Nest complexity correlates with larger brain size but smaller body mass across bird species

Amniotes differ substantially in absolute and relative brain size after controlling for allometry, and numerous hypotheses have been proposed to explain brain size evolution. Brain size is thought to correlate with processing capacity and the brain's ability to support complex manipulation such as nest-building skills. The increased complexity of nest structure is supposed to be a measure of an ability to manipulate nesting material into the required shape. The degree of nest-structure complexity is also supposed to be associated with body mass, partly because small species lose heat faster and delicate and insulated nests are more crucial for temperature control of eggs during incubation by small birds. Here, we conducted comparative analyses to test these hypotheses by investigating whether the complexity of species-typical nest structure can be explained by brain size and body mass (a covariate also to control for allometric effects on brain size) across 1353 bird species from 147 families. Consistent with these hypotheses, our results revealed that avian brain size increases as the complexity of the nest structure increases after controlling for a significant effect of body size, and also that a negative relationship exists between nest complexity and body mass.     

Nest site selection of the great spotted woodpecker Dendrocopus major in two oak woods in southern England and its implications for woodland management

Nest site selection of the great spotted woodpecker Dendrocopus major in two mature oak woods in southern England over an 11-year period is examined. Data describing the characteristics of 106 nest trees and sample surveys of available trees in the woods are used in the analyses. Although approximately equal numbers of nests were found in living and dead trees the latter were so rare in the study woods that this result represented an extremely strong selection for dead trees. Birch Betula spp. and elm Ulmus sp. were the major dead trees used. The smallest diameter tree used for nesting was 18 cm at breast height, although overall 90% of the nests were in trees of diameter 28 cm or greater. Apart from the minimum diameter, there was no strong selection for the use of large diameter trees for nesting, although this would probably not be expected in mature woodlands such as those in this study. The implications of the results for the management of woodlands for nesting woodpeckers are discussed.     

Studies on the Psammolittoral Meiofauna of Algoa Bay

The meiofauna communities at three tide levels on a sheltered and an exposed beach have been analysed and compared. Twenty-nine nematode, eight harpacticoid and two mystacocarid species and species groups have been used. A similarity analysis indicated three distinct communities, one occurring in sand that dries out during low tide, one occurring in fine sand that remains saturated during low tide and one occurring in coarser sand that remains saturated during low tide. Diversities decreased from high to low tide levels on both beaches regardless of meiofauna numbers. The distribution of nematode feeding types is discussed.     

森林道路对山雀类利用人工鸟巢的影响

于2002 年11月至2003年6 月间, 在韩国安养首尔大学冠岳植物园(37°25'05"N,126°56' 85"E)阔叶林、针叶林和针阔混交林内研究了森林道路对山雀类利用人工鸟巢的影响。对在人工巢箱中繁殖的山雀类,杂色山雀(Parus varius)、沼泽山雀( P. palustris)和大山雀(P. major)的繁殖对的数量、巢位、窝大小、卵重及卵大小进行了调查。调查结果显示,在 3 个研究区,杂色山雀在森林内部(距离道路 75–150m)的繁殖对数量,比森林边缘(距离道路 0–75 m)多,其窝大小、卵重等尺寸也明显比森林边缘高,但沼泽山雀基本不受森林道路的影响。在人类活动频繁的地区人工巢箱为洞穴鸟类提供良好的繁殖条件。人工鸟巢的设置将有利于这些鸟类的保护和管理。表 3 参 16。     

利用挂鸟巢招引益鸟防治森林食叶害虫试验

通过对不同的鸟巢类型、在不同坡位悬挂鸟巢招引益鸟防治食叶害虫试验,结果表明:对于大山雀式、寒鸦式,鸟巢悬挂2个.hm-2招引率高,选择在阳坡及阳缓坡,树高4～6 m处悬挂鸟巢效果最佳。间伐地块,翌年鸟巢随即挂上,可提高招引率,降低虫口密度。通过悬挂鸟巢有效地控制了落叶松人工林内食叶害虫的危害。     

内蒙古杭锦旗穿沙公路两侧生态环境建设评价

穿沙公路位于内蒙古伊克昭盟杭锦旗 ,从独贵塔拉到锡尼镇 ,穿越库布齐沙漠 ,全长 1 1 5 km。本文对穿沙公路建设前后两侧植被状况进行考察和对比 ,对路沟两侧沙障内及沙障外沙丘的植物种类及情况进行比较 ,进而找出公路建成后水分、土壤和植物三者的变化情况 ,对公路两侧的植被状况和生态环境作出评价 ,为公路两进一步的生态、环境建设提供依据。     

Factors Affecting Nest Success and Predator Assemblage of Breeding Birds in Semiarid Grasslands

Woody encroachment has influenced wildlife distributions and, thus, predator-prey dynamics, for many taxa in North American grasslands. In 2015 and 2016, we examined how vegetative characteristics influenced avian nest predator assemblages and nest predation rates in semiarid grasslands of south Texas, where encroachment of woody plant species is common. We monitored 253 nests of 17 bird species and deployed infrared cameras at 107 nest sites within four vegetation types at our study sites. We also used data from a concurrent, multispecies monitoring project within our study area to assess predator activity within these same vegetation types. We divided bird species into four nest types based on nest shape and size (i.e., small, medium, and large cup-shaped nests and exposed nests with little structure). We then used logistic regression to examine relationships between shrub cover, concealment, and distance to edge and the probability of nest success and predation by snakes. We observed a significant decrease in nest success of our medium-sized, cup-shaped nest type when shrub cover increased at the nest site, indicating small increases in shrub cover (≈ 10%) could have substantial impacts on birds using this nest type. Snakes were our primary predator at camera-monitored nests (59%), and snake activity increased by 6.7% with every 10% increase in shrub cover at the nest site. Mesomammalian and large mammalian predators were most active in vegetation types predominated by herbaceous cover, small mammals were most active in vegetation types predominated by woody cover, and snake activity was highly variable. Predator activity did not reflect predator identity at camera-monitored nests, suggesting that potential nest predator activity may not accurately reflect the risk of nest predation. Results of our study will help inform management of bird species using semiarid grasslands affected by woody encroachment and offer recommendations for improved nest success.     

背负式喷雾喷粉机的现状及发展

作物病虫草害是农业生产的最大障碍,实施防治其危害的植保机械,是保证增产稳产的重要措施.植保机械使用技术严重落后的现状与高速发展的农药水平极不相称,已严重妨碍了农作物病虫草害的防治,带来了诸如农药有效利用率低、农产品中农药残留超标、环境污染、作物药害、操作者中毒等负面影响,造成了不应有的损失以及其他不良后果.为此,植保机械需从结构、配套产品、药水配制和用材等多方面进行改进,以推进植保技术发展.     

沙地治理与利用的现实途径—毛乌素沙地中日合作研究综述

为了探讨沙地治理途径，改善沙区环境条件，合理利用沙地的光、热、水、土、生物资源，整治毛乌素沙地，提高沙地生产力，发展沙区经济，并为其他沙地的治理与利用寻求科学方法，制定优化模式，中日两国研究者在毛乌素沙地从事１０年合作研究，现已摸清了沙丘移动规律，掌握了综合治理与开发利用的有效途径，并建立了相应的地面模式，而且还提出了今后的发展方向和具体建议。     

金环胡蜂及其洞穴内其他节肢动物研究初报

报道了闽南山区金环胡蜂巢的营巢小生境、营巢洞穴以及蜂巢的结构 .蜂群由 10 2只成虫组成 ,其中雌蜂 57只 ,雄蜂 4 5只 .测量了成蜂体长 ,其中 7只雌蜂的体长最长 (平均 4 .6 cm) .在洞穴底部发现 5种节肢动物 ,其中 4种为昆虫 ,最多的是一种食蚜蝇科幼虫 ,其次是一种步甲科幼虫 ,此外还有螟蛾科幼虫、垫跗螋科的成虫和蜈蚣 ,洞穴内还有白蚁 .这些虫子很可能均是金环胡蜂洞穴内的共栖物