Feeding ecology of the common sun skink,Eutropis multifasciata (Reptilia: Squamata: Scincidae), in the plains of central Vietnam

We studied the feeding ecology of Eutropis multifasciata in the tropical plains of central Vietnam to understand better the foraging mode, spatiotemporal and sexual variation in dietary composition, and rarefaction curves of prey-taxon richness for males and females. Stomach contents (n = 161) were collected from October 2013 to May 2014 using a nonlethal stomach-flushing technique. A total of 680 food items (624 animal items and 56 plant items) was found in 161 stomachs of skinks, representing 19 unique animal categories. We found that the diet of E. multifasciata is composed mainly of small, sedentary and clumped prey and that this skink specialises on spiders, insect larvae, snails, grasshoppers and crickets (with a combined importance index of 60%). Dietary composition, prey size and total prey volume in E. multifasciata changed between dry and rainy seasons and among regions. The total volume of food items consumed by males was larger than that of females, and the diversity and evenness index of prey categories were larger in males than in females. However, using rarefaction curves revealed that females have the higher prey-taxon richness after points between 130 and 140 prey items for frequency, and between 160 and 170 prey items for number of items, and the differences were not statistically significant. The foraging behaviour of E. multifasciata best fits a ‘widely foraging’ model.     

基于细菌觅食优化算法的图像聚类方法研究

利用细菌觅食优化算法研究图像聚类问题,采用群体智能模式实现问题解的搜索.首先提取图像特征以确定解的编码形式,初始化种群,在此基础上利用细菌觅食优化算法的细菌迁徙算子、繁殖算子和趋化算子实现群体内个体之间的相互合作和竞争,提高了算法的搜索能力,实验证明该算法具有较强的适应性和鲁棒性.     

基于云模型的细菌觅食优化算法

针对细菌觅食优化算法收敛速度慢、容易陷入局部极值点出现早熟的问题,提出一种新的基于云模型优化的细菌觅食优化算法.首先给出了细菌灵敏度的概念,结合云模型随机性和稳定倾向性的特点,运用了X条件云发生器来调整细菌灵敏度,控制游动步长,进行了趋向性操作和复制操作,改进了标准的细菌觅食优化算法,提高了算法的收敛速度.然后利用正向正态云发生器,修正非线性自适应的迁移概率,进行了迁移操作,增强了算法的全局寻优能力.将该算法应用于自动组卷系统中,与遗传算法进行实验比较分析,结果表明:该算法的收敛速度与优化质量均优于遗传算法.     

基于出动效率最大的离场优化排序

飞机离场优化排序对于缓解跑道拥挤现象、提升作战体系出动效率具有重要意义。针对军航双跑道离场优化排序问题,首先建立了基于飞机在预定空域形成“任务包”时间最小为目标函数的优化排序模型,然后设计了一种基于精英反向学习策略和黏菌觅食行为的改进海洋捕食者算法进行求解,最后通过一个仿真实验,与其他算法的优化结果进行对比,改进的海洋捕食者算法使得“任务包”形成时间明显缩短,有效提升了作战飞机的出动效率,可以应用于解决飞机离场优化排序问题。     

趋药性人工蜂群算法训练神经网络研究

本文设计了一种复合人工蜂群算法,将细菌觅食优化算法中的趋药性行为引入到人工蜂群算法中,使得引领蜂和观察蜂进行局部探查时像细菌觅食时那样翻转到有利的方向上进行游动;另一方面,让蜜蜂尝试在所有维度产生扰动并择优选择,这两种策略大大增强了人工蜂群算法的局部探查能力.将此算法应用于训练人工神经网络,实验表明改进后的算法性能比人...     

The varied foraging mode of the subtropical eublepharid gecko Goniurosaurus kuroiwae orientalis

Insectivorous lizards usually employ one of two foraging modes, ambush ‘sit-and-wait’ or active ‘widely foraging’, but in the Gekkonomorpha the situation has been unclear. Therefore we quantified the foraging mode of the eublepharid gecko Goniurosaurus kuroiwae orientalis on Tokashikijima near Okinawajima, Japan, in September 1999. The taxon is rare, endangered and protected. On the selected semi-urban study site the gecko was confirmed as a nocturnal cursorial gecko, which also ascends trees up to 1.8 m. Foraging regimes of marked individuals, during repeated 30-min observation periods, could vary from immobility throughout, to active locomotion 84% of the time. Foraging mode was not significantly affected by sex, body length, mass or state of tail regeneration of the individuals, or by the timing of the observation. In males, at higher temperatures single moves became longer, while time allocated to moving was stable. In both sexes longer observation bouts included longer sitting pauses, which, given stable move duration, reduced the share of time spent moving and the moves per minute. Goniurosaurus kuroiwae orientalis averaged moving during 23% of the time, moving 0.39 times per minute, the moves lasting 77 s and the pauses lasting 745 s. Compared to other geckos, G. k. orientalis may be defined as a widely foraging animal, despite its mixed behaviour. This result supports the definition of the Eublepharidae as widely foraging and is compatible with two hypotheses, that early Gekkonomorpha were widely foraging or that they had an intermediate, undefined, foraging mode.     

Foraging by the flower-dwelling spider,Misumenops argenteus (Thomisidae), at high prey density sites

In this study, the foraging sites of the crab spider Misumenops argenteus on Trichogoniopsis adenantha (Asteraceae) were investigated over a 2-year period. The choice of sites was examined in relation to prey density in rainy and dry seasons, in leaves versus stems, reproductive branches versus vegetative branches, and in flowerheads in different phenophases. Misumenops argenteus generally occupied sites where the prey frequency was high, indicating that this species was able to evaluate the quality of the foraging sites, as predicted by optimal foraging theory. One exception to the rule was that adult males occurred at all sites, independently of prey density, as also observed in other spider species in which males search for females and not for prey. In addition, young (third and fourth instar) spiders occupied flowerheads with few prey, but which provided shelter.     

Genotypic variation in foraging responses to environmental stimuli by honey bees,Apis mellifera

We experimentally tested a model predicting that colony-level genotypic diversity contributes to colonylevel foraging flexibility in honey bees. We established a colony into which we placed individually marked workers from three genetically distinct groups. The colony was placed in an enclosure that contained feeding stations with pollen and sugar syrup. Foraging resources, stores of pollen and the quantity of brood within the colony were varied temporally. Individual foragers switched between resource types in response to changes in relative resource quality and colony need, demonstrating flexibility in resource choice at the individual level. However, genetic groups within the colony varied in their tendency to collect pollen versus nectar, and in lability of response to changes in foraging stimuli. Our data suggest that within-colony genotypic diversity contributes to a resilient foraging response to environmental variation.     

动物行为研究的新进展（四）：食物贮藏与计划未来

动物前脑大小与觅食创新之间存在着神经生物学联系,通常是前脑越大觅食创新能力越强,觅食创新能力可大大提高鸟类的食物摄取率,从而对鸟类的生存和生殖有利。松鸦具有令人难以置信的记忆力,它常常为了未来的需要而贮藏大量的食物,并能在以后重新找到它们。当检查贮藏食物的行为与脑海马大小之间关系的时候,发现很多鸟类都表现出极明显的正相关关系,海马体积越大,贮食行为就越发达,这表明海马的大小是鸦科鸟类空间记忆力和觅食行为进化的关键因素。鸦科鸟类的祖先是适度贮藏食物者,这就是说,原始鸦科鸟类中的一些物种朝着专化贮藏食物者的方向进化,而另一些种类则走向了完全丧失贮藏食物的能力。通过观察和巧妙的实验,现已证实动物确实具有计划未来的能力。     

紫藤传粉昆虫与花粉多型性研究

定位观测了紫藤的访花昆虫种类及觅食行为,用扫描电镜观察了花粉形态。结果表明：紫藤的主要访花昆虫为膜翅目的黄胸木蜂和意大利蜂,两者都有传粉行为,属传粉者。意大利蜂除有传粉行为外还有偷蜜行为。花粉在形态上表现出多型性：长球形（赤道观长椭圆形,极面观近三裂圆形）,三孔沟;三菱锥形（赤道观近三角形,极面观近三角形）,六孔沟;赤道观近三角形,极面观近菱形,四孔沟。外壁纹饰均为橘皮状。