湖北武汉发现小美洲黑雁

正2015年11月22日,在湖北省武汉市东西湖区府河柏泉段(30°45′10″N,114°9′15″E)观察并拍摄到小美洲黑雁(Branta hutchinsii)1只(图1),隶属于雁形目鸭科黑雁属。该雁所发现之处,为长江一级支流——府河流经武汉柏泉的河段,该河段夏季被高水位所淹,冬季水位降低后,露出草滩,河道则因人为挖筑的堤岸而形成一个面积数百亩的开阔水面,中间有若干泥土堆积而成的小岛。同域分布有豆雁(Anser fabalis)、灰雁(A.anser)、绿头     

云南省鸟类新纪录——黑腹滨鹬、彩鹮

<正>2010年11月21日在云南省昆明市呈贡大学城关山水库(海拔1940m,地理坐标102°50'E,24°49'N)进行鸟类调查时,观察并拍摄到一只鹬,拍摄距离约为10m。经查阅有关文献资料,该鹬为黑腹滨鹬Calidris alpine,系云南省鸟类新纪录。关山水库是一个以灌溉为主的小型水库,但在冬季会有多种水鸟在此越冬。除了黑腹滨鹬外,在调查中还记录到白鹭、牛背鹭、池鹭、苍鹭、红嘴鸥、反嘴鹬、黑翅长脚鹬、矶鹬、白腰草鹬、金眶鸻、小、凤头、普通鸬鹚、赤麻鸭、翘鼻麻鸭、斑嘴鸭等水禽。     

内蒙古鸟类新纪录——丑鸭

<正>2014年6月15日,在内蒙古赛罕乌拉国家级自然保护区(44°13'28″N,118°43'9″E)进行野生动物多样性调查时,于上午11∶00左右在阿山河水库发现1只体长约40 cm的雁形目鸭科游禽在水中取食,在距其约100 m处,利用施华洛世奇ATS25-60×65单筒望远镜观察发现:该鸟虹膜暗褐色,嘴和脚均为灰色;上体羽及胸部以棕黑色为主,嘴基部有大片白斑,扩展至鼻基部,头部耳羽后侧有一个大白斑;胁部为褐色,下腹褐色较浅。根据其形态特征,查对相关资料(约翰·马敬能等,2000;郑光     

湖北武汉发现长嘴半蹼鹬

正2014年4月7至25日,在湖北省武汉市江夏区汤逊湖千亩塘(30°26'48″N,114°24'27″E)观测到长嘴半蹼鹬(Limnodromus scolopaceus)1只,隶属于鸻形目鹬科半蹼鹬属。该鹬被发现于一大型荷塘内,同域分布有扇尾沙锥(Gallinago gallinago)、林鹬(Tringa glareola)、鹤鹬(T.erythropus)、泽鹬(T.stagnatilis)等鹬科鸟种。借助蔡司60倍单筒望远镜观察,并拍摄下图片及视频后发现,该鹬中等体型,与扇尾沙锥近似,但比鹤鹬小。具长而粗的嘴,全嘴色深。白色眉纹明显。上体体羽深褐色,具浅色羽缘。尾上覆羽具横斑。下体色浅,胸     

吉林向海发现白颊黑雁

正2018年5月3日傍晚在位于吉林省白城市通榆县的吉林向海国家级自然保护区鹤类核心区青年坝附近(44°59′51.5″N,122°17′52.1″E,海拔168 m)使用NIKON-D4相机800 mm定焦镜头拍摄到1只黑白相间雁类,拍摄距离约120 m。经查阅相关文献(段文科等2017)确定本次发现的鸟类为白颊黑雁(Branta leucopsis)。     

河南三门峡湿地发现斑头雁

正2019年3月5日16:30时在河南三门峡市天鹅湖湿地的双龙桥(111°08′E,34°46′N,海拔330 m)附近湖边发现1只灰色的雁混杂在大天鹅(Cygnus cygnus)群中一起取食。该灰色雁头顶部白而头后有两道黑色条纹,喉部白色延伸至颈侧(图1),查阅相关工具书(约翰×马敬能等2000),鉴定为斑头雁(Anser indicus)。观察期间发现该个体还飞到青龙湖大坝附近浅滩上取食和休息。3月6日继续在双龙桥附近观察到1只斑头雁,推测应为同一个体,至3月7日以后再也没有观察到斑头雁。根据郑光     

DHEA levels and social dominance relationships in wintering brent geese (Branta bernicla bernicla)

After testosterone, dehydroepiandrosterone (DHEA) is the main hormone involved in aggressive behaviour in birds. While the role of DHEA has been verified for wintering territorial passerines, it has not been shown for gregarious species. In wintering geese species, both sexes present very low testosterone levels and aggression in a non-sexual context is not testosterone-related. Therefore, testosterone does not seem to be responsible for aggressive behaviour by geese during winter and the role of DHEA must be explored. We used brent geese (Branta bernicla bernicla) to examine the roles of testosterone and DHEA in dominance relationships. For the first time, we highlighted the presence of plasma DHEA in free-living geese. As the level of DHEA was lower than that of testosterone, and there was no obvious impact of DHEA level on dominance status, our results failed to confirm the role of plasma DHEA in the social hierarchies of this species during winter. Nevertheless, because DHEA levels were greater in singletons than in paired birds, we discuss the need to explore hormonal and/or behavioural mechanisms implicated within dominance status acquisition and maintenance within each reproductive status class, to underline the role of the presence of relatives as a signal of dominance abilities. We also acknowledge and discuss the possibility that the long handling time may have affected DHEA levels and masked subtle differences between individuals.     

Variation in body mass dynamics among sites in Black Brant Branta bernicla nigricans supports adaptivity of mass loss during moult

Birds employ varying strategies to accommodate the energetic demands of moult, one important example being changes in body mass. To understand better their physiological and ecological significance, we tested three hypotheses concerning body mass dynamics during moult. We studied Black Brant in 2006 and 2007 moulting at three sites in Alaska which varied in food availability, breeding status and whether geese undertook a moult migration. First we predicted that if mass loss during moult were simply the result of inadequate food resources then mass loss would be highest where food was least available. Secondly, we predicted that if mass loss during moult were adaptive, allowing birds to reduce activity during moult, then birds would gain mass prior to moult where feeding conditions allowed and mass loss would be positively related to mass at moult initiation. Thirdly, we predicted that if mass loss during moult were adaptive, allowing birds to regain flight sooner, then across sites and groups, mass at the end of the flightless period would converge on a theoretical optimum, i.e. the mass that permits the earliest possible return to flight. Mass loss was greatest where food was most available and thus our results did not support the prediction that mass loss resulted from inadequate food availability. Mass at moult initiation was positively related to both food availability and mass loss. In addition, among sites and years, variation in mass was high at moult initiation but greatly reduced at the end of the flightless period, appearing to converge. Thus, our results supported multiple predictions that mass loss during moult was adaptive and that the optimal moulting strategy was to gain mass prior to the flightless period, then through behavioural modifications use these body reserves to reduce activity and in so doing also reduce wing loading. Geese that undertook a moult migration initiated moult at the highest mass, indicating that they were more than able to compensate for the energetic cost of the migration. Because Brant frequently change moult sites between years in relation to breeding success, the site‐specific variation in body mass dynamics we observed suggests individual plasticity in moult body mass dynamics.     

Shared or Unshared Parental Care in Overwintering Brent Geese (Branta bernicla hrota)

We examine brood size effects on the behaviour of wintering parent and juvenile brent geese (Branta bernicla hrota) to test predictions of shared and unshared parental care models. The behaviour of both parents and offspring appear to be influenced by declining food availability over the winter. Parental vigilance increased with brood size and may be explained by vigilance having functions in addition to antipredator behaviour where the benefits are shared among the brood. There was no increase in parental aggression with brood size and this does not fit the prediction of shared care. Nevertheless, large families are able to monopolize better feeding areas compared with smaller families and large families static feed more but walk feed less than do small families, the former apparently being the preferred mode. The presence of additional young, rather than increasing the amount of parental aggression, seems to enhance the family's competitive ability. Because parents with large broods benefit from enhanced access to resources there is likely to be no additional significant cost in the parental care of larger broods (sensu Trivers 1972 ).