基于取食行为探究北京居民区鸟类的食源特征及多样性

城市是鸟类的重要栖息地, 城市绿地中占比最大的为居住绿地, 是容纳鸟类的重要生境。对于鸟类生存来说, 食物的种类和数量是关键的限制因子。本研究从鸟类的食物偏好入手, 旨在构建北京居住区鸟类的食源关系, 探究鸟类在居住区中取食的影响因素。研究选取40个居住小区作为调查样地, 于2020年6月至2021年5月每月调查1次, 采用广义线性模型评估鸟类在居住区中取食的影响因素, 并对鸟类的食源多样性指数与多度、分布范围进行线性回归。结果表明: (1)本研究共记录到取食行为的鸟种共14科35种2,242只, 丰富度为春季 > 秋季 > 冬季 > 夏季, 多度为春季 > 冬季 > 秋季 > 夏季, Shannon-Wiener多样性指数为秋季 > 春季 > 冬季 > 夏季。(2)鸟类的食源依次为昆虫(33.87%)、翅果(18.33%)、浆果(9.77%)、球果(8.16%)、草籽(5.17%)等。(3)鸟类对植物的直接利用高达60.4%, 间接利用为39.6%, 食源植物Shannon-Wiener多样性指数为秋季(3.1612) > 冬季(2.9651) > 春季(2.9203) > 夏季(2.1763)。(4)食源树种是影响鸟类在居住区中取食最关键的外界环境因素, 食源越丰富的鸟种, 其种群数量越大, 分布范围越广泛。居住区的食源植物具有类型丰富、种类繁多、从早春到晚秋覆盖全物候的特点, 在规划设计时应多配置北京乡土树种以及金银木(Lonicera maackii)等观果植物, 减少绿篱配置, 倡导低干扰的近自然园林养护管理措施。     

Arthropod prey of shelterbelt-associated birds: linking faecal samples with biological control of agricultural pests

Abstract  The value of insectivorous birds as agents for biological control of arthropod pests has been little studied, especially in Australia. This paper reports on the extent to which arthropods from various pest and non-pest taxa feature in the diets of birds captured in farm shelterbelts in central western New South Wales. The parameters examined were the types of arthropod fragments in bird faeces and percentage volume and frequency of occurrence of each component. The faecal data were compared with samples of the arthropod fauna trapped in shelterbelts during the period the birds were captured. In 26 of 29 faecal samples, arthropod fragments were the predominant components, the most common being from Coleoptera, Hymenoptera (especially Formicidae), Orthoptera and Araneae. The recognisable pest taxa in faecal samples were Scarabaeidae and wingless grasshopper Phaulacridium vittatum (Sjöstedt) (Orthoptera: Acrididae). The results indicate that the native bird species common in farm shelterbelts preyed on a range of arthropod taxa including several that are pests of crops and pastures. Accordingly, conservation of birds in farmlands could contribute to suppression of arthropod pests.     

Links between the detritivore and the herbivore system: effects of earthworms and Collembola on plant growth and aphid development

Effects of Collembola (Heteromurus nitidus and Onychiurus scotarius) and earthworms (Aporrectodea caliginosa and Octolasion tyrtaeum) on the growth of two plant species from different functional groups (Poa annua and Trifolium repens), and on the development of aphids (Myzus persicae) were investigated in a laboratory experiment lasting 20 weeks. Using soil from a fallow site which had been set aside for about 15 years, we expected that nitrogen would be of limited supply to plants and hypothesized that the soil animals studied, particularly earthworms, would increase nutrient availability to plants and thereby also modify aphid reproduction and development. Plant growth was modified strongly by the presence of soil animals. Earthworms caused a more than twofold increase in shoot and root mass of P. annua but increased that of T. repens by only 18% and 6%, respectively. However, earthworms neither affected plant shoot/root ratio nor the nitrogen concentration in plant tissue. In contrast, the presence of Collembola caused a reduction in plant biomass particularly that of P. annua roots, but plant tissue nitrogen concentration was increased, although only slightly. Aphid reproduction on T. repens was lowered in the presence of Collembola on average by 45% but on P. annua increased by a factor of about 3. It is concluded that Collembola decrease aphid reproduction on more palatable host plants like T. repens but increase that on less palatable ones like P. annua. Earthworm presence also affected aphid reproduction but the effect was less consistent than that of Collembola. In the presence of earthworms, aphid reproduction was in one experimental period increased by some 70%. Earthworms also modified the numbers of Collembola and their vertical distribution in experimental chambers. Exploitation of deeper soil layers by H. nitidus was increased but, generally, O. scotarius numbers were reduced whereas those of H. nitidus increased in earthworm treatments. The presence of Collembola also influenced earthworm body mass during the experiment. In general it declined, but in the presence of Collembola loss of body mass of A. caliginosa was more pronounced. We conclude that inhibiting effects between Collembola and earthworms resulted from the use of a common resource, litter material rich in nitrogen. This is supported by the higher C/N ratio of the litter material in the presence of earthworms and Collembola by the end of the experiment. Effects of soil invertebrates like Collembola and earthworms on plant performance and aphid development are assumed to be modified by complex direct and indirect interactions among soil animal groups. Received: 6 July 1998 / Accepted: 1 March 1999     

基于DNA宏条形码技术的杭州萧山国际机场家燕春夏食性分析及防治策略

2022—2023年期间,杭州萧山国际机场累计鉴定鸟击残留物样本154例,涉及54种鸟类,其中家燕(Hirundo rustica)为出现频率最高的鸟种,共检测到9次,鸟击风险较高。为降低家燕对飞行安全的威胁,利用DNA宏条形码技术(DNA metabarcoding technology)检测肠道内容物,对机场春夏两季的家燕进行食性分析。同时结合机场调查数据,有效地掌握了家燕的食源分布。结合机场实地调研数据,研究结果发现麻蝇科、果蝇科、蚊科、丽蝇科、蝇科和灰蝶科都属于动物性食物,其中麻蝇科为主要食物,而滋养食源的相关植物有蔷薇科、禾本科、伞形科、千屈菜科、桑科、榆科、百合科和柏科,蔷薇科则是主要滋养物。通过α多样性指数比较发现,动物性食物多样性在夏季显著高于春季(Shannon指数,P<0.05),群落物种分布更均匀,而与家燕食源相关的植物丰富度在春季则显著高于夏季(Chao1和Observed＿species指数,P<0.05),造成这种差异动态的因素可能是机场区域温度变化。通过β多样性指数比较发现,动物性食物和食物链相关植物组成差异在春、夏季不明显。针对家燕的食性组成以及食物资源的分布模式,我们建议机场应提高收割植物籽实频率,扩大收割面积,排查家燕营巢区域,规范水稻、大豆等作物种植,妥善处理机场垃圾,定期喷洒杀虫剂,设立昆虫诱捕装置,清理植草区虫卵虫蛹,以降低家燕鸟击事件的发生概率。与传统食性分析相比,通过DNA宏条形码技术比较了不同季节食性,补充了目前发现的家燕食物组成,并且对机场的鸟击防范政策实施具有指导意义。     

四种昆虫饵料对穴蚁蛉幼虫生长发育及消化利用的影响

选择4种可规模化饲养的昆虫——米蛾Corcyra cephalonica、家蝇Musca domestica、斜纹夜蛾Spodoptera litura、甜菜夜蛾Spodoptera exigu幼虫来饲养穴蚁蛉Myrmeleon sagax(Walker)幼虫(俗称蚁狮),研究这4种饵料对蚁狮生长发育及消化利用的影响。结果显示,用家蝇幼虫饲养的蚁狮,其体重增长、相对生长率、化蛹率、蛹重均显著高于用斜纹夜蛾和甜菜夜蛾幼虫饲养的蚁狮,而幼虫历期则比斜纹夜蛾和甜菜夜蛾幼虫饲养的短;用米蛾幼虫饲养,虽然蚁狮体重增长、化蛹率和蛹重与用家蝇幼虫饲养的差异不显著,但其相对生长率却显著低于用家蝇幼虫饲养的蚁狮,幼虫历期也比用家蝇幼虫饲养的明显延长。同时食物消化利用的结果显示,用4种饵料饲养蚁狮,它们的近似消化率差异不显著,但食物利用率和食物转化率均以家蝇幼虫饲养的蚁狮最高。经分析比较,在4种饵料昆虫中,以用家蝇幼虫每4d喂蚁狮1次的饲养效果最佳。     

Intrapopulation variation in carbon and nitrogen stable isotope ratios in the earthworm Aporrectodea longa

The natural abundance variations in carbon and nitrogen stable isotope ratios in a population of the earthworm Aporrectodea longa, a species known to feed on both soil and plant litter, is reported in this paper. Worms were collected from a small land area of an old white clover field and body tissue and mucus were analyzed separately. The range of isotopic values was small, but patterns of variation were not random. Tissue carbon and nitrogen isotope ratios were significantly higher in adult than in juvenile A. longa and tissue nitrogen isotope ratios tended to increase with increasing biomass of individuals. Further, carbon and nitrogen isotope ratios were positively correlated in both tissue and mucus. Possible causes of the observed patterns, including physiological effects, body composition and assimilation of C and N from different plant, soil and microbial sources are discussed. It is concluded that the causes of natural variability in isotopic composition must be understood and validated experimentally before natural abundance stable isotope methods can be used for the analysis of trophic relations among detritivorous soil invertebrates.     

The diet and digestive energetics of an Australian short-necked turtle, Emydura macquarii

We described the diet of Emydura macquarii, an omnivorous turtle from south-eastern Australia, compared its digestive performance on diets of fish or plants at two temperatures, and related how both diet and temperature affect its food selection in nature. Filamentous algae constituted 61% of the stomach content of E. macquarii. The turtles rarely fed on motile prey, but selected carrion from the lagoon bottom and terrestrial insects (Diptera, Hymenoptera and Coleoptera) trapped on the surface of the water. Digestive efficiency of E. macquarii was affected little by body temperature, in contrast to consumption rates and rates of passage which were strongly influenced by both temperature and diet. In combination, these responses resulted in a slower rate of digestion at 20°C than at 30°C. Digestive efficiency of E. macquarii on a herbivorous diet at 30°C (49%) was about half that of turtles on a carnivorous diet (91%), but they had longer transit times (118 h on the plant diet versus 70 h). Lower consumption rates and longer mean retention times in turtles fed plants compared those fed fish relate to slower digestive processing of the plant. Rapid processing and higher consumption rates of fish by E. macquarii resulted in higher energy gains compared to turtles consuming plants (almost 100 times more energy at 30°C). The laboratory results suggest that fish carrion and aquatic and terrestrial invertebrates are probably essential dietary items of E. macquarii in the wild, because its metabolic requirements cannot be met from aquatic macrophytes alone.     

The effects of agriculture on farmland bird assemblages on the Agulhas Plain, Western Cape, South Africa

Coastal Fynbos on the Agulhas Plain of the Western Cape, South Africa, has been transformed extensively by crop and pastoral agriculture. Many bird species, e.g. sunbirds, nightjars and mousebirds have consequently been affected negatively by the reduction of suitable habitat for daily requirements. However, populations of certain bird species, especially granivores and omnivores, such as sparrows, larks and pipits, as well as Egyptian Geese and Helmeted Guineafowl have proliferated on the Agulhas Plain. This study investigates the effects of agricultural development on overall bird diversity on the Agulhas Plain. In 1998, twice monthly transect counts at 13 farmland sites recorded 106 bird species. Fifteen species occurred at 75% or more of the sites. Highest avian diversity was recorded at the sites with a mixture of crops and Coastal Fynbos (Mixed regime). A small number of species, e.g. sunbirds, are reliant on the natural Coastal Fynbos for their survival. With the exception of the Mixed regime that gained 50 species, all the other agricultural regimes reflected a loss of diversity when compared with Fynbos. To provide more suitable habitat for a greater diversity of birds, mixed landscapes should be maintained, and further destruction of natural Fynbos habitat should be prevented.     

Classification and measurement of fungal pellets by automated image analysis

An automated image analysis method for classifying and measuring pellets of filamentous fungi growing in submerged fermentations has been developed. The method discriminates between pelleted mycelial growth and loose aggregates of dispersed hyphae. Pellets are classified into smooth and hairy types. In both cases, the core of the pellet is identified and its shape and size characterized. For hairy pellets the annular region is also characterized. The method was tested on pellets of Aspergillus niger ATCC 11414 grown in a defined medium in shake flasks. This rapid method makes practical extensive studies on the morphology of pellets in submerged fermentations and the influence of fermentation conditions on that morphology.     

无尾两栖类食物资源利用研究进展

食物资源的利用是无尾两栖类生态学研究的一个重要组成部分,针对食物资源的竞争策略和食物资源竞争对群落结构的影响都有比较深入的研究,本文总结近年来本领域的理论成果与发展动态,并对我国的研究现状和未来作了讨论.     

Invasibility of a reservoir to exotic Daphnia lumholtzi: experimental assessment of diet selection and life history responses to cyanobacteria

SUMMARY 1. In reservoirs of the south-central United States, the exotic cladoceran Daphnia lumholtzi is common during warm midsummer conditions, when cyanobacteria are abundant and native Daphnia are rare. In the current study, we employed surveys, field experiments, and a life table experiment to investigate the role of food quality in explaining the distribution and phenology of D. lumholtzi , relative to two native species ( Daphnia parvula and Daphnia mendotae ).
2. During May–September 2000 in eutrophic McDaniel Lake, Missouri U.S.A., cyanobacteria (primarily Oscillatoria ) first appeared at 6-m depth and then became abundant throughout the epilimnion.
3. During the May field experiment, D. lumholtzi , D. parvula and D. mendotae all consumed a similar diet of algae, showing positive selection for small greens (chlorophytes and cryptophytes <20 μm). During the July experiment, when the epilimnion exceeded 25 °C and cyanobacteria were common in the lake, D. lumholtzi consumed significantly more total algae and more cyanobacteria than the two native species. Although the Daphnia selected against cyanobacteria, all three species consumed about 25% of this food in their diet.
4. A life table experiment compared the responses of D. lumholtzi and D. parvula with variation in density of high-quality food ( Ankistrodesmus ) and concentration of a toxic strain of cyanobacteria ( Anabaena flos-aquae ). Both Daphnia species showed reduced survivorship, fertility and intrinsic rates of increase in response to elevated concentrations of cyanobacteria, particularly at the higher food level.
5. The results suggest that D. lumholtzi shows similar inhibition from cyanobacteria as does the native Daphnia . However, their continued high in situ feeding rates imply that D. lumholtzi is less affected by midsummer conditions in warm-water reservoirs than are native Daphnia .