Habitat selection and bird community in a mature beech forest

在长野县东北部Kaya-no-daira的一片成熟的山毛榉森林中建立了一块10公顷的研究地块。鸟儿被捕获，并用彩带进行个体识别。我收集了三年来鸟类的繁殖表现数据，从5月份建立领地到7月份最晚的幼鸟羽化，以及包括觅食和互动在内的所有其他类型的行为数据。由于冬季积雪很深，只有一小部分繁殖鸟类(主要是洞巢鸟)在那里过冬。在繁殖群落中，越冬种如Parus ater、P.Major、Dendrocopos main、Sitta Europaea等占主导地位。另外两个数量丰富的物种(夏季访客)是水仙(Ficedula Narcissina)和变色水母(Emberiza Aribilis)。前者是洞巢鸟，后者是沙地草丛中的巢鸟。丰富的6种物种在整个地块形成了领地，而其他一些物种，如Cettia diphone，E.spdocephala，其领地仅限于t…。更多的是林缘和林冠林隙，这表明林冠林隙为边缘栖息物种提供了森林内的繁殖栖息地。这六个物种中的一些雄性在一年多的时间里形成了地块。在这些情况下，雄性在不同年份的领地位置几乎是一样的，这表明个体雄性可以根据“定居在你以前繁殖过的地方”的原则来选择栖息地。这六个丰富的物种通常在它们的觅食位置上垂直分开。但这种隔离在5月中旬随着积雪融化和树叶剥落而瓦解；所有物种都将觅食地点转移到树叶上，并反复攻击山毛榉的叶子。这种转变可能与这一时期食叶昆虫的大量涌现有关，并表明在融雪前严重的食物匮乏时期，存在一个决定鸟类群落结构的重要过程。此外，还提出了洞巢鸟类间存在种间竞争的现象。较少

A study plot of 10ha was set up in a mature beech forest at Kaya-no-daira in north-eastern part of Nagano Prefecture. Birds were captured and color-banded for individual identification. I collected data on breeding performances of birds starting from territory establishment in May to fledging of the latest young in July for three years, with all other kinds of behavioral data including foraging and interactions. As the plot is covered with deep snow during winter, only small portion of breeding bird species (mainly cavity-nesters) winter there. The wintering species, e.g.Parus ater, P.major, Dendrocopos major, Sitta europaea, however, dominated in the breeding community. Two other abundant species (summer visitors) were Ficedula narcissina and Emberiza variabilis. The former is a cavity-nester and the latter is a nester in sasa-bush. The abundant six species formed territories all over the plot, while some other species, e.g.Cettia diphone, E.spodocephala, had territories confined to t … More he forest-edge and canopy gaps, which suggests that canopy gaps supplied edge-dwelling species with breeding habitats within the forest. Some males of the six abundant species formed territories in the plot for more than a year. In these cases, the positions of the territories of a male were almost the same between years, suggesting that individual males could select habitats on the Principle 'settle where you bred before.'The six abundant species were generally segregated vertically in their foraging positions. But this segregation collapsed with snow-melting and foliation in mid-May ; all the species shifted their foraging sites to the foliage and repeatedly attacked leaves of beech. This shift is probably related to the flush of leaf-eating insects at this period, and suggests the existence of an important process determining the bird community structure during the severe, food-poor period before snow-melting. Existence of interspecific competition between cavity-nesters for nest-cavities was also suggested. Less