Nest site tenacity and mate fidelity in the Black-headed Gull(Chroicocephalus ridibundus)

Breeding philopatry is well known in the Black-headed Gull(Chroicocephalus ridibundus).Using a capture-markrecapture method,we studied if Black-headed Gulls show nest site tenacity and mate fidelity as well,and investigated if there are differences between a stable,and a newly established and fast-growing colony,as well as for differences between the center and edges of these colonies located in north-eastern Germany.We found a high level of nest site tenacity in the center of the stable colony on B?hmke Island,and lower degrees of nest site tenacity at the edge of the same colony and in the newly established and fast-growing colony on Riether Werder.Mate fidelity was very strong in all individuals which returned to their previous breeding place,regardless of the nest site location.

Distribution and Status of the Pallas’s Gull Ichthyaetus ichthyaetus(Pallas,1773)in the Reservoirs of the Palearctic:Review

The Pallas’s Gull Ichthyaetus ichthyaetus is a piscivorous gull,some local populations of which are rare and vulnerable.The review presents data on the status and distribution of the Pallas’s Gull in the reservoirs of the Palearctic-water bodies in which the water level is controlled by humans.The aim of the study was to assess the current state of the species in the reservoirs of the Palearctic.The review was based on 1080 publications found in the search engines Yandex,Google,Google Scholar,eLybrary.During the last 35 years,the Pallas’s Gull has been found in 63 reservoirs of the Palearctic.Breeding has been established in 11 reservoirs,breeding has not been established in 43 reservoirs,and birds were present in 9 reservoirs,but the status was not specified.Two-thirds of the reservoirs where the gull was recorded or bred were located in the European part and only 1/3 in Asia.It is assumed that up to 5000 adults(0.45%-4.0%of the global population of the species)breed annually in the reservoirs of the Palearctic,and the reservoirs are not the main habitats for maintaining and reproducing the population of the species.The majority of the breeding population reproduces in natural water bodies,and the reservoirs of the Palearctic are important for the maintenance of non-breeding individuals.Detection of presumed breeding and new breeding colonies in reservoirs north of the historical range of the species has been established on the Russian Plain,in the Urals and Trans-Urals.The reservoirs of Russia play a leading role in providing breeding sites for the species in water bodies of this type.An analysis of the data allows us to state the important and increased role of reservoirs in the modern distribution and expansion of the range of the Pallas’s Gull in the Palearctic.

卫星跟踪青海湖繁殖地渔鸥的迁徙路线

2006年7月下旬至2007年7月底,共有4只佩带卫星信号发射器(PTT)的渔鸥完成秋季和春季迁徙并返回青海湖。ARGOS公司提供的信息表明,渔鸥最早离开青海湖繁殖地的时间是8月2日,最晚在8月14日。离开青海湖后没有直接飞往越冬地,而是在青海湖周围游荡或逗留。游荡或逗留地点距离青海湖最近约200km,最远约1300km,逗留时间长达80余天。4只渔鸥的越冬地点都在孟加拉湾,与青海湖间的直线距离约2100km。最早到达越冬地的日期是11月3日,最迟12月3日,历时81～116d。渔鸥在孟加拉湾的居留时间长达4个月(118～149d)。最早离开的日期是3月1日,最迟3月30日。最早返回青海湖的日期是3月23日,最迟4月17日。除1只以外,其他3只渔鸥的春、秋2季迁徙路线很不相同。春季迁徙历时最短只用6d,另外3只分别历时15、18和32d。历时32d的渔鸥先到宁夏逗留20d,然后再返回青海湖。结合分析春、秋2季的迁徙路线,分别确定了不同迁徙季节的主要停歇地点。

卫星跟踪青海湖繁殖水鸟的迁徙

2006年7月至2007年7月,利用卫星跟踪技术,全年跟踪15只青海湖繁殖水鸟的运动。其中,4只渔鸥和1只斑头雁成功到达越冬地并安全返回青海湖。本文结合卫星跟踪在鸟类迁徙方面的应用,比较详细地介绍青海湖繁殖水鸟渔鸥和斑头雁的迁徙动态和迁徙路线,可为分析青海湖周边地区乃至中亚—印度迁徙通道内鸟类迁徙与禽流感的关系提供重要依据。

青海可鲁克湖水鸟季节动态及渔鸥活动区分析

2008—2010年,对青海可鲁克湖的水鸟季节动态进行了调查。共记录到54种34828只水鸟,隶属于6目11科,雁鸭类水鸟最多,共统计到28445只,占水鸟总数的81.7%;其次是鸥类和鸻鹬类。可鲁克湖在水鸟春秋季迁徙高峰期在4月和10月,这也是水鸟多样性较高的两个月,其主要原因是由于迁徙鸭类数量和种类的增加。卫星跟踪表明,可鲁克湖是青海湖繁殖渔鸥重要的停歇地,渔鸥在可鲁克湖的停歇天数每年也有所不同,2007年和2008年秋季较2006年停歇时间短一些,初步判断与当地的人为干扰有关。当地政府对道路进行修建,其正好位于渔鸥的活动区内,这对渔鸥的日常活动造成较大影响,迫使渔鸥提前离开可鲁克湖。春季停歇天数的不同主要与青海湖面冰融的时间有关,若青海湖由于温度较高,冰融的时间早一些,渔鸥可能提前离开可鲁克湖,前往青海湖进行繁殖活动。

西藏鸟岛考察

１９８６—１９９１年，考察了西藏近９０９％的地区，共发现鸟岛１７座。其中１６座位于青藏高原，１座位于横断山脉之中，每座鸟岛的面积１ｈｍ２左右，大部分鸟岛位于海拔４２００—４７００ｍ之间，淡水湖与咸水湖均有、但盐湖中未发现鸟岛。鸟岛中鸟类栖息密度达１—２只／ｍ２，而鸥类可达１０．只／ｍ２。主要繁殖鸟类有棕头鸥（Ｌａｒｕｓ，ｂｒｕｎｎｉｃｅｐｈａｌｕｓ）、渔鸥（Ｌａｒｕｓｉｃｈｔｈｙｏｅｔｕｓ）、斑头雁（Ａｎｓｅｒｉｎｄｉｃｕｓ）和普通鸬鹚（Ｐｈａｌａｃｒｏｃｏｒａｘｃａｒｂｏ）等。鸟岛是青藏高原多种水鸟的重要集中繁殖地，应注意保护和研究。