José Javier Cuervo

The National Museum of Natural Sciences · Department of Evolutionary Ecology

To understand wildlife responses to the changing environment, it is useful to examine their physiological responses and particularly their endocrine status. Here, we validated an enzyme immunoassay (EIA) to non-invasively quantify fecal corticosterone metabolites (FCM) in the fossorial amphisbaenian reptile Trogonophis wiegmanni from North Africa....

Conspecific cues often provide social information on habitat quality that is considered when deciding to settle at a specific site. The type of sensory cues useful for this will depend on the environment. For amphisbaenians, reptiles adapted to an underground life with highly reduced sight, chemoreception is especially useful to recognize conspecif...

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...

Avian feathers need to be replaced periodically to fulfill their functions, with natural, social, and sexual selection presumably driving the evolution of molting strategies. In temperate birds, a common pattern is to molt feathers immediately after the breeding season, the pre-basic molt. However, some species undergo another molt in winter-spring...

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...

Background The movement and spatial ecology of an animal depends on its morphological and functional adaptations to its environment. In fossorial animals, adaptations to the underground life help to face peculiar ecological challenges, very different from those of epigeal species, but may constrain their movement ability. Methods We made a long-te...

[EtoloGuía 26: 47-58] La elección de pareja es uno de los mecanismos fundamentales de la selección sexual, pero parece existir cierta confusión sobre qué es y qué incluye ese término. Aquí hago un breve repaso de cómo el concepto de elección de pareja ha cambiado a lo largo del tiempo, haciendo especial hincapié en la hipótesis de la inversión dife...

Sexual signals can be evolutionarily stable if they are condition dependent or costly to the signaler. One of these costs may be the trade-off between maintaining the immune system and the elaboration of ornaments. Experimental immune challenges in captivity show a reduction in the expression of sexual signals, but it is not clear whether these det...

Context Human land-use transformation has fragmented natural landscapes around the world, with fragmentation currently being considered a global threat to biodiversity conservation. Landscape fragmentation, however, does not affect all species similarly, suggesting that some species characteristics may render species more sensitive to fragmentation...

Identification of high levels of intraspecific genetic variability is common among assessments of reptiles from the Iberian Peninsula, conforming to the “refugia within refugia” hypothesis. Divergent genetic lineages are often found to be allopatric, or with limited contact or hybrid zones; such zones are more widely reported in Northern Europe, le...

The offspring of many animals are conspicuous during parental dependence, despite juveniles generally suffering from high predation risk. However, to date, it is unclear whether offspring structural ornaments play a role in intrafamily communication. This is the case of conspicuous plumage in young birds, which is worn unchanged during a long perio...

Breeding coloration of females often signals aspects of their reproductive status, suggesting a link between colour and sex steroid hormones. In this study, we examined the relationships between two sex steroid hormones (progesterone and β-estradiol) and reproductive coloration in female spiny-footed lizards Acanthodactylus erythrurus. We first exp...

Factors affecting the evolution of plumage conspicuousness in females are nowadays the focus of debate, and here we explore the possibility that the conspicuousness of female plumage and male participation in nest building are associated in birds. We hypothesize that males that participate in nest building will gain higher fecundity from high-quali...

Los costes de producción de las señales sexuales de los machos, permiten que las hembras las consideren señales honestas indicadoras de la condición y la calidad del macho. En la lagartija carpetana (Iberolacerta cyreni), las características de las señales químicas (secreciones femorales) de los machos constituyen una señal honesta en el contexto d...

Sexual signals that males produce to attract females may be honest if they are costly and dependent on the condition and quality of the male. In the Carpetan rock lizard (Iberolacerta cyreni), the characteristics of males' chemical signals (femoral secretions) may constitute an honest signal in the context of female mate choice. Those males able of...

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...

Female mate choice for male display traits is widely observed across animal taxa and is a well-established mechanism of evolution. However, males are increasingly seen to exhibit mate choice for female display traits, even in species with traditional sex roles, although this continues to be an understudied aspect of sexual selection. We evaluated t...

Due to the reduced conspicuousness of female signals, their evolution has traditionally been interpreted as a by-product of sexual or natural selection in males. Recent studies have argued that they may be the result of sexual or social selection acting on females. Here, we explored the role of the white wing patch during the incubation period in f...

Las señales sexuales químicas (secreciones femorales) usadas para marcar sustratos por los machos de lagartija carpetana (Iberolacerta cyreni) parecen tener un papel importante en la elección de pareja. Las hembras parecen evaluar la calidad de un macho a partir de las proporciones de dos formas de la provitamina D (cholesta-5,7-dien-3-ol y ergoste...

Understanding temporal variability in population size is important for conservation biology because wide population fluctuations increase the risk of extinction. Previous studies suggested that certain ecological, demographic, life-history and genetic characteristics of species might be related to the degree of their population fluctuations. We che...

Relationships between the magnitude of population fluctuations and abundance, total breeding range, coloniality and population trend of European breeding bird species. (DOCX)

Information on ecological, demographic, life-history and genetic characteristics of European bird species. (DOCX)

Ontogenetic colour changes in animals generally involve cryptic juveniles developing conspicuous coloration when they achieve sexual maturity. However, there are several species in which juveniles develop conspicuously coloured tails that become cryptic in adults. In lizards, colourful tails may act as an antipredator mechanism, either by diverting...

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 (...

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...

1.Many partially migratory species show phenotypically divergent populations in terms of migratory behaviour, with climate hypothesized to be a major driver of such variability through its differential effects on sedentary and migratory individuals. 2.Based on long-term (1947-2011) bird ringing data, we analysed phenotypic differentiation of migrat...

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...

Animal populations are currently under pressure from multiple factors that include human land use and climate change. They may compensate for such effects by reducing, either by habituation or by natural selection, the distance at which they flee from humans (i.e., flight initiation distance), and this adaptation may improve their population trends...

In many animal taxa, coloration is a visual signal used for communication among conspecifics, for example between age classes. Juvenile coloration has been hypothesized to reduce aggression from adults in some species, in what is called the aggression avoidance hypothesis. Spiny-footed lizards are good subjects for testing this hypothesis, as juven...

The decoy or deflection hypothesis, which states that conspicuous colouration is present in non-vital parts of the body to divert attacks from head and trunk, thus increasing survival probability, is a possible explanation for the presence of such colouration in juveniles of non-aposematic species. To test this hypothesis we made plasticine and pla...

Some studies have suggested that tail streamers in the barn swallow Hirundo rustica may have been elongated 10–12 mm by sexual selection, but according to other studies, the length of these feathers is at the aerodynamic optimum or very close to it. To shed light on this issue, outermost tail feathers were experimentally shortened in male and femal...

In the Northern Hemisphere, global warming has been shown to affect animal populations in different ways, with southern populations in general suffering more from increased temperatures than northern populations of the same species. However, southern populations are also often marginal populations relative to the entire breeding range, and marginal...

The questions of whether carotenoids are mobilized from storage organs or the blood during food shortages or in stressful situations and the amount of carotenoids available in these situations remain contentious. We study the amount of carotenoids circulating in the blood stream in Gentoo Penguins (Pygoscelis papua), taking advantage of the physiol...

Animals often announce their unprofitability to predators through conspicuous coloured signals. Here we tested whether the apparently conspicuous colour designs of the four European Coraciiformes and Upupiformes species may have evolved as aposematic signals, or whether instead they imply a cost in terms of predation risk. Because previous studies...

In spiny-footed lizards (Acanthodactylus erythrurus), adult females (but not males) show conspicuous red colouration in the tail and hind legs. To investigate the function of this red colouring and proximal causes of seasonal colour change, we captured adult females before the reproductive season and kept them in captivity in one of the three follo...

Recent observations on the western Antarctic Peninsula have suggested that changing climatic conditions may be increasing pressure on breeding seabirds due to higher exploitation rates by the tick Ixodes uriae. Using data from 8 microsatellite markers and ticks from 6 Pygoscelis spp. colonies, we employed a population genetics approach to specifica...

Vegetation structure and composition, and parameters of the bird community (richness and abundance) were studied in managed beech-fir forests in Navarre (Spain). Relationships between bird parameters and vegetation variables differed in different avian nesting guilds. Whereas secondary cavitynesting bird parameters were not significantly related to...

Hematocrit, the proportion of blood volume occupied by packed red blood cells, is frequently used as an estimate of phenotypic condition. Some studies in birds, however, suggest that hematocrit might not always be a good estimate of condition. We tested the reliability of hematocrit as an estimate of condition by investigating the relationship betw...

The distribution of the tick Ixodes uriae is studied in the South Shetlands and different locations along the Antarctic Peninsula. Ticks were found beneath stones close to penguin rookeries of chinstrap, gentoo and adelie penguin, although no individuals were found parasitized. Our results showed that ticks are not distributed evenly along the Anta...

There is currently no agreement about the suitability of fluctuating asymmetry (FA) as an estimate of individual quality. We investigated the relationship between FA and health, a proxy for individual quality, in captive populations of three endangered gazelle species: Gazella cuvieri, G. dama, and G. dorcas. FA indices including information from s...

We carried out a study to investigate the presence of some protozoan parasites (Cryptosporidium sp., Giardia sp., Toxoplasma gondii) on three species of Antarctic penguins: Adélie (Pygoscelis adeliae), gentoo (Pygoscelis papua) and chinstrap (Pygoscelis antarctica) from different locations along the Antarctic Peninsula and the South Shetland Island...

Aims To compare nest size and location between the two species and to test whether there were inter-species differences that might suggest specific nesting adaptations, and to investigate possible correlates between hatching success and nest location. Methods Nest-site selection, characteristics and hatching success were studied during 1989 in a la...

Gentoo penguins (Pygoscelis papua) have conspicuous red beak spots, the function of which is currently unknown. We hypothesized that beak spots might be sexual ornaments and investigated sexual dichromatism, assortative mating and the possible relationship between beak spot colouration and body condition. Beak colouration was measured with a portab...

Amos suggested recently that a previously reported positive relationship between minisatellite mutation rates and extra-pair paternity among species of birds was confounded by transcription errors and selective inclusion of studies. Here we attempted to replicate the results reported by Amos, but also tested for the relationship by expanding the da...

The static allometry of secondary sexual characters is currently subject to debate. While some studies suggest an almost universal positive allometry for such traits, but isometry or negative allometry for nonornamental traits, other studies maintain that any kind of allometric pattern is possible. Therefore, we investigated the allometry of sexual...

Supplementary table 2. Comparative information on extra-pair paternity, mutation rate, sample size and mean number of bands scored as reported by Amos [1] and according to the publications.

Protandry is the difference in arrival date between males and females, with competition among males for access to preferred territories (the rank advantage hypothesis) or mating success (the mate opportunity hypothesis) supposedly driving the evolution of protandry. The fitness costs and benefits of protandry accruing to individuals differing in de...

Background: Amos [1] suggested recently that a previously reported positive relationship between minisatellite mutation rates and extra-pair paternity among species of birds [2] was confounded by transcription errors and selective inclusion of studies. Here we attempted to replicate the results reported by Amos [1], but also tested for the relation...

It has been recently proposed that the blue-green coloration in eggs of many avian species may constitute a sexually selected female signal. Blue-green color intensity would reflect the physiological condition of females, and hence it might also affect the allocation of male parental care. In this study, we use three different experimental approach...

Aims: To ascertain whether cavity-nesting bird communities are limited by experimentally-manipulated hole availability at managed beech and pine forests in northern Spanish highlands and to study the responses of non-cavity-nesting birds. Location: North of Navarre (Spain). Methods: Bird censuses were taken at breeding and wintering periods in stud...

The hypothesis that nestling coloration is important for parent–offspring communication, because it influences parental feeding decisions, has received strong experimental support. In European starlings, Sturnus vulgaris, and Alpine swifts, Apus melba, manipulation of ultraviolet reflectance of nestlings' mouth and skin affected the amount of food...

Sexual dichromatism is common in lizards, and may play an important role in sex recognition and mating systems. Nonetheless, relatively few published papers provide quantitative analyses of colour, deal with Australian taxa or are based on large-bodied species. Water dragons Physignathus lesueurii (Agamidae) from eastern Australia are very large (u...

Summary 1. Although post-hatching parental care is uncommon in reptiles, reproducing females may none the less contribute to the nutritional state of their offspring by depositing more yolk into the egg than is needed for embryogenesis. This 'extra' yolk (i.e. residual yolk) is drawn into the offspring's body prior to hatching and is widely assumed...

Currently, there is no agreement about the suitability of haematocrit (the proportion of blood volume occupied by packed red blood cells) as a predictor of condition in birds. In order to clarify this point, genetic and environmental components of phenotypic variation for a number of traits were estimated in nestling Barn Swallows Hirundo rustica b...

At the beginning of the breeding season, the outermost tail feathers of 31 male Barn Swallows Hirundo rustica were either shortened by 20 mm, elongated by 20 mm or left unmanipulated. In first broods, the number of feeding bouts (per nestling per hour) by males and females did not differ significantly among experimental groups. However, in second b...

Patterns of selection are widely believed to differ geographically, causing adaptation to local environmental conditions. However, few studies have investigated patterns of phenotypic selection across large spatial scales. We quantified the intensity of selection on morphology in a monogamous passerine bird, the barn swallow Hirundo rustica, using...

Summary 1. Recent studies in Scotland suggest that the outermost tail feathers of Barn Swallows ( Hirundo rustica Linnaeus) may be around 10-12 mm longer than the aerodynamic optimum, with sexual selection for long tails accounting for this extra length. 2. To test this hypothesis, we shortened the outermost tail feathers in male and female Barn Sw...

Aims To investigate the effect of clutch size, colony size, reproductive phenology and nesting period on hatching success of Avocets and Black-winged Stilts. Methods The study was undertaken at two localities in southwestern Spain (Doñana and Odiel Natural Parks) during 1990 and 1991 breeding seasons. The Mayfield method was used to estimate hatchi...

As collaborators of Anders Pape Moller, we were shocked and surprised to read that he was accused of data fabrication (“Ecologists roiled by misconduct case,” G. Vogel, F. Proffitt, R. Stone, News of the Week, 30 Jan., p. [606][1]). We have never had cause to be concerned about any aspect of

Previous studies have shown no significant effect of experimental tail length manipulation in female barn swallows (Hirundo rustica) at the beginning of a breeding season on reproductive success or behavior during that breeding season. In the present study, we investigate if tail length manipulation had any effect on reproductive performance the fo...

The breeding behaviour of black-winged stilts (Himantopus himantopus) was studied in southwestern Spain. In the prelaying period males devoted more time than females to agonistic encounters, locomotion, and nest building. During egg laying, males spent more time than females at the nest, mostly building the nest and covering the eggs, while females...

An important component of sexual selection arises because females obtain viability benefits for their offspring from their mate choice. Females choosing extra-pair fertilization generally favor males with exaggerated secondary sexual characters, and extra-pair paternity increases the variance in male reproductive success. Furthermore, females are a...

Supplementary table 1. Information on species, research laboratory, number of individuals with 0, 1, 2, 3, 4, 5 or 6 novel bands due to mutations, mean number of bands scored (always from nestlings if there were data for both adults and nestlings), number of offspring used for mutation estimation, total number of offspring, estimated mutation rate,...

Extravagant tails of many male birds are morphological structures affected by both natural and sexual selection. Elongated tail feathers may be more vulnerable to damage than feathers of short length. Feather breakage maythus act as a constraint on the evolution of elongated tails, regardless of mode of selection. Feather damage can affect flight p...