城市公园植被特征对陆生鸟类集团的影响

城市公共绿地是城市生态系统中重要的鸟类栖息地,其植被特征对鸟类集团存在显著影响。在通过分析植被特征对陆生鸟类集团的作用,从而为公园合理配置植被来提高其作为野生动物栖息地的生态服务功能提供理论基础。2009年10月至2011年10月,采用样线法对上海滨江森林公园进行鸟类调查,利用主成分分析划分鸟类集团,用高度定义植被层次,用卡方检验分析鸟类行为在植被层次上的差异。结果表明,滨江森林公园陆生鸟类群落在乔木层的栖息行为和运动行为频次显著多于其在灌木层和地被层的行为频次,在地被层的取食行为频次显著多于其在乔木层和灌木层的行为频次。陆生鸟类可划分为8个鸟类集团,鸟类集团之间存在栖息、运动和取食空间生态位的重叠。食虫拾取集团、杂食拾取集团、食肉飞取集团和植食拾取集团在栖息、运动和取食空间生态位上均存在较高的重叠度,其通过食性分离各自空间生态位。食虫探取集团和食虫飞取集团互为栖息空间生态位重叠度最高集团,其通过取食方式的不同来实现生态位的分离。根据公园植被特征对鸟类集团的影响结果对上海市公园绿地植被配置提出了建议。     

大别山山地次生林鸟类群落集团结构的季节变化

2007年12月—2008年12月,在大别山鹞落坪,对落叶阔叶次生林鸟类的集团结构的季节变化特征进行了研究。采用连续取样法采集鸟类取食行为数据,用聚类分析法对繁殖和非繁殖季节鸟类群落进行集团划分,通过无倾向对应分析（DCA）对32种森林鸟类的两个季节资源利用特点进行了研究。结果表明,鸟类群落在非繁殖季节可以分为地面、灌丛、树干（枝）、冠层等4个取食集团,而在繁殖季节还出现空中取食集团;候鸟影响鹞落坪次生林鸟类群落取食集团的结构,产生新的取食集团。DCA的第一轴主要代表鸟类取食高度信息,第二轴主要代表鸟类取食位置信息,第三轴代表鸟类取食方式和取食基质信息;用DCA前两轴对32种鸟类排序表明,有6种鸟主要在第一轴发生变化,有4种鸟主要在第二轴发生变化。     

广西弄岗喀斯特森林繁殖鸟群落的集团结构

于2010、2011和2012年5—7月在广西弄岗国家级自然保护区对喀斯特森林繁殖鸟类群落的集团结构进行了研究。对44种繁殖鸟类的取食方式、取食基层和取食高度进行聚类分析和主成分分析。其结果如下:(1)鸟类群落可分为6个取食集团,分别为地面取食集团、下层取食集团、上层取食集团、多层取食集团、树干取食集团和空中出击集团;(2)与其他森林类型的鸟类群落集团结构相比,喀斯特季节性雨林的鸟类群落以中、下层取食鸟类为主,多层取食集团次之。其原因可能是:弄岗喀斯特森林植被结构和鸟类食性特点形成了中下层取食的鸟类种数占优势的现象;鸟类以扩展各自生态位宽度方式来缓解竞争压力,从而形成了多层取食集团这一特点。     

安徽沿江浅水湖泊越冬水鸟群落的集团结构

长江中下游湖泊是越冬水鸟的重要栖息地,随着湖泊渔业养殖强度的不断加大,湖泊湿地严重退化,水鸟的越冬生态受到影响。为揭示长江中下游浅水湖泊越冬水鸟对湿地资源的利用特征,2008年12月至2009年3月,通过扫描取样法采集安徽省长江沿江升金湖、菜子湖和武昌湖3个浅水湖泊30种越冬水鸟的取食行为百分比数据,利用聚类分析法对越冬水鸟进行集团划分,并采用无倾向对应法(DCA)分析越冬水鸟的取食特征。聚类分析结果表明,安庆沿江湖泊越冬水鸟群落可分为4个集团,即深水取食集团G1、挖掘和啄取集团G2、浅水取食集团G3和泥滩拾取集团G4。G2集团的鸟种最多,共有13种,优势种为鸿雁(Anser cygnoides)、豆雁(Anser fabalis);G3集团次之,共6种,优势种为小天鹅(Cygnus columbianus)、白琵鹭(Platalea leucorodia);G4集团共5种,优势种为黑腹滨鹬(Calidris alpina)、鹤鹬(Tringa erythropus)和红脚鹬(Tringa totanus);G1集团水鸟种类有6种。这些水鸟的觅食生境主要在湖泊滩涂和浅水区域,其食物资源的可利用性和觅食对策共同决定群落组成结构。DCA分析表明,取食方式及取食时运动方式组成的觅食对策决定了集团食物资源的分割,草滩中取食鸟类主要采用静止取食和啄取方式,泥滩取食集团主要采取拾取及奔-停取食,深水区取食集团则主要采用潜水方式取食,因此,维持湖泊不同区域的丰富食物资源对于保护湖泊丰富的水鸟资源具有重要意义。     

鼎湖山森林鸟类群落的集团结构

本文应用生态学中正在发展的集团理论,分析了鼎湖山季风常绿阔叶林繁殖季节鸟类群落的组成。该鸟类群落由28种鸟组成。根据鸟类的取食方法、取食基层和取食高度取定的取食行为格局,使用了聚类分析法和主分量分析法把这鸟类群落划分为8个不同的取食集团。由于集团内成员的取食行为格局十分相似,把群落划分为集团后,更有利于研究群落内种间的相互作用,也便于了解群落内资源分割的情况。文中讨论了划分鸟类集团的依据,并就集团理论及其应用作了探讨。     

森林/草原过渡地带鸟类群落空间结构研究

1993～ 1998年夏季间研究了森林 /草原过渡地带鸟类群落结构及与该生境的关系。共记录鸟类 10 3种。该地区不同生境类型鸟类相互渗透 ,鸟类组成混杂 ,4种环境梯度鸟类群落的相似性系数较低 ,鸟类群落结构随环境变化而呈现出明显的水平梯度变化。森林区是鸟类栖息的主要生境 ,由林缘至林内 5 0m和由林缘至草原 3 0m范围内为鸟类的高密度带。鸟类群落结构随森林植被垂直空间层次复杂性的不同而有明显的空间变化 ,群落物种多样性和均匀性具有垂直空间变化。通过聚类分析和主分量分析将鸟类群落划分为 6个垂直空间栖息取食集团 ,各集团根据各自的栖息取食行为格局分割了生境的空间和食物资源 ,集团内部的鸟类则通过更为细致的生态分割和加剧生态位重叠而得以共存。     

南京中山植物园鸟类对香樟 果实（种子）的取食

香樟(Cinnamomum camphora)是亚热带地区广泛分布的常绿阔叶树种,其果实数量多、果期长,可为鸟类提供大量食物资源。2018年11月至2019年2月,借助Safari 10×26变焦双筒望远镜,采用焦点扫描法对南京中山植物园内访问香樟果实(种子)的鸟类行为进行观察,详细记录鸟类的种类、取食基质、取食次数、取食时间、取食数量和取食方式等信息。研究期间有效记录达48d,累计记录到27种鸟类1021次取食香樟果实(种子)行为,存在2种取食基质(地面和树上)和3种取食方式(整吞果实、啄食果肉和取食种子)。T检验显示,不同鸟类对香樟果实(种子)的取食次数存在显著差异(t=3.096,df=26,P 0.01);不同月份间鸟类对香樟香樟果实(种子)的平均访问只数、平均取食次数、平均取食时间和取食数量均存在极显著差异(P0.001)。白头鹎(Pycnonotussinensis)、乌鸫(Turdusmendarinus)和灰喜鹊(Cyanopicacyanus)是访问次数及取食量最多的3种鸟类。单因素方差分析(One-way ANOVA)表明,上述这3种鸟类的取食数量存在极显著差异(F3, 598=25.219,P 0.001)。按照时间统计,11月份访问的鸟类种类和数量最多,1月份鸟类的取食次数、时间和数量最多。鸟类的形态特征(体重、体长和嘴峰长)与取食数量呈显著正相关,其中,体重和体长对取食数量的影响比嘴峰长的影响更显著,但嘴峰长影响鸟类对果实的取食方式。在鸟类常活动和停歇的树木下方地面往往散落着较多表面洁净、无果肉包裹的香樟种子,且园内人工林和自然更新林地可见许多香樟幼苗,表明鸟类对香樟具有潜在传播作用。     

黄臀鹎秋冬季食性及取食生态位的初步观察

2009年10月14日～12月30日,用定点直接观察法对云南曲靖地区(103°14ˊ～103°37ˊE,25°41ˊ～25°52ˊN)黄臀鹎Pycnonotus xanthorrhous的食性和取食空间生态位进行了初步观察.黄臀鹎秋冬季主要在乔木中层、树冠、灌丛等处取食,以乔木中层取食频次最高,占总取食频次的62.98%,其次是树冠和灌从,分别占15.64%和12.74%.虽然黄臀鹎秋冬季为杂食性鸟类,但其主要以植物性食物为主,占总取食频次的97.6%,而动物件食物仅占2.4%.     

人类休闲活动对森林鸟类群落无有害影响

我们对西班牙马德里森林深处(未受到人类干扰)、森林小路沿线(间或有徒步旅行者经过)以及森林野餐区(有较持久干扰)的鸟类进行了调查,以查明人类休闲活动对该地区鸟类群落的分布和多度的影响.结合样方法对以上3类区域鸟类群落的总体特征(如:鸟类的多度、物种的丰富度和多样性)、不同鸟类群体的特征(如:鸦科鸟类的多度,营巢或者取食集团的特征)、各鸟种的多度等参数进行了比较.结果表明:小路沿线和野餐区样方内鸟类的多度和物种丰富度比森林深处更高,已查明14种鸟类的多度在人为干扰区域比森林深处高,只有5种鸟类的多度在森林深处更高一些;在树冠层筑巢的鸟类、在树干和地面觅食的鸟类及鸦科鸟类在休闲活动区有更高的多度;地巢性鸟类在休闲区的多度较低,这种差别尤以阔叶落叶林中加明显.而森林小路的鸟类群落结构与森林内部非常相似,说明人类休闲活动对这些林区鸟类群落的影响更多缘自野餐.原因是野餐区常常具有以下特点:具有高大的乔木、中层植被稀疏、有较多的洞和缝隙以及野餐后会遗留下一些垃圾.以上结论与研究的预期目标正好相反,人类的这些休闲活动可能会降低地巢性鸟类的适宜度,但是对大多数鸟的类栖息地没有不利影响.     

鸟类取食中国沙棘果实的方式及其对种子的传播作用

2003年9月～2004年3月,定期观察取食中国沙棘果实的鸟类及其取食方式。共记录取食中国沙棘果实的鸟类18种,其取食果实的方式主要有：1)直接在树冠上吞食果实,有时候在吞食后将种子呕出;2)将果实从树上衔走后,在栖息处吞食或啄食;3)将果实啄落至地面,然后取食果肉和种子,留下果皮;4)啄破果皮,吸食果肉,留下果皮及种子;5)从顶端将果皮啄破后,仅取食里面的种子。不同的取食方式决定了它们对沙棘种子的传播作用不同。收集鸟粪便中的种子与完整的干果实及人工剥离果肉和内果皮的种子做萌发对比实验,结果表明,鸟类消化道过程对种子的萌发有一定影响,但萌发率仍较高。沙棘为多种鸟类提供食物,而鸟类则为沙棘传播种子,它们之间形成一种互利关系。     

Seasonal dynamics of guild structure in a bird assemblage of the central Monte desert

Most studies of ecological guilds consider guild membership as a fixed attribute of species, and the guild structure as a fixed attribute of a community. Consequently, almost no study tackled the examination of temporal changes in the guild structure of a particular assemblage. We used data on foraging patterns of central Monte desert birds to assess seasonal differences in resource use by resident species, and to examine seasonal changes in the guild structure of the assemblage. From 1993 until 1999, we quantified the use of foraging substrates, manoeuvres, and height strata, and the utilisation of plants by 18 bird species. Resident species showed different kinds of seasonal dynamics, from no noticeable to drastic changes in their foraging patterns. Seasonal changes in guild structure were remarkable. Only two guilds were present all year round (ground foragers and foliage foragers), although they suffered important species turnover. Three other guilds had a seasonal occurrence: graminivores (during the non-breeding season), arboreal herbivores, and aerial feeders (during the breeding season). Two species changed from one guild to another between seasons. Both presence–absence of migrant species, and changes in the feeding ecology of resident species had an influence on the temporal dynamics of guild structure. These factors appeared to be related with changing resource availability, especially with the birds’ ability for facing lean conditions through migration and with the opportunistic use of seasonally superabundant resources. Our results undermine the trust in studies in which guild structure was assessed irrespective of temporal variations. We show also that guild membership is not a fixed attribute of a species: we should rather evaluate the individuals’ resource use in a given moment to assign them to a guild, instead of obtaining a single measure purporting to represent a species’ fixed attribute.     

Effects of windthrow disturbance on a forest bird community depend on spatial scale

Community structure is expected to be affected by spatial heterogeneity in a landscape. We examined the spatial-scale-dependent effects of windthrow caused by a large typhoon on a forest bird community. Typhoon events of this magnitude are rare in Hokkaido, Japan, occurring only once or twice a century. To assess the “functional spatial scale” at which bird groups (community, species, body-size class, and foraging guild) specifically responded to landscape heterogeneity, the canopy gap rate (CGR, gap percentage) was evaluated at different spatial scales by varying the radius of a circular landscape sector from 100 to 500 m stepwise by 10 m. We then analysed bird community responses, in terms of species richness and abundance, to CGR. Bird species richness did not significantly depend on CGR. In contrast, abundance was significantly dependent on CGR in many groups (species, body-size class, and foraging guild). The guild-level response was clearer than the species-level response, which suggests that the integration and filtration of species traits by guild can reveal a clear response of bird abundance to the extent of canopy gaps. For example, the scale dependence of responses to disturbance clearly varied among body-size classes, where larger birds had larger functional spatial scales. These results reveal that different groups of organisms have different functional spatial scales at which they respond to habitat heterogeneity. Our results also suggest that monitoring only a small number of species could be misleading for conserving biodiversity at the landscape level.     

The impact of cattle grazing regimes on tropical savanna bird assemblages

Globally, agricultural land use is implicated in the decline of avifauna. In rangelands (areas used for livestock grazing), bird community responses to grazing can be complex, species‐specific and scale dependent. A greater understanding of bird responses to grazing will lead to more meaningful management recommendations. We tested the hypothesis that foraging height predicts bird species’ responses to grazing, such that species using lower vegetation strata are most likely to respond to the impacts of livestock grazing. We examined the response of a tropical savanna bird community to four grazing strategies at a long‐term grazing trial in northern Australia. We predicted that ground‐foraging guilds would be more responsive to grazing treatment than foliage‐ or aerial‐foraging guilds. We analysed the bird community assemblage using generalised linear mixed models and examined individual species’ abundance in relation to microhabitat variables. We found that while ground‐foraging guilds were more responsive to grazing treatment, individual species dynamics within a foraging guild could be contradictory. For example, the red‐backed fairy‐wren decreased in abundance with increased grazing and was positively associated with grass and shrub (Carissa ovata) cover, whereas Australian magpies increased in abundance in the most heavily grazed paddocks. In general, the responses of bird species to grazing were more pronounced in guilds that forage closer to the ground, but whether the responses were positive or negative was driven by bird species ecology. Measures examining the responses of individual species are more useful than assemblage measures (such as richness) to describe the impacts of anthropogenic disturbance such as grazing.     

Relationships between bird community and habitat structure in shelterbelts of Hokkaido,Japan

Summary The relationship between the bird community and habitat structure in wind shelterbelts of Ishikari district was examined.Breeding birds were classified into nesting guilds (hole, canopy, and bush) and also into foraging guilds (outside, canopy, and bush) Both density and species richness in the outside-foraging guild were positively related to forest age variables. On the other hand, bird density in all three nesting guilds and the other two foraging guilds (canopy and bush) was correlated with the vegetation cover of their nesting or foraging sites, and species richness was positively correlated with tree species complexity variables.Bird species diversity (BSD) was closely related to tree species complexity, but not to foliage height diversity (FHD) within woods. However, if woods were re-classified into two groups such as natural and artificial and these were separately analysed, the correlation between BSD and FHD was significant.From these results, it is concluded that both FHD and tree species complexity should be considered together in order to predict BSD within forests. A new index is proposed for this purpose, and its usefulness discussed.     

千岛湖陆桥岛屿鸟类集团对栖息地片段化的敏感性及其季节变化

为探究千岛湖陆桥岛屿不同鸟类集团对栖息地片段化敏感性的差异和季节变化,于2009年4月—2012年1月鸟类繁殖季(4、5、6月)和冬季(11、12、1月)对千岛湖41个陆桥岛屿鸟类集团进行了研究。结果表明,冬季杂食鸟对片段化敏感性高于食虫鸟,繁殖季时二者无显著差异,繁殖季和冬季时下层鸟对片段化敏感性均高于林冠鸟,冬季留鸟对片段化敏感性高于候鸟,繁殖季则无显著差异。杂食鸟和留鸟对片段化敏感性存在季节差异,而食虫鸟、林冠鸟、下层鸟和候鸟对片段化敏感性均无季节差异。不同鸟类集团对栖息地片段化敏感性的差异和季节变化规律,有助于人们在栖息地管理和保护区设计时采取更有针对性的鸟类保护措施。     

Vertical stratification of an avian community in New Guinean tropical rainforest

Vertical stratification of avian communities has been studied in both temperate and tropical forests; however, the majority of studies used ground-based methods. In this study we used ground-to-canopy mist nets to collect detailed data on vertical bird distribution in primary rain forest in Wanang Conservation Area in Papua New Guinea (Madang Province). In total 850 birds from 86 species were caught. Bird abundance was highest in the canopy followed by the understory and lowest in the midstory. Overall bird diversity increased towards the canopy zone. Insectivorous birds represented the most abundant and species-rich trophic guild and their abundances decreased from the ground to canopy. The highest diversity of frugivorous and omnivorous birds was confined to higher vertical strata. Insectivorous birds did not show any pattern of diversity along the vertical gradient. Further, insectivores preferred strata with thick vegetation, while abundance and diversity of frugivores increased with decreasing foliage density. Our ground-to-canopy (0–27 m) mist netting, when compared to standard ground mist netting (0–3 m), greatly improved bird diversity assessment and revealed interesting patterns of avian community stratification along vertical forest strata.     

The ecology of mangrove forest birds in Peninsular Malaysia

The density, distribution and feeding ecology of birds of mangrove forests in Selangor on the west coast of Peninsular Malaysia were investigated between February and May 1989. Excluding aerial hunters and wading birds, 47 species were recorded from four mangrove forest sites in Selangor, though undoubtedly some rarer species were missed due to the brevity of the study. The estimated density of birds, using fixed-width transects, ranged from 15 to 26 birds per ha. One quarter of all birds counted belonged to just one species, the Ashy Tailorbird Orthotomus ruficeps. Excluding ground feeders (three species), four foraging guilds were recognized among 17 of the commonest bird species: obligate foliage-foraging insectivores (seven species), bark-foraging insectivores (four), facultative nectar-ivores (five) and aerial hawkers (one). Species within the first and third guilds apparently were partitioned by foraging technique and heights, while those of the second guild (woodpeckers) differed mainly in their selection of plant species. The horizontal distribution of several species corresponded to the zonation of mangroves. Avifaunal differences between sites reflected differences in forest floristics. The greatest number of species occurred at the dry landward edge site, which supported seven bird species not encountered elsewhere in Selangor. This habitat has almost completely disappeared from much of the peninsula owing to land reclamation. Four of the six resident mangrove-specialized bird species in Selangor were regularly recorded at two or more sites, another (Greater Gol-denback Woodpecker Chrysocolaptes lucidus) occurred at only one site and the last (Ruddy Kingfisher Halcyon coromanda) was never recorded. Two species of sunbirds probably play an important role in the pollination of several species of mangroves. The colonization of anthropogenic habitats by many mangrove-dwelling bird species is attributed partly to their generalized foraging niches, which may have evolved in response to regular fluctuations in food availability and the dynamic physiography of mangrove communities.