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Increasing abundance of large ungulates is raising human-wildlife impacts and the effectiveness of recreational hunting to reduce their population growth is increasingly questioned. We report on long-term trends (> 15 years) in wildlife-vehicle collisions (WVC) and hunting bags, and on associations between the annual growth rate of WVC and that of hunting bags for three ungulates – the wild boar, the red deer, and the roe deer – and the grey wolf in northwest Spain to evaluate the regulating capacity of recreational hunting at large spatial scale. Wildlife-vehicle collisions increased by 332% in 16 years and 91% of all traffic accidents were caused by collisions with these three ungulates. All ungulate species showed significant positive trends in WVC and hunting bags, but we did not observe a negative association between annual growth rate of hunting bags and that of WVC except for the wild boar. Results suggest that recreational hunting was unable to reduce ungulate population growth at the regional scale. There was no upward trend of vehicle collisions with wolves over the study period, possibly reflecting stable wolf populations. Natural mortality due to predation could be promoted through the protection of apex predators, but the lethal management of apex predators, often based on sociopolitical pressures rather than damage levels, can conflict with the strategy for mitigating ungulate impacts. Ungulate management needs to be reconsidered from an ecological perspective that integrates human management measures, including recreational hunting, based on the population dynamics and the recovery of predator–prey interactions by favoring the expansion of apex predators.

A comprehensive review of the natural history of the calandra lark Melanocorypha calandra in Spain.

Habitat degradation and climate change are major threats to the long-term persistence of reptile populations. However, their roles on primary productivity instability remain unclear at certain scales. Besides, the design of protected areas has often overlooked reptiles or assumed that their ecological requirements are represented under the umbrella of more charismatic species. Here, we assess the vulnerability of areas of high diversity of reptiles in the Iberian Peninsula to global change using data from satellite imagery. We focused on primary productivity, climate and land-use change because they are indicators of environmental variability that might impair ecosystem functioning and alter wildlife communities. We used linear regressions to detect monotonic temporal trends in primary productivity (through the enhanced vegetation index, EVI) and climate (mean temperature and accumulated precipitation) at two spatial resolutions (10-km2 UTM squares and CORINE land-cover polygon level) over the period 2000–2020. We also determined how the strength of land-use and climate change affected the intensity of change in primary productivity at both spatial scales with multivariate linear regressions. We identified 339 hotspots (10-km2 UTMsquares) andmonotonic increments of temperature, EVI or both occurred in 43%, 16%and 22%of them, respectively. Positive trends of the EVI were related to increasing temperatures and changes in shrubland and forest cover. Within the hotspots with monotonic increments in EVI and temperature, EVI increments occurred in 65 % of the CORINE polygons that did not change their land-cover type, with stronger increases in tree crops. Finally, the Natura 2000 network provides only moderate protection to reptile hotspots, being most of the vegetation types relatively underrepresented. The proportion of forest and shrubland protected by the Natura 2000 network was higher in hotspots where EVI changed. Our procedures are relevant to prioritize hotspots r

Farmland ecosystems are seasonally dynamic habitats shaped by meteorological fluctuations and anthropogenic land-use changes. Farmland birds may be seasonally constrained with limited foraging and breeding resources (so-called “resource bottlenecks”), especially when there is a loss of natural and semi-natural habitats. During spring, the growth of cereal crops makes a large proportion of arable land unsuitable for specialist steppe birds with narrow vegetation structure requirements. We investigated the existence of a seasonal bottleneck of suitable habitats for steppe birds using the endangered Pin-tailed sandgrouse (Pterocles alchata) as a model species. We used for first time lightweight GPS tags to study habitat selection and movement patterns throughout the cereal crop cycle during three years in north-eastern Spain. We also evaluated if conservation measures promoting suitable vegetation structures for steppe birds (Targeted Fallow Management, TFM) influenced habitat selection. Sandgrouse avoided cereal crops when cereal vegetation was high, resulting in a 30% reduction of suitable habitat area at the start of the breeding season. This proved the existence of a spring habitat bottleneck when sandgrouse only selected open natural habitats and fallows. Sandgrouse similarly selected TFM and conventionally managed fallows during and after the bottleneck, possibly because of their similar vegetation structure and the scarcity of alternative suitable habitats. Halting the ongoing loss of fallow land is paramount for the conservation of steppe birds like sandgrouse because they constitute a key refuge to buffer the impacts of seasonal habitat bottlenecks.

European green agricultural policies have been relaxed to allow cultivation of fallow land to produce animal feed and meet shortfalls in exports from Ukraine and Russia. However, conversion of semi-natural habitats will disproportionately impact long term biodiversity and food security.

Agri-environment schemes (AES) are a major conservation tool for protecting declining farmland birds in Europe. Most studies evaluate AES effectiveness on taxonomic diversity but there is a knowledge gap about how AES affect functional responses. We evaluate the effects of different AES on taxonomic and functional responses of open-land and overall farmland birds in extensive cereal croplands of Spain. Specifically, we analyse how the proportion of food to shelter prescriptions and landscape features (length of field boundaries and proportion of herbaceous crops) influence AES effectiveness by comparing the response of bird diversity in AES-managed and paired control fields. We found that increased proportion of food prescriptions increased species richness and Shannon diversity of birds whereas balanced AES (similar proportion of food and shelter prescriptions) increased their abundance. AES with more food prescriptions also led to increased functional diversity of diet plasticity and wingspan for open-land birds. The functional diversity of diet plasticity in all bird species and of habitat specialisation in all and open-land birds increased with balanced AES in control fields but remained unaltered in focal fields with variation in the proportion of food to shelter prescription. This suggests that AES application reached maximum effects for these traits in focal fields independently of prescription types and further landscape-level benefits of the promotion of shelter in AES-managed fields. Overall, the length of field boundaries increased taxonomic and functional diversity of birds while the proportion of herbaceous crops decreased them. Both landscape variables showed non-linear relationships, fitting predictions from the landscape complexity-local diversity hypothesis. Our findings indicate ways to improve AES effectiveness for both traditional and new relevant conservation goals and encourage the evaluation of functional diversity in AES monitoring.

Transcurridos 14 años del primer censo nacional sobre la especie, en 2019, con la inestimable colaboración de las comunidades autónomas y miles de voluntarios, se ha vuelto a repetir el trabajo que actualiza la situación poblacional de la especie.

Transcurridos 14 años del primer censo nacional sobre la especie, en 2019, con la inestimable colaboración de las comunidades autónomas y miles de voluntarios, se ha vuelto a repetir el trabajo que actualiza la situación poblacional de la especie.

[ES]¡Qué pocas van quedando! Es la conclusión rápida, un tanto melancólica, que el presente trabajo arranca a quienes, como el autor de estas líneas, se ocuparon durante años y aún se preocupan por el porvenir de gangas y ortegas. Aquí se ofrecen los resultados de un censo, en 2019, que por el esfuerzo empleado, el rigor metodológico y la calidad de los análisis estadísticos, aporta por primera vez una estimación altamente fiable de las poblaciones hispanas de ambas especies. Nuestro agradecimiento por ello a SEO/BirdLife, a los voluntarios y al personal de las administraciones que efectuaron el trabajo de campo, así como a los científicos que dirigieron las operaciones y han analizado y publicado los resultados. Se trata del segundo censo nacional tras el llevado a cabo en 2005. El cálculo de la detectabilidad de estas aves –mediante la repetición de recorridos de censo en gran número de localidades– ha permitido en particular una notable mejoría en cuanto a la fiabilidad de las estimas. No obstante, el cotejo de los resultados de ambos censos es todavía factible, sujeto a la necesaria cautela. En números redondos, en 2019 contaríamos con una población de 7.500 gangas ibéricas y 7.000 ortegas, correspondiendo 2.200 ortegas a la población de la isla de Fuerteventura. Las cifras equivalentes de 2005 se situaron en 9.500 gangas ibéricas y 10.500 ortegas. De manera que en apenas tres lustros la población de la primera especie habría disminuido en una quinta parte y la de la segunda, en un tercio. Un análisis más fino, basado en la comparación de índices de abundancia en localidades concretas, sugiere caídas aún más acusadas: 27% en la ganga ibérica y hasta 43% en la fracción peninsular de la población de la ortega., [EN] The pin-tailed sandgrouse Pterocles alchata (PTS) and black bellied sandgrouse Pterocles orientalis (BBS) populations were surveyed in the whole of Spain (Iberian Peninsula and Canary Islands) during 2019 in order to estimate their current distribution ranges and population sizes. The survey data were used to calculate population indicators (occurrence, abundance index) that can be compared to similar indices from the previous national census of 2005, and to estimate occupancy-using multilevel occupancy models- and population size – using hierarchical distance sampling models. As in 2005, the sampling method was based on walked transects covering habitats used by both species within their distribution ranges, and a distance sampling methodology. The sampling units were 10 x 10 km UTM squares, where transects were conducted covering suitable habitats for sandgrouse. A proportion of transects were visited repeatedly, allowing to account for imperfect detection when estimating occupancy and abundance. During the 2019 survey, a total of 3.001 visits to 2.409 transects (4.829 kms) were completed during April-June, with a total survey effort of 9.050 kms of walked transects, including the repetitions. A total of 862 UTM squares were surveyed, with an average effort of 10.5 km of transects per UTM square. Overall, the 2019 national census had a better coverage and sampling effort than the 2005 census, allowing to obtain good inferences regarding population changes and better population estimates for some regions.

[EN]: The next reform ofthe EU Common Agricultural Policy (CAP) for the period 2021-2027 (currently extended to 2023-2030) requires the approval by the European Commission of a Strategic Plan with environmental objectives for each Member State. Here we use the best available scientific evidence on the relationships between agricultural practices and biodiversity to delineate specific recommendations for the development of the Spanish Strategic Plan. Scientific evidence shows that Spain should (1) identify clear regional biodiversity targets and the landscape-level measures needed to achieve them; (2) define ambitious and complementary criteria across the three environmental instruments (enhanced conditionality, eco-schemes, and agri-environmental and climate measures) of the CAP’s Green Architecture, especially in simple and complex landscapes; (3) ensure that other CAP instruments (areas of nature constraints, organic farming and protection of endangered livestock breeds and crop varieties) really support biodiversity; (4) improve farmers’ knowledge and adjust measures to real world constraints; and (5) invest in biodiversity and ecosystem service monitoring in order to evaluate how the Plan achieves regional and national targets andto improve measures if targets are not met. We conclude that direct assessments of environmental objectives are technically and economi- cally feasible, can be attractive to farmers, and are socially fair and of great interest for improving the environmental effectiveness of CAP measures. The explicit and rigorous association of assessments and monitoring, relating specific environmental indicators to regional objectives, should be the main criterion for the approval of the Strategic Plan in an environmentally-focused CAP2023-2030., [ES]: La reforma de la Política Agraria Común (PAC) para el periodo 2021-2027 (extendido en la actualidad a 2023-2030) exige que la Comisión Europea apruebe un Plan Estratégico por cada Estado Miembro con claros objetivos ambientales. En este trabajo desarrollamos recomendaciones específicas para la elaboración del Plan Estratégico para los sistemas agrícolas españoles, basadas en la mejor evidencia científica disponible sobre las relaciones entre la gestión agrícola y los componentes de la biodiversidad. La evidencia científica muestra que España debe 1) identificar objetivos regionales claros relativos a la biodiversidad de los medios agrarios y las medidas a nivel paisajístico necesarias para alcanzarlas; 2) definir criterios ambiciosos y complementarios para los tres instrumentos ambientales (condicionalidad extendida, eco-esquemas y medidas agroambientales y climáticas) de la Arquitectura Verde de la PAC, especialmente en paisajes sencillos y complejos; 3) garantizar que otros instrumentos de la PAC (zonas desfavorecidas, agricultura ecológica y protección de razas ganaderas y variedades de cultivos en peligro de extinción) favorecen realmente la diversidad biológica; 4) mejorar el conocimiento de los agricultores y ajustar las medidas a las limitaciones del mundo real; y 5) invertir en seguimiento de la biodiversidad y sus servicios ecosistémicos asociados con el fin de evaluar si el Plan alcanza los objetivos regionales y nacionales y mejorarlos adaptativamente si no lo consigue. Concluimos que la evaluación directa de los objetivos ambientales es técnica y económicamente viable, puede ser atractiva para los agricultores, es socialmente justa y de gran utilidad en la mejora de la efectividad de las medidas de la PAC. Una combinación rigurosa de seguimiento y evaluación de medidas y objetivos adaptados regionalmente mediante indicadores ambientales directos y claros debería ser el criterio que guíe la aprobación del Plan Estratégico para una PAC 2023-2030 cent

Un estudio llevado a cabo por investigadores del Consejo Superior de Investigaciones Científicas (CSIC) asegura que una gestión extensiva del barbecho podría reconciliar la agricultura con la conservación de la avifauna que habita en ambientes agrícolas.

Resumen del trabajo presentado al SETAC (Society of Environmental Toxicology and Chemistry) Europe 30th Annual Meeting: Open Science for Enhanced Global Environmental Protection, celebrado Online del 3 al 7 de mayo de 2020.

Understanding spatiotemporal variations of movements and habitat selection by animals living in changing, heterogeneous environments under increasing human pressure is crucial for biodiversity conservation. We report here on shifts in habitat selection and movements during the breeding and non-breeding periods in a vulnerable and specialist bird, the pin-tailed sandgrouse Pterocles alchata, to understand the importance of remnant natural or semi-natural habitats. We used a 7-year dataset from 91 radio-tracked birds living under two contrasting landscapes: a farmland-dominated area (agricultural landscape) in central Spain and a low-intensive farmland area with natural steppe-like vegetation (mixed landscape) in northern Spain. We found that sandgrouse selected sites of natural vegetation (short shrubs and sparse annual plants) across all periods in the mixed landscape. Birds performed long movements in the agricultural landscape to exploit patchy resources and expanded their distribution during the breeding period, possibly because of an increased scarcity of non-cropped habitats in farmland. During the non-breeding period, sandgrouse used dry arable lands in both landscapes, with birds in the mixed landscape displaying a highly mobile pattern to visit dry arable regions. Dry arable lands become structurally more suitable during winter for seed-eating birds such as sandgrouse that can use ploughed fields and exploit seeds during cereal sowing. Effective conservation measures for specialist birds of farmland should promote a greater availability of non-cropped habitats of natural and semi-natural vegetation to enhance their space use and reproductive opportunities.

Farmland bird populations have declined sharply due to agricultural intensification. In Europe, these negative population trends have been linked to the loss of semi‐natural vegetation types, particularly fallow land. The work of Sanz‐Pérez et al. (2019) has far‐reaching implications for the conservation of farmland biodiversity. We argue that it supports a new paradigm for the understanding and management of fallows that should be integrated into the forthcoming post‐2020 Common Agricultural Policy (CAP). Following the abolition of mandatory set‐aside by the European Union in 2008, fallows declined steadily in Europe until 2015, when the CAP implemented greening measures. These restored the requirement to leave 5% of arable land as ecological focus areas (EFAs) to enhance biodiversity. While fallows are one of the most beneficial forms of EFA for farmland birds, farmers prefer the less conservation effective planting of nitrogen‐fixing and catch crops (currently more than 70% of EFAs). CAP incentives have been insufficient to make unproductive EFAs such as fallows more attractive to farmers. Sanz‐Pérez et al. (2019) evaluated the impact of different fallow land management practices on the abundance of specialist farmland birds. They concluded that extensive practices – such as tilling or shredding once or twice per year before the breeding season – were more beneficial to these declining species than leaving fallows unmanaged and recommended their incorporation into agri‐environment schemes. But such schemes have had low uptake, and thus a limited potential to drive the widespread recovery of farmland birds at either national or European levels. The post‐2020 CAP, currently under development, should integrate simple fallow management practices within new conditionalities or eco‐schemes to address this problem. Synthesis and applications. The loss of fallow land underlies the decline of farmland birds. The post‐2020 CAP must overcome past mismatches between incentiv

Agricultural intensification has profoundly affected European farmlands in the last decades, and their associated biodiversity has undergone a widespread decline. Although largely considered by farmers to be a threat to crop productivity, weeds and arthropods are key factors in farmland ecosystems and provide multiple ecosystem services. We analyze variations between three arable habitats—cereals, plowed and fallow fields—in the biomass of weeds, seeds and arthropods in an extensive rotation system of Central Spain. We also investigate the effect of the vegetation structure in the overall biomass of arthropods and that of the most abundant orders found, Coleoptera and Orthoptera, which constitute key resources for many declining farmland birds. Our results show that fallows had the greatest biomass of weeds and seeds, whereas no differences were found between cereal and plowed fields. Although vegetation structure was related to the biomass of total arthropods, as well as that of coleopterans and orthopterans of a large size, arthropod biomass did not vary between the three arable habitats. Overall, higher weed cover and denser vegetation favored higher biomass of arthropods. Our results suggest a process of ecological homogenization, where arthropod populations may be suffering a widespread decline across habitat types, likely due to high tillage frequency or agrochemical use, despite the extensive rotation system and the mosaic landscape of our study site. Short- and mid-term fallows might function as a source habitat for weeds and arthropods, although this role might be compromised by their progressive disappearance and isolation within the landscape.

Traffic noise is an associated effect of roads, potentially impacting wildlife. In the case of birds, it may alter spatial distribution, behavioural responses and physiological status, frequently masking the acoustic signals of conspecifics and predators. We analyse how road traffic noise affects habitat selection of Little Bustard males during the breeding season, when they produce brief territorial snort calls. The study site is in a typical agrarian area in central Spain, markedly affected by traffic noise. A noise map was built using specific environmental noise modelling software. The habitat in the territories of 26 individually-recognisable males (62% of the male population in the study year) was characterised in relation to noise levels, agrarian substrate composition and distance to nearest males. Habitat selection models were performed using MaxEnt, and an averaged model of the first 20 significant ones was generated. The noise map revealed high noise pollution levels for the whole study area (range: 50.13–62.35 dB). Distance to the nearest male was the most important variable in habitat selection models, so that as distance increased suitability decreased, while the effect of traffic noise was nearly negligible. This lack of traffic noise effect on the habitat selection of Little Bustard males might be explained by the low overlap between their snort call frequency and that of traffic noise, but it also suggests a poor capacity by this bird to cope with recent, anthropogenic disturbance. In this respect, noisy but otherwise suitable habitats could be functioning as ecological traps for this rapidly declining species. El ruido del tráfico es un efecto asociado a la presencia de carreteras con un impacto potencialmente importante sobre la fauna. En el caso de las aves, puede alterar la distribución espacial de los individuos, su comportamiento y su condición fisiológica, con frecuencia enmascarando las señales emitidas por coespecíficos y depredadores. Anal

Traffic noise is an associated effect of roads, potentially impacting wildlife. In the case of birds, it may alter spatial distribution, behavioural responses and physiological status, frequently masking the acoustic signals of conspecifics and predators. We analyse how road traffic noise affects habitat selection of Little Bustard males during the breeding season, when they produce brief territorial snort calls. The study site is in a typical agrarian area in central Spain, markedly affected by traffic noise. A noise map was built using specific environmental noise modelling software. The habitat in the territories of 26 individually-recognisable males (62% of the male population in the study year) was characterised in relation to noise levels, agrarian substrate composition and distance to nearest males. Habitat selection models were performed using MaxEnt, and an averaged model of the first 20 significant ones was generated. The noise map revealed high noise pollution levels for the whole study area (range: 50.13-62.35 dB). Distance to the nearest male was the most important variable in habitat selection models, so that as distance increased suitability decreased, while the effect of traffic noise was nearly negligible. This lack of traffic noise effect on the habitat selection of Little Bustard males might be explained by the low overlap between their snort call frequency and that of traffic noise, but it also suggests a poor capacity by this bird to cope with recent, anthropogenic disturbance. In this respect, noisy but otherwise suitable habitats could be functioning as ecological traps for this rapidly declining species.

Interspecific competition is a dominant force in animal communities that induces niche shifts in ecological and evolutionary time. If competition occurs, niche expansion can be expected when the competitor disappears because resources previously inaccessible due to competitive constraints can then be exploited (i.e., ecological release). Here, we aimed to determine the potential effects of interspecific competition between the little bustard (Tetrax tetrax) and the great bustard (Otis tarda) using a multidimensional niche approach with habitat distribution data. We explored whether the degree of niche overlap between the species was a density-dependent function of interspecific competition. We then looked for evidences of ecological release by comparing measures of niche breadth and position of the little bustard between allopatric and sympatric situations. Furthermore, we evaluated whether niche shifts could depend not only on the presence of great bustard but also on the density of little and great bustards. The habitat niches of these bustard species partially overlapped when co-occurring, but we found no relationship between degree of overlap and great bustard density. In the presence of the competitor, little bustard's niche was displaced toward increased use of the species' primary habitat. Little bustard's niche breadth decreased proportionally with great bustard density in sympatric sites, in consistence with theory. Overall, our results suggest that density-dependent variation in little bustard's niche is the outcome of interspecific competition with the great bustard. The use of computational tools like kernel density estimators to obtain multidimensional niches should bring novel insights on how species' ecological niches behave under the effects of interspecific competition in ecological communities.

The expression of elaborate sexual displays is associated with individual quality ensuring reliable information about the bearers. However, the associated cost of expressing enhanced sexual traits is expected to change according to environmental circumstances. Specifically, the cost of maintaining or producing a signal is predicted to increase when environmental conditions are unfavorable, which may lead to a reduction in signal expression as shown in several species. Here, we compared the calling behavior of male red grouse Lagopus lagopus scoticus living in an area of experimentally increased intra-sexual competition to that of males living in a control area. Levels of intra-sexual competition were experimentally manipulated by testosterone implants in a subset of captured males. In addition, we compared the association between two sexual traits, calling behavior and comb size, of males living in these two areas. Although call frequency was not affected by different levels of intra-sexual competition, males from the control area performed shorter calls than individuals from the treatment area. Additionally, a positive association between comb size and call duration was found only for males in the area of lower aggressiveness. We suggest that environmental conditions influence the expression of multiple plastic sexual traits, depending on the costs and the information conveyed about different individual qualities.

Human recreational activities are becoming increasingly widespread and frequent, a fact that may potentially exacerbate their effects on wildlife. These human-related disturbances on animals may induce behavioural and physiological changes that can ultimately affect their fitness, showing a similar anti-predator response that against natural predator or other threats. Here, we combine the use of behavioural and physiological approaches to assess the potential effect of winter human activities on a threatened farmland bird in Europe, the pin-tailed sandgrouse (Pterocles alchata). We compared before, during and after weekend variations in human activity rates, pin-tailed sandgrouse behaviour (flocking and flying behaviour, interspecific association in mixed flocks and habitat use) and faecal glucocorticoid metabolite concentrations. Human disturbances, in particular those associated with hunting activities, peaked during weekends. Sandgrouse showed significant behavioural changes (increased sandgrouse-only flock sizes, increased proportion of birds flying and changes in habitat use) during weekends and higher faecal glucocorticoid metabolite concentrations after the weekends compared with during or before weekends. Therefore, physiological stress levels could be modulated by behavioural adjustments such as increased flock sizes and changes in habitat use that may allow sandgrouse to cope with increased human disturbance rates during weekends. Nevertheless, temporal and spatial organization of hunting days among groups of estates might be good strategies to buffer these potential adverse effects on wintering pin-tailed sandgrouse and other steppe species of conservation concern, while preserving a socio-economically important activity such as hunting.

Animals may perceive humans as a form of predatory threat, a disturbance, triggering behavioral changes together with the activation of physiological stress responses. These adaptive responses may allow individuals to cope with stressful stimuli, but a repeated or long-term exposure to disturbances may have detrimental individual- and population-level effects. We studied the effects of human activities, particularly hunting, on the behavior and physiological status of a near-threatened nongame steppe bird, the little bustard. Using a semiexperimental approach, we compared before, during, and after weekends: 1) the type and intensity of human activities and 2) the behavior and 3) physiological stress (fecal corticosterone metabolites) of wintering birds. Higher rates of human activity, in particular those related to hunting, occurred during weekends and caused indirect disturbance effects on birds. Little bustards spent more time vigilant and flying during weekends, and more time foraging in the mornings after weekend, possibly to compensate for increased energy expenditure during weekends. We also found increased physiological stress levels during weekends, as shown by higher fecal glucocorticoid metabolite concentrations. Increased corticosterone metabolite levels were associated with the highest levels of hunting-related disturbances. Little bustard showed marked behavioral and physiological (stress hormones) responses to human activities that peaked during weekends, in particular hunting. The long-term effect of this particular activity carried out during weekends from autumn throughout winter might adversely impact wintering populations of this nongame endangered species, potentially counteracting conservation efforts conducted on local as well as foreign breeding populations.