Prey choice in insectivorous steppe passerines: New insights from DNA metabarcoding

Food availability plays a key role affecting almost every aspect of bird ecology, including bird population, distribution, reproduction, and behavior. Understanding the functional relationship between prey availability and insectivorous birds’ diet is important in the current scenario of habitat loss and declining of insect and bird populations. We used a fecal metabarcoding approach coupled with prey availability sampling (arthropod abundance and biomass) to test for evidence of selective foraging in a shrub-steppe passerine assemblage over the 2017–2019 breeding seasons in semi-natural steppes of central Spain. The results showed that the six bird species selected specific arthropod taxa. Heteroptera, Orthoptera, Araneae, Lepidoptera and some Coleoptera families were the main selected prey taxa, while Formicidae appeared to be avoided, suggesting that shrub-steppe passerines tend to select prey items providing essential nutrients and energy during the breeding season, while poor quality ones are neglected. Our findings highlight the utility of metabarcoding dietary data to assess prey selection patterns in insectivorous passerines and provide valuable information for the development of conservation and management programs to ensure the long-term availability of crucial food resources for shrub-steppe birds and other insectivores.This study was supported by the European Commission LIFE Ricotí (LIFE15-NAT-ES-000802) and LIFE Connect Ricotí (LIFE20-NAT-ES-000133) projects. This is a contribution to the Excellence Network Remedinal TE-CM (S2013/MAE2719). JG-C is funded by a Margarita Salas Postdoctoral Fellowship (CA4/RSUE/2022-00205) provided by the Spanish Ministry of Universities and Universidad Autónoma de Madrid (Spain)

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

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

The role of demography and grazing in the patterns of endangerment of threatened plants

This study explores the effect of two types of threat on a group of rare plants at risk of extinction in Spain, distributed across altitudinal and latitudinal gradients, under a scenario of rapid changes in land use. On the one hand, we focused on livestock herbivory as one source of risk for these plants, also taking into account factors such as altitude and the protection status of the area. On the other hand, we explored a threat which has been little documented so far, namely, rapid changes of the dynamics of plant communities. Field data from 54 populations of 37 different threatened plant species were analyzed using contingency tables and linear models (ANCOVA and GLM) to study the effect of livestock and herbivory. In addition, we used an asymmetry index of population structure to look for deviations and asynchronies with respect to general vegetation dynamics. Our results point to an overestimation of grazing as a threat to these plants, its effect having declined as a result of rapid changes in land use. Altitude was found to provide a dual conservation shield, preventing grazing for different reasons. Hence, we recommend that herbivory to threatened plants should be reported by accurately quantifying individual losses and damage. We found no relationship between population structure and plant conservation status. In addition, we detected no asynchronies between threatened plant population structure and community dynamics. New indicators related to size and distance between populations as well as density distribution within patches should be explored

Selecting the best: Interspecific and age-related diet differences among sympatric steppe passerines

Parental food provisioning is crucial for the growth and survival of offspring. Growth rate depends on food quality and food supplied to offspring may differ from what adults use for their own. In the case of steppe passerine birds, detailed characterization on nestling dietary composition, as well as prey choice and resource partitioning among species, is a pending subject. Dietary differences between nestlings and adults remain also largely unexplored. By using faecal DNA metabarcoding, we described the diet of nestlings and adults of five shrub-steppe passerine species over the 2017–2019 breeding seasons in central Spain. We also monitored arthropod availability in the field to assess dietary selection. We expected interspecific dietary differences to limit competition for food resources among sympatric species, as well as parental selection of high quality prey for nestlings. We also predicted age-related differences, with nestlings being fed nutrient-rich prey more frequently than adults. The main arthropod orders provisioned to nestlings were Orthoptera, Julida, Araneae and Lepidoptera. Nestlings of the different species showed high interspecific diet overlap, indicating both a coincidence in growth needs among bird species and no or little limitation of the most profitable resources during the breeding season. Adults of all species showed higher diet richness than nestlings, and age-related differences in prey composition were mainly driven by the selection of the most easily digestible, larger protein- and calcium-rich prey for nestlings, which may favour their rapid growth, and avoiding highly sclerotized and less nutritional prey such as ants. Our study sheds light on the basic ecology and conservation of these declining steppe birds, indicating that interspecific competition may not be a major factor during the breeding season. Given the current global decline of arthropods, further long-term research would be necessary, along with the implementation of effective conservation measures that ensure a sufficient availability of resources identified as key prey in the diet of steppe bird nestlings.This study was supported by the European Commission LIFE Ricotí (LIFE15-NAT-ES-000802) and LIFE Connect Ricotí (LIFE20-NAT-ES-000133) projects. This is a contribution to the Excellence Network Remedinal TE-CM (S2013/MAE2719). JG-C is funded by a Margarita Salas postdoctoral fellowship (CA4/RSUE/2022–00205) provided by the Spanish Ministry of Universities and Universidad Autónoma de Madrid (Spain). CPG acknowledges support from Ministerio de Educación y Formación Profesional through the Beatriz Galindo Fellowship (Beatriz Galindo-Convocatoria 2020) and JZ acknowledges support from Ministerio de Universidades through the predoctoral FPU fellowship program

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

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

Comparative assessment of satellite- and drone-based vegetation indices to predict arthropod biomass in shrub-steppes

Arthropod biomass is a key element in ecosystems functionality, and basic food item for many species, which must be estimated through traditional costly field sampling in normally just a few sampling points. Arthropod biomass and plant productivity should be narrowly related, as a great majority of arthropods are herbivorous, and others depends on these. Quantifying plant productivity with satellite or aerial vehicles imagery is an easy and fast procedure already tested and implemented in agriculture and field ecology. However, the ability of satellite or aerial vehicles imagery for quantifying arthropod biomass and its relationship with plant productivity has been scarcely addressed. Here, we used Unmanned Aerial Vehicle (UAV) and satellite Sentinel-2 (S2) imagery to establish relationship between plant productivity and arthropod biomass estimated through ground-truth field sampling in shrub-steppes. We UAV sampled 7 plots of 47.6-72.3 ha at 4 cm pixel resolution, and afterwards downscaling spatial resolution to 50 cm resolution. In parallel, we used S2 imagery from same and other dates and locations at 10 m spatial resolution. We related several vegetation indices (VI) with arthropod biomass (epigeous, coprophagous, and four functional consumer groups: predatory, detritivore, phytophagous and diverse) estimated in 41-48 sampling stations for UAV flying plots, and in 67-79 sampling stations for S2. VI derived from UAV were consistently and positively related with all arthropod biomass groups. Three out of seven, and six out of seven S2-derived VI were positively related with epigeous and coprophagous arthropod biomass, respectively. BNDVI and ENDVI showed consistent and positive relationships with arthropod biomass, regardless of the arthropod group and the spatial resolution. Our results point out that UAV and S2-VI imagery data may be a viable and cost-efficient alternative to quantify arthropod biomass at large scales in shrub-steppes. The relationship between VI and arthropod biomass is probably habitat-dependent and thus, future research should address this relationship including several habitats to validate vegetation indices as proxies of arthropod biomass.This study was partially supported by the European Commission (Life Ricotí project LIFE15-NAT-ES-000802 and Life Connect Ricotí project LIFE20-NAT-ES-000133) and the BBVA Foundation (BBVA-Dron Ricotí project). This paper contributes to project REMEDINAL-3 from CAM

Range contraction and population decline of the European Dupont’s lark population

Los autores de la UAM pertenecen al Terrestrial Ecology Group (TEG-UAM)Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, los autores pertenecientes a la UAM y el nombre del grupo de colaboración, si lo hubiereThe Dupont’s lark (Chersophilus duponti) is an endangered passerine typical of Mediterranean shrub-steppes, whose European distribution is restricted to Spain. Here, we update the population size and distribution range of the species at a European scale and evaluate (i) the current status; (ii) the change in population size and distribution range of the species from 2004 to 2009 to the current period (2017–2022); and (iii) the effectiveness of the current network of special protection areas (SPAs) for protecting the Dupont’s lark. The European Dupont’s lark population showed a decrease of 29.9%, declining from ca. 3267 to 2289 territorial males from 2004 to 2009 to the current period. Moreover, the species has suffered a contraction in its distribution range of 35.9%, with only 39.3% of the species’ territories located within the current network of SPAs. Our findings agree with the previously described decline of the Dupont’s lark in Europe. The population decline was even larger in peripheral regions, which suggests that the species is suffering a centripetal process of contraction and extinction. These results indicate that if there is no change in present-day declining forces, several peripheral populations will reach extinction in a few decades and the overall population size of the species will continue decreasing. Our study should be considered as a last call for action and used for implementing urgent conservation measures to protect the species and its habitat. Future studies should focus on analyzing and managing the factors driving the species’ extinction and future actions for the conservation of the species should focus on increasing the percentage of the Dupont’s lark territories within protected areas, since the data are alarmingly low for a species that is facing clear risk of extinctionThis study was partially funded by the LIFE programme (LIFE Ricotí LIFE15-NAT-ES000802 and LIFE Connect Ricotí LIFE20-NAT-ES-000133), by the European Commission, Levantina y Asociado de Minerales, S.A., with the project “Estudios de investigación aplicado a la conservación de las poblaciones de alondra ricotí (Chersophilus duponti) en el entorno del municipio de Vallanca”, by the Dirección General de Política Forestal y Espacios Naturales de la Junta de Comunidades de Castilla La Mancha with the project “SSCC/046/2017 Censo de Alondra ricotí en la provincia de Guadalajara. Año 2017” and by the Junta de Castilla y León with the project “Estudio para la Mejora del Conocimiento de las Poblaciones de Alondra Ricotí Chersophilus duponti en Castilla y León”. Censuses in Catalonia were carried out with the support of the Generalitat of Catalonia. CPG acknowledges the support from the Ministerio de Educación y Formación Profesional through the Beatriz Galindo Fellowship (Beatriz Galindo—Convocatoria 2020). JGC is funded by a Margarita Salas postdoctoral fellowship (CA4/RSUE/2022-00205) provided by the Spanish Ministry of Universities and Universidad Autónoma de Madrid (Spain

First documented case of Tawny Pipit Anthus campestris nest parasitism by common cuckoo Cuculus canorus in Spanish steppes

Primo caso documentato di parassitismo di un nido di calandro Anthus campestris da parte del cuculo Cuculus canorus nelle steppe spagnole. Il parassitismo interspecifico della covata o del nido è un comportamento riproduttivo relativamente comune negli uccelli. Attraverso questa tattica riproduttiva, i parassiti di cova evitano i costi associati all’allevamento e al mantenimento dei pulcini deponendo le uova nei nidi della specie ospite nella quale sono specializzati. Il cuculo (Cuculus canorus) segue questa strategia di parassitismo di cova. Le femmine di cuculo depongono le uova nei nidi di altre specie di uccelli, imitando la forma, le dimensioni e il colore delle uova della specie ospite. In questo lavoro riportiamo il primo caso documentato di parassitismo di nidi di calandro da parte del cuculo in habitat steppici spagnoli, dove finora non sono stati registrati casi di parassitismo su questa speci

Leer en comunidad: creación y desarrollo de clubes de lectura de literatura escrita por mujeres dentro y fuera de la universidad

Depto. de Lengua Española y Teoría de la LiteraturaFac. de FilologíaFALSEsubmitte