18 research outputs found

    Uso ganadero y diversidad de pastizales: relaciones con la disponibilidad y el movimiento de propágulos

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    Tesis doctoral inédita de la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Ecología. Fecha de lectura: 28-04-200

    Wind farms affect the occurrence, abundance and population trends of small passerine birds: The case of the Dupont's lark

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    "This is the peer reviewed version of the following article: Journal of Applied Ecology 55.4 (2018): 2033-2042, which has been published in final form at https://doi.org/10.1111/1365-2664.13107. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited"The assessment of the effects of wind farms on bird populations is commonly based on collision fatality records. This could undervalue the effect of wind farms on small-sized birds. We evaluate the effect of wind turbines on occurrence, abundance and population trends of a threatened small passerine species, the Dupont's lark Chersophilus duponti. To our knowledge, this is one of the first studies addressing the effect of wind farms on population trends using time-series data from multiple wind farms. We estimated population trends by fitting a switching linear trend model with the software trim (Trend & Indices for Monitoring data). We used multiannual data surveys of five populations in the presence of wind farms and nine in their absence (2008–2016 period). Furthermore, we fitted a logistic and a negative binomial regression model to test the effect of wind farm proximity on species occurrence and abundance in 2016, respectively. We incorporated local connectivity and habitat availability estimates in both models as predictors. Results showed a negative trend overall, but that was significantly more regressive in the presence of wind farms: 21.0% vs. 5.8% average annual decline in the absence of wind farms. Dupont's lark occurrence and abundance in 2016 were negatively affected by measures of population isolation and positively affected by the distance to wind farms. These results highlight the negative effect of isolation and wind farm proximity on Dupont's lark population parameters. Taking into account the metapopulation structure exhibited by the species in the study area, this work established a 4.5-km threshold distance from wind farms, beyond which Dupont's lark populations should be unaffected. Synthesis and applications. This work highlights the negative impact of wind farms on small-sized birds and provides a 4.5-km threshold distance that should be taken into account in the design of future wind energy projects. Moreover, we suggest an analytical approach based on population trends, species abundance and occurrence variation in relation to wind farms, useful for the assessment of wind farm impacts on small-sized birdsEuropean Comission, Grant/Award Number: Life Ricotí (LIFE15-NAT-ES-000802); Excellence Network Remedinal 3CM (S2013/MAE−2719); Fundación Patrimonio Natural de Castilla y León; Biodiversity Foundation - Ministry of Agriculture, Food and Environment; Fundación BBVA, BBVARicotí-project; European Social Fund for the Youth Employment Initiativ

    Aplicaciones de SIG y teledetección en ecología: Manual de prácticas en QGIS

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    Este trabajo surge como resultado de un proyecto de colaboración entre Juan Traba, profesor titular del Departamento de Ecología de la Universidad Autónoma de Madrid, y Sandra Estela Moreno Fernández, estudiante del Grado en Biología, cuyo objetivo estriba en la actualización y transformación del guion de prácticas de la asignatura Aplicaciones de SIG y Teledetección en Ecología impartida en el Máster de Ecologí

    Aplicaciones de SIG y teledetección en ecología: Guión de prácticas de la asignatura

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    Este trabajo surge como resultado del Proyecto de Innovación Docente de la Universidad Autónoma de Madrid – Convocatoria 2013: Adaptación de los recursos informáticos de la asignatura “Aplicaciones de SIG y Teledetección en Ecología” del Máster Oficial en Ecología para la utilización de herramientas de software libre, y elaboración del manual de las prácticas, coordinado por Juan Traba y con la participación de Javier Seoane y Manuel B. Morales; los tres son profesores titulares del Departamento de Ecología de la Universidad Autónoma de Madrid. Ester González de Andrés ha disfrutado de una beca financiada por la la UAM durante la realización de este proyecto. Queremos agradecer expresamente la imprescindible participación de Mª Paula Delgado, Irene Guerrero y Pablo Acebes en la docencia de la asignatura, la preparación y testado de materiales y en la revisión crítica de este documento

    Gradientes abióticos dirigen la composición florística y la estructura de las comunidades de plantas en el Desierto del Monte

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    Defining plant communities in desert zones is difficult due to large scale homogeneity and small scale heterogeneity, thus making provision of systematic information for conservation decisions problematic. We analysed plant communities of the most arid sector of Monte Desert for structure, plant composition and environmental variables. Small-scale variables such as slope, rock cover, bare ground and litter, as well as largescale ones such as species diversity, composition and similarity within and between sites were included. Analyses of floristic composition showed the difficulty of segregating distinct communities due to high internal heterogeneity and overlap between the different sites. Only mesquite woodlands, a community situated at the extreme of the soil moisture gradient was segregated. Ordination on structural variables was somewhat more successful in segregating communities on the basis of substrate type and of tree and shrub cover. Our results showed the difficulty distinguishing plant communities in temperate deserts, suggesting the existence of relatively stable assemblages of species at the extremes of the gradients and of great heterogeneity within and between sites. They cannot be defined by floristic variables solely, but require environmental information also.Fil: Acebes, Pablo. Terrestrial Ecology Group; Australia. Universidad Autónoma de Madrid; EspañaFil: Traba Díaz, Juan. Universidad Autónoma de Madrid; España. Terrestrial Ecology Group; AustraliaFil: Peco, Begoña. Universidad Autónoma de Madrid; España. Terrestrial Ecology Group; AustraliaFil: Reus, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Juan; ArgentinaFil: Giannoni, Stella Maris. Universidad Nacional de San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Malo Arrázola, Juan Esteban. Terrestrial Ecology Group; Australia. Universidad Autónoma de Madrid; Españ

    Effort needed to accurately estimate Vocal Activity Rate index using acoustic monitoring: A case study with a dawn-time singing passerine

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    Los autores del Departamento de Ecología de la UAM pertenecen al Terrestrial Ecology Group (TEG-UAM)Indices based on singing activity have often been used in wildlife surveys conducted with passive acoustic monitoring. For instance, the Vocal Activity Rate index (VAR) has been employed to estimate animal populations and detect changes in abundance between years or sites. VAR may differ greatly between days due to environmental and biological factors, therefore leading to inadequate population size estimations and recommendations. However, there is still little information about the minimum number of monitoring days required for estimating a reliable VAR to assess changes over time or sites. We describe, for first time for a terrestrial bird species, the pattern of variation of VAR as a function of the number of monitoring days. Coefficient of variation sharply decreased with the number of monitoring days, and this pattern was similar during the breeding and post-breeding period. Coefficient of variation was close to 100% when a single monitoring day was surveyed, but decreased up to 30% and 20% after six or seven and nine monitoring days, depending on the monitoring period. Mean VAR was significantly related to bird abundance, but no relationship was found between bird abundance and number of days needed to reach a CV lower than 20%. Our results highlight that prior assessment of effort needed to estimate a reliable VAR should be a prerequisite for future monitoring programmes using singing activity indices. We found large differences in the number of monitoring days needed to obtain a reliable VAR in comparison to prior research on seabirds, suggesting that further research should be developed in different taxa and situationsThis is a contribution to the LIFE Ricoti (LIFE15-NAT-ES-000802), supported by the European Commission, the “BBVA-Dron Ricoti”, funded by the BBVA Foundation and the Excellence Network Remedinal 3CM (S2013/MAE2719), supported by Comunidad de Madri

    Moderate sheep grazing increases arthropod biomass and habitat use by steppe birds

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    Open semi-natural ecosystems have been historically shaped by anthropogenic land-use, and the abandonment or intensification of these activities implied a detrimental alteration of their landscapes. Extensive sheep grazing has gradually decreased during the 20th century in Mediterranean steppes, triggering changes across all taxa. Here, we address the effect of sheep grazing on both arthropod biomass and space use by insectivorous steppe birds, using an endangered passerine as a model species. We found that biomass of different arthropod groups peaked at intermediate levels of grazing, and that both short-term grazing (affecting arthropod biomass) and long-term grazing (affecting vegetation structure) explain space use by insectivorous birds, whereas only long-term processes are decisive for bird territory establishment. Our results emphasise the role of sustained moderate grazing intensity in the conservation of steppe biodiversity. In the current decline context of extensive sheep grazing, agricultural policies should prioritise these practices to ensure the persistence of open semi-natural ecosystemsThis study was partially supported by the European Commission (Life Ricotí project LIFE15-NAT-ES-000802) and the BBVA Foundation (BBVA-Dron Ricotí project). JGC was funded through a Postdoc grant by the Education and Research Department of Madrid Autonomous Region Government (REMEDINAL TE; S2018/EMT4338), and this paper contributes to project REMEDINAL TE-CM (P2018/ EMT4338

    Dietary niche overlap and resource partitioning among six steppe passerines of Central Spain using DNA metabarcoding

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    Trophic niche partitioning is a mechanism that facilitates the coexistence of ecologically similar species by sharing their resource use. However, detailed information of the trophic niche in insectivorous birds is usually limited by the lack of accurate identification of consumed food resources. The use of DNA metabarcoding has proved useful for molecular identification of the taxa present in bird faecal samples. Here, we used this molecular technique to study the diets of six steppe passerine species distributed in two Special Protection Areas in central Spain, and to characterize the dietary niche overlap and the prey composition differences between bird species. In total, we distinguished 112 diet items, covering 39 arthropod families of 13 orders. Although significant dietary differences existed in prey species composition, our results indicated a 74% overlap in steppe bird dietary niche, mostly due to high consumption of abundant arthropod prey such as beetles, grasshoppers and spiders in the breeding season by all bird species. The lowest overlap was found for the dietary niches of the Greater Short-toed Lark Calandrella brachydactyla and Dupont's Lark Chersophilus duponti, a scarce and threatened species, which appeared to be the species with the most distinct dietary niche within the community. Our results make a significant contribution to the knowledge of shrub-steppe bird diets and their trophic interactions, indicating that some extent of interspecific resource partitioning occurs in the study area, notably between Dupont's Lark and the Greater Short-toed Lark. Our study demonstrates the value of DNA metabarcoding in the assessment of passerine diets and provides useful ecological results for the design of biodiversity conservation programmes in the increasingly scarce and threatened steppe habitatsThis study was supported by the European Commission LIFE Ricot ı (LIFE15-NAT-ES-000802) and LIFE Connect Ricot ı (LIFE20-NAT-ES-000133) projects, and the BBVA Foundation Dron Ricot ı project. This is a contribution to the Excellence Network Remedinal 3CM (S2013/MAE2719). Lu ıs P. da Silva and Vanessa A. Mata were funded by Fundac ~ao para a Ci^encia e Tecnologia (FCT) through the research contract CEECIND/02064/ 2017 and 2020.02547.CEECIND, respectivel
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