• Title/Summary/Keyword: Egrets

검색결과 19건 처리시간 0.03초

A Study of Feeding Methods in Five Species of Herons and Egrets in Korea

  • Choi, Yu-Seong;Kwon, In-Ki;Yoo, Jeong-Chil
    • Journal of Ecology and Environment
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    • 제31권2호
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    • pp.147-151
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    • 2008
  • Feeding methods of five species of herons and egrets were studied in an agricultural landscape in Asan city, Chungcheongnam-do, Korea in 2006. Grey herons primarily hunted while standing, whereas great egrets fed while walking slowly. Two smaller species, little and cattle egrets, were active foragers, feeding both while walking quickly and walking slowly. Little egrets were the only species using the foot stirring method. The medium-sized heron, intermediate egrets, foraged mainly while walking slowly or leaning. For grey herons, great egrets and little egrets, the frequency of use of different feeding methods was different between habitats: these species used the leaning method more frequently in rice fields than in reservoirs and ditches. Also, most herons (all species other than great egrets) showed seasonal changes in their feeding methods that are related to changes in habitat condition.

Feeding activity of cattle egrets and intermediate egrets at different stages of rice culture in Korea

  • Choi, Yu-Seong;Kim, Sun-Sook;Yoo, Jeong-Chil
    • Journal of Ecology and Environment
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    • 제33권2호
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    • pp.149-155
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    • 2010
  • This study was conducted to investigate the feeding efficiency of the cattle egret (Bubulcus ibis) and the intermediate egret (Ardea intermedia) in relation to the stage of rice culture during two breeding seasons, 2006 and 2007, in Asan city, Chungcheongnam-do, South Korea. Cattle egrets caught mainly small invertebrate prey (insects and spiders, 98.4%) during all stages of rice cultivation, and had a higher prey capture rate in the plowing stage (14.98 prey/min) than in other stages (2.82-3.51 prey/min). Therefore, the biomass intake rate of cattle egrets was highest in the plowing stage. The intermediate egret captured both loaches (43.4%) and small invertebrates (50.6%). The prey capture rates of intermediate egrets increased gradually from the flooding stage (0.38 prey/min) to the planting stage (1.09 prey/min), and decreased in the growing stage (1.04 prey/min). However, intermediate egrets had the highest biomass intake rates in the plowing stage because more loaches were caught in the plowing stage (0.54 loaches/min) than other stages (0.23-0.36 loaches/min). Consequently, both intermediate egrets and cattle egrets had high energy intakes in the plowing stage and rice fields provided an important feeding habitat for both species.

Foraging Habitat Preferences of Herons and Egrets

  • Choi, Yu-Seong;Kwon, In-Ki;Yoo, Jeong-Chil
    • Journal of Ecology and Environment
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    • 제30권3호
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    • pp.237-244
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    • 2007
  • We investigated the foraging habitat preferences of herons and egrets in an agricultural area in Asan city, Chungcheongnam-do, Korea. In the study area, rice fields were the most abundant habitat type (86.8%) and total suitable feeding habitat was greater in the northern area (59.0%) than the southern area (22.5%) of the colony. Most feeding herons and egrets were located in the northern area of the colony. The number of feeding individuals in a given area was related to the available feeding area (Pearson correlation, r=0.773, p<0.001 for field habitats; r=0.901, p<0.001 for freshwater habitats). Feeding habitat preferences differed among species. Grey herons (Ardea cinerea), great egrets (Egretta alba), and black-crowned night herons (Nycticorax nycticorax) used reservoirs and ditches. However, intermediate egrets (E. intermedia) and cattle egrets (Bubulcus ibis) were dependent on rice fields. The little egret (E. garzetta) was a habitat generalist using all types of habitats. The two largest species, grey herons and great egrets, fed at deeper site than little egrets and foraged in deeper sites in reservoirs than in ditches (${\chi}^2-test,\;{\chi}^2{_3}=26.6$ and p<0.001 for grey herons, ${\chi}^2{_3}=17.5$ and p<0.001 for great egrets). All species displayed seasonal changes in feeding habitat use and these changes were related with changes in availability of feeding habitats.

대구광역시 팔현리 지역 도로공사가 백로류 번식지에 미치는 영향 (The Effects of the Breeding site of the Egrets and Herons by Road Construction, Palhyun-ri, Daegu, Korea)

  • 차재석;김재웅;박희천
    • 한국환경생태학회지
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    • 제22권2호
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    • pp.152-158
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    • 2008
  • 이 연구는 2003년부터 2006년까지 4년간 대구시 수성구 팔현리 백로류 집단번식지 인근의 도로공사가 백로류 번식에 미치는 영향을 분석하였다. 2003년부터 2005년까지 3년간 공사가 진행되면서 백로류 개체수는 감소하였다. 공사가 중단된 2006년에는 황로를 제외한 왜가리와 중대백로의 개체수가 증가하였고, 왜가리는 다른 백로류에 비해 공사의 영향을 가장 많이 받은 것으로 나타났다. 중대백로, 쇠백로 및 해오라기의 개체수도 공사기간동안 감소하였다. 둥지목의 벌목과 번식지의 일부가 절개된 후 백로류의 둥지는 도로변에서 번식지의 안쪽으로 이동하는 경향이 나타났다. 조사기간 동안 번식지내 백로류의 분변으로 인한 고사목의 증가와 태풍으로 인한 도복으로 둥지목의 그루 수는 감소하였고, 둥지목 당 번식 둥지의 수는 늘어났다. 둥지목의 구성비율은 매년 소나무의 비율이 낮아지고, 아카시와 참나무의 비율이 증가하였다.

Salmonella enterica subsp. enterica infections in eastern great egrets (Ardea alba modesta)

  • Jeong, Hansol;Shin, Geewook;Yi, Seungwon;Kim, Eunju;Lee, Haebeom;Yang, Myeon-Sik;Lim, Chae-Woong;Kim, Bumseok
    • 대한수의학회지
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    • 제56권2호
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    • pp.129-131
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    • 2016
  • Five eastern great egrets with a history of ataxia, wry neck, and wet feathers were submitted to the Veterinary Diagnostic Center for pathologic examination. Slightly enlarged livers with diffuse white-grayish nodules were observed. Microscopically, the hepatic and lung parenchyma contained granulomatous lesions consisting of central necrosis. Some hearts showed myofiber necrosis with infiltration of histiocytes and heterophils. Partial 16SrRNA and gyrB gene sequences of all isolates showed high similarities (99-100%) to those of Salmonella (S.) enterica subsp. enterica. Based on pathological and molecular biological results, S. enterica subsp. enterica systemic infections were diagnosed in eastern great egrets of Korea.

강원도 횡성지성 백로의 소장 흡충류 감염상태 (Trematode infections in the small intestine of Egretta alba modesta in Kangwon-do)

  • 양용석;안영겸;윤무부
    • Parasites, Hosts and Diseases
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    • 제29권3호
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    • pp.227-234
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    • 1991
  • 1990연 6월부터 9월 사이에 강원도 횡성군의 백로 서식지에서 12마리의 중대백로를 포획하여 소장 내의 흡충류 감염 상태를 조사하고 아울러 검출된 흡충의 형태 특징을 관찰하여 종을 분류한 결과 5종의 흡충 Metagonimus sp. (67%), Centrocestus armntus(67%), Echinochasmus japonicus(50%), Strigea falconis(83%)와 Diplostomidae요(33%) 감염이 분류동정되었다. 이상의 결과로 중대백로는 인수공통기생충의 보유숙주로서 중요한 인체 기생충의 매개조류임을 알 수 있었다. Key words: Metagonimus sp., Centrocestus armatus, Echinochasmus iaponicus, Strigea falconis, Diplostomidae, Egrets, Hoengseong-gun (Kangwon Province)

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Vertical nest stratification and breeding success in a six mixed-species heronry in Taeseong, Chungbuk, Korea

  • Park, Shi-Ryong;Kim, Kwan-Yong;Chung, Hoon;Choi, Yu-Seong;Sung, Ha-Cheol
    • Animal cells and systems
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    • 제15권1호
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    • pp.85-90
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    • 2011
  • In 2001, we conducted a study to assess the effects of differential arrival times and nest-site selection on reproductive performance in a mixed-species heronry consisting of six species in Taeseong-ri, Chungbuk, Korea. We recorded the arrival dates, nest heights, clutch sizes, and brood sizes after 15-20 days of the age of the birds' chicks. The grey herons and cattle egrets arrived first and last, respectively, on the colony site. In the homogenous vegetation structure of the breeding site, the pitch pine trees (Pinus rigida) were mainly used for building nests on 48 of the 50 pine trees (96%). The breeding species vertically stratifies the nest sites according to their body size, except for the cattle egrets and black-crowned night herons that nested at sites higher than those predicted from their body size. The mean nest success rates of the six species under study were positively correlated with the mean nest heights. Our findings suggest that aggressive interspecific interactions among neighbors influence nest-site selection to enhance breeding success.

시화간척지에 도래하는 물새류 현황 및 보전 방안 (Conservation and Status of Waterbirds on Sihwa Reclaimed Area)

  • 이시완;송민정;이한수;최종인
    • 한국습지학회지
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    • 제6권1호
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    • pp.73-87
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    • 2004
  • 시화간척지에 도래하는 물새류는 70종에 최대개최수 합계가 169,351개체이었다. 군집별로는 오리류가 22종, 도요류 20종, 백로류 9종 및 갈매기류 5종순으로 나타났다. 월별 개체수는 3월이 95,465개체로 가장 많았으며, 2월과 11월에도 70,000개체 이상으로 높게 나타났지만, 4월~6월에는 7,000개체 이하로 나타났다. 연중 1회 최대 출현개체수에서 최우점종은 58,627개체로 34.6%를 점유한 고방오리(Anas acuta)로 나타났다. 다음으로 24.5%인 청둥오리(Anas platyrhynchos), 13.6%인 흰죽지(Aythya ferina), 6.1%인 괭이갈매기(Larus crassirostris), 5.0%인 흰뺨검둥오리(Anas poecilorhyncha) 및 2.69%인 검은머리흰죽지(Aythya marila)순이었다. 시화간척 지에는 노랑부리백로(Egretta eulophotes), 저어새(Platalea minor), 노랑부리저어새(Platalea leucorodia), 혹고니(Cygnus olor), 큰고니(Cygnus cygnus) 및 검은머리물떼새(Haematopus ostralegus) 등의 희귀조류가 서식 및 번식하고 있었다. 주로 시화호의 수변부에서 먹이활동을 하고 있었으며, 수변부 뒤쪽의 간척지(배후습지)를 휴식 및 서식공간으로 활용하고 있었다. 특히 검은머리물떼새는 칠면초(Suaeda japonica)와 퉁퉁마디(Salicornia herbacea) 등이 자라고 있는 간척지를 번식지로 이용하고 있었다. 시화호가 매립과 간척, 수변부에 조성되는 해안도로, 송전철탑 건설 및 농지확보를 위한 방조제 조성 등으로 물새류의 서식 및 번식지가 훼손되고 있는 시점에서, 이곳에 도래하는 물새류를 번식조류, 통과조류 및 겨울철새로 구분하여 각각에 대한 보전 방안이 마련되어야 한다. 특히, 먹이원 확보, 서식지인 수변부와 번식지인 수변부 뒤쪽의 배후습지의 유지 및 외지섬, 형도, 음섬과 시화 상류갯골이 연계되는 생태계 벨트 구축 등에 의한 물새류 보전이 필요하다.

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