太湖鼋头渚地区鹭类觅食生境研究

连续 2a实地调查了太湖鼋头渚地区鹭鸟的觅食生境 ,并搜集其雏鸟的反吐物 ,初步掌握了该地区不同鹭鸟对觅食生境的选择与食物组成情况。结果表明 ,无锡鼋头渚地区白鹭与夜鹭主要在鱼塘、湖泊觅食 ,白鹭在湖滨觅食 ,而夜鹭还会到湖中央水面觅食 ;池鹭觅食区域较广 ,主要在鱼塘。鹭群主要的食物类型是鱼类 ,白鹭食物几乎全为鱼类 ,夜鹭 95 %的食物为鱼类 ,兼有少量的蛙类、甲壳类和小型哺乳类动物。

Karyological and morphometric variation of the North African green frog Pelophylax saharicus (Anura) in northeastern Africa

Morphometric variation ofPelophylax saharicus was analysed using univariate and multivariate statistics, with both traditional and geometric morphometrics, based on 148 specimens from four different geographical localities in Tunisia and Algeria. The results show the existence of three morphotypes in Tunisia and one in Algeria, and indicate a significant degree of variation in morphometric characters between regions. Specimens from the southernmost region have the smallest body size and the greatest morphometrie divergence from other populations. This pattern of morphometric variation probably results from phenotypic plasticity in response to local environmental factors. The results of our chromosomal study （C-, Ag-NOR-, endonuclease digestion, DAPI, CMA3 and Q-banding） reveal this species to exhibit the plesiomorphic Pelophylax karyotype of 2n=26 biarmed chromosomes and NORs on the eleventh pair. Similarities and differences of the North African green frog are discussed in relation to the different forms of data collected （chromosomal, morphometric, ecological） [Current Zoology 56 （6）： 678~586, 2010].

Comparison of the water-crossing behavior of Western Marsh Harriers(Circus aeruginosus) and European Honey Buzzards(Pernis apivorus) during autumn migration

We investigated the water-crossing behavior of Western Marsh Harriers(Circus aeruginosus),mostly adults,and European Honey Buzzards(Pernis apivorus),mostly juveniles,in relation to wind conditions,time of the day,flocking and age classes,at a watchsite in central Italy during the autumn migration en route to Africa.Although European Honey Buzzards are less suited than Western Marsh Harriers to undertake long sea crossings,they were more inclined to leave the coast when migrating in flocks.Few birds of both species chose to fly along the coast.Western Marsh Harriers,such as European Honey Buzzards migrating alone,undertook the water crossing rather than stopping migration(birds roosting at the site or flying back inland) during the absence of wind and vice versa during head winds.Conversely,European Honey Buzzards migrating in flocks were not affected in their decision(crossing or stopping migration) by wind direction.Both species undertook the water crossing rather than stopping migration during mornings and vice versa during afternoons.Finally,in both species,adults and juveniles showed the same behavior in front of a water barrier.This result was expected in the case of the Western Marsh Harrier but not from the European Honey Buzzard since,in this species,the water-crossing tendency is age dependent with adults avoiding sea crossings.Our study confirms that flocking significantly affects the water-crossing behavior of European Honey Buzzards during migration.Moreover,in this species,inexperience of juveniles and presumably younger adults,about the high energetic costs of long powered flight and about the existence of shorter routes over water,might explain the strong water-crossing tendency shown by migrants independently from their age.

西西里:欧洲南缘内陆水的管理:呼唤部门之间相互对话

自60年代末期以来,在北欧和中欧之间,以及在地中海周边各个国家之间,在环境意识上存在着一种日益增长的矛盾。直至最近,在南欧,巨大的公共工程被看作是发展经济的主要推动力,并被认为是解决失业问题的一项措施,而反对破坏自然资源却被看成是对发展经济的一种'威胁'。在这种情况下,政府机构和私人公司均认为没有必要考虑他们工程计划的前因和后果。其结果是。