered about one-third of the area of this province,recorded a total of 1587 nests of five species,i.e.,Little Egret (Egretta garzetta),Cattle Egret (Bubulcus ibis),Chinese Pond Heron (Ardeola bacchus),Black-crowned Night Heron (Nycticorax nycticorax) and Grey Heron (Ardea cinerea) at 11 nesting colonies.The largest colonies were recorded at Fengyunyan and Yanfu resorts,the smallest one at Luobolin.The Little Egret was the dominant nesting species (49.7% of the total number of nests) and the Grey Heron was the least abundant (0.1%).All nesting colonies were located in the northern and central parts of Guizhou;no colonies were found in the Leigongshan area,the southern part of this province.The distribution of nesting colonies in central Guizhou appears to be affected by the relative composition of winter (wheat and vegetable) and summer (rice) crops during the breeding season (between late March and June).No colonies were found around farmlands with winter crops and most colonies were situated around rice paddies.The farmland use pattern is affected by rainfall.The summer crop is delayed if the rainy season starts late and the rainfall is light.Priority for conservation of the Ardeids in central Guizhou should be given to the larger colonies i.e.,Yanfu and Fengyunyan resorts.展开更多
文摘The population dynamics and breeding behaviors of Black-crowned Night Herons （ Nycticorax nycticorax ）, Egrets （Egtetta garzetta）, Chinese Pond Herons （Ardeola bacchus） and Great Egrets （Casmerodius albus） were observed in Tanghai Wetlands, Hebei Province from August 2004 to July 2005. Further, we studied the relationship of nest space distribution and directly calculated the nest density of vertical and horizontal levels, the niche overlapping index and the niche breadth. The results showed that there were two breeding areas, named Area Ⅰ and Area Ⅱ . The maximum population occurred in the period from April to September and was approximately 5800 individuals. Area Ⅰ was occupied earlier than Area Ⅱ by approximately half a month. In the breeding period, Black-crowned Night Herons were dominant in numbers and most occupied the upper nests of the core areas. Great Egrets also took the upper nests but they have the smallest population. Most Egrets took the middle nests of the edges of the area. Chinese Pond Herons, with a smaller population than the Egret, mostly nested in the edges, but some of them also took the lower nests of the core area. On the whole, the vertical niche of Egrets is the widest, the horizontal niche of Black-crowned Night Herons is the widest and the niche breadth of Chinese Pond Herons is the largest. The nest distribution pattern is the most similar between Chinese Pond Herons and Black-crowned Night Herons, and the niche overlapping index of Chinese Pond Herons and Egrets is the largest. Black-crowned Night Herons and Great Egrets control Egrets and Chinese Pond Herons in competition. Rich food and the optimal ecological environments lead to plenty of herons in the wetlands. In addition, it is a distinguishing feature of the four species that nests are built in poplar trees over 22 m tall.
基金funded by the National Nature Science Foundation of China(Grant No.31172067)the National Nature Science Foundation of China-Guang dong Joint Fund(U0833005)Guangdong Plan Projects(2010B060200034,2011B031100004)
文摘The White-eared Night Heron (Gorsachius magnificus) is a Class II protected species in China. It is difficult to observe in the field and its population is small. The present study reports a new distribution site in Nanxiong County, in northern Guangdong Province, where observations of an active nest were made from 4 May to 14 July 2012, the first time consecutive observations have been made for a period of more than two months. The adults flew away from the nest at night, with a peak at 19:00-20:00 and returned in the mornings with a peak at 04:30-05:30. The peak time for feeding young was at 05:00-05:30, accounting for 26.5%of total feeding activities. No feeding occurred from 10:00 to 16:00. The results of our study of its behavior explain why the White-eared Night Heron is usually observed in the evening just before dark, or in the morning before sunrise, at least during the breeding season. There were about 67 days from hatching to fledging, longer than the fledging time of most heron species. This study is the first to cover the entire period of parental care and fills a gap in previous knowledge.
基金Zoologische Gesellschaft für Arten und Populationsschutz e. V. (ZGAP) in Germanythe Royal Society for the Protection of Birds (RSPB) in the United Kingdom
文摘Once,in 2007,the authors had written:regarding to the endangerment of the White-eared Night Heron (Gorsachius magnificus),it would be evidentially to say that no longer the status of the bird is to meet the Criteria EN C1 but more likely still marginally meet EN C2a(i),and hence the bird might be currently remained amongst those Endangered (EN),with caveats that,if any bird could have been found in an area outside the range of any known subpopulation,it will then warrant a lower threat status.Now,it is time for due consideration.
基金Supported by the Department of Education of Zhejiang Province(20070509)the Research Project of the Higher Education Teaching Reform in the New Century 2008 Zhejiang(yb08072)
文摘A survey of Ardeid nesting colonies in central Guizhou,southwestern China in May 2006,which covered about one-third of the area of this province,recorded a total of 1587 nests of five species,i.e.,Little Egret (Egretta garzetta),Cattle Egret (Bubulcus ibis),Chinese Pond Heron (Ardeola bacchus),Black-crowned Night Heron (Nycticorax nycticorax) and Grey Heron (Ardea cinerea) at 11 nesting colonies.The largest colonies were recorded at Fengyunyan and Yanfu resorts,the smallest one at Luobolin.The Little Egret was the dominant nesting species (49.7% of the total number of nests) and the Grey Heron was the least abundant (0.1%).All nesting colonies were located in the northern and central parts of Guizhou;no colonies were found in the Leigongshan area,the southern part of this province.The distribution of nesting colonies in central Guizhou appears to be affected by the relative composition of winter (wheat and vegetable) and summer (rice) crops during the breeding season (between late March and June).No colonies were found around farmlands with winter crops and most colonies were situated around rice paddies.The farmland use pattern is affected by rainfall.The summer crop is delayed if the rainy season starts late and the rainfall is light.Priority for conservation of the Ardeids in central Guizhou should be given to the larger colonies i.e.,Yanfu and Fengyunyan resorts.
