大嘴乌鸦繁殖生态的初步研究

本文为大嘴乌鸦繁殖生态的研究报告。研究内容主要有大嘴乌鸦的栖息生境。数量统计,繁殖习性。观察得知大嘴乌鸦５月上旬产卵,窝卵数３－６枚,大小平均３４．９×３６．９毫米,卵重平均１５．３克,孵化期１５－１６．５天,育雏期２７－３１天。     

大嘴乌鸦繁殖生态的初步研究

大嘴乌鸦繁殖生态的初步研究任建强,安文山,薛恩祥,胡玉娥,杨向明,郝映红山西庞泉沟国家级自然保护区交城０３０５１０关于大嘴乌鸦Ｃｏｒｖｕｓｍａｃｒｏｒｈｙｎｃｈｕｓ的繁殖生态资料甚少。我们于１９９０、１９９１和１９９２年的３－７月,在庞泉沟地区（东经...     

大嘴乌鸦种群结构及活动规律的初步研究

1985—1987年在山西庞泉沟国家级自然保护区对大嘴乌鸦的种群结构和活动规律进行了研究。指出在251只样本中,有成体136只、幼体115只;成幼体之比:1∶0.85;雌雄之比:1∶0.79。阐明该鸟全年活动规律具有5个时期:1.越冬期(12月至翌年2月)。2.动乱期(每年的3月)。3.繁殖期(4—6月)。4.同巢鸟活动期(6月下旬—7月底)。5.集群活动期(8—11月)。     

高寒地区大嘴乌鸦春季集群与活动规律

在2004年春季,对高寒地区大嘴乌鸦（Corvus）的集群与活动规律进行了调查研究,共设置了35个有代表性的样线。大嘴乌鸦的集群大小以小规模为主,特别是以配对的形式进行繁殖活动（占46％）,平均每群（±SD）1．9±1．1只。大嘴乌鸦栖息的生境类型主要划分为电线杆生境、住宅区生境、土堆．矮桩生境、树林生境和草地生境等,其中大嘴乌鸦在住宅区生境、土堆-矮桩生境中的集群具有多样化的形式。显示出它们特有的反捕食策略和取食特性。在大嘴乌鸦3种主要的活动中,觅食行为主要集中在中午一段时间（12：00-14：00）,飞行行为高峰在下午（16：00-17：00）,上午活动比例最高的是停息行为（07：00～12：00）。这些都说明了它们长期地对高寒环境的适应性。     

海口地区鹊鸲（Copsychus saularis）在人工巢箱中的繁殖参数及巢捕食

繁殖是鸟类生活史的重要环节;巢捕食被认为是影响鸟类生活史特征的生态因子之一。准确估测鸟类的繁殖成功率;掌握巢捕食及其影响因子对了解其种群动态具有重要意义。本研究于2021年和2022年两个繁殖期;对海口地区人工巢箱内繁殖的鹊鸲（Copsychus saularis）的繁殖生态以及巢捕食进行了研究。结果表明:（1）鹊鸲最早产卵日期为3月19日;最晚产卵时间为7月4日;窝卵数（4.47±0.57）枚（n=57）;孵化期（13.30±1.47）d（n=33）;卵重（2.28±0.65）g（n=25）;卵长径和短径分别为（22.21±0.84）mm和（16.38±0.37）mm（n=25）;日坐巢率70.85%±5.92%（n=40）;不同时间段内坐巢时长无显著性差异（F=0.479, df=5, P=0.820）;（2）育雏期（13.32±1.18）d（n=37）;不同时间段内亲鸟喂食次数存在显著差异（F=19.832,df=14, P<0.05）;05:00—06:00（P=0.023）和18:00—19:00（P=0.043）时段喂食次数明显小于其他时段;（3）繁殖成功率为69.49%;孵化率为73.36%;出飞率为73.16%;繁殖力为2.36只;（4）巢捕食率为18.64%;主要巢捕食者包括隐纹花松鼠（Tamiops swinhoei）、黄胸鼠（Rattus tanezumi）和蚁类（Formicidae spp.）等。本研究记录到鹊鸲的清巢行为和非亲雄性杀雏案例;为后续探究鹊鸲的性选择研究奠定了基础。     

大山雀对巢箱颜色的识别和繁殖功效

为了确定大山雀对巢箱颜色是否能够识别和对繁殖功效的影响,以利于更好的进行保护,于2007—2010年3—7月,在吉林省左家自然保护区,通过悬挂黑、蓝、绿、白和红色巢箱,对大山雀的入住状况和繁殖参数进行了调查和分析。结果显示:2007、2008、2010年红色巢箱的入住率最高,2009年低于平均值;窝卵数除2010年红色巢箱组略低于其它颜色组平均值外,其它年份略高于其它组,而各年份的出飞数红色组均高于其它组。将其它组的合并均值与红色组进行了方差分析,结果表明,窝卵数之间无显著差异,而出飞数之间则有显著差异(F=17.65,df=1,P=0.04),表明红色组的出飞数高于其他组的平均值。     

人工巢箱条件下白眉姬鹟的繁殖参数

2005～2006年,在吉林省左家自然保护区的次生林中,对人工巢箱条件下白眉姬鹟(Ficedulazanthopygia)的繁殖参数开展了初步研究.结果表明,人工巢箱中自眉姬鹟的窝卵数为5～7枚,平均6.0枚;卵重平均为1.6 g.卵大小平均为17.0 mm×13.1 mm.孵化期平均为13.1 d,每巢平均出雏5.4只,育雏期平均为12.8 d,每巢平均出飞雏鸟5.3只.白眉姬鹟的营巢成功率为70.0%,繁殖成功率为81.3%.     

悬挂巢箱对次级洞巢鸟类选择天然洞的影响

于2005～2007年3～7月采用在试验样地中添加巢位(悬挂巢箱)与对照样地比较的方法,探讨悬挂巢箱是否影响天然洞的入住率,并为次级洞巢鸟类提供巢位资源,进而增加繁殖种群的数量.结果发现,无论是试验样地还是对照样地,总的入住数量年间差异不显著,种类间差异显著;天然洞之间(无论是否悬挂巢箱)的入住率差异不显著;人工巢箱与...     

人工巢箱条件下的大山雀巢捕食

于2004—2008年在次生阔叶林中,采用悬挂巢箱的方法对大山雀的巢捕食作了研究。结果表明:不同年龄巢箱的被捕食率显著不同,新巢箱被捕食率最低,第2年被捕食率最高,第3年下降很大,第4年又略有上升。被捕食巢的窝卵数极显著的低于未被捕食巢的窝卵数。影响巢捕食的主要生境因子为巢箱高度和巢上盖度,其次为灌木的密度和高度。     

不同纬度洞巢鸟类对人工巢箱的利用及差异

迄今对洞巢鸟类生活史特征的纬度变异（特别是热带洞巢鸟类的繁殖）了解还十分有限。我们于2018年3至8月,分别在海南吊罗山（热带）、河南董寨（亚热带）和河北塞罕坝（温带）的林缘地带,悬挂相同规格的人工巢箱招引洞巢鸟类繁殖,用以比较不同地理区域的洞巢鸟类对人工巢箱的利用情况及其孵化成效和繁殖成功率。野外共悬挂577个木制巢箱,3个研究地的利用率在海南吊罗山为最低（32.6%）,河南董寨最高（92.0%）。3个地点均有大山雀（Parus cinereus）入住（占总巢数的84.3%）,其孵化成效和繁殖成功率在3个地点不存在显著差异（P > 0.05）。但在河北塞罕坝,大山雀的孵化成效（75.7%）和繁殖成功率（65.7%）显著低于同域繁殖的褐头山雀（Poecile montanus）（97.7% 和97.7%）和煤山雀（Periparus ater）（93.5%和90.3%）（P < 0.05）。研究表明,3个地理区域利用巢箱繁殖的洞巢鸟的种类、数量以及对巢箱的利用率均存在差异,但对于广布种大山雀来说,地理位置的差异并不影响其孵化成效和繁殖成功率。     

Hybrid zone maintenance by non-adaptive mate choice

In a spatial simulation we show that formation of a stable, narrow hybrid zone requires no selection, only that individuals can recognize their own population type since this is a prerequisite for assortative mating. The European crow occurs in two species/subspecies that meet in a long hybrid zone, the black carrion crow Corvus corone and the grey and black hooded crow C. cornix. In a previous study (Brodin A, Haas F (2006) Anim Behav 72:139) we mimicked sexual imprinting in nestling crows with artificial neural networks, using a learning process that simulates proximate retina perception. The networks were trained on 700 images to recognize either carrion, hooded or hybrid phenotypes as their own. After training the networks were exposed to 300 new, unfamiliar pictures of crows. The networks that had been trained on pure subspecies then showed strong preference for their own type. Networks trained on hybrid crows showed weaker preference for their own type. Assuming that these preferences will determine mate choice preferences we have combined them with empirical data on dispersal of young crows to investigate what kind of geographical distribution pattern this would create. We then assume that the two subspecies meet and hybridize along a straight border. In only 60 generations a stable, narrow hybrid zone that resembles the real hybrid zone was formed. This zone remained stable over time. With minor adjustments of parameters the results would not only fit the width but also the shapes of the clines in the field. An erratum to this article can be found at     

Adoptions in a coδoperative population of Carrion Crow Corvus corone corone

Capsule Adoptions occurred at low rate (2.6% of successful nests and 1.1% of fledglings), probably as a result of a mistake in early offspring recognition.     

Formation of linear dominance relationship in captive jungle crows (Corvus macrorhynchos): implications for individual recognition

Jungle crows (Corvus macrorhynchos) flexibly change their social forms depending on their age, time of the day, and the season. In the daytime, paired adults behave territorially and unpaired subadults form small flocks of ten birds, whereas at night hundreds of birds roost together. In the breeding season, pairings remain in their nest all day. This fission-fusion raises questions about the underlying social structure and the cognitive capability of jungle crows. In this study, dyadic encounters were used to investigate dominance relationships (linear or non-linear) and the underlying mechanisms in captive jungle crows. Fourteen crows were tested in 455 encounters (i.e., 5 encounters per dyad), and a stable linear dominance relationship emerged. Sex and aggressiveness were determinants as individual characteristics for dominance formation. Males dominated females, and more aggressive individuals dominated less aggressive ones. Aggressive interactions in dyads occurred primarily during the first encounter and drastically declined during subsequent encounters without any signs of a confidence effect. These results suggest that, in captive jungle crow, a linear form of dominance is intrinsically determined by sex and aggressiveness and maintained extrinsically by memories of past outcomes associated with specific individuals, implying individual recognition.     

Increased landscape heterogeneity supports the conservation of European rollers (Coracias garrulus) in southern Hungary

European rollers (Coracias garrulus) were almost extinct from large parts of Hungary in the 1970–1980s. However up till now their population size increased considerably, mainly due to a nature conservation campaign, supplying artificial nest-boxes for breeding. We studied which factors affected rollers’ occurrences at the landscape scale in southern Hungary, under natural circumstances and when artificial nest-boxes were supplied. We analyzed the composition and the configuration of the landscape at two spatial scales. We found that beside the presence of natural grasslands, heterogeneous landscape provided high quality breeding and hunting sites favorable for rollers. Even though habitat characteristics of roller territories with natural holes or nest-boxes were similar, breeding sites without artificial nest-boxes harbored higher coverage of forests and heterogeneous agricultural areas. Sites with occupied and unoccupied nest-boxes considerably overlapped, suggesting that the available habitats were not saturated. Nest-box supplementation proved to be an effective tool for rollers’ conservation in areas where natural nesting sites were limited, but prey resources were available. Consequently, the preservation of landscape heterogeneity is a key factor which should be taken into consideration in the conservation management of roller populations.     

The hollow shell: Loïc Wacquant's vision of state,race and economics

Wacquant's ‘Marginality, Ethnicity and Penality in the Neo-liberal City’ makes important contributions to our understanding of the role of state in shaping patterns of racial domination under neo-liberal regimes. As important as his contributions are, however, two major flaws in his conceptual framework undermine the utility of his approach for either scholarly analysis or political intervention. First, Wacquant systematically and incorrectly downplays the role of capitalism in shaping the dynamics of racial domination under neo-liberalism. Second, Wacquant, by focusing on what he calls ‘hierarchies of honour’, misses the essence of the racial order in the USA and worldwide – a racial order that continues to promote white supremacy as a system of exploitation and domination.     

Interracial status competition and southern lynching, 1882–1930

This article provides theoretical grounds and empirical evidence that different types of lynching in the post-Reconstruction South were driven by social processes at different levels of analysis. County-level analyses based upon new detailed data on lynchings in Georgia and Louisiana from 1882 to 1930 reveal that ‘private' lynchings, perpetrated by small groups outside the public purview without manifest ritual, were related to whites’ interracial status and social identity concerns on the interpersonal level, whereas ‘public' lynchings, involving larger mobs and ritualized violence, appear unaffected by such dynamics. These results validate relational and interactionist perspectives on violence, lend support to calls for disaggregation in the study of racial, ethnic, and nationalist violence, and shed light on the intertwining of racial identity formation with the generation of racial inequalities. They also carry implications for the study of contemporary ethno-racial hate crime.