A wintering waterbird community in an artificial wetland: Laguna de Meco

[EN]: The progressive loss of natural wetlands throughout Europe has led to the use of human infrastructures such as gravel pits, irrigation ponds and reservoirs by waterbirds as an alternative habitat. In Central Spain, the presence of man-made wetlands is essential for waterfowl conservation. The temporal dynamics of the wintering waterbird community was studied in an artificial wetland located in Madrid, Central Spain (Laguna de Meco). We carried out fortnightly censuses between October 2011 and February 2012 (total of 10) to describe variations in patterns of abundance and of species and taxonomic group richness. A total of 27 aquatic species and 2,901 birds were recorded. Diversity, number of birds and species richness varied between months. The highest numbers of birds occurred in October and February, while the greatest diversity and species richness were recorded during the postnuptial migration in October and November due to the large number of shorebirds occurring in those months. The most abundant species over the study period was the Common Coot Fulica atra, with 38% of the total birds counted, the only exception being the last half of February when the Black-headed Gull Chroicocephalus ridibundus was commonest. Despite only having been created in 2008, this lagoon hosts one of the most important waterfowl communities in Madrid and plays a crucial role in shorebird migration and waterbird conservation in the area. The information provided here could be useful for management strategies in this artificial wetland, which include protecting the lagoon and discarding the idea of moving it to a nearby area.[CA]: La pèrdua progressiva de zones humides naturals fa que les aus aquàtiques facin servir cada cop més, com a hàbitats alternatius, infraestructures humanes, com graveres, basses de reg o embassaments. Al centre d’Espanya, la presència de zones humides d’origen humà és fonamental per a la conservació de les aus aquàtiques. Es va estudiar la dinàmica temporal de la comunitat d’aus aquàtiques hivernants en un aiguamoll artificial de Madrid, la llacuna de Meco. Es van dur a terme deu censos quinzenals entre octubre de 2011 i febrer de 2012 amb l’objectiu de descriure el patró de variació temporal en l’abundància i riquesa de les espècies i grups taxonòmics. Es van detectar un total de 102 espècies, 27 de les quals eren aquàtiques, amb un total de 2.901 aus censades. La diversitat, el nombre d’aus i la riquesa d’espècies va variar entre mesos. Els valors més alts d’abundància d’individus es van obtenir a l’octubre i febrer, mentre que la major diversitat i riquesa d’espècies es van donar durant la migració postnupcial a l’octubre i novembre, a causa del gran nombre de limícoles presents en aquells mesos. L’espècie més abundant durant tot el període d’estudi va ser la Fotja Vulgar Fulica atra, que va suposar el 38% total dels individus censats, exceptuant la segona meitat de febrer durant la qual l’espècie més abundant va ser la Gavina Vulgar Chroicocephalus ridibundus. La llacuna de Meco, en només quatre anys des de la seva creació, ha estat capaç d’albergar una de les comunitats d’aus aquàtiques més importants de Madrid. La presència i estructura d’aquesta llacuna juga un paper clau per a les limícoles en migració i per a la conservació de les aus aquàtiques a la regió. Els resultats d’aquest estudi proporcionen informació útil per a la gestió d’aquesta zona humida artificial, com la seva protecció en lloc de la seva translocació a una zona propera a causa de l’ampliació de les infraestructures que l’envolten.[ES]: La pérdida progresiva de humedales naturales ha hecho que las aves acuáticas usen cada vez más, como hábitats alternativos, infraestructuras humanas, tales como graveras, balsas de riego o embalses. En el centro de España, la presencia de humedales de origen humano es fundamental para la conservación de las aves acuáticas. Se estudió la dinámica temporal de la comunidad de aves acuáticas invernantes en un humedal artificial de Madrid, la laguna de Meco. Se llevaron a cabo diez censos quincenales entre octubre de 2011 y febrero de 2012, con objeto de describir el patrón de variación temporal en la abundancia y riqueza de las especies y grupos taxonómicos. Se registraron un total de 102 especies, 27 de ellas acuáticas, con un total de 2.901 aves censadas. Los valores más altos de abundancia de individuos se obtuvieron en octubre y febrero, mientras que la mayor diversidad y riqueza de especies se dieron durante la migración postnupcial en octubre y noviembre, debido al gran número de limícolas presentes en aquellos meses. La especie más abundante durante todo el periodo de estudio fue la Focha Común Fulica atra, que supuso el 38% total de los individuos censados, exceptuando la segunda mitad de febrero en que la especie más abundante fue la Gaviota Reidora Chroicocephalus ridibundus. La laguna de Meco, en tan solo cuatro años de existencia, ha sido capaz de albergar una de las comunidades de aves acuáticas más importantes de Madrid. La presencia y estructura de esta laguna juega un papel clave para las limícolas en migración y para la conservación de las aves acuáticas en la región. Los resultados de este estudio proporcionan información útil para la gestión de este humedal, como su protección en vez de la translocación a una zona cercana debido a la ampliación de las infraestructuras que la rodean.Peer Reviewe

Hierarchical genetic structure shaped by topography in a narrow-endemic montane grasshopper

[Background]: Understanding the underlying processes shaping spatial patterns of genetic structure in free-ranging organisms is a central topic in evolutionary biology. Here, we aim to disentangle the relative importance of neutral (i.e. genetic drift) and local adaptation (i.e. ecological divergence) processes in the evolution of spatial genetic structure of the Morales grasshopper (Chorthippus saulcyi moralesi), a narrow-endemic taxon restricted to the Central Pyrenees. More specifically, we analysed range-wide patterns of genetic structure and tested whether they were shaped by geography (isolation-by-distance, IBD), topographic complexity and present and past habitat suitability models (isolation-byresistance, IBR), and environmental dissimilarity (isolation-by-environment, IBE).[Results]: Different clustering analyses revealed a deep genetic structure that was best explained by IBR based on topographic complexity. Our analyses did not reveal a significant role of IBE, a fact that may be due to low environmental variation among populations and/or consequence of other ecological factors not considered in this study are involved in local adaptation processes. IBR scenarios informed by current and past climate distribution models did not show either a significant impact on genetic differentiation after controlling for the effects of topographic complexity, which may indicate that they are not capturing well microhabitat structure in the present or the genetic signal left by dispersal routes defined by habitat corridors in the past.[Conclusions]: Overall, these results indicate that spatial patterns of genetic variation in our study system are primarily explained by neutral divergence and migration-drift equilibrium due to limited dispersal across abrupt reliefs, whereas environmental variation or spatial heterogeneity in habitat suitability associated with the complex topography of the region had no significant effect on genetic discontinuities after controlling for geography. Our study highlights the importance of considering a comprehensive suite of potential isolating mechanisms and analytical approaches in order to get robust inferences on the processes promoting genetic divergence of natural populations.VN was supported by a FPI pre-doctoral scholarship (BES-2012-053741) from Ministerio de Economía y Competitividad. JO was supported by Severo Ochoa (SEV-2012-0262) and Ramón y Cajal (RYC-2013-12501) research fellowships. This work received financial support from research grants CGL2011-25053 (Ministerio de Ciencia e Innovación and European Social Fund), POII10-0197-0167, PEII-2014-023-P (Junta de Comunidades de Castilla-La Mancha and European Social Fund) and UNCM08-1E-018 (European Regional Development Fund).We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe

Discordant patterns of genetic and phenotypic differentiation in five grasshopper species codistributed across a microreserve network

Conservation plans can be greatly improved when information on the evolutionary and demographic consequences of habitat fragmentation is available for several codistributed species. Here, we study spatial patterns of phenotypic and genetic variation among five grasshopper species that are codistributed across a network of microreserves but show remarkable differences in dispersal-related morphology (body size and wing length), degree of habitat specialization and extent of fragmentation of their respective habitats in the study region. In particular, we tested the hypothesis that species with preferences for highly fragmented microhabitats show stronger genetic and phenotypic structure than codistributed generalist taxa inhabiting a continuous matrix of suitable habitat. We also hypothesized a higher resemblance of spatial patterns of genetic and phenotypic variability among species that have experienced a higher degree of habitat fragmentation due to their more similar responses to the parallel large-scale destruction of their natural habitats. In partial agreement with our first hypothesis, we found that genetic structure, but not phenotypic differentiation, was higher in species linked to highly fragmented habitats. We did not find support for congruent patterns of phenotypic and genetic variability among any studied species, indicating that they show idiosyncratic evolutionary trajectories and distinctive demographic responses to habitat fragmentation across a common landscape. This suggests that conservation practices in networks of protected areas require detailed ecological and evolutionary information on target species to focus management efforts on those taxa that are more sensitive to the effects of habitat fragmentation.JO was supported by a Ramón y Cajal Fellowship (RYC-2013-12501) and a research contract funded by Severo Ochoa Program (SEV-2012-0262). VGN is supported by a Forschungskredit of the University of Zurich (FK-14-103). VN is supported by a FPI predoctoral fellowship from Ministerio de Economía y Competitividad. This work received financial support from grants CGL2011-25053 (Ministerio de Economía y Competitividad), PCI08-0130-3954 and POII10-0197-0167 (Junta de Comunidades de Castilla-La Mancha and European Social Fund) and UNCM08-1E-018 (European Regional Development Fund).Peer reviewe

El valor de los humedales artificiales: el caso de la laguna de Meco

Póster presentado en el XXII Congreso Español de Ornitología, celebrado en Madrid en diciembre de 2014.La pérdida progresiva de humedales naturales ha hecho que las aves acuáticas usen cada vez más hábitats alternativos de origen antrópico, como graveras, balsas de riego o embalses. La laguna de Meco, de origen artificial y situada en el noreste de la Comunidad de Madrid, se ha convertido en uno de los humedales de mayor importancia de la región. Se llevaron a cabo censos quincenales durante la migración e invernada de 2011- 2012 y la reproducción de 2014 para describir el patrón de variación temporal en la abundancia y riqueza de especies y de los principales grupos taxonómicos y la diversidad (índice inverso de Simpson).Peer reviewe

Partage et sélection d’habitat en hiver chez deux rongeurs sympatriques en milieu agricole : Apodemus sylvaticus et Mus spretus

Les patrons de sélection d’habitat des mammifères varient selon l’échelle et il existe différentes vues sur le rôle des facteurs agissant à macro- et à micro-échelles dans l’assemblage des communautés. Dans cette étude, nous évaluons si les différents patrons de sélection du macro- et du microhabitat expliquent la coexistence de deux espèces de rongeurs sympatriques, Mus spretus et Apodemus sylvaticus en milieu agricole au centre de l’Espagne. Nous avons échantillonné les rongeurs des cultures céréalières et des champs noncultivés (jachères et friches) en utilisant une grille de pièges Sherman. La disponibilité de nourriture et la structure de la végétation (variables à l’échelle du microhabitat), ainsi que la composition du paysage (variable à l’échelle du macrohabitat), ont été mesurées à chaque grille d’échantillonnage. L’abondance de chaque espèce a été analysée en utilisant des Modèles Linéaires Généralisés (MLGs) pour déterminer quelles sont les variables d’échelle associées à l’abondance spécifique. Le poids de chaque échelle dans la formation de l’assemblage a été examiné par une procédure de partition de variance. À l’échelle du microhabitat, A. sylvaticus était positivement lié à la couverture de buissons et M. spretus était positivement liée à la disponibilité des graines. À l’échelle du macrohabitat, A. sylvaticus était négativement associé à la distance de l’arbre le plus proche, alors que M. spretus était associée positivement à la même variable. Le macrohabitat explique 39 % de la variance de l’assemblage, alors que le microhabitat n’explique que 8 %. Ces résultats suggèrent une relative ségrégation d’utilisation des ressources par les deux espèces à l’échelle du microhabitat, et un partage de l’espace à macro-échelle, permettant la coexistence des deux espèces conformément aux règles d’assemblage des communautés. Cette étude montre l’importance de considérer l’échelle du macrohabitat pour comprendre la configuration des assemblages de rongeursPatterns of small mammal habitat selection vary according to scale, although there are discrepancies about the importance of macro and micro-scale factors in rodent community assembly. We assess whether differences in their micro and macrohabitat selection patterns explain the coexistence of two sympatric rodents, Mus spretus and Apodemus sylvaticus, in an agricultural area of central Spain. We trapped mice in uncultivated and crop fields using a grid of Sherman traps. Food availability and vegetation structure (microhabitat) and landscape composition variables (macrohabitat) were measured in each plot. We used GLMs to determine the scale predictors related to specific abundance. The importance of each scale in the assemblage was assessed by a variance partitioning procedure. At microhabitat scale, A. sylvaticus was positively related to shrub cover and M. spretus to seed availability. At macrohabitat scale, A. sylvaticus was negatively associated with distance to the nearest tree, whereas M. spretus was positively associated with this variable. Macrohabitat explained 39 % and microhabitat 8 % of the variance in the assemblage. Results suggest a relative segregation of food preferences at microhabitat scale, and a habitat partitioning at macrohabitat scale, which may allow spatial coexistence of both species, according to community assembly theory. This study shows the importance of both micro and macrohabitat in the configuration of rodent assemblage

Short-term effects of a wildfire on the endangered Dupont’s Lark Chersophilus duponti in an arid shrub-steppe of central Spain

In Europe, Dupont’s Lark Chersophilus duponti is a threatened open-habitat bird. Prescribed burning has sometimes been proposed for its conservation, but without evidence of its effectiveness. To evaluate the short-term effects of a summer wildfire on this species, we performed several transect counts in the burnt and unburnt parts of a shrubsteppe in central Spain. The same transects were counted within a three-year interval prior to the fire and were repeated during the first two springs after the fire. We also measured the vegetation during the first two springs after the fire. In the burnt area, we observed a decrease of about 85–100% in Dupont’s Lark abundance, and about 7–15% in the control area. The disappearance of the scrub cover after fire and its slow regeneration, as well as the large increase in grass cover during the second year, may explain the decrease in this habitat-specialist bird species. Fire should be avoided in areas occupied by the Dupont’s Lark, as its negative effects in the short-term may cause local extinctions. However, prescribed burning may be used in neighboring areas to create new open habitats that may be subsequently colonized by this species.Peer Reviewe

Short-Term Effects of a Wildfire on the Endangered Dupont's Lark Chersophilus duponti in an Arid Shrub-Steppe of Central Spain

In Europe, Dupont’s Lark Chersophilus duponti is a threatened open-habitat bird. Prescribed burning has sometimes been proposed for its conservation, but without evidence of its effectiveness. To evaluate the short-term effects of a summer wildfire on this species, we performed several transect counts in the burnt and unburnt parts of a shrubsteppe in central Spain. The same transects were counted within a three-year interval prior to the fire and were repeated during the first two springs after the fire. We also measured the vegetation during the first two springs after the fire. In the burnt area, we observed a decrease of about 85–100% in Dupont’s Lark abundance, and about 7–15% in the control area. The disappearance of the scrub cover after fire and its slow regeneration, as well as the large increase in grass cover during the second year, may explain the decrease in this habitat-specialist bird species. Fire should be avoided in areas occupied by the Dupont’s Lark, as its negative effects in the short-term may cause local extinctions. However, prescribed burning may be used in neighboring areas to create new open habitats that may be subsequently colonized by this species

Coming of age for COI metabarcoding of whole organism community DNA: towards bioinformatic harmonisation

Metabarcoding of DNA extracted from community samples of whole organisms (whole organism community DNA, wocDNA) is increasingly being applied to terrestrial, marine and freshwater metazoan communities to provide rapid, accurate and high resolution data for novel molecular ecology research. The growth of this field has been accompanied by considerable development that builds on microbial metabarcoding methods to develop appropriate and efficient sampling and laboratory protocols for whole organism metazoan communities. However, considerably less attention has focused on ensuring bioinformatic methods are adapted and applied comprehensively in wocDNA metabarcoding. In this study we examined over 600 papers and identified 111 studies that performed COI metabarcoding of wocDNA. We then systematically reviewed the bioinformatic methods employed by these papers to identify the state-of-the-art. Our results show that the increasing use of wocDNA COI metabarcoding for metazoan diversity is characterised by a clear absence of bioinformatic harmonisation, and the temporal trends show little change in this situation. The reviewed literature showed (i) high heterogeneity across pipelines, tasks and tools used, (ii) limited or no adaptation of bioinformatic procedures to the nature of the COI fragment, and (iii) a worrying underreporting of tasks, software and parameters. Based upon these findings we propose a set of recommendations that we think the metabarcoding community should consider to ensure that bioinformatic methods are appropriate, comprehensive and comparable. We believe that adhering to these recommendations will improve the long-term integrative potential of wocDNA COI metabarcoding for biodiversity science

Geography, climate and shifts in host plants distribution explain the genomic variation in the cactus moth

Landscape heterogeneity and the host plant use are factors suggested to play determinant roles in shaping the evolutionary history of herbivorous insects. However, the role of the reconfiguration of host plants distributions linked to Quaternary climate oscillations as drivers of contemporary population genetic structure is still poorly understood. Here, we formally examine the relative contribution of such factors on intraspecific diversification using the South American cactus moth, Cactoblastis cactorum, an herbivore insect specialized in the use of cacti as host plants. We assessed genomic variation using genome-wide SNPs and mitochondrial data in populations sampled across a broad geographical gradient where moths feed on different cactus species. We integrated demographic simulations and ecological niche modeling into a landscape genomics framework, to test alternative hypotheses of past and current population connectivity for both C. cactorum and its host plants. Regions exhibiting higher genomic diversity were evaluated for congruence with areas where suitable climatic conditions remained stable through time. Our results revealed that past spatial configuration of suitable habitat conditions and shifts of host plants distributions are the factors that better explain the intraspecific diversification. Genomic data also supported the hypothesis that areas of long-term habitat stability served as refugia for C. cactorum, enabling the maintenance of high levels of genetic diversity over time. Overall, our study highlights the importance of integrating inter-specific interactions and their spatio-temporal dynamics to better understand the relative importance of abiotic and biotic factors driving the diversification processes in herbivorous insects with broad geographical and restricted host ranges

Digest: Revisiting morphology-derived hypotheses of hybridization in the light of genomics

Genetic exchange between independently evolving lineages may give rise to the formation of new taxa, and hypotheses for this have been derived from species with intermediate phenotypes, when compared to potential parental species. Goulet-Scott and collaborators (2021) evaluate such a hypothesis in a wildflower species complex by integrating genomic and trait information. They find no support for hybrid speciation, despite detecting signatures of genetic admixture in some individuals resulting from interspecific gene flow in a hybrid zone.Peer reviewe