Francisco Valera

• DR
• Spanish National Research Council

Olive groves are the most representative crop of the Mediterranean basin. This agroforestry system is undergoing a strong transformation in recent decades as a result of the agricultural intensification process prevailing in the Northern hemisphere. Although some authors have suggested that farmland biodiversity responds non-linearly to the complex...

The Kunming–Montreal Global Biodiversity Framework (KM–GBF) envisions a world living in harmony with nature by 2050, with 23 intermediate targets to be achieved by 2030. However, aligning international policy and national and local implementation of effective actions can be challenging. Using steppe birds, one of the most threatened vertebrate grou...

Ascertaining the feeding behavior of vectors is a key for understanding epidemiology of the infections they transmit. For some host–vector–parasite systems, this information is biased towards human and peridomestic habitats, frequently underestimating the likely role of wildlife. In addition, studies on vector interactions often focus on a one-to-o...

Recovery debt (RD) measures the interim reduction of biodiversity and functions occurring during the recovery process. We extend the approach of RD to active ecological restoration considering the cessation of disturbance as the time in which an ecosystem under exploitation initiates the change of its management to environmental-friendly practices...

This commentary critiques the methodology, interpretation of results, and broader implications of a study by Jarčuška et al. (2024). We argue that the study's design and analysis fail to conclusively demonstrate any causal link between solar parks and bird diversity or community composition. Furthermore, focusing solely on species diversity and com...

Invasive alien species are one main driver of biodiversity loss and can cause severe economic costs. Effective management of such species requires early detection of colonising individuals, but this is often hampered by biological or economic constraints. Trachymela sloanei (Blackburn, 1896), an Australian Eucalyptus defoliator beetle, is an invasi...

The European Commission and EU Member States have recently promoted legislation (under the REPower EU Plan) to accelerate renewable energy projects by allowing the elimination or reduction of environmental assessment and public participation in the approval procedure. To avoid adverse effects on the environment, these regulations propose the exclus...

The Kunming-Montreal Global Biodiversity Framework (KM-GBF) envisions a world living in harmony with nature by 2050, with 23 intermediate targets to be achieved by 2030. However, aligning international policy and local implementation of effective actions can be challenging. Using steppe birds, one of the most threatened vertebrate groups in Europe,...

The family Simuliidae includes more than 2000 species of black flies worldwide. Their morphological uniformity creates difficulty for species identification, which limits our knowledge of their ecology and vectorial role. We investigated the systematics of black flies in a semi-arid area of the Iberian Peninsula, an ecologically harsh environment f...

La depresión de Tabernas‐Sorbas, donde se ubica el Campo de Tabernas, es un excelente ejemplo de los ecosistemas semiáridos del sureste español, albergando importantes valores naturales que motivaron la declaración de varios espacios Red Natura 2000 (RN 2000) y de otros espacios (ej. ZAPRAE, IBAs) que resaltan la importancia de la biodiversidad de...

Birds' nests hold rich and diverse communities of invertebrates with complex interspecific interactions whose study could improve our understanding of food webs and resource dynamics. To reach this goal, identification of the participants of such interactions is basic but current knowledge on some key groups such as hymenopteran parasitoids is admi...

Abstract Cavities used for avian reproduction in spring often host other organisms for roosting during winter, which should affect their microclimatic conditions and, then, the patterns of emergence of nest‐dwelling ectoparasites of birds and successful parasitism. To prove these cascade effects, we experimentally blocked the entrance of half of ne...

Context dependence arises when ecological relationships vary with the conditions under which they are observed. Context dependence of interactions involving parasites is poorly known, even if it is key to understanding host-parasite relationships and food web dynamics. This paper researches to which extent predation pressure on an avian ectoparasit...

The Lesser Kestrel (Falco naumanni) is an endangered bird species identified in Annex I of the Birds Directive (79/409/EEC) as requiring special protection measures. It is scarce in Almería, where breeding nuclei were restricted to the plains of Los Vélez (on the northern provincial boundary with Granada) and the plains of Fernán-Pérez (in the Cabo...

Solar energy (SE) is essential for the decarbonization of our economy and for energetic transition. Solar energy can be a sustainable economic activity, as long as a balance is struck between the benefits it brings to climate change mitigation and the damage it can cause to biodiversity and ecosystems. Here, we study this balance in an area with hi...

Understanding the causes underlying intraspecific variation in breeding performance and productivity of organisms is crucial to be able to identify potentially limiting factors and design appropriate conservation measures. Such variation in performance can occur at both spatial and temporal scales, stressing the importance of long-term studies thro...

Solar energy (SE) is essential for decarbonization of our economy and for energetic transition. Solar energy can be a sustainable economic activity as long as a balance is struck between the benefits it brings to climate change mitigation and the damage it can cause to biodiversity and ecosystems. Here we study this balance in an area with high bio...

Las aves son usadas como bioindicadores sensibles a la pérdida, fragmentación y degradación de los hábitats. Desempeñan además importantes servicios ecosistémicos en los medios agrícolas, como el control de plagas y patógenos o la dispersión de semillas y la conectividad del hábitat natural. Sin embargo, sus funciones y servicios están siendo impac...

Aim: We investigated taxonomic and functional beta diversity of bird communities inhabiting Mediterranean olive groves subject to either intensive or extensive management of the ground cover and located in landscapes with different degrees of complexity. Location: Andalusia, southern Spain. Methods: We partitioned taxonomic and functional beta dive...

This section includes the abstracts of some of the PhD-Dissertations submitted in Spain during the 2020-2021 academic year as well as some others not published in earlier volumes of Ardeola. They are in alphabetical order by University where they were presented and, then, by year and alphabetical order of the author's surname. This section also inc...

Climate change effects on host–parasite interactions have been poorly studied in arid or semi-arid habitats. Here, we conducted an experiment aimed to increase the temperature inside European roller Coracias garrulus nest boxes located in a semi-arid habitat on different nest-site types to look for effects on different ectoparasite abundances and n...

Studies assessing anthropogenic disturbance impact on insect pollination function have attended fundamentally to changes on abundance and richness of pollinator assemblages while how the pollination function is affected by shifts in assemblage compositions is frequently neglected. Notwithstanding, different insect species/groups are distinctly impa...

Aim We investigated taxonomic and functional beta diversity of bird communities inhabiting Mediterranean olive groves subject to either intensive or low‐intensity management of the ground cover and located in landscapes with different degrees of complexity. Location Andalusia, southern Spain. Methods We partitioned taxonomic and functional beta d...

Anthelmintics are frequently administered to animals to limit fecal egg elimination, so that wild animals in captive breeding programs are treated to maintain a proper health condition. This is effective from a health management perspective, but on the other hand, it could prevent captive animals from developing an effective immunity against parasi...

Anthelmintics are frequently administered to animals to limit fecal egg elimination, so that wild animals in captive breeding programs are treated to maintain a proper health condition. This is effective from a health management perspective, but on the other hand, it could prevent captive animals from developing an effective immunity against parasi...

Polar regions, symbols of wilderness, have been identified as potential sinks of mercury coming from natural and anthropogenic sources at lower latitudes. Changes in ice coverage currently occurring in some areas such as the Antarctic Peninsula could enhance these phenomena and their impacts on local biota. As long-lived species at the top of food...

Agri‐Environmental Schemes (AES) have been proposed to mitigate the impact of agriculture on both taxonomic and functional biodiversity. However, a better knowledge of the mechanisms involved in the loss of agrobiodiversity is needed to implement efficient AES. An unbalanced effort on research towards arable lands compared to permanent crops, and o...

Phenotypic plasticity may help organisms persist in modified habitats. Yet, its adaptive value is frequently ignored because fitness consequences are not explored at the required time scale. Taking advantage of a 16-yr nest-box supplementation program, we explored effects of nest type and two social-ecological indices (breeding cluster size and dis...

The next reform of the 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 bi...

Background The feeding behavior of bloodsucking insects determines the transmission, distribution, host spectrum and evolution of blood parasites in the wild. Conventional wisdom suggests that some vector groups (e.g. black flies, family Simuliidae) are consistently exophagous daytime biters. We aimed to understand more about the exceptions to this...

Background: Ungulates from zoological institutions are frequently used as founders in reintroduction programmes. These animals are subject to specific parasite management as parasitic infections have previously been associated with failed Bovidae reintroductions. Methods: Questionnaires to obtain data on how these institutions screen for seasona...

1. Parasites are one of the main actors in host–parasite interactions. Still, their role as a prey and the related consequences for such interactions and in other respects, such as food webs, are frequently overlooked. 2. This paper analyses predation pressure on a ubiquitous avian ectoparasitic fly, Carnus hemapterus, identifies their main natural...

The knowledge of the distribution, richness and epidemiological importance of soft ticks of the genus Argas is incomplete. In Spain, five Argas species have been recorded, including three ornitophilic nidicolous ticks, but their associated microorganisms remain unknown. This study aimed to investigate ticks from bird nests and their microorganisms....

Coloniality in birds is often associated with an increase in parasite burden, but whether the co-occurrence of several host species influences the prevalence and abundance of ectoparasites and their relationship with colony size or density remains poorly known. Here, we studied mixed-species breeding colonies formed after the provision of artificia...

This section includes the abstracts of some of the PhD-Dissertations submitted in Spain during the 2019-2020 academic year as well as some others not published in earlier volumes of Ardeola. They are in alphabetical order by University where they were presented and, then, by year and alphabetical order of the author's surname. This section also inc...

Nest box supplementation is a widely used technique to aid in the conservation of cavity nesting bird species. However, the criteria to choose the best location for nest boxes has seldom considered the likely exposure of cavity-users to parasites. Birds host an impressive diversity of ectoparasites that may have detrimental effects on their fitness...

Land-use conversion and habitat loss and degradation are among the factors affecting populations and species genetic integrity. Understanding how these factors govern the genetic structure of threatened plant populations is essential to design efficient conservation strategies. Here we analyze how environmental correlates, geographic location and a...

• The expansion of intensive agriculture has severely altered landscapes, a process that has been aggravated by the increase of greenhouse agriculture. However, few studies have considered the combined effects of habitat loss/degradation and greenhouse farming on insect visitors to native plants. • We analysed how habitat loss/degradation and green...

El conocimiento de la ecología del parasitismo y de los factores que afectan a la interacción parásito-hospedador varía en función del tipo de hábitat, siendo en ambos casos mayor en medios mésicos que en ambientes áridos y semiáridos. Estos últimos hábitats se caracterizan por la escasez de agua y, a menudo, por una alta heterogeneidad espacio-tem...

1. Full understanding of the dynamics of host–parasite interactions requires elucidation of the principles governing host colonisation. With respect to mobile parasites, little is known about their dispersal behaviour and the factors affecting host colonisation success. 2. Here, the effect of parasite density manipulations on the colonisation succe...

El proceso de intensificación agrícola (uso de fitosanitarios y fertilizantes y/o labranzas agresivas) junto a la simplificación del paisaje motivada por la conversión de áreas semi-naturales a zonas productivas están entre los principales responsables del fuerte declive de las aves agrarias. Para frenar este declive, la política agraria comunitari...

La alteración de los paisajes naturales y los cambios en el uso del suelo por agricultura y ganadería, son unos de los principales conductores del Cambio Global y de la pérdida de biodiversidad y de servicios ecosistémicos. En las últimas décadas la intensificación agrícola ha conducido, además, a una homogeneización y simplificación de los paisaje...

Studies assessing the effect of extensive versus intensive agricultural practices and addressing how biodiversity patterns and the effectiveness of agri-environmental practices (AES) to recover biodiversity are moderated by the landscape complexity (LMB framework), underlie large-scale biodiversity conservation programs and policies in anthropogeni...

Animals from zoological institutions may be used for reintroductions. These individuals are considered healthy, but they are not necessarily free of parasites, despite the minimum husbandry standards required of zoological institutions as described in the European Association of Zoos and Aquaria guidelines. In this sense, parasitism has been identi...

Highlighting the dispersal ecology of parasites is important for understanding epidemiological, demographic and coevolutionary aspects of host–parasite interactions. Yet, critical aspects of the dispersal stage of parasites, such as longevity and the factors influencing it, are poorly known. Here we study the lifespan of the dispersal stage of an e...

Host range and parasite specificity determine key epidemiological, ecological and evolutionary aspects of host–parasite interactions. Parasites are usually classified as generalists or specialists based on the number of hosts they feed on. Yet, the requirements of the various stages of a parasite may influence the suitability of a given host specie...

Nest box supplementation is widely used to increase nest‐site availability for cavity nesting animals, but the analysis of its effects on individuals breeding in natural cavities is often neglected. This paper offers a novel restoration technique to revert abandonment of natural breeding sites by a secondary cavity avian bird, the European roller (...

Edited by Francisco VALERA This section includes the abstracts of some of the PhD-Dissertations submitted in Spain during the 2017-2018 academic year as well as some others not published in earlier volumes of Ardeola. They are in alphabetical order by University where they were presented and, then, by year and alphabetical order of the author's sur...

Background: Haemosporidians are the most important vector-borne parasites due to their cosmopolitan distribution and their wide range of hosts, including humans. Identification of their vectors is critical to highlight ecologically and epidemiologically relevant features such as host specificity or transmission routes. Biting midges of the genus Cu...

Immune responses vary greatly depending on physiological and ecological circumstances, but the causes of this variation and its consequences for host–parasite interactions are not clear. One problem is whether resource tradeoffs within hosts affect host choice by macroparasites. We aimed experimentally to disentangle the effects of the nutritional...

Global change drivers are currently affecting semiarid ecosystems. Because these ecosystems differ from others in biotic and abiotic filters, cues for plant regeneration and management derived from elsewhere may not be applicable to semiarid ecosystems. We sought to determine the extent to which regional variation in regeneration prospects of a lon...

Differentiation of niche by means of resource partitioning facilitates coexistence of species with similar requirements. Here we analyse the association between different habitats (i.e. nest types) and two Diptera species of the poorly known Family Carnidae that coexist during their larval and pupal stage in the nests of troglodytic bird species. W...

Edited by Francisco VALERA This section includes the abstracts of some of the PhD-Dissertations submitted in Spain during the 2016-2017 academic year as well as some others not published in earlier volumes of Ardeola. They are in alphabetical order by University where they were presented and, then, by year and alphabetical order of the author's su...

Los parásitos en dispersión necesitan superar dos tipos de barreras para poder infectar exitosamente a sus hospedadores: los filtros de encuentro y los de compatibilidad. Los primeros hacen referencia al hallazgo del hospedador mientras que los segundos se refieren a la elección por parte del parásito de un tipo de hospedadores con unas característ...

Reproduction and moulting are costly events in birds. Some studies have pointed out the possibility that the immune response is optimized and traded off against such costly functions. Moreover, it is also known that stressful conditions may lead to the suppression of immune functions. As reproduction and moulting do not overlap in penguins, they of...

The scale of disturbance is of paramount importance to understand the disruptive effect of anthropogenic perturbation on animal seed dispersal and its consequences for plant species conservation at regional level. However, the intricate ways by which landscape and local-scale disturbances affect seed dispersal remain unclear. We propose a conceptua...

Edited by Francisco VALERA This section includes the abstracts of some of the PhD-Dissertations submitted in Spain during the 2015-2016 academic year as well as some others not published in earlier volumes of Ardeola. They are in alphabetical order by University where they were presented and, then, by year and alphabetical order of the author's sur...

Pathogens are major suspects for the current massive losses of honey bee colonies worldwide. Information about circulation and modes of transmission of Nosema ceranae, an emergent microsporidium parasite of Apis mellifera, is currently lacking. Here we examine the dispersion of N. ceranae and N. apis by the blue-tailed bee-eater Merops philippinus,...

La pérdida y fragmentación de hábitat natural es una amenaza global para la biodiversidad. La dispersión de semillas, fundamental para la regeneración de las poblaciones, es gravemente afectada por la fragmentación de hábitat. Analizamos cuál es el efecto de la fragmentación sobre la dispersión y depredación de semillas de Ziziphus lotus, una espec...

Habitat fragmentation, among others, threatens Ziziphus lotus persistence in the SE Iberian peninsula by the disruption of dispersal mutualism. In fact, few seeds achieve dispersal and this probably related to the general paucity of juveniles in these populations.

We identified and compared gross and microscopic lesions associated with the cestode, Parorchites zederi, in the digestive tracts of three species of penguins (Spheniscidae): the Chinstrap ( Pygoscelis antarctica ), Gentoo ( Pygoscelis papua ), and Adélie Penguins ( Pygoscelis adeliae ). The gastrointestinal tracts of 79 recently dead individuals (...

The gastrointestinal tract microbiota is known to play very important roles in the well being of animals. It is a complex community composed by hundreds of microbial species interacting closely among them and with their host, that is, a microbial ecosystem. The development of high throughput sequencing techniques allows studying the diversity of su...

Taxa responsible for the largest contribution (in %) to the dissimilarity between adults and chicks according to SIMPER analysis. (PDF)

The most abundant genera in the cloacal microbiota of Chinstrap penguins. (PDF)

Stegophorus macronectes (Johnston & Mawson, 1942) is a gastrointestinal parasite found in Antarctic seabirds. The original description of the species, which was based only on females, is poor and fragmented with some unclear diagnostic characters. This study provides new morphometric and molecular data on this previously poorly described parasite....

Tracking devices have contributed enormously to our knowledge of avian migration, although their effects on birds are controversial. Here, we study the short- and long-term effects of deploying geolocators on European Rollers Coracias garrulus and assess the optimal weight of tracking devices to use. In nests in which both parents had geolocators,...

Pollutants and toxic contaminants produced in all parts of the world are transported to remote regions including Antarctica. Tourism, research, and fishing activities on this continent are another source of contamination. Toxic substances affect Antarctic species, and some produced genomic damage to the fauna. The genetic damage can be detected by...

AimThe extent to which individuals from different breeding populations mix throughout the non-breeding season (i.e. migratory connectivity') has important consequences for population dynamics and conservation. Given recent declines of long-distance migrant birds, multipopulation tracking studies are crucial in order to assess the strength of migrat...

Extended phenotypes as signals are widely distributed among animal taxa. For example, many bird species build eye-catching nests or structures, which can potentially mirror the quality or ability of the builder. Rock sparrow Petronia petronia nests are usually overly decorated with feathers belonging to different species. Feather carrying in this a...

Edited by Francisco VALERA This section includes the abstracts of some of the PhD-Dissertations submitted in Spain during the 2014-2015 academic year as well as some others not published in earlier volumes of Ardeola. They are in alphabetical order by University where they were presented and, then, by year and alphabetical order of the author's sur...

Long-distance migrants are suffering drastic declines in the last decades. Causes beneath this problem are complex due to the wide spatial and temporal scale involved. We aim to reveal migratory routes, stopover areas, wintering grounds, and migratory strategies for the most southwestern populations of the near-threatened European Roller Coracias g...

Phylogeographic studies are common in boreal and temperate species from the Palearctic, but scarce in arid-adapted species. We used nuclear and mitochondrial markers to investigate phylogeography and to estimate chronology of colonization events of the trumpeter finch Bucanetes githagineus, an arid-adapted bird. We used 271 samples from 16 populati...

The abiotic conditions of the immediate environment of organisms are key factors for a better understanding of ecological and evolutionary processes. Yet, information in this regard is biased towards some habitat types, landscapes, and organisms. Here, we present a 2-year comparative study of the microclimatic properties (temperature, relative humi...

This section includes the abstracts of some of the PhD-Dissertations submitted in Spain during the 2013-2014 academic year as well as some others not published in earlier volumes of Ardeola. They are in alphabetical order by University where they were presented and, then, by year and alphabetical order of the author's surname. * This issue includes...

Climate change potentially has important effects on distribution, abundance, transmission and virulence of parasites in wild populations of animals. Here we analyzed paired information on 89 parasite populations for 24 species of bird hosts some years ago and again in 2010 with an average interval of 10 years. The parasite taxa included protozoa, f...

SUMMARY Understanding the population dynamics and co-evolution of host-parasite systems requires detailed knowledge of their phenology which, in turn, requires a deep knowledge of the effect of abiotic factors on the life cycles of organisms. Temperature is known to be a key environmental influence that participates in the regulation of diapause. Y...

The role of environmental and host-associated factors in synchronization of hostparasite life-cycles is an important question of evolutionary ecology. Yet, only handsome of studies examined this question at the intraspecific level. Here we explore how host-associated traits, such as breeding phenology and host breeding habitat, can influence parasi...

The role of environmental and host-associated factors in synchronization of hostparasite life-cycles is an important question of evolutionary ecology. Yet, only handsome of studies examined this question at the intraspecific level. Here we explore how host-associated traits, such as breeding phenology and host breeding habitat, can influence parasi...

This section includes the abstracts of some of the Ph Dissertations submitted in Spain during the 2012-2013 academic year as well as some others not published in earlier volumes of Ardeola. They are in alphabetical order by University where they were presented and, then, by year and alphabetical order of the author's surname. Esta entrega incluye...

Ornamental colouration is often due to carotenoid pigments and varies inter- and intra-specifically. This paper reports on variation in beak colour of the gentoo penguin, Pygoscelis papua, corresponding to different geographical locations along a latitudinal gradient in the Antarctic Peninsula (from King George Island (62 o15′S-58 o37′W) to Rongé I...

Parasites reduce host fitness and consequently impose strong selection pressures on their hosts. It has been hypothesized that parasites are scarcer and their overall effect on hosts is weaker at higher latitudes. Although Antarctic birds have relatively low numbers of parasites, their effect on host fitness has rarely been investigated. The effect...

A major issue for the proper understanding of the evolution of life-cycle histories is the regulation of voltinism and its variation. Diapause characteristics are known to regulate voltinism, but the underlying mechanisms are poorly understood. This paper studies diapause duration and voltinism variation in a haematophagous diptera parasitizing 2 s...

Knowledge about parasites of Antarctic birds is fragmented and scarce. The aim of this work is to contribute to the knowledge of gastrointestinal parasites of the Chinstrap Penguin (Pygoscelis antarctica) from Deception Island (South Shetlands, Antarctica). Gastrointestinal tracts of 64 fresh dead individuals (61 chicks and three adults) were colle...

In order to understand habitat selection, it is important to consider the way individual animals assess the suitability of a future reproductive site. One way of investigating mechanisms (such as those involved in nest site selection) is to examine breeding success and habitat characteristics in terms of animals returning to a place where they have...

Knowledge about parasites of Antarctic birds is fragmented and scarce. The aim of this work is to contribute to the knowledge of gastrointestinal parasites of the Chinstrap Penguin (Pygoscelis antarctica) from Deception Island (South Shetlands, Antarctica). Gastrointestinal tracts of 64 fresh dead individuals (61 chicks and three adults) were colle...

E l anillamiento científico tiene un notable potencial como actividad recolectora de valio-sa información sobre los parásitos de aves silvestres. No obstante, el valor de esta información depende-rá, en buena medida, del rigor y método con que se tomen los datos. En este artículo se recopila informa-ción sobre los ectoparásitos de aves más frecuent...

This section includes the abstracts of some of the Doctoral Theses submitted in Spain during the 2011-2012 academic year as well as some others not published in earlier volumes of Ardeola. They are in alphabetical order by University where they were presented and, then, by year and alphabetical order of the author's surname. Esta entrega incluye l...