Guillermo Blanco

• Spanish National Research Council

Symbionts are key elements of ecosystems, by playing important roles in shaping the biology and ecology of their hosts. However, the factors determining symbiont loads across host species are still unclear. Nowadays, we know that the intensity and prevalence of feather mites, the most diverse group of avian ectosymbionts, differ strongly between sp...

Accurate identification of decreasing trends is a prerequisite for successful conservation, but can be challenging when immigration compensates local declines in abundance. Here, we show that a potential declining trend driven by low vital rates was overridden and converted into a spectacular increase by massive immigration into the population of a...

Survival is a key demographic parameter for long‐lived bird species as it strongly influences their population dynamics and persistence. In recent decades, several studies have focused on unravelling differential patterns of survival by sex or age in bird populations, as each group may be affected by different ecological and anthropogenic pressures...

With the exception of a few groups of birds, such as large raptors and colonial seabirds, direct counts of nests cannot be conducted over very large areas for most of the abundant and widely distributed species, and thus indirect methods are used to estimate their relative abundances and population sizes. However, many species of the Family Hirundi...

The effects of volcanic eruptions on ecosystems, particularly on oceanic islands, have been widely studied because of their important role in land formation, climate patterns and biological processes. Although these phenomena can lead to habitat loss, population decline and even species extinction, their effects on isolated populations, especially...

Understanding the movements and mortality of individuals across different life stages is crucial for the effective conservation of wild populations. We used data from 32 Egyptian vultures (Neophron percnopterus) tagged with GPS transmitters as nestlings in three Iberian breeding areas to study their dependence period, migration routes, movements in...

We analyzed the variation in the secondary sex ratio of Magellanic Penguin Spheniscus magellanicus breeding in six colonies on the Patagonian coast of Argentina. We tested the effects of laying date and hatching sequence on the probability of producing sons and daughters. The global secondary sex ratio did not differ from equality, and there were n...

Natal dispersal is a critical trait for individual fitness and the viability, structure and genetic identity of populations. However, there is a pronounced information gap for large and long-lived species due to the difficulty of monitoring individuals at appropriate spatio-temporal scales. Here we study how individual traits and social and environ...

In the intricate web of plant–animal interactions, granivore birds can play a dual antagonist–mutualist role as seed predators and dispersers. This study delves into the ecological significance of the house sparrow (Passer domesticus) as seed disperser by endozoochory. A sample of individual droppings and faecal pools were collected from a communal...

Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constrains symbiont populations. We parameterized metabolic theory equations to investigate how bird species' body size and the body size of their feather mites relate to mite abundance accord...

Zoonoses constitute a major risk to human health. Comprehensive assessments on the potential emergence of novel disease outbreaks are essential to ensure the effectiveness of sanitary controls and to establish mitigating actions. Through a continental‐scale survey of rural human settlements conducted over 13 years in 15 Neotropical countries, we do...

Understanding the factors driving phenotypic and genomic differentiation of insular populations is of major interest to gain insight into the speciation process. Comparing patterns across different insular taxa subjected to similar selective pressures upon colonizing oceanic islands provides the opportunity to study parallel evolution and identify...

18 Pharmaceutical contaminants have a recognized negative impact on wildlife health. 19 However, there are still many knowledge gaps on the factors influencing exposure and 20 metabolic processing of compound mixtures as a function of season and individual 21 characteristics such as age and sex. We evaluated age and sex differences in a set of 22 s...

Understanding the factors driving phenotypic and genomic differentiation of insular populations is of major interest to gain insight into the speciation process. Comparing patterns across different insular taxa subjected to similar selective pressures upon colonizing oceanic islands provides the opportunity to study parallel evolution and identify...

The delimitation of African wintering areas of the griffon vulture Gyps fulvus has been established on the basis of ring recoveries, usually from dead individuals and, to a lesser extent, by reading ring and wing marks in human-populated areas. After GPS-tracking of several juvenile griffon vultures from central Spain, we show that a female used an...

The ongoing demand for renewable energy has boosted the development of wind farms worldwide. Given the impact these facilities have on flying species, a spatially explicit assessment of collision risk in vulnerable species is needed to guide management actions and prioritise areas for installing these infrastructures. We used GPS-tracking data of 1...

Natal dispersal is a critical trait for individual fitness and the viability, structure, and genetic identity of populations. However, there is a pronounced information gap for large and long-lived species due to the difficulty of monitoring individuals at appropriate spatio-temporal scales. Here we study how individual traits and social and enviro...

Variation in offspring sex ratio has been studied quite thoroughly in birds, but little attention has been paid to vultures, and particularly no research addressing differences between mainland and island populations has been done. Here, we took advantage of long-term monitoring programs in some of the most important colonies of Egyptian vultures i...

Censo de dormideros invernales de grajilla occidental en Castilla y León Resumen (Corvus mo-nedula) Palabras clave: Copia gratuita / Personal free copy

In this chapter, estimates of the population size of the European Jackdaw (Corvus monedula) obtained by census at winter roosts during the last four decades in the Community of Madrid are shown. In the last census (2021), 9098 jackdaws (range: 8915-9332) were counted in 19 roosts with an average of 479 individuals (range: 10-3164). Most roosts were...

The aim of this paper is to update the population estimate of the Europeann Jackdaw (Corvus monedula) in the Basque Country, Navarra and La Rioja based on censuses carried out in winter (roost concentrations). Furthermore, through comparison with previous estimates, both in the breeding and wintering season, we also aim to infer trends and changes...

Parrots are among the most diverse and widely distributed groups of birds and one of the most threatened bird orders mainly due to habitat loss and illegal poaching. Most parrots are obligate cavity nesters, so the logging of mature trees and the transformation of natural cliffs represent important threats to their conservation. Here, we report nov...

Variation in offspring sex ratio, particularly in birds, has been frequently studied over the last century, although seldom using long-term monitoring data. In raptors, the cost of raising males and females is not equal, and several variables have been found to have significant effects on sex ratio, including food availability, parental age, and ha...

According to models of ecological speciation, adaptation to adjacent, contrasting habitat types can lead to population divergence given strong enough environment-driven selection to counteract the homogenizing effect of gene flow. We tested this hypothesis in the common chaffinch (Fringilla coelebs) on the small island of La Palma, Canary Islands,...

Household waste landfills represent a huge source of trophic resources for opportunistic and versatile wildlife species. Among them, the red kite (Milvus milvus) is one of the most endangered in Europe. Several studies have pointed out the importance of landfills as a source of food for this species during the wintering season, but the information...

Illegal wildlife trade remains highly active in the Neotropics, as indicated by the thousands of parrots annually sold in illicit city markets. However, little is known about where parrots are poached, whether certain parrot species are selected among those available in the wild, their trade routes, and potential conservation impacts. We conducted...

Potential exposure of the Andean Condor (Vultur gryphus) to pharmaceuticals is of high conservation interest, as these compounds can produce catastrophic consequences for populations of avian scavengers. Due to the extensive livestock management in most of Patagonia, we expected Andean condors to be rarely exposed to veterinary pharmaceuticals thro...

Information on the exposure of wild birds to pharmaceuticals from wastewater and urban refuse is scarce despite the enormous amount of drugs consumed and discarded by human populations. We tested for the presence of a battery of antibiotics, NSAIDs, and analgesics in the blood of white stork (Ciconia ciconia) nestlings in the vicinity of urban wast...

Information on the exposure of wild birds to pharmaceuticals from wastewater and urban refuse is scarce despite the enormous amount of drugs consumed and discarded by human populations. We tested for the presence of a battery of antibiotics, NSAIDs, and analgesics in the blood of white stork (Ciconia ciconia) nestlings in the vicinity of urban wast...

Quantifying space use and segregation, as well as the extrinsic and intrinsic factors affecting them, is crucial to increase our knowledge of species-specific movement ecology and to design effective management and conservation measures. This is particularly relevant in the case of species that are highly mobile and dependent on sparse and unpredic...

Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constraints symbiont populations. We parameterized metabolic theory equations to predict how bird species’ body size and the body size of their feather mites relate to mite abundance according...

Capsule Barn Owls Tyto alba and Red-billed Choughs Pyrrhocorax pyrrhocorax show differential breeding outputs as a consequence of sharing nest boxes. Aims To describe for the first time a commensal relationship between the Red-billed Chough and the Barn Owl during the breeding period. Methods During systematic monitoring of 90 nest boxes installe...

Article reference: Morant et al. (2022). Large-scale movement patterns in a social vulture are influenced by seasonality, sex, and breeding region.

In the Copper Age, slate engraved plaques were produced massively in the southwestern corner of the Iberian Peninsula. Researchers have speculated about the function of these palm-sized stone objects for more than a century, although most have favored the idea that they represented goddesses, and served ritual purposes. The plaques are engraved wit...

Carotenoids are diet-based micronutrients important in health and coloration signaling. Related species with similar diets can differ in the kinds and levels of circulating carotenoids, which suggests specific physiological mechanisms to efficiently utilize these micronutrients, regardless of their availability. We explored whether diet and parenta...

In fragile ecosystems, the introduction of exotic species could alter some ecological processes. The Austral parakeet (Enicognathus ferrugineous) shows close ecological and evolutionary relationships with the Andean Araucaria (Araucaria araucana), so any alteration in these interactions may have negative consequences for both partners and for ecosy...

Quantifying space use and segregation, as well as the extrinsic and intrinsic factors affecting them, is crucial to increase our knowledge of species-specific movement ecology and to design effective management and conservation measures. This is particularly relevant in the case of species that are highly mobile and dependent on sparse and unpredic...

Scavenging is a key ecological process controlling energy flow in ecosystems and providing valuable ecosystem services worldwide. As long‐lived species, the demographic dynamics of vultures can be disrupted by spatiotemporal fluctuations in food availability, with dramatic impacts on their population viability and the ecosystem services provided. I...

There is broad consensus that increasing the use of renewable energies is effective to mitigate the global climate crisis. However, the development of renewables may carry environmental impacts, and their expansion could accelerate biodiversity loss (1). However, Dunnett et al. (2) have recently estimated a minimal overlap between renewable energy...

Variation in offspring sex ratios is a central topic in animal demography and population dynamics. Most studies have focused on bird species with marked sexual dimorphism and multiple-nestling broods, where the offspring sex ratio is often biased due to different individual or environmental variables. However, biases in offspring sex ratios have be...

Variation in offspring sex ratios is a central topic in animal demography and population dynamics. Most studies have focused on bird species with marked sexual dimorphism and multiple-nestling broods, where the offspring sex ratio is often biased due to different individual or environmental variables. However, biases in offspring sex ratios have be...

Despite important recent advances in cognitive ecology, our current understanding of avian cognition still largely rests on research conducted on a few model taxa. Vultures are an ecologically distinctive group of species by being the only obligate carrion consumers across terrestrial vertebrates. Their unique scavenging lifestyle suggests they hav...

Parrots (Psittaciformes), with about 400 species widely distributed across continents and oceanic islands, stand out among birds for their poor conservation status [...]

Wildlife trade is a major driver of biodiversity loss worldwide. To regulate its impact, laws and regulations have been implemented at the international and national scales. The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) has regulated the international legal trade since 1975. However, an important volume...

Palms, like all plants, show coevolutionary relationships with animals that have been traditionally categorized as mutualistic (seed dispersers and pollinators) or antagonistic (seed predators). This dual perspective, however, has prevented a full understanding of their true interactions with some animal groups, mainly those that do not ingest enti...

Degradation of natural ecosystems increases the risk of infections in wildlife due to microbiota dysbiosis. However, little is known about its influence on the development of fungal communities in predators and facultative avian scavengers. We evaluated the incidence of oral disease in wild nestling black kites (Milvus migrans) under contrasting en...

Anthropogenic stressors can favor the occurrence of non-infectious disease that can be worsened by the impact of opportunistic pathogens, making the epizootiology of environmental diseases difficult to unravel. The incidence and impact of oral lesions in nestlings of a facultative scavenger species, the black kite Milvus migrans, were examined over...

The transmission of pathogens to native species has been highlighted as one of the most important impacts of biological invasions. In this study, we evaluated the presence of psittacine beak and feather disease virus (BFDV) and other circoviruses in native bird species cohabiting with invasive populations of wild rose-ringed (Psittacula krameri) an...

Bird populations associated with agricultural ecosystems have declined markedly in Europe during the last quarter of the 20th century due to land-use intensification. This has meant that some very common species, in some cases even species considered as pests, are now threatened or subject to management programs to ensure their conservation. Consid...

Bird populations associated with agricultural ecosystems have declined markedly in Europe during the last quarter of the 20th century due to land-use intensification. This has meant that some very common species, in some cases even species considered as pests, are now threatened or subject to management programs to ensure their conservation. Consid...

Bird populations associated with agricultural ecosystems have declined markedly in Europe during the last quarter of the 20th century due to land-use intensification. This has meant that some very common species, in some cases even species considered as pests, are now threatened or subject to management programs to ensure their conservation. Consid...

Certain traits of recipient environments, such as the availability of limiting resources, strongly determine the establishment success and spread of non-native species. These limitations may be overcome through behavioral plasticity, allowing them to exploit alternative resources. Here, we show how a secondary cavity nester bird, the rose-ringed pa...

Evidence is accumulating on the regular and systematic Neanderthal exploitation of birds. However, the motivations, mechanisms, and circumstances underlying this behavior remains little explored despite their potential implications on Neanderthal ecology and capabilities. Fossil remains of choughs (Pyrrhocorax, Corvidae) are among the most abundant...

Oceanic archipelagos are excellent systems for studying speciation, yet inference of evolutionary process requires that the colonization history of island organisms be known with accuracy. Here, we used phylogenomics and patterns of genetic diversity to infer the sequence and timing of colonization of Macaronesia by mainland common chaffinches (Fri...

While most of the knowledge on invasive species focuses on their impacts, little is known about their potential positive effects on other species. Invasive ecosystem engineers can disrupt recipient environments; however, they may also facilitate access to novel resources for native species. The monk parakeet (Myiopsitta monachus) is a worldwide inv...

Parrots stand out among birds because of their poor conservation status and the lack of available information on their population sizes and trends. Estimating parrot abundance is complicated by the high mobility, gregariousness, patchy distributions, and rarity of many species. Roadside car surveys can be useful to cover large areas and increase th...

Understanding of ecosystem structure and functioning requires detailed knowledge about plant–animal interactions, especially when keystone species are involved. The recent consideration of parrots as legitimate seed dispersers has widened the range of mechanisms influencing the life cycle of many plant species. We examined the interactions between...

Vultures and condors are among the most threatened avian species in the world due to the impacts of human activities. Negative perceptions can contribute to these threats as some vulture species have been historically blamed for killing livestock. This perception of conflict has increased in recent years, associated with a viral spread of partial a...

Sexual segregation is widely reported among sexually dimorphic species and generally attributed to intraspecific competition. Prey diversity and human activities can reinforce niche segregation by increasing resource heterogeneity. Here, we explored trophic and spatial sexual segregation in the only avian scavenger that exhibits pronounced sexual s...

Plant–animal interactions are key to sustaining whole communities and ecosystem function. However, their complexity may limit our understanding of the underlying mechanisms and the species involved. The ecological effects of epizoochory remain little known compared to other seed dispersal mechanisms given the few vectors identified. In addition, ep...

Natal dispersal, the movement between the birth and the first breeding site, has been rarely studied in long-lived territorial birds with a long-lasting pre-breeding stage. Here we benefited from the long-term monitoring programs of six populations of Egyptian vultures ( Neophron percnopterus ) from Spain and France to study how the rearing environ...

Avian haemosporidians are a common and widespread group of vector-borne parasites capable of infecting most bird species around the world. They can negatively affect host condition and fitness. Vultures are assumed to have a very low prevalence of these blood parasites, likely due to their strong immunity; however, factors contributing to variation...

The common chaffinch, Fringilla coelebs, is one of the most common, widespread and well-studied passerines in Europe, with a broad distribution encompassing Western Europe and parts of Asia, North Africa and the Macaronesian archipelagos. We present a high-quality genome assembly of the common chaffinch generated using Illumina shotgun sequencing i...

Current bird populations in southern temperate latitudes often represent relicts of glacial refugia from which northern populations expanded as the climate became suitable following the last glacial maximum, 18 000 years before present. Alternatively, these southern populations could be the result of the fragmentation of large distributions and oth...

Introduced organisms have to overcome several obstacles, including the scarcity of conspecific mates before becoming successfully established. We recorded interspecific mating in non‐native areas (Spain) that involved Orange‐winged Amazons Amazona amazonica with three non‐congeneric parrot species: Scaly‐headed Parrot Pionus maximiliani, Rose‐ringe...

Due to their limited ranges and inherent isolation, island species have long been recognized as crucial systems for tackling a range of evolutionary questions, including in the early study of speciation.¹,² Such species have been less studied in the understanding of the evolutionary forces driving DNA sequence evolution. Island species usually have...

Behavioural and socio-cultural traits are recognized in the restriction of gene flow in species with high cognitive capacity and complex societies. This isolation by social barriers has been generally overlooked in threatened species by assuming disrupted gene flow due to population fragmentation and decline. We examine the genetic structure and ec...

Reducing greenhouse gas emissions is a global priority. To meet this goal, the Spanish government is planning 89 GW of wind and solar photovoltaic energy in the draft of the National Integrated Energy and Climate Plan (PNIEC) for 2021–2030 (1). Despite the Spanish government's efforts to prevent a speculative bubble in the secondary market, there a...

Livestock production is a large source ofmicrobial, pharmaceutical, and antimicrobial pollutionworldwide. Vultures are one group of birds with particularly high exposure to food-borne pathogens due to frequent consumption of infected livestock carcasses. The potential origin and spatial-temporal shedding patterns of livestock-adapted Salmonella ser...

The common chaffinch, Fringilla coelebs, is one of the most common, widespread and well-studied passerines in Europe, with a broad distribution encompassing Western Europe and parts of Asia, North Africa and the Macaronesian archipelagos. We present a high-quality genome assembly of the common chaffinch generated using Illumina shotgun sequencing i...

Aim: Oceanic islands have often been colonized by small groups of individuals dispersing from the nearest mainland, giving rise to insular populations characterized by locally adapted phenotypes and low genetic diversity. Alternatively, due to past geo‐climatic changes, the present‐day distribution of the species may not correspond to that found at...

Vultures are one of the most threatened bird groups globally. Although many of the threats faced by vultures have been identified, the impact of human activities on the social life of vultures has received little attention. In this paper, we emphasize the need to integrate vulture sociality into conservation practice. First, we summarize current kn...

Illegal wildlife trade, which mostly focuses on high-demand species, constitutes a major threat to biodiversity. However, whether poaching is an opportunistic crime within high-demand taxa such as parrots (i.e., harvesting proportional to species availability in the wild), or is selectively focused on particular, more desirable species, is still un...

The effects that microorganisms (bacteria, viruses and fungi) have on their hosts remain unexplored for most vulture species. This is especially relevant for vultures, as their diet consists of carcasses in various stages of decomposition, which are breeding grounds for potentially pathogenic microorganisms. Here we review current knowledge of bact...