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We explored the influence of habitat structure on bird density and species richness in the poorly known bird communities in the steppes of Eastern Morocco, along a 200 km long N–S gradient of increasing aridity. The birds were surveyed, and habitat structure was measured in 44 transects regularly distributed along the gradient and during the winter and spring seasons in two consecutive years. After applying a principal component analysis (PCA), five axes were identified, including one related to the latitude–altitude–soil-type gradient and another describing the development of herbaceous vegetation. Generalized linear models were used to explore the relations between bird density and species richness with PCA axes in each season, considering both the entire community and groups of granivorous, insectivorous, and mixed-diet species. More than 90% of the birds were year-round residents, with larks dominating the community in both seasons. We conclude that a distinct multifactorial response can be identified for each functional group of species. In the winter, the community is mainly affected by the structure of the habitat, while aridity (and its assumed relation to primary production) is less influential. In the spring, habitat structure continues to have the greatest explanatory power, but location along the aridity gradient becomes more relevant. These findings reveal the interaction of the negative effects of climatic and anthropogenic changes in the habitat available to these bird communities, with a greater impact expected on birds with diets that include seeds, as well as a general shift of optimal breeding conditions toward more northerly latitudes.

In the Anthropocene, many species are rapidly shifting their ranges in response to human-driven habitat modifications. Studying patterns and genetic signatures of range shifts helps to understand how species cope with environmental disturbances and predict future shifts in the face of global environmental change. We investigated the genetic signature of a contemporary wide-range expansion observed in the Iberian common vole Microtus arvalis asturianus shortly after a colonization event. We used mtDNA and microsatellite data to investigate patterns of genetic diversity, structure, demography, and gene flow across 57 localities covering the historical range of the species and the newly colonized area. The results showed a genetic footprint more compatible with a true range expansion (i.e. the colonization of previously unoccupied areas), than with a model of “colonization from within” (i.e. local expansions from small, unnoticed populations). Genetic diversity measures indicated that the source population was likely located at the NE of the historical range, with a declining gradient of genetic diversity towards the more recently invaded areas. At the expansion front, we observed the greatest gene flow and smallest pairwise differences between nearby localities. Both natural landscape features (rivers) and recent anthropogenic barriers (roads, railways) explained a large proportion of genetic variance among populations and had a significant impact on the colonization pathways used by voles.

Table S1: Number of alleles per locus in the recent past and current periods for Dupont´s lark; Table S2: Observed allele frequencies at each locus in each region at both periods of time (left = recent past; right = current). The number of individuals typed is shown in brackets. Person´s r correlation values (R) between allele frequencies in each period within each region are also indicated. Rare alleles are in bold and private alleles at each period are underlined; Table S3: Paired t-test results for temporal variation of genetic diversity (observed heterozygosity, Ho; unbiased expected heterozygosity, uHe; allelic richness, Ar; and inbreeding, FIS) of Dupont´s lark males at country (Morocco, Spain) and regional level. Significant values are represented with an asterisk; Table S4: Genetic diversity estimates for each of the nine Dupont´s lark regions considering the samples that overlapped geographically (sampled at the same localities) during the recent past (P) and the current (C) period. Sample size (N), observed heterozygosity (Ho), unbiased expected heterozygosity (uHe), allelic richness (AR), inbreeding coefficient (FIS). Paired t-test results for temporal variation of genetic diversity (observed heterozygosity, Ho; unbiased expected heterozygosity, uHe; allelic richness, AR and inbreeding, FIS) at regional level are also shown. Significant values are represented with an asterisk; Table S5: Matrix of pairwise (GST and D) values between regions in Morocco (Anti Atlas, AA; Ain Bni Mathar, ABM; Midelt, MID; Plateau of Rekkam, REKK). Values below diagonal correspond to comparisons in the recent past period and above diagonal in the current period. Values among sampling periods within regions are shown on the diagonal. Asterisks indicate statistically significant values; Table S6: Matrix of pairwise (GST and D) values between regions in Spain (Ebro Valley, EV; Iberian Mountains, IM; Northern Plateau, NP; Southern Plateau, SP and Southern Spain, SS). Values below d

Monitoring temporal dynamics in genetic diversity is of great importance for conservation, especially for threatened species that are suffering a rapid population decline and increased fragmentation. Here, we investigate temporal variation in genetic diversity, structure, and gene flow in the Dupont’s lark (Chersophilus duponti) across most of its range. This species shows increasing levels of population fragmentation, substantial population declines, and severe range contraction, so temporal losses of genetic diversity, increasing differentiation, and decreasing gene flow are expected when comparing present day data with previous situations. To address this, we resampled sites (nine regions in two countries) after 12–15 years (five-to-seven generations) and assessed changes in genetic parameters using 11 microsatellite markers. We found no substantial loss in genetic diversity over time at the species level, but we detected considerable variation among regions in the amount of allelic diversity and heterozygosity lost over time. Temporal variation in allele frequencies (common, rare, and private alleles), and changes in genetic differentiation and gene flow over time suggest a major role of connectivity for the stability of the overall metapopulation. Our results agree with the hypothesis that connectivity rescues genetic diversity via immigration and gene flow. However, evidence of recent genetic bottleneck and the substantial changes detected in some regions are clear signs of genetic erosion and may be signalling a rapid decline of the populations. Urgent actions must be carried out to stop and reverse human impacts on this threatened lark and its habitat.

[EN] Stress in birds has been widely studied through the measurement of heterophil-to-lymphocyte ratio (H/L ratio). In this study we aimed to assess for the first time the potential variation of stress, measured as H/L ratio, associated to geography (between-country variation) and seasonality (between seasons and within the breeding season), as well as the leukocyte profiles, in the threatened Dupont’s Lark (Chersophilus duponti), using samples from Spain and Morocco. Furthermore, we tested whether variation in H/L ratio was associated with variables such as population density, presence of blood parasites and individual body condition. We found that H/L ratio did not vary between countries, but individuals captured during the breeding season showed higher values of H/L compared to non-breeding ones. Neither male density, nor date within the breeding season had an effect on the H/L ratio. In Spain, individuals with higher body condition showed lower H/L ratio regardless of whether they were malaria-infected. In Morocco, malaria-infected individuals showed higher values of H/L ratio than the non-infected birds. Moreover, we found that our average values of H/L ratio in Morocco were within the ranges of other passerines, but not in Spain. Individuals with higher H/L ratios may be more stressed or present higher capability to face stressful situations. Although H/L ratio is a useful and relatively easy way to obtain measure of stress, the impact that the environment might have on stress and the way it is explained by H/L ratio must be addressed carefully. This study provides new insight for this species’ biology and provides useful reference information to test the status and survival of other populations., [DE] Stress bei Vögeln ist durch die Messung des Verhältnisses von Heterophilen zu T-Lymphozyten (H/L-Verhältnis) umfassend untersucht worden. In dieser Studie wollten wir zum ersten Mal die potentiellen Veränderungen des Stresses in Verbindung mit der Geografie (Unterschiede zwischen einzelnen Ländern) und der Saisonalität (zwischen den Jahreszeiten und innerhalb der Brutsaison), gemessen als H/L-Verhältnis, sowie die Leukozytenprofile bei der bedrohten Dupontlerche (Chersophilus duponti) anhand von Proben aus Spanien und Marokko bewerten. Darüber hinaus haben wir untersucht, ob das H/L-Verhältnis mit Variablen wie der Populationsdichte, dem Vorhandensein von Blutparasiten und der individuellen physischen Verfassung zusammenhängt. Wir stellten fest, dass das H/L-Verhältnis zwischen den einzelnen Ländern nicht variierte, aber die während der Brutzeit gefangenen Tiere höhere H/L-Werte aufwiesen als nicht brütende Tiere. Weder die Dichte an Männchen, noch der Zeitpunkt innerhalb der Brutsaison hatten einen Einfluss auf das H/L-Verhältnis. In Spanien wiesen Tiere mit einer besseren physischen Verfassung ein niedrigeres H/L-Verhältnis auf, unabhängig davon, ob sie mit Malaria infiziert waren. In Marokko zeigten malariainfizierte Vögel höhere Werte des H/L-Verhältnisses als nicht infizierte. Außerdem stellten wir fest, dass unsere Durchschnittswerte für das H/L-Verhältnis in Marokko innerhalb der Werte für andere Sperlingsvögel lagen, nicht aber in Spanien. Tiere mit einem höheren H/L-Verhältnis sind möglicherweise gestresster oder besser in der Lage, mit Stresssituationen umzugehen. Obwohl das H/L-Verhältnis ein nützliches und relativ einfach zu beschaffendes Maß für Stress ist, muss der eventuelle Einfluss der Umwelt auf Stress und die Möglichkeiten, diesen durch das H/L-Verhältnis zu erklären, sorgfältig untersucht werden. Diese Untersuchung bietet neue Einblicke in die Biologie dieser Art und liefert nützliche Referenzinformationen für die Bestimmung des aktuellen St

The role of glacial refugia in shaping contemporary species distribution is a long‐standing question in phylogeography and evolutionary ecology. Recent studies are questioning previous paradigms on glacial refugia and postglacial recolonization pathways in Europe, and more flexible phylogeographic scenarios have been proposed. We used the widespread common vole Microtus arvalis as a model to investigate the origin, locations of glacial refugia, and dispersal pathways, in the group of “Continental” species in Europe. We used a Bayesian spatiotemporal diffusion analysis (relaxed random walk model) of cytochrome b sequences across the species range, including newly collected individuals from 10 Iberian localities and published sequences from 68 localities across 22 European countries. Our data suggest that the species originated in Central Europe, and we revealed the location of multiple refugia (in both southern peninsulas and continental regions) for this continental model species. Our results confirm the monophyly of Iberian voles and the pre‐LGM divergence between Iberian and European voles. We found evidence of restricted postglacial dispersal from refugia in Mediterranean peninsulas. We inferred a complex evolutionary and demographic history of M. arvalis in Europe over the last 50,000 years that does not adequately fit previous glacial refugial scenarios. The phylogeography of M. arvalis provides a paradigm of ice‐age survival of a temperate continental species in western and eastern Mediterranean peninsulas (sources of endemism) and multiple continental regions (sources of postglacial spread). Our findings also provide support for a major role of large European river systems in shaping geographic boundaries of M. arvalis in Europe.

1. Agricultural intensification is one of the main drivers of species loss worldwide, but there is still a lack of information about its effect on functional diversity of arable weeds communities. 2. Using a large scale pan European study including 786 fields within 261 farms from eight countries, we analysed differences in the taxonomic and functional diversity of arable weeds assemblages across different levels of agricultural intensification in. We estimated weed species frequency in each field, and collected species’ traits (vegetative height, specific leaf area and seed mass) from the TRY plant trait database. With this information we estimated taxonomic (species richness), functional composition (community weighted means) and functional diversity (functional richness, evenness, divergence and redundancy). We used indicators of agricultural management intensity at the individual field scale (e.g. yield, inputs of nitrogen fertilizer and herbicides, frequency of mechanical weed control practices) and at the landscape scale surrounding the field (i.e. number of crop types, mean field size and proportion of arable land cover within a radius of 500m from the sampling points). 3. The effects of agricultural intensification on species and functional richness at the field scale were stronger than those of intensification at the landscape scale, and we did not observe evidence of interacting effects between the two scales. Overall, assemblages in more intensified areas had fewer species, a higher prevalence of species with ruderal strategies (low stature, high leaf area, light seeds), and lower functional redundancy. 4. Maintaining the diversity of Europe’s arable weed communities requires some simple management interventions, for example, reducing the high intensity of field-level agricultural management across Europe, which could be complemented by interventions that increase landscape complexity., 1. Agricultural intensification is one of the main drivers of species loss worldwide, but there is still a lack of information about its effect on functional diversity of arable weeds communities. 2. Using a large scale pan European study including 786 fields within 261 farms from eight countries, we analysed differences in the taxonomic and functional diversity of arable weeds assemblages across different levels of agricultural intensification in. We estimated weed species frequency in each field, and collected species’ traits (vegetative height, specific leaf area and seed mass) from the TRY plant trait database. With this information we estimated taxonomic (species richness), functional composition (community weighted means) and functional diversity (functional richness, evenness, divergence and redundancy). We used indicators of agricultural management intensity at the individual field scale (e.g. yield, inputs of nitrogen fertilizer and herbicides, frequency of mechanical weed control practices) and at the landscape scale surrounding the field (i.e. number of crop types, mean field size and proportion of arable land cover within a radius of 500m from the sampling points). 3. The effects of agricultural intensification on species and functional richness at the field scale were stronger than those of intensification at the landscape scale, and we did not observe evidence of interacting effects between the two scales. Overall, assemblages in more intensified areas had fewer species, a higher prevalence of species with ruderal strategies (low stature, high leaf area, light seeds), and lower functional redundancy. 4. Maintaining the diversity of Europe’s arable weed communities requires some simple management interventions, for example, reducing the high intensity of field-level agricultural management across Europe, which could be complemented by interventions that increase landscape complexity.

The least weasel (Mustela nivalis Linnaeus, 1766) is the world’s smallest carnivore (King & Powell 2007) and probably one of the most difficult to detect (García & Mateos 2009). It is widely distributed throughout the northern hemisphere (McDonald et al. 2016), and seems to be a common and relatively abundant species, at least in some areas of the European continent (Larivière & Jennins 2009, Tikhonov et al. 2010). However, many basic aspects of its biology, distribution, population dynamics and ecology remain largely unknown in most areas of its range, a lack of information that is especially striking in Spain (Palazón 2017).

La comadreja Mustela nivalis es el más pequeño de los carnívoros Ibéricos y uno de los más desconocidos. Pese a mostrar una amplia distribución según el Atlas y Libro Rojo de Mamíferos Terrestres de España (SECEM, 2007), se desconoce si la ausencia de registros en algunas áreas del país podría deberse a su dificultad de detección más que a una ausencia real. Por lo tanto, el aporte de nuevos datos sobre presencia segura de la especie es imprescindible para mejorar y actualizar la escasa información existente sobre este mustélido. Desde 2012 nuestro grupo de investigación viene desarrollando varios proyectos en Castilla y León enfocados a un mejor entendimiento de la dinámica poblacional y dispersión del topillo campesino Microtus arvalis, así como distintos aspectos relacionados con su genética, parásitos, enfermedades y principales depredadores, como la comadreja. Gracias a esta investigación, se han recopilado -de forma no estandarizadadatos de presencia segura de comadrejas (individuos capturados) a lo largo de varios años de muestreo en diferentes zonas de Castilla y León. Hemos realizado diversos tipos de muestreo en un total de 43 cuadrículas UTM (10x10 km), lo que supone un 4,6% del total de cuadrículas de Castilla y León. Se han logrado capturar más de 150 ejemplares, confirmando la presencia de la especie en 37 de las 43 cuadrículas muestreadas (86%). Estos resultados amplían en 15 nuevas cuadrículas UTM la distribución actual conocida de la especie en Castilla y León, y corroboran su presencia en otras 22. No se han encontrado cuadrículas en las que la especie estuviera presente en 2007 (Atlas y Libro Rojo de los mamíferos terrestres de España) y no se haya detectado en nuestros muestreos. Los datos sugieren que la ausencia aparente de la especie en determinadas cuadrículas de la comunidad podría deberse únicamente a su dificultad para ser detectada o a la falta de estudios específicos sobre este carnívoro.

Dupont's lark Chersophilus duponti was categorized globally as Near Threatened on the IUCN Red List in 2005, largely because of reported declines in Spain and an estimated population of 2,000–3,000 breeding pairs in Morocco. However, the range and size of the species' North African populations were still unknown, despite being critical for assessment of the species' global conservation status. Here we report on the breeding distribution of Dupont's lark in Morocco, probably the largest population in its North African range, as well as on its preferred habitat, population density and size. Fieldwork and analysis of satellite images were combined to locate suitable habitat for the species, assess its presence (eliciting territorial calls by broadcasting the males’ songs and calls), and estimate densities using 83 km of linear censuses. Total number of birds located was 461 (305 from song playback and 156 from transects) across an extent of occurrence of c. 11,000 km2, comprising 2,067 km2 of suitable habitat and an effective area of occupancy of 1,645 km2. Mean density was 0.60 ± SD 0.52 birds per 10 ha and was highest in dense stands of Stipa tennacissima. Our estimate of Dupont's lark breeding population in Morocco is c. 15,400 singing males (lower and upper limits 11,220–20,167, respectively). Evidence of habitat loss and degradation was found in one of the main areas of the species' distribution in Morocco, although this does not seem to be a general pattern in the lark's Moroccan range. Further studies are required of the dynamics of suitable habitat for the species to prevent long-term consequences for the conservation of Dupont's lark and other bird species of the steppe.