José A. Díaz

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• Professor
• Professor at Complutense University of Madrid

The effects of forest fragmentation on ecosystems are pervasive, but little is known about the factors that influence lizard abundance in fragmented landscapes. We studied the roles of patch size and shape, thermal quality, and refuge availability as predictors of the relative abundance of Psammodromus algirus lizards at deciduous or evergreen fore...

In ecosystems threatened by the expansion of croplands, habitat fragmentation and climate change, two of the main extinction drivers, may have thermoregulation-mediated interacting effects on demographic trends of terrestrial ectotherms. We studied the thermal biology of a metapopulation of the widespread Mediterranean lacertid Psammodromus algirus...

Although the effects of global warming on thermoregulation are usually explored using predictions of climate envelop modelling, such effects should best be analysed empirically, studying the same population with the same methods after a long enough period of temperature rise. We used a 30‐year long database about body temperatures (Tbs) of field‐ac...

Usually, adaptive phenotypic differentiation is paralleled by genetic divergence between locally adapted populations. However, adaptation can also happen in a scenario of nonsignificant genetic divergence due to intense gene flow and/or recent differentiation. While this phenomenon is rarely published, findings on incipient ecologically driven dive...

Usually, adaptive phenotypic differentiation is paralleled by genetic divergence between locally adapted populations. However, adaptation can also happen in a scenario of non-significant genetic divergence due to intense gene flow and/or recent differentiation. While this phenomenon is rarely published, findings on incipient ecologically-driven div...

During the historical building of a species range, individual colonizers have to confront different ecological challenges, and the capacity of the species to broaden its range may depend on the total amount of adaptive genetic variation supplied by evolution. We set out to increase our understanding of what defines a range and the role of underlyin...

During geographical expansion of a species individual colonizers have to confront different ecological challenges, and the capacity of the species to broaden its range may depend on the total amount of adaptive genetic variation supplied by evolution. We set out to test whether the distribution of loci under selection along a contrasting environmen...

Abstract Local adaptation is a dynamic process by which different allele combinations are selected in different populations at different times, and whose genetic signature can be inferred by genome‐wide outlier analyses. We combined gene flow estimates with two methods of outlier detection, one of them independent of population coancestry (CIOA) an...

Isolation owing to anthropogenic habitat fragmentation is expected to increase the homozygosity of individuals, which might reduce their fitness as a result of inbreeding depression. Using samples from a fragmented population of the lizard Psammodromus algirus, for which we had data about two correlates of fitness, we genotyped individuals for six...

In the context of the immunocompetence handicap hypothesis, we explored how differences in parasite load affect the way in which sexual ornaments codify information about individual quality. We studied variation in sexual signals in two Iberian populations of the lizard Psammodromus algirus, a species in which sexually active males display a red he...

Interpopulational variation in sexual signals may lead to premating reproductive isolation and eventually may result in speciation. We explored the role of chemical cues secreted by the femoral glands of male lizards Psammdoromus algirus in chemosensory recognition between two distinct genetic lineages from Central Spain. We hypothesized that if th...

Studies on range limits clarify the factors involved in the extent of species occurrence and shed light on the limits to adaptation. We studied the effects of elevational variation on the thermal dependence of fitness-related traits (incubation time, hatching rate, and survivorship, size, and condition of hatchlings) to assess the role of incubatio...

The trade-off between clutch and offspring size, which is a central topic in life-history research, is shaped by natural selection to maximize the number of surviving offspring, but it also depends on the resources available for reproduction. Conspecific populations living in different environments may differ in adult body size, clutch mass, clutch...

Tail autotomy has clear advantages regarding predator escape, but it also has several associated costs (i.e., impaired locomotion, loss of social status, and reduced growth and reproductive output). We examined the costs of severe autotomy on growth rates of hatchlings of the lacertid lizard Psammodromus algirus during the first weeks of postnatal...

Widely distributed terrestrial ectotherms from the southern European peninsulas show patterns of subdivision (related to isolation in temperate refugia) that allow us to test the relative importance of phylogeographic lineage, population of origin and familial effects as sources of variation for life-history traits. We collected gravid females from...

Widely distributed terrestrial ectotherms from the southern European peninsulas show patterns of subdivision (related to isolation in temperate refugia) that allow us to test the relative importance of phylogeographic lineage, population of origin and familial effects as sources of variation for life-history traits. We collected gravid females from...

We analysed the effects of a 25-year-old motorway on the distribution of five vertebrates inhabiting a fragmented forest landscape and differing in their ability to move across linear infrastructures. We found clear evidence of barrier effects on the distribution of the forest lizard Psammodromus algirus. The roe deer (Capreolus capreolus) was also...

Intraspecific variation in morphology has often been related to fitness differences through its effects on performance. In lizards, variation in hind limb length can be shaped by natural selection for increased locomotor performance, sexual selection on the number or size of femoral pores involved in chemical signalling, or both. Here, we analyse t...

El estudio a largo plazo de los efectos de la fragmentación del hábitat en un mismo territorio tiene dos ventajas: facilita la comprensión de procesos no siempre evidentes en aproximaciones puntuales y permite incorporar con rapidez nuevas ideas y metodologías en un laboratorio natural bien conocido. En este artículo describimos la progresión de nu...

In birds, molt duration is an important parameter that can affect plumage functionality and consequently the fitness of individuals. However, our knowledge about the factors affecting variation in molt speed is scarce, mostly because of the methodological difficulties of studying avian molt. In this study, we used a ptilochronology-based approach t...

A relationship between sunlight and bird abundance in cold climates may seem intuitive and perhaps obvious. However, there is, surprisingly, little or no evidence to support it. We investigated the effects of solar radiation on the winter abundance of insectivorous birds inhabiting a Mediterranean montane forest with a high frequency of cold, cloud...

I studied the activity, spacing patterns, courtship behavior, and survival of males (classified into two groups according to the development of the sexual coloration of the head) and females from a population of the lacertid lizard Psammodromus algirus. Brightly colored (C +) males were significantly larger (and probably older) than dull-colored (C...

Interspecific competition can limit the distribution of species along altitudinal gradients. It has been suggested that Western European rock lizards (genus Iberolacerta) are restricted to mountains due to the expansion of wall lizards (Podarcis), but there is no experimental evidence to corroborate this hypothesis. This study examines if interfere...

a b s t r a c t Whereas the range size of endangered species is undoubtfuly useful to predict risk of extinction, the role of their life-history characteristics is much less clear, and their effects may depend on the nature of the threatening factors. Such factors, for instance, are known to be different on islands and on the mainland. We used phyl...

Relationships among Psammodromus algirus populations from the Iberian Peninsula and North Africa, including recently described P. jeanneae and P. manuelae, were estimated from mitochondrial DNA gene sequences. This enlarged data set confirmed the presence of two divergent eastern and western mitochondrial DNA lineages on the Iberian Peninsula, the d...

West European Rock Lizards within the Iberolacerta group have a restricted distribution, with small, widely separated ranges in highland areas. The aim of this study was to identify possible habitat requirements (including habitat structure, type of vegetation, and refuge availability) and topographic factors (altitude and orientation) that may det...

In lizards, locomotor costs of gravidity may depend on habitat structure and refuge avail-ability. We compared the locomotor performance and escape tactics in the laboratory, before and after oviposition, of two populations of Psammodromus algirus separated by 700 m al-titude. When gravid, females escaped using a larger number of slower and shorter...

Ex situ conservation of animal populations may benefit from captive-breeding programmes, but these are criticised because they are assumed to be difficult, time-consuming and expensive, while they do not guarantee success. However, such assumptions remain untested in most organisms; for example, introductions could be very useful for recovering pop...

Aim In an effort to disentangle the ecological processes that confine ectotherms to alpine environments, we studied the thermoregulatory and microhabitat selection behaviours of the rock lizard Iberolacerta cyreni , which is endemic to some mountains of central Spain, and of the wall lizard Podarcis muralis , which is a potential competitor of rock...

Birds moult to maintain plumage function through life, but the factors that determine moult duration are poorly understood. In temperate areas, variation in moult duration could be largely associated with between-species differences in migratory behaviour (migrants have less time for moulting after breeding), and body mass (because the aerodynamic...

Se explican los conceptos de isometría y alometría y su aplicación al crecimiento de los animales, como procesos determinantes del tamaño y forma de los mismos.

We examined activity rates prior to hibernation, age-adjusted body size, growth rates, and probability of recapture after spring emergence of juveniles from 2 populations of the lizard Psammodromus algirus separated by 600-700 m altitude. We captured gravid females, incubated the eggs, and released the juveniles into the wild. We used a reciprocal...

Organisms often face a higher risk of local extinction in fragmented than in continuous habitat. However, whether populations are affected by reduced size and connectivity of the habitat or by changes in habitat quality in fragmented landscapes remains poorly investigated. We studied the regional distribution and microhabitat selection of the lacer...

Oviposition site choice, which is one of the most important forms of parental care in oviparous reptiles, has major effects on incubation duration, reproductive success, and offspring phenotype. We determined the thermal characteristics of nest-sites selected by females of the lacertid lizard Psammodromus algirus in laboratory thermal gradients, an...

We followed a field population of the alpine lizard Iberolacerta cyreni over 2 consecutive breeding seasons and assigned paternity to the offpring using 8 microsatellite markers. Paternity data, combined with observations of the behavior, morphology, and spacing patterns of lizards, allowed us to document the extent of polygamy, the phenotypic corr...

The range boundaries of organisms are frequently interpreted in terms of a decline in the extent to which the life histories of outer populations are able to adapt to local environmental conditions. To test this hypothesis, we compared the reproductive characteristics of two Iberian populations of the lizard Psammodromus algirus (Linnaeus, 1758). O...

In reptiles, growth is subject to proximate environmental influences, such as food availability and temperature, that may be crucial during the early stages of postnatal development. Mediterranean regions, with their severe summer drought, offer an excellent opportunity to examine the effects of environmental variations in precipitation and product...

1. We compared the mean, limits and breadth of the preferred thermal range (PTR) of two Iberian populations of the lizard Psammodromus algirus separated by 700 m altitude in May and July.2. Seasonality had a pronounced effect on the mean and limits of PTR, but altitude and sex did not. The breadth of PTR remained constant between seasons.3. The obs...

The utility of radiotelemetry as a tool for estimating the size and microhabitat requirements of a population of Lacerta lepida, the largest European lacertid, was investigated in central Spain. Population density estimates based on repeated marking and recapture (3.2 lizards ha−1) were much higher than those based on line transects (0.22 lizards h...

We studied the effect of habitat fragmentation on female reproductive investment in a widespread lacertid lizard (Psammodromus algirus) in a mixed-forest archipelago of deciduous and evergreen oak woods in northern Spain. We captured gravid females infragments (≤ 10 ha) and forests (≥ 200 ha) and brought them to the laboratory, where they laid thei...

We studied the thermal consequences of microhabitat selection by Psammodromus algirus lizards by combining data on the frequency of use and relative availability of three different types of microhabitats, with information about the environmental operative temperatures, and their deviations from the lizards' selected thermal range, available in thes...

We studied seasonal changes in the thermoregulatory behaviour of the lacertid lizard Psammodroums algirus in a Mediterranean evergreen forest. Body temperatures ( T b ), environmental operative temperatures ( T e ) and upper and lower limits of the selected thermal range ( T sel ) were lower in May than in July. On average, mean deviations of T b f...

Predation risk may compromise the ability of animals to acquire and maintain body reserves by hindering foraging efficiency and increasing physiological stress. Locomotor performance may depend on body mass, so losing mass under predation risk could be an adaptive response of prey to improve escape ability. We studied individual variation in antipr...

We studied the effect of solar radiation on the winter biology of Short-toed Treecreepers Certhia brachydactyla inhabiting a montane forest in Spain. We hypothesized that, in temperate latitudes of cold winter climate, with low cloudiness and under windless conditions, birds should select sunlit sites (i.e., forest sectors or trunk patches with hig...

A relationship between sunlight and bird abundance in cold climates may seem intuitive and perhaps obvi- ous. However, there is, surprisingly, little or no evidence to support it. We investigated the effects of solar radiation on the winter abundance of insectivorous birds inhabiting a Mediterranean montane forest with a high frequency of cold, clo...

This study reports the population responses of the lizard Psammodromus algirus to forest fragmentation by comparing its distribution in two contrasting situations of habitat conservation: a well connected mosaic landscape (forest patches larger than 2000 ha and/or connected by corridors that prevent their isolation), and an archipelago of forest re...

1. Although thermal factors are of paramount importance to the quality of the habitats occupied by small ectotherms (e.g. lizards), the hypothesis that the relative abundance of squamate populations is related to the thermal quality of their habitats remains untested. If differences in the availability of thermally suitable microhabitats was the pr...

It is well known that lizard species from thermally diverse areas differ in their use of thermoregulatory behaviors as a means of making short-term adjustments to differences in ambient conditions. In contrast, the extent of long-term adjustments in thermal physiology is poorly documented and still under debate. In this study we report a clear inte...

Body temperatures, heat exchange rates, behavioral thermoregulation, and movement behavior (as an index of foraging mode) were studied in two widely distributed, medium-sized lacertid lizards (Acanthodactylus erythrurus and Psammodromus algirus). P. algirus mainly inhabits broad-leaved forests, whereas A. erythrurus prefers open, sandy areas with s...

It is well known that lizard species from thermally diverse areas differ in their use of thermoregulatory behaviors as a means of making short-term adjustments to differences in ambient conditions. In contrast, the extent of long-term adjustments in thermal physiology is poorly documented and still under debate. In this study we report a clear inte...

I studied the thermoregulatory behavior of a field population of the Canarian lizard Gallotia galloti, using null hypotheses based on (1) the measurement of operative temperatures available in full sun land in the shade (T-e), and (2) the distribution of randomly positioned models with respect to sun and shade. The activity curve of the lizard popu...

We studied the seasonal variations of reproductive characteristics in a wild population of the lacertid lizard Psammodromus algirus by measuring gonadal weight, germinal epithelium height, sexual steroids (testosterone, estradiol, and progesterone), and lipid reserves (in fat bodies and liver) in three phases of the reproductive cycle: early breedi...

Maximizing the average rate of energy intake (profitability) may not always be the optimal foraging strategy for ectotherms with relatively low energy requirements. To test this hypothesis, we studied the feeding behaviour of captive insectivorous lizards Psammodromus algirus, and we obtained experimental estimates of prey mass, handling time, prof...

The frequency with which lizards were found in different positions around shrubs was negatively related to the average distance between shrub edge and nearest available sunlit perch; the shrub sectors preferred were always those in the direction of the sun, so that behavioral thermoregulation could be performed with little movement and risk. In the...

1. I studied the thermoregulatory behaviour of the diurnal basker Psammodromus algirus (Reptilia, Lacertidae) in the mosaic of sunshade patches of a Mediterranean evergreen forest. 48 behavioural sequences associated with measurements of the thermal environment provided data on the percentages of time spent basking by focal animals, the duration of...

Tras haber revisado los conocimientos disponibles sobre la historia natural de la Lagartija Colilarga (Psammodromus algirus), se estudia su distribucion a escala regional, identificandose los factores ambientales que determinan las variaciones de su abundancia. A continuacion se consideran las estrategias de termorregulacion, analizandose las aputa...

We studied the distribution of a common Mediterranean lacertid lizard, Psammodromus algirus (L.) 1758, on nineteen sites within a regional gradient of homogeneous yet contrasted habitats. This scale was large enough to allow line-transect estimates of lizard abundance, which were related to quantitative (and when possible multivariate) measurements...

We studied the influence of group size and distance to protective cover on scanning behaviour of Black-billed Magpies, considering their effects on scanning rate and scan duration. The percentage of time spent vigilant increased with increasing group size and with increasing distance to the nearest tree, but the way in which vigilance changed was d...

The summer diet of the lacertid lizard Psammodromus algirus and the availability of potential prey were compared at a Mediterranean evergreen woodland in central Iberia. Prey size proved to be the main factor implied in the selection of both prey taxa and individual prey items: lizards were selective in the sizes of the arthropods they captured, th...

Juveniles occupied less wooded microhabitats with a denser low vegetation. Intraspecific hostile interactions and predator avoidance are probably involved, rather than thermal requirements. -from Authors

En este trabajo se presentan una serie de ecuaciones alométricas que predicen la longitud seco de las presas ingeridas por vertebrados insectívoros, a partir de los fragmentos que aparecen con mayor frecuencia en muestras de su alimentación.

We studied summer activity patterns and thermoregulation in the Mediterranean lizard Psammodromus algirus in a holm oak wood in Central Spain. The circadian rhythm curve was bimodal, with a pronounced peak after sunrise, a minimum at noon and a second lower peak in the afternoon. Increased activity in the morning could be explained by insolation le...

Habitat selection of Psammodromus algirus and P. hispanicus was studied along a successional vegetation gradient in Southern Spain. The two species select areas with a high cover of herbs and bushes at ground level and at a height of 10 cm above ground. Whereas P. algirus avoids sandy substrates and selects wooded areas, P. hispanicus, which does n...

Visual detectability of birds censused by car. This paper analyzes the variations in the detectability of eight bird species censused by car in open areas of Central Spain during winter. Species-specific detectability was highly and positively correlated with bird size, bird-group size and percentage of time spent flying. These three variables expl...