Santiago Merino

The National Museum of Natural Sciences · Departamento de Ecología Evolutiva - MNCN

Sexual differences in pathogen prevalence in wildlife often arise from varying susceptibility influenced by factors such as sex hormones and exposure to pathogens. In the case of vector-borne pathogens, host selection by insect vectors determines the exposure of hosts to infections, largely affecting the transmission of these infectious diseases. W...

Abstract BACKGROUND AND AIM[|]Although felids can be observed in almost any habitat thanks to their adaptability, their populations are increasingly affected by various threats. Anthropogenic pressure is the main cause of the decline of these carnivores, forced to adapt to urban areas. This may imply a change in the variety of prey they feed on, st...

Female and male hosts may maximise their fitness by evolving different strategies to compensate for the costs of parasite infections. The resulting sexual dimorphism might be apparent in differential relationships between parasite load and body condition, potentially reflecting differences in energy allocation to anti‐parasitic defences. For exampl...

The major histocompatibility complex (MHC) is a genetic region in jawed vertebrates that contains key genes involved in the immune response. Associations between the MHC and avian malaria infections in wild birds have been observed and mainly explored in the Northern Hemisphere, while a general lack of information remains in the Southern Hemisphere...

Many models predict changes in the distribution and incidence of diseases associated with climate change. However, studies exploring the effect of microclimatic changes on host–parasite relationships are scarce. In this study, we increased temperature or humidity in Eurasian Blue Tit Cyanistes caeruleus nestboxes during the breeding season, to anal...

Many factors may affect the diversity and abundance of arthropods in their natural habitats including changes in temperature and humidity. Sometimes, large arthropods remain undetected in unsuspected habitats such as bird nests. Here, we explore the effects of an experiment modifying temperature and relative humidity inside the nest of a troglodyte...

We explored the potential influence of temperature and precipitation on the abundance of two nest‐dwelling ectoparasites (blowflies and mites) of Eurasian blue tits ( Cyanistes caeruleus ) during a period of 21 years and compared the results with those of a shorter period. The abundance of blowflies was negatively related to precipitation, which co...

A male Gallotia galloti basking on an ancient lava flow in the south of Tenerife

Host abundance might favour the maintenance of a high phylogenetic diversity of some parasites via rapid transmission rates. Blood parasites of insular lizards represent a good model to test this hypothesis because these parasites can be particularly prevalent in islands and host lizards highly abundant. We applied deep amplicon sequencing and anal...

The wattled ibis (Bostrychia carunculata) is a little-known endemic Abyssinian species living in the Ethiopian and Eritrean Highlands. This bird species lives in close contact with humans in several parts of its range. Nothing is known about parasites infecting the wattled ibis and its distribution across populations, with the exception of some lic...

Male of Cyren's rock lizard, a mountain specialist from central Iberian Peninsula. Tragedy of the common parasites Karyolysus (Apicomplexa: Adeleorina) is a blood parasite of lizards in the family Lacertidae from the western Mediterranean. Negative effects on these hosts remain elusive although nucleus distortion of infected erythrocytes gives nam...

Studies exploring the effect of microclimatic changes on host-parasite relationships are scarce, however, many models predict changes in the distribution and incidence of diseases associated with climate change. In this study, we increased both temperature and relative humidity in blue tit nest-boxes during the breeding season, trying to discern be...

The genus Karyolysus was originally proposed to accommodate blood parasites of lacertid lizards in Western Europe. However, recent phylogenetic analyses suggested an inconclusive taxonomic position of these parasites of the order Adeleorina based on the available genetic information. Inconsistencies between molecular phylogeny, morphology, and/or l...

Ontogeny is expected to be a determinant factor affecting production of colour patches in lizards, while immune challenges or sudden weight loss may impair the maintenance of pigment-based coloration within a breeding season. We translocated males of the lizard Psammodromus algirus between two sampling plots that differed in distance to a road, veg...

Several models predict changes in the distributions and incidences of diseases associated with climate change. However, studies that investigate how microclimatic changes may affect host-parasite relationships are scarce. Here, we experimentally increased the temperature in blue tit Cyanistes caeruleus nest boxes during their breeding season to det...

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...

Models on climate change have predicted an increase of temperature over the earth's surface with potential drastic effects on living organisms. We analyzed the relationships between climatic conditions (temperature, rainfall and wind speed) and the abundance of blood-sucking flying insects (biting midges and blackflies) and nest-dwelling ectoparasi...

Several studies of lizards have made an erroneous interpretation of negative relationships between spectral brightness and parasite load, and thus provided misleading support for the Hamilton–Zuk hypothesis (HZH). The HZH predicts that infected hosts will produce poorer sexual ornamentation than uninfected individuals as a result of energetic trade...

Although different predictive models forecast that climate change will alter the distribution and incidence of parasitic diseases, few studies have investigated how microclimatic changes may affect host-parasite relationships. In this study, we experimentally increased the temperature inside nest boxes of the blue tit Cyanistes caeruleus during the...

Although parrot species are infrequently infected by hemoparasites in the wild, some fatal infections have been reported in captive individuals. Conversely birds of prey are frequently infected by hemoparasites. In this study, 193 captive birds from Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) centers in M...

This chapter provides a brief overview of how natural gradients (e.g., latitude, altitude, and landscape gradients) affect host–parasite interactions involving blood parasites in wildlife and how biotic and abiotic factors act as disruptors. These gradients have a direct impact on prevalence, parasitemia, and the observed relationships between para...

We studied the relationship between temperature and the coexistence of great tit Parus major and blue tit Cyanistes caeruleus, breeding in 75 study plots across Europe and North Africa. We expected an advance in laying date and a reduction in clutch size during warmer springs as a general response to climate warming and a delay in laying date and a...

The presence of nestlings and other nest dwelling organisms in cavity nests alters the composition of gasses inside the cavity. Differential concentrations of gasses could be used by some parasites as a cue to localize their hosts. Here, we explored temporal variation in the concentration and isotopic signature of carbon dioxide (CO2) and methane (...

Anthropization of insular ecosystems may have negative impacts on native populations of lizards, which provide core ecosystem services on islands. We aimed to identify environmental factors to explain the interlocal variation in faecal glucocorticoids, parasite intensity, and body condition in populations of insular lizards. A cross-sectional desig...

During the last years, models on the effects of climate change predict the arrival of milder climates to higher latitudes and altitudes, and as a consequence, the spread of disease from lower latitudes and altitudes. Bird-parasite interactions are not an exception and could be affected by these changes. However, several reviews on the effects of cl...

Some passerines incorporate aromatic plants in their nest cups, and several hypotheses have been formulated to explain this behaviour. One of those, the Drug Hypothesis, states that aromatic plants present in nests have positive effects on nestlings’ development through increased immune function. In this study, we aimed to examine if experimental a...

Adaptive explanations for the evolution of extra‐pair paternity (EPP) suggest that females seek extra‐pair copulations with high quality males. Still, the link between ornamentation, individual quality and paternity remains unclear. Moreover, honest signaling is essential when explaining EPP because it is needed for sexual selection to occur; yet,...

The presence of nestlings and other nest dwelling living beings in nests built in cavities could alter the composition of gases inside the cavity. In addition, this different concentration of gases could be used by some parasites as a cue to localize their hosts. Here, we explored the temporal variation in the concentration and isotopic signature o...

Knowledge on hemoparasites and immunological parameters in wild birds with Arctic distribution is limited. In this study, we chose the Snow Bunting (Plectrophenax nivalis) as model species to address this issue. Using nestlings, we aimed at (i) detecting hemoparasites with vector-borne transmission (via microscopic and molecular methods) and nest-d...

Supplemental information

Background: Parasites can exert selection pressure on their hosts through effects on survival, on reproductive success, on sexually selected ornament, with important ecological and evolutionary consequences, such as changes in population viability. Consequently, hemoparasites have become the focus of recent avian studies. Infection varies significa...

Current and past parasite transmission may depend on the geographic contact between hosts, potentially affecting host specificity and co-evolutionary processes. Nonetheless, divergent evolution in sympatry might be especially relevant in parasite systems that infect hosts with low mobility. Here, we test the co-speciation hypothesis between lizard...

Several models predict changes in the distributions and incidences of diseases associated with climate change. However, studies that investigate how microclimatic changes may affect host‐parasite relationships are scarce. Here, we experimentally increased the temperature in blue tit (Cyanistes caeruleus) nest boxes during their breeding season to d...

Model selection for female behavioral traits (Table A1)

Model selection for male behavioral traits (Table A2)

Carry-over effects refer to processes that occur in one season and influence fitness in the following. In birds, two costly activities, namely reproduction and moult, are restricted to a small time window, and sometimes overlap. Thus, colour in newly moulted feathers is likely to be affected by the costs of reproduction. Using models of bird vision...

Parasites generally have a negative influence on the color expression of their hosts. Sexual selection theory predicts high quality resistant individuals should show intense coloration, whereas susceptible low quality individuals would show poor coloration. However, intensely colored males of different species of Old and New World lizards were more...

Background: Species of Schellackia Reichenow, 1919 have been described from the blood of reptiles distributed worldwide. Recently, Schellackia spp. detected in European and Asian lizards have been molecularly characterised. However, parasites detected in American lizard hosts remain uncharacterised. Thus, phylogenetic affinities between the Old and...

The honesty of structural-based ornaments is controversial. Sexual selection theory predicts that the honesty of a sexual signal relies on its cost of production or maintenance. Therefore, environmental factors with negative impact on individuals could generate high costs and affect the expression of these sexual signals. In this sense, parasites a...

Many passerines lay protoporphyrin-pigmented eggs, and the degree of spotting seems to be related to female condition and environmental characteristics. However, most studies have ignored the relationship between the male's quality and eggshell pigmentation. Because ornaments can act as honest indicators of individual quality, spottiness could be r...

In wild bird populations nestlings are commonly infested by ectoparasites. The effects that ectoparasites exert on host fitness usually become evident after the complete elimination of parasites or a substantial reduction in their abundance. Among the most common elimination methods in ecological studies, the use of chemical insecticides is traditi...

Host species in populations under strong pressures from parasitic diseases may evolve ornaments to signal individual host quality to conspecifics. Colour ornaments in lizards result from the interaction of different layers in the skin. When inner layers of melanin and well-arranged iridophores are combined, UV-blue structural colouration results. O...

The increase in size of human populations in urban and agricultural areas has resulted in considerable habitat conversion globally. Such anthropogenic areas have specific environmental characteristics, which influence the physiology, life history, and population dynamics of plants and animals. For example, the date of bud burst is advanced in urban...

Figure S1. Intensity of urbanisation according to (A) classification by scientists. Box plots show medians, quartiles, 5‐ and 95‐percentiles, and extreme values, and (B) CORINE land cover code (red = discontinuous urban, purple = industrial or commercial units, pink = green urban sites, brown = arable land and rice field, orange = agriculture lands...

Figure S2. Distribution of study plots across Europe, North Africa and the Middle East.

Table S1. Summary data for study plots. See Material and methods for definitions. Table S2. Correlation matrix of explanatory variables. Table S3. Mixed linear model investigating laying date in four passerines species (CF: Collared Flycatcher, GT: Great tit and PF: Pied Flycatcher) as a function of habitat characteristics (intensity of urbanisat...

Figure S3. Box plots of latitude of study plots in four passerine birds in Europe, North Africa and the Middle East.

The increase in size of human populations in urban and agricultural areas has resulted in considerable habitat conversion globally. Such anthropogenic areas have specific environmental characteristics, which influence the physiology, life history, and population dynamics of plants and animals. For example, the date of bud burst is advanced in urban...

Ardeola is the scientific journal of the Spanish Ornithological Society. We analyse historical changes in citation, topics and foreign authorship of articles published in Ardeola from its first publication in 1954 up to last year, 2015, to test to what extent the persistence of the journal during the last 61 years has been due to support of authors...

Ardeola is the scientific journal of the Spanish Ornithological Society. We analyse historical changes in citation, topics and foreign authorship of articles published in Ardeola from its first publication in 1954 up to last year, 2015, to test to what extent the persistence of the journal during the last 61 years has been due to support of authors...

Pigment-based ornaments in vertebrates may reflect the body condition or health status of the individual in correlation with environmental stress and hormonal balance. Among the environmental factors shaping sexual colouration, parasitic infections have been stressed as an important evolutionary pressure constraining the maintenance of pigment-base...

In this study, several species of Isospora infecting lizards were genetically characterized. Specifically, five described and four newly described species of Isospora were included in a phylogeny of the family Eimeriidae. These species were isolated from hosts originally inhabiting all geographic continents except Europe. Phylogenetic analyses of t...

Major histocompatibility complex (MHC) genes are central for the adaptive immune response against parasites. Here, we investigated potential associations among MHC-I alleles and blood parasite infections in a natural breeding population of a passerine bird, the blue tit Cyanistes caeruleus, in central Spain. We screened both infection status (prese...

Blood parasites exert great selective pressure that can alter population dynamics. The introduction of new parasite lineages in a region could lead to the extinction of endemic bird species which have not coevolved with them. The avifauna of Pampa del Tamarugal in the desert of Atacama, Chile is highly depauperate, with two species accounting for t...