Abundance,feeding, and morphology of passerine birds at Kowhai Bush,Kaikoura, New Zealand

Abstract

Five-minute stationary counts of birds at Kowhai Bush over 17 months suggest that the scores for grey warblers and chaffinches may reflect vocal conspicuousness, rather than abundance, and that the scores for shining cuckoos, goldfinches, and redpolls may reflect vocal and visual conspicuousness in combination. Counts in three types of kanuka forest show that cuckoos, robins, and bellbirds favoured the more dense and diverse suocessional stages; that riflemen, brown creepers, fantails, chaffinches, goldfinches, and redpolls were most abundant in less mature habitats; and that warblers and silvereyes were almost uniformly common. Cuckoos and robins overlapped the most in use of habitat, robins and redpolls the least. For both warblers and robins, indices of abundance varied between two of the habitats in proportion to the densities of resident adults, permitting calibration of the indices. Excepting creepers and robins, native species were apparently less abundant at Kowhai Bush than in climax forest near Reefton. At Kowhai Bush in winter, creepers, warblers, and silvereyes (three of the four small native gleaners of foliage) collected prey almost entirely from kanuka, the dominant tree. Warblers foraged on 80% of occasions from living foliage, whereas creepers fed almost equally from trunks, branches, twigs, and leaves, and silvereyes concentrated on leaves and trunks. Creepers and silvereyes overlapped the most in use of feeding stations. Also, they were exclusively gleaners, whereas warblers caught prey on 40% of occasions by hovering. Warblers gleaned only in the upright position, but creepers and silvereyes often gleaned from vertical surfaces or by hanging upside down. The greatest overlap in feeding behaviour was between creepers and silvereyes. Data for four of the five small native insectivores show that warblers were half as heavy as creepers and silvereyes, and lighter on average than fantails. The tail was longer than the wing in fantails, shorter than the wing in silvereyes, and equal to the wing in warblers and creepers. The ratio of wing length to tarsometatarsus length was greatest for fantails (3.4), as befits an aerial feeder. Warblers, silvereyes, and fantails had bills that were wider than deep; the creeper’s was slightly deeper than wide. Silvereyes had the longest bill, and creepers the longest tarsometatarsus. Indices of morphological difference show that silvereyes and creepers differed least.     

豚鹿的饲养管理与繁殖

本文报道成都动物园豚鹿的饲养管理、疾病预防和繁殖。适宜的饲养环境、宽敞的兽舍、高纤维含量和多样化的食物是豚鹿正常生长发育、繁殖的重要因素。     

The impact of intra- and interspecific interactions on young-of-the-year brook charr, in temperate lakes

The abundance, growth, spatial distribution, and feeding habits of five allopatric brook charr, Salvelinus fontinalis, populations (young-of-the-year, 0+ juveniles; YOY) were compared with five other populations living sympatrically with white sucker, Catostomus commersoni. The study was made in oligotrophic lakes of the Laurentian Shield (Québec, Canada) during three sampling periods in 1989 (July, August and September). The abundance of YOY charr was significantly higher in allopatric than in sympatric populations (45·3 ± 3·8 vs 3·4 ± 3·8 fish/lake caught in 1773 m² of gillnets; P<0·005). The mean length of YOY charr did not differ among allopatric and sympatric populations at each sampling period; July: 60·2 ± 3·0 vs 60·0 ± 4·5 mm; August: 61·9 ± 4·5 vs 63·2 ± 4·1 mm; September: 77·9 ± 8·7 vs 77·3 ± 7·8 mm respectively. Horizontal distribution of allopatric YOY charr did not differ from that of sympatric charr, 65% of the fish being captured within the first 2 m depth and the rest between 2 and 7 m depth. In contrast, the vertical distribution of allopatric YOY charr from both communities was significantly different; 81% of allopatric charr were captured within 0·5 m from the substrate compared to 64% for sympatric charr (P<0·001). Differences in vertical distribution of the fish were related to differences in diet; allopatric charr fed mainly on benthic and large planktonic organisms whereas sympatric charr fed less on these organisms and more on terrestrial organisms. In the lake where YOY charr were most abundant, individuals were spatially segregated into two groups; one ‘littoral’, found in 0–2m depth, and one ‘profundal’, found in 3–6 m depth. Growth, condition, and feeding habits of charr from the two groups were different, especially during the last sampling period.     

Feeding preference of Zetzellia mali: does absolute or relative abundance of prey matter more?

The importance of the acarine predator, Zetzellia mali, in the control of phytophagous mites in apple orchards is not well understood. Zetzellia mali tends to prefer the eriophyid, Aculus schlechtendali, over the economically more significant tetranychid, Panonychus ulmi, but quite a wide range of preference values have been reported in the literature. In sets of laboratory choice trials, we determined that prey preference of this predator varies with the relative but not absolute density of its prey. We attempt to explain these results in terms of behavioural mechanisms and discuss the potential implications of our results for the effectiveness of Z. mali in the biological control of phytophagous mites in apple orchards.     

Cleaning Activity of Juvenile Angelfish, Pomacanthus paru, on the Reefs of the Abrolhos Archipelago, Western South Atlantic

Studies on fish cleaning symbiosis in the tropical western Atlantic concentrate on specialized cleaner gobies and wrasses. On the reefs of the Abrolhos Archipelago, off the eastern Brazilian coast, juvenile french angelfish, Pomacanthus paru, clean a rich and varied community of fish clients. We recorded 31 reef fish species, including large predators such as groupers, jacks, and morays, being serviced by the french angelfish on cleaning stations situated mostly on seagrass flats. The angelfish performs a characteristic fluttering swimming at the station and, during cleaning events, touches the body of the clients with its pelvic fins. Frequency of encounters between the cleaner and its clients do not reflect the local abundance of client species; most of these move from the reefs to the sand flats to be cleaned. We found no correlation between client size and duration of cleaning events. The conspicuous black and yellow pattern, the fluttering swimming, the tenure of cleaning stations, the physical contact with the client, and the varied community of clients, qualify the juveniles of P. paru as specialized cleaners comparable to the gobies of the genus Elacatinus.     

长白山北坡阔叶红松林及其次生白桦林高等植物物种多样性比较

应用Ｓｉｍｐｓｏｎ和Ｓｈａｎｎｏｎ多样性指数及其相应的均匀度,对阔叶红松林及其次生白桦林的高等植物物种多样性进行了对比研究．结果表明,对于木本植物,次生白桦林物种多样性高于阔叶红松林;而对于草本植物,情况正好相反．但在次生白桦林中,无论木本植物还是草本植物,占优势的物种都是一些常见种,而许多阔叶红松林中的珍稀或特有物种在次生白桦林中数量很少,有些甚至完全消失．对群落各种群多度分布的检验表明,２种森林类型中,无论木本植物还是草本植物,各种群的多度分布都遵从对数级数分布．     

Histopathology of Soybean Roots Infected with Heliocotylenchus dihystera

Soybean roots infected with Helicotylenchus dihystera in a greenhouse were stained with acid fuchsin in lactophenol or sectioned and stained with safranin and fast green. Adults and larvae were observed in semi-endoparasitic and endoparasitic feeding positions. Adults, larvae and eggs were observed within the root cortex posterior to the region of maturation. Small brown lesions, affecting the walls of six to ten cells, were observed in the immediate vicinity of the nematode. Endoparasitic nematodes were usually coiled within the walls of one or two cells. Cytoplasm of the infected cells appeared normal, and there was no indication of nuclear proliferation. Walls of the infected cells were thickened and llgnified, but there was no indication of swelling or giant cell formation. Uncoiled nematodes usually were aligned parallel to the vascular tissue, but were not consistently oriented with respect to the root apex. Nematodes moved through cell walls rather than between them; however, no persistent burrows were observed.     

北京东灵山地区植物群落多样性的研究 Ⅲ.几种类型森林群落的种-多度关系研究

选用描述种－多度关系的二类共８个模型（对数级数分布ＬＳ、对数正态分布ＬＮ、负二项分布ＮＢ和几何分布ＧＯＭ以及“分割线段”模型ＢＳＭ、生态位优先占领模型ＮＰＭ、Ｚｉｐｆ模型ＺＭ和Ｚｉｐｆ－Ｍａｎｄｅｌｂｒｏｔ模型ＺＭＭ）对东灵山地区９个类型的森林群落进行了研究。结果表明,ＬＳ和ＮＢ对大多数群落可以很好地拟合,ＬＮ和ＧＯＭ对每一个群落都不能很好地拟合;ＺＭＭ可以很好地、ＮＰＭ也可以较好地拟合每一个群落,ＺＭ可以很好地拟合大多数群落,而ＢＳＭ则反之。ＬＳ中的参数α与４个丰富度指数呈极强的线性关系,与３个多样性指数也有较强的线性关系。因此,α可以作为群落的一个多样性指数使用,并且它更多地反映了群落的丰富度。本研究也表明,将包含多个参数的非线性方程组逐渐化为只含一个参数的非线性方程,再将ＭｏｎｔｅＣａｒｌｏ方法、区间二分法和迭代法相结合以求解该方程,从而实现参数估计,这种算法是可行的;在拟合三参数模型ＺＭＭ时,先固定参数β,再通过线性化求出另外２个参数,经过多次计算,求出一组参数值作为下一步非线性方程拟合的初值,这种算法也是成功的。在进行种重要性顺序－多度表模型的评价时,不能只考虑剩余标准差或相关指数,它们是基于误差平方和的两个指标,对真实的误差有某种夸张作用;应该尽可能地考虑平均绝对误差这个指标。     

江苏常州地区农林甲虫调查初报

1991～2002年对江苏常州地区农林鞘翅目昆虫进行了调查,共采集到甲虫83种,隶属于16科69属,其中11种为江苏省新记录。同时记述了各种甲虫的学名和食性。     

长白山阔叶红松林物种多度和空间分布格局的关系

应用随机分布多度模型和聚集分布多度模型,探讨不同研究尺度下物种多度和空间分布格局的关系.结果表明,预测的物种多度不仅受物种分布面积大小的影响,还受其聚集程度的影响.物种多度和空间分布格局的关系存在着明显的尺度效应,即随着研究尺度的增加,无论是随机分布多度模型还是聚集分布多度模型,通过物种空间分布格局来预测物种多度的准确度都在下降.聚集分布多度模型预测物种多度的结果要好于随机分布多度模型,这表明该区大多数物种是聚集分布的.由于物种的空间分布格局不同,不同物种多度的预测值和真实值之间的差异也不同.因此,为了进一步提高模型预测的准确性,进一步考虑不同物种的生活史特性是必要的.     

纺锤水蚤摄食生态学研究进展

纺锤水蚤(Acartia)是温带、亚热带近岸水域优势的小型桡足类,在区域生态系统的物质循环与能量流通中起着重要作用。综述了国内外对纺锤水蚤食性、摄食机制、摄食影响因子及摄食转化效率的研究工作:纺锤水蚤为杂食性,偏爱高营养的动物性饵料,摄食浮游植物和微型浮游动物时分别采取滤食策略和伏击策略,摄食过程受到自身生理状态和环境因子的共同调节。其对食物的利用效率约为60%,其他40%通过Sloppy feeding和排泄等方式以溶解形式释放到海水中。目前摄食研究多以实验模拟为主,自然现场研究手段有限,分子生物学技术有望促进认识其在自然生态系统中的地位与作用。     

干季晴天橡胶林林窗温度剖线分布特征

以林窗北侧林缘为中心,研究了西双版纳地区橡胶林林窗及周国Ｎ－Ｓ样带上气温水平梯度分布。结果表明：干季落叶期林窗及周边主要热力作用面在地面,但林缘的增温效应也相当明显,各热力作用面热量收支是林窗小气候形成的物理基础;林缘冠层结构,林缘乔木高度与林窗直径之比,太阳高度角,方位角,天气状况将影响林窗辐射平衡各分量的变化,林缘乔木群落结构的不同是造成林窗小气候差异最直接的原因;