Alfredo Salvador

• Spanish National Research Council

Investing in the current reproduction requires diverting energy resources from other metabolic functions, which may compromise future reproduction and lifespan. To solve this trade-off, an individual may consider its labile state to decide how much to invest in current reproduction. We tested experimentally whether the “state quality” of male rock...

Esta guía tiene como objetivo la identificación de las 31 especies de anfibios y sus larvas y 83 especies de reptiles, tanto nativas como introducidas, que se encuentran en la península ibérica, islas Baleares e islas Canarias. Contiene claves de identificación, dibujos detallados (204 de anfibios y 302 de reptiles) y fotografías (95 de anfibios y...

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...

Las señales sexuales dependientes de la condición han sido ampliamente estudiadas en el contexto de la comunicación animal. Muchos de estos estudios asumen que los machos con señales más atractivas serán los que más se reproduzcan, pero esto raramente se ha comprobado. Los machos de la lagartija carpetana (Iberolacerta cyreni) atraen a las hembras...

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...

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...

A doctoral thesis presented in the late 1990s by oscar J. Arribas has been frequently cited as the authority for the nomenclatural status of two generic names in the lizard family Lacertidae, Darevskia and Iberolacerta. These names were again introduced, along with the addition of the subgeneric name Pyrenesaura, in 1999 via publication in an inter...

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...

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...

We experimentally studied the effects of genetic legacy (eastern vs. western phylogeographic lineage) and population of origin (lowland vs. highland) on the sensitivity of lizard embryos and juveniles to incubation temperature and moisture among four populations of the lacertid Psammodromus algirus. Incubation time was longer at lower temperature,...

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...

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...

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...

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...

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...

Many species of lizards have colour spots on the flanks that may function as ornaments. We investigate the between-years stability of the blue patch colour saturation and the relationships between colour saturation, mating success, and survival in males of the lizard Psammodromus algirus. Saturation values of the anterior blue patch of males were s...

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...

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...

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...

The lacertid lizard Psammodromus algirus has been considered a uniform species across its distribution area in North Africa and southwestern Europe. Coloration data and discriminant function analysis of morphological data corroborate mitochondrial DNA and allozyme data to indicate northern and southern Iberian populations represent unknown species...

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...

The home ranges of radio-collared eyed lizards (Lacerta lepida) were studied in the mountains of central Spain. The home range of females and males varied from 2800-5844 m2 and 1424-22106 m2 respectively. Two measures of core area and home range covaried significantly with mass. Home range and 75% core area were significantly larger in males than i...

Elevation of circulating testosterone levels during the breeding season stimulates the development of breeding coloration and favors traits that maximize reproductive success, but it may have several costs. Retardation of growth by testosterone has been proposed as one of these costs to males of long-lived species. We examine the results of a field...

To examine factors related to overwinter survival of Psammodromus algirus hatchlings, we performed a capture-mark-recapture study of a cohort of hatchlings. In this work, we examine the effects of body size, vegetation structure of the home range, tail condition, sex, and estimated hatching date on hatchling survivorship to the next spring. Results...

Many species of lizards have skin invaginations that contain ectoparasites. These structures could concentrate ectoparasites and reduce their harmful effects, but experimental evidence supporting this hypothesis is largely lacking. Mie report here the first experimental test of this hypothesis which we conducted with the lacertid lizard Psammodromu...

Life-history theory predicts that there is a trade-off between reproductive effort and several traits that determine fitness. Infectious disease has gained acceptance as a crucial Factor linking both variables. In most instances phenotypic manipulation is necessary to convincingly demonstrate a causal relationship of reproductive effort on parasiti...

We studied the thermal ecology of the amphisbaenian reptile Blanus cinereus in central Spain, focusing on the relationship between the available underground thermal environment and the thermal biology of B. cinereus. We specifically examined which soil microhabitats might be used by amphisbaenians, given thermal preferences measured in the laborato...

The authors analyzed the ability of male amphisbaenian ( Blanus cinereus) to distinguish self-produced chemical cues from those of other conspecific males. In experiments using randomized block designs, males were presented cotton swabs bearing male stimuli, their own stimuli, and deionized water in counterbalanced sequence. Blanus cinereus direct...

Many lizards use caudal autotomy as an antipredatory strategy. We experimentally examined the effect of tail loss on the time-budgets, movement patterns, and home range size of the Iberian rock lizard Lacerta monticola in the field during the mating season. Our results indicate that tail loss did not alter most variables in male and female time-bud...

We describe microhabitat selection in the Iberian rock lizard Lacerta monticola, a species endemic to some high mountains of the Iberian peninsula. This species is potentially threatened, in particular, by changes in habitat conditions on the ski slopes and from associated buildings in resorts that proliferate precisely in areas it favours. We anal...

According to the immunocompetence hypothesis, testosterone stimulates the expression of male sexually selected traits while decreasing immunocompetence. This proposed trade-off was studied by experimental supplementation of testosterone to small, subordinate, dull-colored male lizards, Psammodromus algirus. Experimental males showed a tendency to o...

The theory that fluctuating asymmetry is sensitive to both environmental and genetic stress is gaining acceptance among evolutionary biologists. Most empirical work has focused on ornamental traits on the assumption that they are more susceptible to stress. In tegumentary coloration is a common ornament in nature, and frequently has a hormonal basi...

This study deals with a general description of haematology and plasma chemistry of free-living males of the lacertid lizards Psammodromus algirus subjected to an experiment of testosterone supplementation. In control lizards the number of red blood cells — 1700000 cells/l — was smaller than those published for birds and mammals. Haematocrit and hae...

According to current evolutionary theory, advertising traits that honestly indicate an organism's genetic quality might be costly to produce or maintain, though the kind of costs involved in this process are controversial. Recently the immunocompetence hypothesis has proposed that testosterone (T) stimulates the expression of male sexually selected...

Numerous lizard species use caudal autotomy as an antipredator device even though there must be significant costs during the period of tail regeneration. Strategies used by tailless individuals to enhance survival in natural populations are still poorly understood. We experimentally examine tail loss in large, dominant males of Psammodromus algirus...

We studied the relationships between thermoregulatory basking pastures and heating rates in the Iberian rock lizard (Lacerta monticola). Heating rates were high when body size was small, the substrate temperature was high, and the angle of incidence of the sun's rays was high (i.e., the rays were perpendicular to the lizard's body). However, heatin...

Detection of conspecific chemical stimuli and their use to discriminate males from females is demonstrated in an amphisbaenian, Blanus cinereus. In two experiments using randomized blocks designs, males were presented cotton swabs bearing male stimuli, female stimuli, and deionized water in counterbalanced sequence. Detection of conspecific stimuli...

Many lizards autotomize their tails to escape when grasped by a predator. It is hypothesized that tail loss causes a reduction in social status, thereby potentially lowering their reproductive success. We experimentally induced tail loss in Lacerta monticola in a semi-natural enclosure, and show that tail loss reduced social status and mating acces...

Many lizards autotomize their tail to escape when attacked by a predator. The foraging tactics of tailless lizards may be affected by changes in behavior aimed at compensating tail loss per se as well as associated costs of regeneration. The authors tested this hypothesis in a population of the Iberian rock lizard during the reproductive season. Ta...

The consequences of tail loss on the thermal biology of high-altitude rock lizards (Lacerta monticola) were studied by comparing field body temperatures, selected body temperatures in a gradient, and behavioural patterns of thermoregulation of tailed and tailless lizards in the field. Neither field nor selected body temperatures differed significan...

This paper presents an observational and experimental study of the basking behaviour and heat exchange rate of the montane lizard Lacerta monticola. The results obtained by these procedures were coupled in order to understand behavioural mechanims promoting effective thermoregulation at high altitudes. Heating rate was higher when body size was sma...

Habitat preferences in lizards are often associated with specific morphological traits and locomotor behavior. Caudal autotomy occurs in many lizards and is often used for escape from predators. Autotomy produces an immediate benefit in terms of survival, although associated costs during tail regeneration may reduce individual fitness. Tail loss ma...

Responses of amphisbaenians (Blanus cinereus) to deionized water, a control for pungency (cologne), and integumental prey odors (coleopteran larvae and adult ants) on cotton swabs were studied in experiments with a randomized blocks design to discover whether amphisbaenians use chemical cues to detect and identify prey. No individual bit the applic...

Compared the availability of soil invertebrates in a Mediterranean locality in C Spain with the actual diet of Blanus cinereus. This species is somewhat opportunistic and mainly feeds on insect larvae and ants, which are the most abundant invertebrates, but larvae of larger size are selected in higher proportion than their availability, and some ge...

Body temperatures of Blanus cinereus recorded in the field in central Spain were positively correlated with corresponding substrate and air temperatures. Mean body temperature was 1.2°C higher than corresponding mean substrate temperature. Mean body temperature varied with time of day. Presence under stones during daylight hours was bimodal and sea...

Food availability and diet composition were examined in sympatric populations of Lacerta schreiberi and Podarcis bocagei at a locality in the Cantabrian mountains (province of León, Spain). Neither species uses trophic resources in proportion to their relative abundance. Extensive overlap in diet composition has been found between P. bocagei and ju...

Microhabitat use of Lacerta schreiberi was studied at one locality in the Cantabrian mountains of León province, Spain. Lizards do not use the microhabitat categories in proportion to their availability. Ontogenetic shifts in microhabitat selection have been observed. Juveniles are found in grass and rush areas, while adults prefer bushes. Subadult...

En este trabajo se estudia la actividad de Lacerta schreiberi en dos parcelas de Camposagrado (León). En ambas poblaciones se realizaron censos horarios de abril a septiembre. Para calcular el porcentaje de población activa en cada censo, se estimó simultáneamente y por separado para machos, hembras, subadultos y jóvenes el tamaño de población en c...

Se estudian en este trabajo los ciclos de cría de anuros en una laguna de León durante 1980. La secuencia de especies que se encontró es primero, B. calamita y P. cultripes, y después Hyla arborea y R. perezi. Se sugiere como tiene lugar el reparto de recursos en la comunidad de cría. Se han encontrado larvas invernales de R. perezi en Noviembre. R...

The behavioral thermoregulation of P. pityusensis was studied for a period of one week during August, 1980. The cloacal temperatures and the ground and air temperatures were recorded by means of thermistors. P. pityusensis behaves like a heliotermic species with a temperature range between 28.5 and 41.5 ° C. Very significant correlations were found...