江西南矶湿地斑背大尾莺食性初步分析

为了填补斑背大尾莺食性研究的空白和比较其繁殖期和非繁殖期是否有食性差异,于2011年4月繁殖期,在江西南矶湿地用望远镜观察和录像机拍摄斑背大尾莺亲鸟育雏行为,记录育雏食物的种类和数量;在11月秋季非繁殖期,斑背大尾莺专项环志过程中采集7只意外死亡的个体,进行实验室胃容物解剖分析。两种分析方法分别得出:1)春季取食动物性食物,主要有直翅目蝼蛄科成虫或幼虫、鳞翅目成虫或幼虫、蜻蜓目的成虫,蛛形纲的小型蜘蛛;2)秋季食物由动物性食物(70.24%)和植物性食物(29.76%)组成,动物性食物主要为鞘翅目、直翅目、蜻蜓目、鳞翅目、蜘蛛目等节肢动物,植物性食物为一些植物种子和少量的叶片组织。本研究表明,繁殖期和非繁殖期斑背大尾莺食性有差异,这种差异性是随季节变化生境中的食物组成不同,及育雏期雏鸟需高蛋白营养食物而导致的。     

高通量测序技术在野生动物食性分析中的应用

食性研究是动物生态学颇受关注的一个重要内容,而食性分析方法由于受到技术和适用范围的限制,也在不断改进和更新。随着高通量测序技术的发展,该技术逐渐扩展到野生动物的食性分析,使食性分析的效率得到极大提升,并拓宽了食性分析的应用范围。尽管高通量测序应用于食性分析在数据量、灵敏度和分辨率方面的优势较为明显,但由于涉及到的步骤较多,受到的影响因素较为复杂,目前高通量测序应用于食性分析还属于研究比较薄弱的领域。概述了高通量测序技术应用于食性分析的基本流程,总结了该技术在食物组成分析、种内和种间食性关系、食物与栖息地、行为关系方面的研究动态,分析了PCR、污染和定量分析对该技术应用性的影响,提出了相应的解决对策和建议,并对其应用前景进行了展望。     

大鸨繁殖期觅食地的选择

2000年和2001年的4～7月,在内蒙古自治区科尔沁右翼前旗东南部的草原地带,采用样方法研究了火烧地和非火烧地上繁殖期大鸨的觅食地选择.结果表明,在火烧地和非火烧地,大鸨觅食地的植株高度均为13cm左右,最高高度不超过30cm,植被结构上具有共性;植物种类丰盛密集,盖度较大,喜食的植物和昆虫丰富.但在喜食食物选择上,火烧对大鸨有一定影响.在非火烧地,大鸨多关注动物性食物的丰盛;而在火烧地则关注植物性食物的丰盛.     

广州地区犬蝠的食性

2004年5月-2006年4月采用拾遗法、粪便内容物分析法及实地观察对广州地区常见的食果蝙蝠-犬蝠(Cynopterus sphinx)进行了食性研究。对26份食物残留物和粪便样品的分析结果表明:犬蝠的食物包含13科21种的植物果实,3科3种的植物叶片,如:蒲桃(Syzygium jambos)、蒲葵(Livistona subglobosa)及龙眼(Dimocarous longan)的果实。其食性随果实的成熟季节而出现明显的季节性变化,夏秋两季大量食用各种水果,而在食物欠缺的春冬两季则主要食用棕榈科蒲葵的种子。广州地区犬蝠的繁殖期在每年的5-10月。     

大鸨繁殖期觅食地的选择

2000年和2001年的4～7月,在内蒙古自治区科尔沁右翼前旗东南部的草原地带,采用样方法研究了火烧地和非火烧地上繁殖期大鸨的觅食地选择.结果表明,在火烧地和非火烧地,大鸨觅食地的植株高度均为13cm左右,最高高度不超过30cm,植被结构上具有共性;植物种类丰盛密集,盖度较大,喜食的植物和昆虫丰富.但在喜食食物选择上,火烧对大鸨有一定影响.在非火烧地,大鸨多关注动物性食物的丰盛;而在火烧地则关注植物性食物的丰盛.     

利用rbcL-a序列模拟检测小鼠食性

动物食性是研究动物生活习性中非常重要的一环,利用DNA条形码进行检测变得非常快捷和方便。利用这项技术,模拟生态环境研究动物食性,来检测小白鼠的食物组成。首先,给小白鼠喂食了6种植物(白菜、玉米、胡萝卜、小麦、生菜、花椰菜)并收集其粪便,然后对这些样本进行DNA提取、PCR扩增与克隆,最后测序并获得来自质体的rbcL基因(ribulose-1,5-bisphosphate carboxylase large subunit gene)的部分序列(rbcL-a)。粪便样本中得到的序列分别与GenBank数据库和实验中得到的作为食物的5种植物的rbcL-a序列(玉米中未发现)进行比对,确定其分类单元。利用GenBank数据库,共鉴定出了3科和1属。与实验中的5种植物rbcL-a序列比对能鉴定出3个植物物种。表明实验用的rbcL-a序列在检测粪便中物种方面具有很大的潜力,对野生动物的食性分析及分子生态学的研究具有重要的意义。     

贺兰山同域分布高山麝和阿拉善马鹿秋季食性的比较研究

对贺兰山同域分布的高山麝和阿拉善马鹿秋季的粪便进行采集,利用粪便显微分析法对二者秋季食性进行了研究。分别采集高山麝和阿拉善马鹿活动区域内粪样和植物样本,分别获得两种动物40个复合粪便样本,采用频率转换法对数据处理计算,得到贺兰山同域分布的高山麝和阿拉善马鹿秋季的食性组成及组成比例。结果显示,高山麝秋季共取食植物20科30种(属),其中蓝锭果忍冬(11.96%)、秦氏黄芪(10.17%)、密齿柳(8.32%)、折枝绣线菊(6.82%)、内蒙野丁香(6.18%)组成了高山麝的主要食物;阿拉善马鹿秋季共取食植物12科29种(属),其中针茅(22.15%)、灰榆(21.14%)、早熟禾(16.90%)、小叶金露梅(11.62%)、山杨(10.00%)为阿拉善马鹿秋季的主要食物。高山麝和阿拉善马鹿共有9种食物重叠,生态位重叠指数为83.75%。秋季高山麝取食的Shannon-Wiener指数、Pieou均匀性指数、食物生态位宽度指数和最大的物种多样性指数均高于阿拉善马鹿。     

黄山短尾猴（Macaca thibetana）的主要食性分析

2011年11月至2012年10月,作者采用粪便显微分析法研究了黄山短尾猴的四季食性.结果表明：黄山短尾猴共取食植物26科50种;不同季节间黄山短尾猴食性具有明显变化,冬季取食13科25种植物,春季取食23科46种植物,夏季取食14科32种植物,秋季取食17科37种植物;壳斗科、樟科是黄山短尾猴全年的主要食物,占短尾猴总取食量的51.26%～59.75%,其他科属植物也占有重要地位;甜槠在四季均为黄山短尾猴的主要取食食物,豹皮樟在冬季取食量相对较高,秋季最低,红楠、杉木在冬春季节的取食比例差异最大;黄山短尾猴采取与其他灵长类相似的觅食策略;黄山短尾猴四季食物生态位宽度差异不明显,受人为影响较为明显.     

广州地区犬蝠的食性

2004年5月—2006年4月采用拾遗法、粪便内容物分析法及实地观察对广州地区常见的食果蝙蝠¬—犬蝠(Cynopterus sphinx)进行了食性研究。对26份食物残留物和粪便样品的分析结果表明：犬蝠的食物包含13科21种的植物果实,3科3种的植物叶片,如：蒲桃（Syzygium jambos）、蒲葵（Livistona subglobosa）及龙眼（Dimocarous longan）的果实。其食性随果实的成熟季节而出现明显的季节性变化,夏秋两季大量食用各种水果,而在食物欠缺的春冬两季则主要食用棕榈科蒲葵的种子。广州地区犬蝠的繁殖期在每年的5—10月。     

黄山陈村水库河源溪流鱼类群落的食性

基于2010年11月在黄山陈村水库河源溪流中所采集的鱼类标本,对其中9种优势鱼类的食性特征进行了研究。结果表明:宽鳍鱲(Zacco platypus)、光唇鱼(Acrossocheilus fasciatus)和麦穗鱼(Pseudorasbora parva)等9种鱼类都以有机碎屑、藻类和无脊椎动物为主要食物,属典型的杂食性或无脊椎动物食性鱼类;食物组成的相似性分析结果表明,不同物种间的食物组成差异显著但存在部分重叠(P<0.001)。不同物种间的食物多样性和食性宽度也存在显著性差异(P<0.05),其中底栖型鱼类具有相对较高的饵料来源,而鱼类的食物多样性可能与其小生境选择性有关。根据食物重叠指数,9种优势鱼类之间存在明显的食物重叠(D>0.3),尤其是宽鳍鱲、光唇鱼、麦穗鱼、高体鰟鮍(Rhodeus ocellatus)和稀有花鳅(Cobitis sinensis)间的食物重叠指数超过0.9。陈村水库河源溪流的鱼类群落所表现出的食物组成、食物多样性、食性宽度和种间食物重叠性等特征,可能与其生态系统所具有的营养外源性和物理栖息地周期动荡性等密切相关。     

High-throughput sequencing offers insight into mechanisms of resource partitioning in cryptic bat species

Sympatric cryptic species, characterized by low morphological differentiation, pose a challenge to understanding the role of interspecific competition in structuring ecological communities. We used traditional (morphological) and novel molecular methods of diet analysis to study the diet of two cryptic bat species that are sympatric in southern England (Plecotus austriacus and P. auritus) (Fig. 1). Using Roche FLX 454 (Roche, Basel, CH) high-throughput sequencing (HTS) and uniquely tagged generic arthropod primers, we identified 142 prey Molecular Operational Taxonomic Units (MOTUs) in the diet of the cryptic bats, 60% of which were assigned to a likely species or genus. The findings from the molecular study supported the results of microscopic analyses in showing that the diets of both species were dominated by lepidopterans. However, HTS provided a sufficiently high resolution of prey identification to determine fine-scale differences in resource use. Although both bat species appeared to have a generalist diet, eared-moths from the family Noctuidae were the main prey consumed. Interspecific niche overlap was greater than expected by chance (O(jk) = 0.72, P < 0.001) due to overlap in the consumption of the more common prey species. Yet, habitat associations of nongeneralist prey species found in the diets corresponded to those of their respective bat predator (grasslands for P. austriacus, and woodland for P. auritus). Overlap in common dietary resource use combined with differential specialist prey habitat associations suggests that habitat partitioning is the primary mechanism of coexistence. The performance of HTS is discussed in relation to previous methods of molecular and morphological diet analysis. By enabling species-level identification of dietary components, the application of DNA sequencing to diet analysis allows a more comprehensive comparison of the diet of sympatric cryptic species, and therefore can be an important tool for determining fine-scale mechanisms of coexistence.     

Meta‐barcoding insights into the spatial and temporal dietary patterns of the threatened Asian Great Bustard (Otis tarda dybowskii) with potential implications for diverging migratory strategies

Food resources are often not sufficient to satisfy the nutritional and energetic requirements during winter conditions at high latitudes. Dietary analysis is a prerequisite to fully understanding the feeding ecology of a species and the nature of trophic interactions. Previous dietary studies of Asian Great Bustard (Otis tarda dybowskii) relied on behavioral observations, resulting in categorization of diet limited to broad taxonomic groupings. Here, we applied a high‐throughput sequencing meta‐barcoding approach to quantify the diet of resident and migratory Asian Great Bustard in three wintering sites during early winter and late winter. We detected 57 unique plant taxa in the bustard diet, among which 15 species were confirmed by a local plant database we generated. Both agricultural and natural foods were detected, indicating a relatively broad dietary niche. Spatiotemporal dietary changes were discovered, revealing diet differences among wintering sites and a general shift toward lower plant diversity later in winter. For the nonmigratory population, we detected a significantly more diverse array of plant species in their diet. We hypothesize that dietary variation between resident and migratory populations could be involved in the recent transition to partial migration in this species, although climate change can not be excluded. Collectively, these results support protecting unharvested grain fields and naturally unplowed lands to help conserve and promote population growth of Asian Great Bustard.     

巴基斯坦旁遮普中部横斑腹小鸮的食性

横斑腹小鸮(Athene brama)是巴基斯坦旁遮普中部农业生态系统中最常见但研究匮乏的猛禽。我们通过分析吐弃块(n=498)以了解其季节性和地域性食性变化。结果显示:小型哺乳类占所有食物生物量的98.4%,而昆虫类在数量上占据绝对优势(56.4%)。在小型哺乳类食物中,鼠类(38.8%)是稳定的食物成分。而在昆虫食物中,甲虫最多(42.8%)。横斑腹小亦捕食鼩鼱类(2.3%)和鸟类(1.7%)。昆虫类食物还有蟑螂(6.4%)、臭虫(3.3%)、蝗虫(6.7%)和蚂蚁(3.2%)。小家鼠(Mus musculus)和柔毛鼠(Rattus meltada)在鼠类食物中出现频次最多。不同地区中,Hafizabad的食物多样性最高(2.07),而秋季的食物多样性最高(1.99)。     

Dietary changes of Mediterranean Shags Phalacrocorax aristotelis desmarestii between the breeding and post-breeding seasons in the upper Adriatic Sea

Capsule?Shags move between breeding and non-breeding areas and this is associated with a significant change in diet.

Aims?To determine whether the diet of Shags nesting on islets off the Croatian coast is the same as their diet after the post-breeding move to the Gulf of Trieste.

Methods?Diet was determined by the analysis of 611 regurgitated food pellets.

Results?A total of 23 988 prey items were identified in the sample of pellets. Post-breeding Shags in the Gulf of Trieste focused on demersal and relatively immobile Gobiidae (81.5% by number, 87.1% by biomass). The most frequent prey species was Gobius niger (70.8% by number). In the breeding season at Oruda island, Croatia, the diet was more varied. Breeding Shags fed on bentho-pelagic, mobile prey such as Atherina boyeri (28.4% in frequency), Serranus hepatus (16.1%) and Crenilabrus tinca (12.0%), while Gobiidae had a dietary frequency of only 18.1%. With respect to biomass the most important prey were Crenilabrus tinca (19.0%) and Serranus hepatus (18.4%).

Conclusion?We suggest that the movement of Shags within the Adriatic Sea is driven by dietary requirements. Most previous studies of Shag diet have shown that Shags tend to have a more specialized diet during the breeding season, concentrating upon demersal prey species. However, we have found that birds breeding at the Croatian study colony show dietary diversity. We suggest that lack of dietary specialization is a facultative response to local prey abundance, and is probably the result of over-fishing of demersal species in the areas around the breeding locations in which the birds find suitable sites and are little disturbed by human activity. Shags may move immediately after breeding to the Gulf of Trieste because demersal species are likely to be more abundant there. As a consequence, the diet becomes more specialized and is then more similar to the diet of other populations of Shags.     

Do the evolutionary interactions between moths and bats promote niche partitioning between bats and birds?

Ecological theory suggests that the coexistence of species is promoted by the partitioning of available resources, as in dietary niche partitioning where predators partition prey. Yet, the mechanisms underlying dietary niche partitioning are not always clear. We used fecal DNA metabarcoding to investigate the diets of seven nocturnal insectivorous bird and bat species. Low diet overlap (2%–22%) supported resource partitioning among all species. Differences in diet corresponded with species identity, prey detection method, and foraging behavior of predators. Insects with ultrasonic hearing capabilities were consumed significantly more often by birds than bats, consistent with an evolved avoidance of echolocating strategies. In turn, bats consumed a greater proportion of noneared insects such as spruce budworms. Overall, our results suggest that evolutionary interactions among bats and moths translate to dietary niche partitioning and coexistence among bats and nocturnal birds.     

Intra-population variation in the diet of an avian top predator: generalist and specialist foraging in Great Black-backed Gulls Larus marinus

ABSTRACT

Capsule: Great Black-backed Gulls Larus marinus breeding on Skokholm, UK, fed predominantly on seabirds, rabbits, refuse, and marine prey, with the majority of pairs being dietary generalists, but with some specialist pairs.

Aims: To understand the significance of Great Black-backed Gulls as top predators on a small offshore island with internationally important numbers of breeding seabirds (Skokholm, UK) by quantifying their diet and to determine how this varies within the breeding season, to test for pair-level dietary specialization and to examine the consequences of dietary differences for reproductive performance.

Methods: Regurgitated pellets were collected and analysed from 26 breeding pairs on Skokholm during 2017 and related to breeding success.

Results: Analysis of 1035 pellets revealed that, overall, Great Black-backed Gulls fed on seabirds (48% – mostly Manx Shearwaters Puffinus puffinus), mammals (38% – mostly European Rabbits Oryctolagus cuniculus), anthropogenic waste (7%), and marine prey (7%). Diet varied among pairs with 18 (73%) generalist pairs and 7 (27%) specialist pairs (of which, 5 were bird specialists and 2 were mammal specialists). Diet also varied seasonally, but pair-level dietary diversity was repeatable through the breeding season. Dietary diversity did not covary with breeding success.

Conclusion: Great Black-backed Gulls are top predators on Skokholm. Variation in diet among pairs emphasizes that not all individuals contribute equally in terms of predation. Understanding the incidence of this variation has important ecological implications, particularly where apex predators may exert a strong top-down influence.     

The role of pigeon consumption in the population dynamics and breeding performance of a peregrine falcon (<Emphasis Type="Italic">Falco peregrinus</Emphasis>) population: conservation implications

In this paper, we describe and analyze the diet of peregrine falcons during a long-term period (1982–2002). A combination of direct observations of prey brought to nests, prey remains, and regurgitated pellets were used to calculate diet diversity and dietary overlap between peregrine pairs. We also examined diet diversity in relation to breeding performance. All peregrine pairs fed mainly on birds, with pigeons the most common prey. An increase in pigeon availability has been associated with both an increase in population size and an increase in breeding performance (measured as the average productivity of pairs per year) of a small peregrine falcon population in eastern Spain. Average productivity was lower when dietary breadth was higher. We speculate that our results were the synergistic effect of declining persecution and increased pigeon availability through increased popularity of keeping racing pigeons. There is a conflict of interests between pigeon fanciers and peregrine conservation. As a consequence, this could result to an increased risk of mortality by direct persecution. In accordance with this, conservation measures aimed at preventing direct persecution are encouraged.     

Insectivorous bats selectively source moths and eat mostly pest insects on dryland and irrigated cotton farms

Insectivorous bats are efficient predators of pest arthropods in agroecosystems. This pest control service has been estimated to be worth billions of dollars to agriculture globally. However, few studies have explicitly investigated the composition and abundance of dietary prey items consumed or assessed the ratio of pest and beneficial arthropods, making it difficult to evaluate the quality of the pest control service provided. In this study, we used metabarcoding to identify the prey items eaten by insectivorous bats over the cotton‐growing season in an intensive cropping region in northern New South Wales, Australia. We found that seven species of insectivorous bat (n = 58) consumed 728 prey species, 13 of which represented around 50% of total prey abundance consumed. Importantly, the identified prey items included major arthropod pests, comprising 65% of prey relative abundance and 13% of prey species recorded. Significant cotton pests such as Helicoverpa punctigera (Australian bollworm) and Achyra affinitalis (cotton webspinner) were detected in at least 76% of bat fecal samples, with Teleogryllus oceanicus (field crickets), Helicoverpa armigera (cotton bollworm), and Crocidosema plebejana (cotton tipworm) detected in 55% of bat fecal samples. Our results indicate that insectivorous bats are selective predators that exploit a narrow selection of preferred pest taxa and potentially play an important role in controlling lepidopteran pests on cotton farms. Our study provides crucial information for farmers to determine the service or disservice provided by insectivorous bats in relation to crops, for on‐farm decision making.     

The influence of prey abundance on the feeding ecology of two piscivorous species of coral reef fish

Despite the potential importance of predation as a process structuring coral reef fish communities, few studies have examined how the diet of piscivorous fish responds to fluctuations in the abundance of their prey. This study focused on two species of rock-cod, Cephalopholis cyanostigma (Valenciennes, 1828) and Cephalopholis boenak (Bloch, 1790) (Serranidae), and monitored their diet in two different habitats (patch and contiguous reef) at Lizard Island on the northern Great Barrier Reef, Australia, over a 2-year period. The abundance of the rock-cods and the abundance and family composition of their prey were monitored at the same time. Dietary information was largely collected from regurgitated samples, which represented approximately 60% of the prey consumed and were unbiased in composition. A laboratory experiment showed that fish were digested approximately four times faster than crustaceans, leading to gross overestimation of the importance of crustaceans in the diet. When this was taken into account fish were found to make up over 90% of the diet of both species. Prey fish of the family Apogonidae, followed by Pomacentridae and Clupeidae, dominated the diet of both species of rock-cod. The interacting effect of fluctuations in prey abundance and patterns of prey selection caused dietary composition to vary both temporally and spatially. Mid-water schooling prey belonging to the families Clupeidae and to a lesser extent Caesionidae were selected for over other families. In the absence of these types of prey, apogonids were selected for over the more reef-associated pomacentrids. A laboratory experiment supported the hypothesis that such patterns were mainly due to prey behaviour. Feeding rates of both species of rock-cod were much higher in summer than in winter, and in summer they concentrated on small recruit sized fish. However, there was little variation in feeding rates between habitats, despite apparent differences in prey abundance. In summary, our observations of how the feeding ecology of predatory fish responded to variation in prey abundance provide potential mechanisms for how predation may affect the community structure of coral reef fishes.