Alejandro Cantarero

Alejandro Cantarero
Complutense University of Madrid | UCM · Department of Physiology (Animal Physiology)

PhD

About

53
Publications
12,850
Reads
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621
Citations
Citations since 2017
30 Research Items
456 Citations
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2017201820192020202120222023020406080100
2017201820192020202120222023020406080100
Introduction
My main research interests lie in the behavioural ecology and evolutionary biology of birds, with main focus on sexual and natural selection, parent-offspring conflict, sex allocation and life-history evolution. My research mostly focuses on birds under natural conditions.
Additional affiliations
January 2020 - February 2022
The National Museum of Natural Sciences
Position
  • PostDoc Position
January 2019 - December 2020
University of Turku
Position
  • PostDoc Position
September 2018 - December 2018
University of Padova
Position
  • PostDoc Position
Education
December 2011 - April 2015
University of Cordoba (Spain)
Field of study
  • Natural Resources and Sustainable Management
September 2010 - October 2011
University of Cordoba (Spain)
Field of study
  • Ethology
September 2005 - June 2010
University of Cordoba (Spain)
Field of study
  • Enviromental Sciences

Publications

Publications (53)
Article
Full-text available
Nests of cavity-nesting birds usually harbor some species of haematophagous ectoparasites that feed on the incubating adults and nestlings. Given the negative impact of ectoparasites on nestlings there will be selection on hosts to reduce parasite infestations through behavioural means. We have experimentally reduced the abundance of all ectoparasi...
Article
Nesting holes are a scarce resource for obligated cavity nesting birds and an important selective force for the evolution of aggressive female behaviours, which may be mediated by testosterone (T) levels. It is known that during periods of intense intrasexual competition such as initial breeding stages, females are highly aggressive towards intrudi...
Article
Full-text available
The ‘female nutrition’ hypothesis proposes that food provided by males during incubation is an important energy source for females in bird species where females alone incubate. Females should be able to communicate their needs through begging signals to mates and males may compensate the energetic limitations of females through their feeding visits...
Article
Full-text available
Nest size has been suggested to be a sexually selected signal, allowing individuals to obtain reliable information about partner quality and thereby optimize paternal investment in reproduction. Studies concerning the potential role of nests as signals are scarce for avian species in which the female is the only builder. We have aimed at understand...
Article
Full-text available
In a substantial number of species, females show some development of secondary sexual characters. These traits can function as signals of individual phenotypic or genetic qualities and status to conspecifics. Individuals may benefit potentially from expressing signals or badges of status if they are reliable and honest signals of individual quality...
Article
Full-text available
In many bird species, physical aggression between males become more frequent during the female's fertile period, as female encounters with extra-pair males are more frequent and can entail paternity losses. Male aggressiveness during this stage has been proposed as crucial for ensuring male reproductive success. Thus, plumage ornaments could repres...
Article
Full-text available
Oscine birds preferentially respond to certain sounds over others from an early age, which focuses subsequent learning onto sexually relevant songs. Songs vary both across species and, due to cultural evolution, among populations of the same species. As a result, early song responses are expected to be shaped by selection both to avoid the fitness...
Article
Full-text available
In many vertebrates, the enzymatic oxidation of dietary yellow carotenoids generates red keto‐carotenoids giving color to ornaments. The oxidase CYP2J19 is here a key effector. Its purported intracellular location suggests a shared biochemical pathway between trait expression and cell functioning. This might guarantee the reliability of red colorat...
Article
Full-text available
Parasites are known to be a key driving force in mate choice and are important for the expression and evolution of ornaments and behavioural traits being used. However, there is little experimental evidence on how parasite’s burden of the choosing individual is integrated in the mate-choice process and how it affects decision-making, especially in...
Article
Full-text available
Background The animal signaling theory posits that conspicuous colorations exhibited by many animals have evolved as reliable signals of individual quality. Red carotenoid-based ornaments may depend on enzymatic transformations (oxidation) of dietary yellow carotenoids, which could occur in the inner mitochondrial membrane (IMM). Thus, carotenoid k...
Preprint
Full-text available
The animal signaling theory posits that conspicuous colorations exhibited by many animals have evolved as reliable signals of individual quality. Red carotenoid-based ornaments may depend on enzymatic transformations (oxidation) of dietary yellow carotenoids, which could occur in the inner mitochondrial membrane (IMM). Thus, carotenoid ketolation a...
Article
Full-text available
Extra-pair paternity (EPP) has been broadly reported in socially monogamous bird species and it has been hypothesized that females engage in extra-pair copulations to increase the genetic variability of the offspring and to reduce the risk of inbreeding and genetic incompatibilities. This hypothesis makes two predictions: within populations, female...
Article
Full-text available
Telomere length and shortening rate are increasingly used as biomarkers for long-term costs in ecological and evolutionary studies because of their relationships with survival and fitness. Both early-life conditions and growth, and later-life stressors can create variation in telomere shortening rate. Studies on between-population telomere length a...
Preprint
Full-text available
Sexual and social selections promote the evolution of many conspicuous colorations in animals. These traits would act as individual quality signals when they transmit reliable information. Reliability should be assured by production costs unaffordable for low-quality trait bearers or guaranteed if trait expression is tightly linked to individual qu...
Preprint
Full-text available
Telomere length and shortening rate are increasingly used as biomarkers for long-term costs in ecological and evolutionary studies because of their relationships with survival and fitness. Telomere length can be heritable, but both early-life conditions and later-life stressors can create variation in telomere shortening rate. Studies on between-po...
Article
Full-text available
1. The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long‐term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the w...
Article
Full-text available
Ornaments can evolve to reveal individual quality when their production/maintenance costs make them reliable as “signals” or if their expression level is intrinsically linked to condition by some unfalsifiable mechanism (“indices”). The latter has been mostly associated with traits constrained by body size. In red ketocarotenoid-based colourations,...
Preprint
Full-text available
The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild...
Article
Full-text available
The mechanisms involved in the production of red carotenoid‐based ornaments of vertebrates are still poorly understood. These colorations often depend on enzymatic transformations (ketolation) of dietary yellow carotenoids, which could occur in the inner mitochondrial membrane (IMM). Thus, carotenoid ketolation and cell respiration could share bioc...
Article
Full-text available
Sexual steroids can play an important role as life-history organizers. In males, high circulating testosterone levels induce physiological/behavioral costs and benefits, leading to trade-offs. However, studies simultaneously testing the impact of these levels in both fitness components (survival and fecundity) during lifetime are scarce and limited...
Preprint
Full-text available
Conspicuous ornaments in animals can evolve to reveal individual quality when their production/maintenance costs make them reliable as signals or if their expression level is intrinsically linked to quality by some unfalsifiable mechanism (quality indices). The latter has been mostly associated with traits constrained by body size. However, red ket...
Article
Full-text available
Female mass in most altricial birds reaches its maximum during breeding at egg laying, which coincides temporally with the fertile phase when extra-pair paternity (EPP) is determined. Higher mass at laying may have two different effects on EPP intensity. On the one hand, it would lead to increased wing loading (body mass/wing area), which may impai...
Preprint
Full-text available
The mechanisms involved in the production of red carotenoid-based ornaments in vertebrates are still poorly understood. Those colours generated by red carotenoids often depend on the enzymatic production (ketolation) of these pigments from dietary yellow carotenoids. Recently, it has been proposed that this conversion takes place at the inner mitoc...
Preprint
Female mass in most altricial birds reaches its maximum during breeding at egg-laying, which coincides temporally with the fertile phase when extra-pair paternity (EPP) is determined. Higher mass at laying may have two different effects on EPP intensity. On the one hand, it would lead to increased wing loading (body mass/wing area), negatively corr...
Article
Full-text available
Sexual selection promotes the evolution of conspicuous animal ornaments. To evolve as signals, these traits must reliably express the “quality” of the bearer, an indicator of individual fitness. Direct estimates of individual fitness may include the contribution of longevity and fecundity. However, evidence of a correlation between the level of sig...
Article
Full-text available
There is no consensus yet on the reasons why females engage in extra-pair copulations (EPC). In some species, females have been shown to accrue some indirect benefits, but these effects are not consistent across species and studies. The sexual conflict hypothesis posits that extra-pair paternity (EPP) is the result of strong selection for male purs...
Article
Full-text available
As parental care is costly, it can be expected that there will be a sexual conflict between parents over the individual levels of parental investment because each parent has limited resources to invest in a reproductive event. Theoretical models of parental investment predict that when one parent reduces its parental effort, the other parent should...
Article
Adaptive phenotypic plasticity may respond to present ambient conditions. Sexual and social signals in both sexes may express phenotype performance. Plumage signals that change discontinuously allow relating discrete variation to previous performance. Both sexes of the Pied flycatcher Ficedula hypoleuca present white patches on the wings and on the...
Article
Full-text available
Complex body designs, such as plumage ornaments in birds, can be described by fractal geometry. These complex patterns could have a role as visual signals during courtship and social interactions, but an empirical validation in the wild is currently lacking. Here, we investigated whether the fractal dimension (FD) of a complex plumage pattern displ...
Article
Full-text available
According to theory, in species in which male variance in reproductive success exceeds that of the females, sons are more costly to produce; females mated with high quality males or those in better condition should produce more sons. In monogamous species, however, the variance in the reproductive success of the two sexes is often similar and mate...
Article
Oxidative stress can contribute to an acceleration of telomere erosion leading to cellular senescence and ageing. Increased investment in reproduction is known to accelerate senescence, generally resulting in reduced future reproductive potential and survival. To better understand the role of oxidative status and telomere dynamics in the conflict b...
Article
Full-text available
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...
Article
Full-text available
The evolution and mechanisms of red carotenoid-based ornaments in animals is poorly understood. Recently, it has been suggested that enzymes transforming yellow carotenoids to red pigments (ketolases) in animal cells may be positioned in the inner mitochondrial membrane (IMM) intimately linked to the electron transport chain. These enzymes may most...
Article
Full-text available
Carotenoid-based colouration in birds has been suggested to be a sexually selected signal, allowing individuals to obtain reliable information about the quality of antioxidant resources. Moreover, oxidative stress levels during early development may have medium and long term fitness consequences. Rock sparrows (Petronia petronia) display a caroteno...
Article
Conditions experienced during early development can affect the fitness of an organism. During early life, oxidative stress levels can be particularly high due to the increased metabolism and the relatively immature antioxidant system of the individual, and this may have medium- and long-term fitness consequences. Here we explore variations between...
Article
Full-text available
Social selection is expected to favor the evolution of female aggressive defence of nesting resources in cavity nesting birds, which may be also mediated by testosterone (T) levels. Male T levels could express male dominance and thereby territorial safety for female partners and thereby reduce their need for aggressive defence. Here, we explored th...
Article
Full-text available
Ectoparasites may imply a cost in terms of oxidative stress provoked by the inflammatory responses in hosts. Ectoparasites may also result in costs for nestlings and brooding females because of the direct loss of nutrients and reduced metabolic capacity resulting from parasite feeding activities. These responses may involve production of reactive o...
Article
Full-text available
Despite many studies of how male characteristics affect paternity in predominantly monogamous birds, relatively little attention has been given to the traits of females that may influence extra-pair paternity (EPP). However, the occurrence of EPP may be the result of behavioural interactions in which both male and female traits are important for de...
Article
Full-text available
The association between skin bacterial communities and nestling growth is poorly understood. We estimated the abundance of heterotrophic bacteria on skin of nestlings and their association with growth in the pied flycatcher Ficedula hypoleuca. At two different nestling ages, we swabbed a delimited area of the naked belly skin of nestlings and measu...
Article
Full-text available
Selection of nest sites and nesting material may have important implications for avian reproductive behaviour and performance. Nest construction may involve costs arising from transporting material that may be reduced considerably if nest materials are located close to the nest-site. Nuthatch Sitta europaea nests in our nest-box study area are main...
Article
Full-text available
Nest structure and nesting material may have important consequences for avian reproductive behaviour and performance. Nuthatches Sitta spp. build nests made of loose bark flakes without any structure or nest cup to contain eggs and nestlings. We have aimed at understanding the implications of unstructured bark flake nests in Nuthatches for microcli...
Article
Full-text available
A key aspect in the study of plumage traits with a potential role in communication is the cost associated with trait production and maintenance, as considered in terms of oxidative stress. In the Pied Flycatcher Ficedula hypoleuca (Pallas, 1764) males and some females exhibit a white forehead patch and both sexes present conspicuous white patches o...
Article
Full-text available
It is not clear at present if variation in testosterone (T) levels is associated with variation in plumage signal expression in female birds. In Iberian populations of Pied Flycatchers Ficedula hypoleuca, some females exhibit a distinctive white forehead patch similar to that found in males. Both sexes also exhibit conspicuous white patches on wing...
Article
Full-text available
Nest-dwelling ectoparasites may result in costs for nestlings of cavity nesters in terms of compromised growth and condition before fledging. The reduction or elimination of nest ectoparasites to study their effects on avian hosts can be conducted through physical methods like heat-treatment or through chemical methods using insecticides. Pyrethroi...
Article
Full-text available
Direct benefits of female mate choice may concern female fertility and fecundity but also physiological status. In birds with biparental care, males may contribute to improve the condition and health of their pair-mates through help in constructing nests, incubation or incubation feeding and nestling provisioning. They may also reduce harassment of...
Article
Full-text available
Badges of status may be controlled by costs derived from increased aggression from dominant individuals. This cost could be translated into elevated metabolic levels and a concomitant disruption of oxidative balance. Some females in Iberian pied flycatcher Ficedula hypoleuca populations exhibit a white forehead patch similar to that exhibited by al...
Article
Full-text available
Nesting cavities constitute micro-environments very likely to be colonized by ectoparasites which feed on blood of the incubating female and the nestlings. Given the negative impact of ectoparasites on nestlings there will be selection on hosts to minimize ectoparasite loads through behavioural defenses. We have addressed the implications of ectopa...
Article
Full-text available
Extra-pair paternity (EPP) in socially monogamous species has been associated with the genetic benefits incurred by females through extra-pair mate choice. There is conflicting evidence in the literature concerning the importance of such benefits possibly due to their context-dependence. To ascertain if there are such context-dependent genetic bene...
Article
Full-text available
.—Nest re-use in birds is rare but since appropriate cavities may be scarce, cavity-nesting birds may often re-use those that were occupied in previous seasons. Old nest material may contain and/or attract more ectoparasites than fresh material. Therefore it is important to understand the effects of nest re-use on the abundance of different ectopar...
Article
Full-text available
Bacteria may colonize avian nests with unknown repercussions on nestling growth and health, although bacteria on nest materials may easily colonize nestling skin and growing feathers. Cavity nesters may have to build their nests on top of used nest materials, given restrictions on cavity availability. Nest reuse may favour bacterial colonization of...
Article
Full-text available
The female nutrition hypothesis posits that provisioning intensity of incubating females by their mates may depend on female needs and ensure proper incubation and a corresponding high hatching and breeding success of breeding pairs. Here, we have handicapped female pied flycatchers Ficedula hypoleuca at the beginning of incubation by clipping two...
Article
Full-text available
Melanin-based plumage ornaments may express individual quality in the context of social and sexual selection. Oxidative stress and antioxidant defences may be expressed through melanin-based plumage traits. Male Pied Flycatchers Ficedula hypoleuca exhibit eumelanic dorsal plumage and white feather patches on forehead and wing feathers. Although the...

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Projects (3)
Project
In evolutionary trade-offs, the expression of one trait competes with the expression of another one as both depend on the same limited resource. The most known trade-off is that established between reproduction and longevity investments. However, reproduction investment may also generate direct damage (costs) on the organism affecting longevity independently of resources. We will term these two models as resource allocation trade-offs (RATO) and direct cost trade-offs (DCTO). Some findings have challenged this, providing physiological pathways that apparently uncouple trade-off branches, stimulating both reproduction and longevity. Another challenge has recently arrived from the signalling theory. This theory proposes that conspicuous traits evolved as signals of individual quality whether its expression is particularly costly to low-quality individuals who cannot cheat receivers (handicap principle). Alternative, these traits may evolve as quality indices when its expression level inherently shows the bearer quality, such as the size of some traits tightly correlated to total body size. In vertebrates, many conspicuous colours are produced by carotenoid pigments (many yellow-to-red colours). They are also involved in homeostasis, as antioxidants or immune-boosters. Animals cannot synthesize carotenoids, which are supposedly scarce in food. Thus, these colourations could have evolved as signals if only high-quality individuals are able to find enough dietary carotenoids. Some authors suggested that carotenoid-based traits could have also evolved due to RATOs but also DCTOs, as its accumulation could exert some damage. However, a recent hypothesis points to a close link to mitochondrial respiration independent of any limited resource. They would hence be indices. This applies to red traits created by (keto)carotenoids, which are transformed from dietary yellow carotenoids by enzymes (ketolases). It has been suggested that this enzyme should be placed at the mitochondrial membrane, sharing cell respiration pathways and, thus, revealing individual quality (shared-pathway hypothesis; SPH). We will test these ideas in two avian models (zebra finches and red crossbills) by taking advantage of recently proposed candidate genes to carotenoid acquisition and allocation.
Archived project
The importance of female ornamental traits during intrasexual communication in social contexts
Project
Since mitochondrial integrity involves a variety of cellular and physiological processes, we will test the role of mitochondria as a mediator in phenotypic integration. We will do this by stimulating mitochondrial activity and measuring well-defined personality traits, and testing the effect of mitochondria efficiency on personality profiles as well as physiological and lifehistory traits.