期刊文献+
共找到31篇文章
< 1 2 >
每页显示 20 50 100
Ecological Models Reveal a Weakened Population Structure, and Distribution Drivers of Osyris lanceolata (Santalaceae) in the Karamoja Sub-Region, Uganda
1
作者 Ben Belden Mugula Samuel Kuria Kiboi +6 位作者 James Ireri Kanya Harald Meimberg Manuel Curto Paul Okullo Anthony Egeru Jenipher Biira Salamula Stephen F. Omondi 《Open Journal of Ecology》 2025年第2期153-173,共21页
Osyris lanceolata is heavily and illegally exploited in East Africa for its essential oils, yet little is known about its population status and ecological requirements. This study examined its population structure and... Osyris lanceolata is heavily and illegally exploited in East Africa for its essential oils, yet little is known about its population status and ecological requirements. This study examined its population structure and environmental factors influencing its distribution in the semi-arid Karamoja sub-region, Uganda. We surveyed 388 plots (5 m radius) at different altitudes, recording life stages, stem diameters, and regeneration patterns, and analyzed soil samples. Multivariate analyses, including Canonical Correspondence Analysis (CCA), Detrended Correspondence Analysis (DCA), Non-metric Multidimensional Scaling (NMDS), and Multiple Regression Modeling (MRM), identified key environmental factors affecting its distribution. Findings show that O. lanceolata populations in Moroto, Nakapiripirit, and Amudat districts are severely degraded due to overexploitation. The species is primarily regenerating through coppicing rather than seedlings, with an exploitation intensity of 56.6%. Population densities are low, distribution is irregular, and sustainable harvesting is not viable. Soil properties, particularly Ca2+, N, P, K+, Na+, and organic matter, significantly influence its abundance. Conservation efforts should focus on identifying suitable provenances for genetic preservation and plantation establishment. Areas with at least 9 trees per hectare in Moroto, Nakapiripirit, and Amudat could serve as potential sites for ex-situ plantations. Further research should explore how biotic interactions, genetic diversity, and morphology affect oil yield and quality to support restoration, breeding, and domestication initiatives. 展开更多
关键词 Plant Ecology Hemiparasites Edaphic Drivers Ecological Modelling Multivariate Analysis Essential Oils “R”
在线阅读 下载PDF
Biodiversity responses to insular fragmentation in Amazonia: Two decades of research in the Balbina Hydroelectric Reservoir 被引量:2
2
作者 Ana Filipa Palmeirim Maíra Benchimol +4 位作者 Danielle Storck-Tonon Anderson S.Bueno Isabel L.Jones Gilmar Klein Carlos A.Peres 《Zoological Research(Diversity and Conservation)》 2024年第2期106-116,共11页
As hydropower development expands across lowland tropical forests,flooding and concomitant insular fragmentation have become important threats to biodiversity.Newly created insular landscapes serve as natural laborato... As hydropower development expands across lowland tropical forests,flooding and concomitant insular fragmentation have become important threats to biodiversity.Newly created insular landscapes serve as natural laboratories to investigate biodiversity responses to fragmentation.One of these most iconic landscapes is the Balbina Hydroelectric Reservoir in Brazilian Amazonia,occupying>400000 ha and comprising>3500 forest islands.Here,we synthesise the current knowledge on responses of a wide range of biological groups to insular fragmentation at Balbina.Sampling has largely concentrated on a set of 22 islands and three mainland sites.In total,39 studies were conducted over nearly two decades,covering 17 vertebrate,invertebrate,and plant taxa.Although species responses varied according to taxonomic group,island area was consistently included and played a pivotal role in 66.7%of all studies examining patterns of species diversity.Species persistence was further affected by species traits,mostly related to species capacity to use/traverse the aquatic matrix or tolerate habitat degradation,as noted for species of vertebrates and orchid bees.Further research is needed to improve our understanding of such effects on wider ecosystem functioning.Environmental Impact Assessments must account for changes in both the remaining habitat amount and configuration,and subsequent long-term species losses. 展开更多
关键词 Habitat loss Hydropower dams Landbridge Local extinctions Species-area relationships Species diversity Tropical forests
在线阅读 下载PDF
Environmental determinants of social wasp diversity and assemblage structure in an Amazonian archipelagic landscape 被引量:1
3
作者 Jose Victor Alves Ferreira Alexandre Somavilla +3 位作者 Maíra Benchimol Ana Filipa Palmeirim Carlos A.Peres Danielle Storck-Tonon 《Zoological Research(Diversity and Conservation)》 2024年第2期121-129,共9页
Hydropower development has become an important driver of habitat loss and fragmentation across lowland tropical forests.Despite ample evidence on the detrimental effects of insular habitat fragmentation on biodiversit... Hydropower development has become an important driver of habitat loss and fragmentation across lowland tropical forests.Despite ample evidence on the detrimental effects of insular habitat fragmentation on biodiversity,invertebrate taxa,that may be critical to ecosystem functioning,have been overlooked.We assessed the assemblage-level responses of social wasps to forest insularization induced by the Balbina Hydroelectric Dam in Central Brazilian Amazonia.Employing Malaise trapping,we captured wasps on 27 forest islands and three continuous forests.We constructed Generalized Linear Models and employed a model selection approach to examine the impact of local variables(fire severity(FIRE)and basal area of pioneer tree species(PIONEER))and landscape-scale variables(amount of habitat(COVER))on patterns of species richness,composition,and body size of wasps.A total of 374 individuals(29 species)were collected across all sampling sites.COVER was the main predictor of species richness,while PIONEER was the only variable that explained variation in community composition,with a negative effect on body size.Our results add evidence to the pervasive impacts of large hydroelectric dams on tropical forest biodiversity,and suggest that social wasps,among other invertebrates,can be used as bioindicators in infrastructure development projects. 展开更多
关键词 Habitat amount hypothesis Habitat fragmentation Habitat loss Hydroelectric dams Invertebrates
在线阅读 下载PDF
Feeding ecology and interactions with mammal hosts in a symbiotic genus of birds(Buphagus spp.)in Namibia
4
作者 Michael S.Lukubwe Daniel Velarde-Garcéz +3 位作者 Fernando Sequeira Susana Lopes Adrian J.F.K.Craig Vanessa A.Mata 《Avian Research》 SCIE CSCD 2024年第3期336-344,共9页
As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the... As the sole obligate symbiotic birds in Africa,oxpeckers offer a unique model for studying symbiotic relationships.Due to the multitrophic level they occupy and the context dependent foraging behavior they exhibit,the type of symbiotic relationship can be variable.In addition to providing a cleaning service to the host by removing ticks,oxpeckers frequently feed on blood,mucus,and saliva,inflicting potential damage on the host.Here,we used DNA metabarcoding on faecal samples to analyze the taxonomic composition of the trophic interactions of the Yellow-billed Oxpecker(Buphagus africanus)and Red-billed Oxpecker(B.erythrorhynchus)in northeastern Namibia.In contrast to conventional methods,DNA metabarcoding allows for a detailed identification of dietary resources encompassing both mammal hosts and consumed arthropods within the same samples.With this information,we examined differences in the diet composition between oxpecker species and localities,as well as the co-occurrence between host and arthropod species.Our findings revealed that oxpeckers predominantly source their diet from mammals,ticks,and flies;however,ticks and flies rarely co-occur in the diet of an individual.We observed variability among individuals in their feeding ecology,which is strongly correlated with locality and,to a lesser extent,with the mammal host.We noted a high degree of mobility between hosts within relatively short periods,with 32%of the samples showing traces of at least two mammal hosts.This study illustrates the dynamic foraging behavior of these specialized symbiotic birds,shedding light on their potential role in pest control services and disease transmission. 展开更多
关键词 COMMENSALISM Diet DNA metabarcoding Oxpeckers PARASITISM Trophic ecology
在线阅读 下载PDF
Natural parasites in conjunction with behavioral and color traits explain male agonistic behaviors in a lizard
5
作者 Rodrigo Megia-Palma Dhanashree Paranjpe +2 位作者 Robert D.Cooper Pauline Blaimont Barry Sinervo 《Current Zoology》 SCIE CAS CSCD 2024年第1期59-69,共11页
Male competition conforms to a cost-benefit model,because while aggression may increase reproductive prospects,it can also increase the risk of injury.We hypothesize that an additional cost in aggressive males would b... Male competition conforms to a cost-benefit model,because while aggression may increase reproductive prospects,it can also increase the risk of injury.We hypothesize that an additional cost in aggressive males would be an increase in parasite load associated with a high energy investment into sexual competition.Some of these infections,in turn,may downmodulate the level of host aggression via energetic trade-offs.We staged dyadic male contests in the lab to investigate the relationships of multiple parasites with the agonistic behavior of lizard hosts,Sceloporus occidentalis.We also included both color and behavioral traits from opponents in the analyses because(1)color patches of lizards may serve as intraspecific signals used by conspecifics to assess the quality of opponents,and(2)contests between male lizards fit classical models of escalated aggression,where lizards increase aggression displays in response to an opponent's behavior.The results conform to our hypothesis because male lizards displayed more pushups when they had more ticks.Moreover,some parasites may modulate the levels of aggression because lizards infected by hematic coccidians performed fewer pushups.Interestingly,lizards also displayed fewer pushups when both the chroma and size of the opponent's blue patch were greater.The results thus also supported the role of the blue patch of s.occidentalis as a sexual armament,because it contributed to the deterrence of aggression from opponent lizards.We revealed that natural parasitic infections in lizard hosts can contribute to their agonistic behavior.We encourage future studies to account for parasites in behavioral testswithlizards. 展开更多
关键词 Ixodes pacificus Lankesterella sexual selection social interactions TICKS
原文传递
Individual repeatability in timing and spatial flexibility of migration routes of trans-Saharan migratory raptors 被引量:4
6
作者 Pascual LOPEZ-LOPEZ Clara GARCLA-RIPOLLES Vicente URIOS 《Current Zoology》 SCIE CAS CSCD 2014年第5期642-652,共11页
Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, t... Satellite-tracking technology has allowed scientists to make a quantum leap in the field of migration ecology. Nowadays, the basic description of migratory routes of many species of birds has been reported. However, the investigation of bird migration at individual level (i.e. repeatability in migratory routes and timing) still remains seldom explored. Here, we investigated repeated migratory trips of a trans-Saharan endangered migratory raptor, the Egyptian Vulture Neophron percnopterus, tracked by GPS satellite telemetry. We compared between- and within-individual variation in migratory routes and timing in order to assess the degree of repeatability (or conversely, the flexibility) in migration. To this end, we analysed a dataset of 48 trips (23 springs and 25 autumns) recorded for six adult birds during 2007-2013. Our results showed consistent migration timing at the individual level, both in spring and autumn. Interestingly, there was a high degree of flexibility in the routes followed by the same individual in different years, probably due to variations in meteorological conditions. Contrary to expectations of a faster migration in spring than in autumn owing to a time-minimization strategy for breeding, birds spent less time in autumn migration (13 ± 2 days, range = 9-18 d) than in spring migration (19 ± 3 days, range = 13-26 d), which can be explained by differences in environmental con- ditions en route. Egyptian vultures showed a consistent clockwise loop migration through western Africa, following more easterly routes in autumn than in spring. Finally, our results provide supporting evidence of low phenotypic plasticity in timing of migration (i.e. strong endogenous control of migration) and high flexibility in routes [Current Zoology 60 (5): 642-652, 2014]. 展开更多
关键词 Egyptian vulture Endogenous control GPS Loop migration Neophron percnopterus Random routes Satellite tracking Simulation
原文传递
Preliminary notes on brain weight variation across labrid fish species with different levels of cooperative behaviour 被引量:1
7
作者 Marta C. SOARES Goncalo I. ANDRE Jose R. PAULA 《Current Zoology》 SCIE CAS CSCD 2015年第2期274-280,共7页
Brain size and weight vary tremendously in the animal kingdom. It has been suggested that brain structural develop- ment must evolve balanced between the advantages of dealing with greater social challenges mad the en... Brain size and weight vary tremendously in the animal kingdom. It has been suggested that brain structural develop- ment must evolve balanced between the advantages of dealing with greater social challenges mad the energetic costs of maintain- ing and developing larger brains. Here we ask if interspecific differences in cooperative behaviour (i.e. cleaning behaviour) are related to brain weight variations in four close-related species of Labrid fish: two are obligatory cleanerfish throughout their en- tire life (Labroides dimidiatus and L. bicolor), one facultative cleaner fish Labropsis australis and one last species that never en- gage in cleaning Labrichthys unilineatus. We first search for the link between the rate of species' cooperation and its relative brain weight, and finally, if the degree of social complexity and cooperation are reflected in the weight of its major brain sub- structures. Overall, no differences were found in relative brain weight (in relation to body weight) across species. Fine-scale dif- ferences were solely demonstrated for the facultative cleaner L. australis, at the brainstem level. Furthermore, data visual exami- nation indicates that the average cerebellum and brainstem weights appear to be larger for L. dimidiatus. Because variation was solely found at specific brain areas (such as cerebellum and brainstem) and not for the whole brain weight values, it suggests that species social-ecological and cognitive demands may be directly contributing to a selective investment in relevant brain areas. This study provides first preliminary evidence that links potential differences in cognitive ability in cooperative behaviour to how these may mediate the evolution of brain structural development in non-mammal vertebrate groups . 展开更多
关键词 Brain weight Body weight Macro-area weight LABRIDAE Cooperation Cleaning behaviour
原文传递
数字地面模型新进展:TIN2.0、3D表面塑型线和自由形态建模工具 被引量:4
8
作者 +1 位作者 原茵(译) 李傲雪(译) 《中国园林》 北大核心 2020年第9期36-41,共6页
竖向设计是人类在景观中进行的基本活动。人类对室外空间的任何干预都涉及对地表形态的设计。在过去的几十年中,数字设计的发展不仅改变了表现的方法,而且改变了设计的过程。就地形建模而言,该技术实现了三维可视化和任务自动化,例如土... 竖向设计是人类在景观中进行的基本活动。人类对室外空间的任何干预都涉及对地表形态的设计。在过去的几十年中,数字设计的发展不仅改变了表现的方法,而且改变了设计的过程。就地形建模而言,该技术实现了三维可视化和任务自动化,例如土方计算和自动产生横截面。但在重点考察最新的建筑信息模型(BIM)如何应用和实施这项技术时,不难发现地形建模过程并没有充分利用技术带来的潜在优势。实际上,三维建模工具、基于组件的建模和分析、设计验证,以及协同设计是可以集成到数字地面模型中的。识别了现有数字建模解决方案中的主要缺陷并为其进一步发展提供机会,提出了一项整合性的数字地面模型建模过程,该过程引入了TIN2.0曲面,对现有的TIN曲面进行了升级,允许在同一曲面中同时存在规则三角网和不规则三角网,并开发了一套基于三维线和自由形态设计工具的建模工具,推动风景园林信息模型框架的发展以满足风景园林师及其他专业人士,如建筑师和土木工程师进行地形建模的需求。通过案例研究对提出的建模过程进行了测试和验证。结果表明,生成的数字曲面具有较高精度,可以具象地表现地形,允许设计过程在三维线或自由形态设计工具的基础上进行。所有地形建模均在三维数字模型上进行。 展开更多
关键词 风景园林 数字地面模型 风景园林信息模型(LIM) 竖向设计 数字模型工具
在线阅读 下载PDF
Viability,behavior,and color expression in the offspring of matings between common wall lizard Podarcis muralis color morphs 被引量:1
9
作者 Javier ABALOS Guillem PEREZ I DE LANUZA +3 位作者 Alicia BARTOLOME Fabien AUBRET Tobias ULLER Enrique FONT 《Current Zoology》 SCIE CAS CSCD 2022年第1期41-55,共15页
Color polymorphisms are widely studied to identify the mechanisms responsible for the origin and maintenance of phenotypic variability in nature.Two of the mechanisms of balancing selection currently thought to explai... Color polymorphisms are widely studied to identify the mechanisms responsible for the origin and maintenance of phenotypic variability in nature.Two of the mechanisms of balancing selection currently thought to explain the long-term persistence of polymorphisms are the evolution of alternative phenotypic optima through correlational selection on suites of traits including color and heterosis.Both of these mechanisms can generate differences in offspring viability and fitness arising from different morph combinations.Here,we examined the effect of parental morph combination on fertilization success,embryonic viability,newborn quality,antipredator,and foraging behavior,as well as inter-annual survival by conducting controlled matings in a polymorphic lacertid Podarcis muralis,where color morphs are frequently assumed to reflect alternative phenotypic optima(e.g.,alternative reproductive strategies).Juveniles were kept in outdoor tubs for a year in order to study inter-annual growth,survival,and morph inheritance.In agreement with a previous genome-wide association analysis,morph frequencies in the year-old juveniles matched the frequencies expected if orange and yellow expressions depended on recessive homozygosity at 2 separate loci.Our findings also agree with previous literature reporting higher reproductive output of heavy females and the higher overall viability of heavy newborn lizards,but we found no evidence for the existence of alternative breeding investment strategies in female morphs,or morphcombination effects on offspring viability and behavior.We conclude that inter-morph breeding remains entirely viable and genetic incompatibilities are of little significance for the maintenance of discrete color morphs in P.muralis from the Pyrenees. 展开更多
关键词 alternative breeding strategies color polymorphism controlled matings lizard behavior morph ontogeny newborn viability
原文传递
Thermoregulatory function and sexual dimorphism of the throat sack in Helmeted Guineafowl(Numida meleagris)across Africa 被引量:1
10
作者 Johann H.Van Niekerk Rodrigo Megía-Palma Giovanni Forcina 《Avian Research》 SCIE CSCD 2022年第3期239-248,共10页
The responses of ground-dwelling birds to heat and cold stress encompass a variety of behavioural,physiological and even morphological mechanisms.However,the role of glabrous skin in this respect has been marginally a... The responses of ground-dwelling birds to heat and cold stress encompass a variety of behavioural,physiological and even morphological mechanisms.However,the role of glabrous skin in this respect has been marginally addressed so far.The Helmeted Guineafowl(Numida meleagris)is a landfowl distributed across Sub-Saharan Africa with eight traditionally recognised extant subspecies.Among the most prominent morphological traits underlying intraspecific variability are size and pigmentation of the bare throat skin(or sack),which might be related to the different habitats and environmental conditions across its wide range.In order to explore the Helmeted Guineafowl range-wide sack variation and pigmentation in relation to thermoregulation and sexual signalling,we collected morphometric and environmental information for N.m.coronata integrating field data with the inspection of photographic material encompassing seven subspecies and environmental information from their habitats.Field data evidenced that sack size was significantly correlated with ambient temperature,thus pointing to a likely involvement of the throat sack in thermoregulation.When the pictorial data from all subspecies were pooled,sack size correlated negatively with biomass,rainfall and humidity,while a positive correlation was found with annual solar irradiation.Sack size correlated positively with monthly temperature variation among the bluethroated subspecies from southern Africa as opposed to the black-throated subspecies ranging north to Zambia and Mozambique.Still,in this latter group the sack was often larger during winter months,possibly to maximise solar radiation absorbance.Noteworthy,sack size was related to sex dimorphism in two subspecies.Sack morphology and colour in the Helmeted Guineafowl likely modulate body temperature by evaporative cooling or heating upon needs,but in some subspecies it is also seemingly related to sexual signalling.Additional studies are needed to fully understand the multifunctionality of this important morphological feature in this species. 展开更多
关键词 Evaporative cooling Helmeted guineafowl Sexual size dimorphism Sub-Saharan Africa THERMOREGULATION Throat sack
在线阅读 下载PDF
Changes in potential mammal diversity in national parks and their implications for conservation
11
作者 Alba ESTRADA A.Marcia BARBOSA Raimundo REAL 《Current Zoology》 SCIE CAS CSCD 2018年第6期671-679,共9页
Observed species richness (OSR)is a widely used and well-studied biodiversity metric.However, non-observed species in favorable ecosystems are also relevant.Two metrics that include observed and potential species were... Observed species richness (OSR)is a widely used and well-studied biodiversity metric.However, non-observed species in favorable ecosystems are also relevant.Two metrics that include observed and potential species were recently defined:potential biodiversity (hereafter potential species richness--PSR)and geometric mean of favorabilities (GMF).We used these metrics to evaluate the national park network of mainland Spain at two time periods (2002 and 2015),using terrestrial mammals on a UTM 100-km^2 grid.PSR and GMF are based on the favorability function, a species distribution model that assesses how favorable an area is for the presence of a species, over and above its prevalence in the study area.For each park and for the whole network,we calculated the mean and sum of OSR,PSR,and GMF in each time period,as well as changes between periods.OSR and PSR were higher inside than outside the park network in both time periods. Thus,although the network covers a very small proportion of the country,it performs well for the representation of mammal species and their favorable areas.However,mean PSR was lower in 2015 than in 2002 inside the national park network,whereas the opposite was the case outside the network.Mountainous Parks generally not only concentrated highly favorable areas for mammals, but they also showed less favorable areas in 2015 compared to 2002,although the reduction was moderate to low.This is a result to consider for future analyses because if the tendency increases, it may have consequences for the conservation of mammals and for the adequacy of the national park network. 展开更多
关键词 CONSERVATION planning DARK DIVERSITY environmental favorability POTENTIAL BIODIVERSITY protected areas
原文传递
Factors determining the occupancy of nest-boxes by Great Tits(Parus major)in eucalypt plantations
12
作者 Ricardo S.Ceia Pedro B.Lopes Luís Pda Silva 《Avian Research》 SCIE CSCD 2023年第2期200-205,共6页
Providing nest-boxes as surrogate tree cavities can be of great importance to increase the breeding populations of cavity-nesting birds in managed forests.However,the exact placement of nest-boxes should be taken into... Providing nest-boxes as surrogate tree cavities can be of great importance to increase the breeding populations of cavity-nesting birds in managed forests.However,the exact placement of nest-boxes should be taken into consideration to enhance their occupancy according to species-specific preferences.In this study,we investigated which factors can better predict nest-box occupancy by the Great Tit(Parus major)in eucalypt plantations.We used generalised linear mixed-effects models to analyse the influence of topography,nest-box positioning,vegetation cover and landscape variables on three-year occupancy records from 80 newly provided nest-boxes.Non-random patterns of nest-box occupancy were found with respect to all categories except topography.Results suggest that Great Tits prefer to occupy high-placed nest-boxes,close to areas that can provide them with supplementary resources either within or in the vicinity of the stand(i.e.,trees other than eucalypts,riparian vegetation,and large patches of adjacent habitats).Overall,this study provides important recommendations for nest-box placement and spatial distribution in managed forests and enhances the potential of nest-box interventions as a biodiversity offset and management tool. 展开更多
关键词 Eucalyptus globulus Managed forest Nest-site attributes Secondary cavity-nester Species-specific preferences Tit
在线阅读 下载PDF
Feeding ecology of a highly aerial bird during its long breeding season
13
作者 Sandra Fernandes Vanessa A.Mata Luis P.da Silva 《Avian Research》 SCIE CSCD 2023年第1期62-69,共8页
Pallid Swifts(Apus pallidus),as other swifts,are birds extremely adapted to an aerial lifestyle,showing unique adaptations that allow them to fly almost continuously.The diet of these non-stopping high-altitudinal aer... Pallid Swifts(Apus pallidus),as other swifts,are birds extremely adapted to an aerial lifestyle,showing unique adaptations that allow them to fly almost continuously.The diet of these non-stopping high-altitudinal aerial birds has been mostly studied through techniques that fail to produce highly resolved prey identifications,and for that have been replaced by molecular techniques,such as DNA metabarcoding.Faecal samples of Pallid Swifts were monthly collected from a colony in the north of Portugal during the breeding season.DNA from the faecal samples was used to sex the birds and to identify the arthropods present in the diet through DNA metabarcoding.From the detected prey items,74 families were identified belonging to 16 orders,with Hymenoptera and Hemiptera being the most frequently consumed.There were seasonal variations in diet richness,composition and prey size.Regarding the diet of males and females,although no differences were found between the diet of males and females in terms of composition and richness,there were differences in the size of arthropods preyed by the different sexes,with males feeding on larger arthropods.The large seasonal variation in Pallid Swifts’diet during the breeding season is probably a result of spatiotemporal variation in aerial prey,of which swifts likely predate opportunistically.Although no significant differences were detected in diet richness and composition between sexes,the fact that males consumed larger prey may suggest the existence of sexual dietary segregation in this group of birds.At last,several pest species were found in these swifts’diet,which,if studied through DNA metabarcoding,can be used to monitor small arthropods,including airborne pests. 展开更多
关键词 AMerial foraging Apus plius Dietary s-ssonal variation FReeding omlogy Metahercoding Opimel foraging theoary
在线阅读 下载PDF
Ecological significance of dorsal polymorphism in a Batesian mimic snake
14
作者 Xavier SANTOS Jairo S.AZOR +3 位作者 Sergio CORTES Elisa RODRIGUEZ Jose LARIOS Juan M.PLEGUEZUELOS 《Current Zoology》 SCIE CAS CSCD 2018年第6期745-753,共9页
Batesian mimicry is the process in which harmless species adopt the appearance of a dangerous, aposematic species.In some prey species,both Batesian mimetic and non-Batesian morphs coexist,presupposing that both morph... Batesian mimicry is the process in which harmless species adopt the appearance of a dangerous, aposematic species.In some prey species,both Batesian mimetic and non-Batesian morphs coexist,presupposing that both morphs have to be evolutionarily advantageous.The viperine snake, Natrix maura,exhibits a zigzag dorsal pattern and antipredatory behavior that mimics European vipers.This snake also has a striped dorsal pattern that coexists with the zigzag pattern.We have examined whether individuals belonging to different geographically structured clades were more likely to exhibit a certain dorsal pattern,and whether the zigzag pattern has a protective function by exposing artificial snakes to predation in natural environments,in addition to comparing antipredatory behavior between zigzag and striped snakes also in natural environments.Our results indicate that the striped pattern was not geographically structured,but habitat-dependent.Aerial predators less frequently attacked zigzag plasticine models than striped or unpatterned models.We detected a shift in antipredator behavior between the 2 morphs,as Batesian mimicking N.maura responded to an approaching potential predator by remaining immobile or fleeing at shorter distances than did striped ones.We conclude that Batesian mimics maintain the cryptic and aposematic value by resembling vipers,whereas in open habitats the non-Batesian mimic has altered its antipredator behavior to maintain its fitness. 展开更多
关键词 antipredatory strategies APOSEMATISM Batesian MIMICRY CRYPSIS DORSAL pattern Natrix maura
原文传递
Conflictive management of small mammals considered as pests: A long way to evidence-based policy making
15
作者 Catarina FERREIRA Miguel DELIBES-MATEOS 《Current Zoology》 SCIE CAS CSCD 2012年第2期353-357,共5页
This paper discusses the controversial management decisions made by policy-makers worldwide regarding poisoning campaigns aimed to control small mammal populations, often considered harmful economic pests. Aside from ... This paper discusses the controversial management decisions made by policy-makers worldwide regarding poisoning campaigns aimed to control small mammal populations, often considered harmful economic pests. Aside from considerations re- garding the biological consequences of these campaigns, we argue that when society rejects all values of science and expertise then only badly supported and negligent decisions will be made about conservation and management issues. The extermination of small mammal species, some of which play crucial ecological roles in several regions of the world, is just an example of such discredit and misinformation. Without a strong commitment towards evidence-based policy-making, economic investments in re- search and development could be entirely compromised 展开更多
关键词 Evidence-based policy Pest management Poisoning campaigns Small mammals
原文传递
Phylogeography and diversification of Oriental weaverbirds(Ploceus spp.):A gradual increase of eurytopy
16
作者 Abdul Razaq Giovanni Forcina +5 位作者 Urban Olsson Qian Tang Robert Tizard Naing Lin Nila Pwint Aleem Ahmed Khan 《Avian Research》 SCIE CSCD 2023年第4期511-522,共12页
Weaverbirds are a speciose group of colorful passerines inhabiting the Old World Tropics.Nevertheless,the Oriental weaverbirds(Ploceus spp.),widespread across southern Asia,are much less diverse and restricted to a fe... Weaverbirds are a speciose group of colorful passerines inhabiting the Old World Tropics.Nevertheless,the Oriental weaverbirds(Ploceus spp.),widespread across southern Asia,are much less diverse and restricted to a few ecological niches compared to their African counterpart.To investigate their phylogeography,we retrieved 101 samples of Baya Weaver(P.philippinus),Streaked Weaver(P.manyar),Black-Throated Weaver(P.benghalensis)and Asian Golden Weaver(P.hypoxanthus)along with GenBank sequences of Finn's Weaver(P.megarhynchus).We reconstructed the first molecular phylogeny based on a dataset consisting of both mitochondrial and nuclear genes,dating the most recent common ancestor of Oriental Ploceus to~11 mya.Subsequent speciation appears to have been a combination of divergence within the Indian subcontinent and dispersal across a barrier situated between the Indian subcontinent and the Indochinese region,which provided habitats with a varying degree of isolations and ultimately promoted divergences in allopatry.Two descendants of the earliest nodes,P.megarhynchus and P.hypoxanthus,are both rare and local,often found near large river systems,which perhaps reflects niche conservatism and a lack of adaptive potential.The three smaller species are all widespread,common and less habitat specific.The most recent divergence,between western and eastern P.philippinus populations,is supported by both phylogenetic and morphological evidence,pointing toward limited gene flow between them.However,a zone of intergradation may exist in Myanmar and Brahmaputra flood plains,thus preventing a recommendation for species level recognition without further study. 展开更多
关键词 Avian phylogenetics Indian subcontinent Indochinese region Multilocus analyses Ploceidae
在线阅读 下载PDF
Reproductive Strategies of a Terrestrial Snail along an Altitudinal Gradient on an Oceanic Island
17
作者 Ana Filipa Ferreira Antonio Manuel de Frias Martins +2 位作者 Regina Tristao da Cunha Paulo Jorge Melo Armindo dos Santos Rodrigues 《Journal of Life Sciences》 2013年第1期31-41,共11页
This study reports how the reproductive cycle of a land snail endemic from an oceanic island is shaped by abiotic factors over an altitudinal gradient of 800 m. In addition, the validity of two morphometric shell para... This study reports how the reproductive cycle of a land snail endemic from an oceanic island is shaped by abiotic factors over an altitudinal gradient of 800 m. In addition, the validity of two morphometric shell parameters (maximum diameter and total height) was assessed, as maturation diagnostic characteristics. The authors' findings suggest that, at Piedade (200 m), individuals are active and mature from October/November to March, and they exhibit dormancy in the remaining months, as a consequence of soil dryness. Thus, at low altitude, gonadal maturation was considered to be primarily influenced by photoperiod, rainfall and temperature At Cabeqo da Bola (1000 m), in turn, individuals are mature from March to July/August and they seem to have minimal gametogenic conditions throughout the remaining months of the year to reproduce. As soil moisture is never a limiting factor, gonadal maturation is mainly shaped by photoperiod and temperature at high altitude. The morphometric shell parameters under analysis were unable to diagnose gonadal maturation, as recently described for related Azorean species. 展开更多
关键词 Adaptation land mollusk climate soil moisture.
在线阅读 下载PDF
Biodiversity Assessment of Sugar Beet Species and Its Wild Relatives:Linking Ecological Data with New Genetic Approaches
18
作者 Filipa Monteiro Maria MRomeiras +1 位作者 Dora Batista Maria Cristina Duarte 《American Journal of Plant Sciences》 2013年第8期21-34,共14页
The value of crop wild relatives has long been acknowledged and this wild resource has been used to improve crop performance with clear economic benefits. Sugar beet (Beta vulgaris subsp. vulgaris) is the most economi... The value of crop wild relatives has long been acknowledged and this wild resource has been used to improve crop performance with clear economic benefits. Sugar beet (Beta vulgaris subsp. vulgaris) is the most economically valuable crop species in the order Caryophyllales, B. vulgaris subsp. maritima being the ancestor of the cultivated beets. The wild species of the genus Beta s.l. are commonly found in coastal areas of Europe and Mediterranean Region, where a rich genetic heritage still exists. Broadening the genetic base of sugar beet by introgression with wild relatives is a growing need regarding the maintenance of ecologically important traits. Since wild relatives have adapted to specific habitats, they constitute an important source of novel traits for the beet breeding pool. So, we conducted a broader research project aiming to delimit taxa and identify priority locations to establish genetic reserves of the wild Beta species occurring in Portugal (Western Iberian Peninsula). The aim of this study was: 1) to identify and characterize the main habitats of these wild Beta species;and 2) to present a review of some genetic tools available for future application in sugar beet breeding. In this review, we have focused on EcoTILLING as a molecular tool to assess DNA polymerphisms in wild populations of Beta and identify candidate genes related to drought and salt tolerance, as well as addressed some issues related to next-generation sequencing (NGS) technologies as a new molecular tool to assess adaptive genetic variation on the wild relatives of sugar beet. 展开更多
关键词 Crop Wild Relatives Beta vulgaris subsp.maritima Single Nucleotide Polymorphisms(SNPs) Western Mediterranean Region EcoTILLING
暂未订购
Medicinal Plants Used to Treat Neurological Disorders in West Africa: A Case Study with Guinea-Bissau Flora
19
作者 Maria M. Romeiras Maria Cristina Duarte +1 位作者 Bucar Indjai Luís Catarino 《American Journal of Plant Sciences》 2012年第7期1028-1036,共9页
The sub-Saharan region holds a wide variety of indigenous plant species, still offering the possibility to discover very interesting new natural products with potential therapeutic value. Most of the African populatio... The sub-Saharan region holds a wide variety of indigenous plant species, still offering the possibility to discover very interesting new natural products with potential therapeutic value. Most of the African population depends on traditional medicine for primary health care, however, neurological disorders are often not considered as common diseases and many people with mental illnesses, like epilepsy, are severely affected by health-related stigma and discrimination. Epilepsy is the most common serious chronic brain disorder, estimated to affect at least 10 million people in Africa. Guinea-Bissau is located in West Africa, and its population is mainly rural with very few health services available. Since the earliest times, Guinea-Bissau flora has constituted the main source of materials used in folk medicine and the local population, who is well versed in the uses of these plants and their properties. The aim of this study was to document the existing knowledge and practices related to the treatment of neurological disorders, namely epilepsy and seizures, in Guinea-Bissau and in other West African countries. The results presented from this study provide information not only on the specific plants used to treat neurological disorders, but also on social knowledge brought in by various ethnic groups, each one having its own culture, beliefs and ways of nature appropriation. Taking into account the existing knowledge on the medicinal properties of plants for treatment of neurologic disorders, it is believed that research in the areas of ethnomedicine and ethnopharmacology in Guinea-Bissau can bring promising results capable of adding value to the very rich natural resources of this country of West Africa. 展开更多
关键词 West Africa Medicinal Plants ETHNOBOTANY Epilepsy GUINEA-BISSAU
暂未订购
上一页 1 2 下一页 到第
使用帮助 返回顶部