The uropygial glands of birds serve multiple functions, and there is great interspecific variabil... more The uropygial glands of birds serve multiple functions, and there is great interspecific variability in the composition and properties of their secretions. A special case is the secretion in the hoopoes Upupa epops, and green woodhoopoes Phoeniculus purpureus, which, contrary to the commonly white and odourless secretions, are dark with pungent odour. Recently, bacteria have been isolated from glands of both woodhoopoes and hoopoes and here we test the hypothesis that bacteria are responsible of some of the special properties of glands and secretions of this group of birds. We explore natural seasonal changes and intersexual differences in the properties of hoopoe glands and secretions, check the natural occurrence of bacteria within secretions, and analyse the effect of experimental injection of antibiotics on uropygial gland properties. Male glands underwent no seasonal changes, and their secretions were invariably white and odourless, very similar to female glands outside the breeding season. However, in comparison to the uropygial gland of non-breeding females, those of incubating females showed a marked increase in size and volume of secretion produced, which became dark and pungent. All these parameters increased until the hatching date and returned to values similar to those in the prelaying phase towards the end of the nestling period. Nestling glands produced secretions similar to those of females in colour and odour. Gland size of both females and nestlings predicted the amount of secretion produced. Microscopic techniques confirmed the presence of bacteria at high density and in active division in all dark secretions examined. The antibiotic treatment significantly reduced the load of enterococci in nestling glands, did not affect size of glands, but diminished the volume of secretion, which was lighter in colour than that of control nestlings. In nesting females, the experimental injection of antibiotic affected some measurements of gland size and secretion colour. Because the experiment did not affect general health estimates (immunocompetence, body condition or growing) of nestlings, our results suggest that some of the special properties of hoopoe glands are mediated by the presence of symbiotic bacteria.
Individual variability influences the demographic and evolutionary dynamics of spatially structur... more Individual variability influences the demographic and evolutionary dynamics of spatially structured populations, and conversely ecological and evolutionary dynamics provide the context under which variations at the individual level occur. Therefore, it is essential to identify and characterize the importance of the different factors that may promote or hinder individual variability. Animal signaling is a prime example of a type of behavior that is largely dependent on both the features of individuals and the characteristics of the population to which they belong. After 10 years studying the dynamics of a population of a long-lived species, the eagle owl (Bubo bubo), we investigated the emergence and maintenance of traits that reveal individual identity by focusing on vocal features. We found that individuals inhabiting a high density population characterized by a relative lack of heterogeneity (in terms of prey availability and breeding success) among breeding sites might be selected for reducing the levels of identity. Two non-mutually exclusive hypotheses may explain the structural call patterns we detected: (1) similarity in calls may be principally a consequence of the particular characteristics of the population; and (2) high density may encourage individuals to mimic each other's vocalizations in a cascade effect, leading to a widespread and unique communication network.
Size and isolation of local populations are main parameters of interest when assessing the geneti... more Size and isolation of local populations are main parameters of interest when assessing the genetic consequences of habitat fragmentation. However, their relative influence on the genetic erosion of local populations remains unclear. In this study, we first analysed how size and isolation of habitat patches influence the genetic variation of local populations of the Dupont's lark (Chersophilus duponti), an endangered songbird. An information-theoretic approach to model selection allowed us to address the importance of interactions between habitat variables, an aspect seldom considered in fragmentation studies, but which explained up to 65% of the variance in genetic parameters. Genetic diversity and inbreeding were influenced by the size of local populations depending on their degree of isolation, and genetic differentiation was positively related to isolation. We then identified a minimum local population of 19 male territories and a maximum distance of 30 km to the nearest population as thresholds from which genetic erosion becomes apparent. Our results alert on possibly misleading conclusions and sub-optimal management recommendations when only additive effects are taken into account and encourage the use of most explanatory but easy-to-measure variables for the evaluation of genetic risks in conservation programmes.
Host identification from mosquito blood meals has been routinely used to identify the feeding pre... more Host identification from mosquito blood meals has been routinely used to identify the feeding preferences of insects in studies on transmission of vector-borne pathogens. Here, we identified for the first time the susceptibility of the endangered Iberian lynx (Lynx pardinus) to the attack of a wild mosquito female, the mosquito Anopheles atroparvus. Furthermore , we used 11 microsatellite markers to test for the utility of vertebrate DNA isolated from insect blood meals for individual identification of wildlife. Only the three smallest markers were successfully amplified; however, this genotype did not match with any of the previously genotyped individuals in southern Spain. These results support the use of DNA from mosquito blood meals as a non-invasive source of DNA and a powerful tool on epidemiological and conservation biology studies. However, as may be the case of other non-invasive sampling methods, the utility of this technique is probably limited by the quantity and quality of vertebrate DNA.
Intraspecific geographic variation in morphology is common in animals along geographic or climati... more Intraspecific geographic variation in morphology is common in animals along geographic or climatic clines. Local ecological factors are likely to act simultaneously at smaller spatial scales, but have hardly been contrasted with wide-ranging predictors. We tested here whether the morphological variation of Dupont's Larks (Chersophilus duponti) responded to ecological parameters at two different spatial scales. First, we investigated the effects of geographic and climatic gradients over its breeding range. Second, we focussed at a smaller spatial scale on a fragmented population and tested additionally several fine-grained ecological factors related to key components in the species' habitat. Contrary to Bergmann's rule, wing length and cranium size decreased with rainfall and increased with aridity and maximum temperature at the large scale, so birds tend to be larger at lower latitudes. At the same time, wing and tarsus length increased at high elevations where minimum temperatures are lower, providing some support to Bergmann's rule. At the small spatial scale we failed to detect any relationship between body size and positional or climatic variables, nor did food availability, intra-and inter-specific competition and predation pressure produce any significant effect on morphology. Nevertheless, cranium size and wing length differed between habitats as measured by soil and vegetation types, and wing length decreased with patch size. This later result could be explained in the context of strong habitat fragmentation if larger individuals have a higher propensity of dispersing or a higher probability of surviving dispersal events. Our study indicates that several geographic and environmental sources may occur simultaneously at different spatial scales. Further, even at the same scale, intraspecific morphological variation may show contrasting patterns for climatic, latitudinal, and elevational gradients that make their interpretation difficult in the context of ecogeo-graphical rules. The effects elicited by aridity, habitat loss, and fragmentation on body size should be considered in future studies of global change, as they may have serious consequences for the distribution, abundance, and ultimately the persistence of birds in arid environments.
1. It has been recently showed that one bacterial strain isolated from the uropygial gland of a n... more 1. It has been recently showed that one bacterial strain isolated from the uropygial gland of a nestling hoopoe Upupa epops produced antimicrobial peptides active against a broad spectrum of pathogenic bacteria. These bacteria might thus mediate antimicrobial properties of the uropygial secretions as a consequence of the symbiotic association with hoopoes. 2. We study antimicrobial properties of white (from males and non-breeding females) and brown (from nestlings and breeding females) uropygial gland secretions of hoopoes Upupa epops , as well as the association with the presence of bacteria living inside their uropygial gland. 3. We found that brown, but not white secretions contained bacteria and showed antimicrobial activity against the feather degrading bacterium Bacillus licheniformis. The antagonistic activity of bacterial colonies was mediated by antimicrobial peptides because protease inhibited antimicrobial properties. 4. All except one identified bacterium in aerobic cultures were of the genus Enterococcus , and the microscopic study of uropygial secretions and glands confirmed a high density of bacteria within the gland. 5. Furthermore, we studied potential benefits of antimicrobial peptides produced by symbiotic bacteria of hoopoes by adding protease to incubating nests. 6. The experiment increased bacterial growth and hatching failures in hoopoes but not in spotless starlings Sturnus unicolor , a species that does not harbour bacteria in its uropygial gland. 7. Thus, microbiological, anatomical and ecological results suggest a tight symbiotic interaction between bacteria that produce antibiotic substances and the hoopoes.
Identifying the genetic processes derived from habitat fragmentation is critical for the conserva... more Identifying the genetic processes derived from habitat fragmentation is critical for the conservation of endangered species. We conducted an integrated analysis of genetic patterns in the endangered Dupont's lark (Chersophilus duponti), a circum-Mediterranean songbird threatened by the loss and fragmentation of natural steppes in recent decades. After sampling all the remaining Spanish populations and the two closest North African ones, we found that the Mediterranean Sea acts as a major barrier against gene flow and that recent habitat fragmentation is isolating Spanish populations at different spatial scales. While we found a historical signal of gene flow among Spanish regions, a coalescent model supported that the ancestral panmictic population is evolving into several different units in the absence of current gene flow, genetic drift being more intense in the smaller and more isolated populations. Moreover, small-scale spatial autocorrelation analyses showed that genetic differentiation is also acting within populations. The spatial genetic structure, significant levels of inbreeding and high relatedness within patches raise concerns on the viability of most of the extant populations. We highlight the urgency for steppe patches to be protected, expanded and reconnected, considering the genetic clusters identified here rather than the previously considered eco-geographic regions occupied by the species. Meanwhile, translocations could be considered as a complementary, faster management action to attenuate the crowding and genetic effects of population fragmentation and the extinction risk of small populations without compromising the current local adaptations, culture diversity and genetic clusters already known for the species.
Sex determination of Dupont's lark Chersophilus duponti using molecular sexing and dis-criminant ... more Sex determination of Dupont's lark Chersophilus duponti using molecular sexing and dis-criminant functions. Aims: To test for sexual size dimorphism in external measurements of the Dupont's lark Cher-sophilus duponti, using a sample of live birds previously sexed by molecular techniques, and to obtain dis-criminant functions to easily sex birds in hand. Location: Birds were captured in different populations throughout Spain and Morocco. Most birds were trapped in the Ebro Valley (north-eastern Spain). Methods: A total of 317 adult and 42 yearlings were captured, banded, weighted and measured. A drop of blood was extracted for molecular sexing. After testing for sex differences in body size, discriminant function analyses were performed to identify the best traits for sexing both juveniles and adults. Results: All the measured parameters differed significantly between sexes in adult Dupont's larks. The best discriminant function accurately assigned sex to 99.0 % of the adults. The parameter which gave the best single factor correlation with sex was wing length, and the discriminant function with only this variable classified correctly 97.5 % of all the adults. An adult would be a male if wing length > 97 mm and a female if wing length < 97 mm. Sex had a significant effect on all parameters of juvenile individuals as well, except for bill depth. The best discriminant function, using wing length and cranium size, predicted correctly the sex of 97.6 % of the juveniles. Conclusions: Dupont's lark showed clear size dimorphism, males being heavier and larger than females in nearly all measured traits. From an evolutionary perspective, this difference could be explained by processes of intra-and inter-sexual competition, and even by potential costs linked to song flight in males. In any case, the discriminant functions produced using morphometry of individuals previously sexed by molecular procedures provided a highly accurate, inexpensive and fast method for sexing this threatened species in hand, which can help to interpret and understand many questions about its behav-ioural and population ecology. RESUMEN.-Determinación del sexo en la alondra de Dupont Chersophilus duponti utilizando técni-cas moleculares y funciones discriminantes. Objetivos: Examinar el dimorfismo sexual en medidas corporales de la alondra de Dupont Cherso-philus duponti, utilizando una muestra de aves vivas cuyo sexo se determinó con técnicas moleculares, y obtener funciones discriminantes para sexar las aves fácilmente en mano. Localidad: Las aves se capturaron en varias poblaciones tanto en España como en Marruecos. La mayoría de las aves fue capturada en el Valle
Exploring processes of coevolution of microorganisms and their hosts is a new imperative for life... more Exploring processes of coevolution of microorganisms and their hosts is a new imperative for life sciences. If bacteria protect hosts against pathogens, mechanisms facilitating the intergenerational transmission of such bacteria will be strongly selected by evolution. By disentangling the diversity of bacterial strains from the uropygium of hoopoes (Upupa epops) due to genetic relat-edness or to a common environment, we explored the importance of horizontal (from the environment) and vertical (from parents) acquisition of antimicrobial-producing symbionts in this species. For this purpose, we compared bacterial communities among individuals in nonmanipulated nests; we also performed a cross-fostering experiment using recently hatched nestlings before uropygial gland development and some nestlings that were reared outside hoopoe nests. The capacity of individuals to acquire microbial symbionts horizontally during their development was supported by our results, since cross-fostered nestlings share bacterial strains with foster siblings and nestlings that were not in contact with hoopoe adults or nests also developed the symbiosis. Moreover, nestlings could change some bacterial strains over the course of their stay in the nest, and adult females changed their bacterial community in different years. However, a low rate of vertical transmission was inferred, since genetic siblings reared in different nests shared more bacterial strains than they shared with unrelated nestlings raised in different nests. In conclusion, hoopoes are able to incorporate new symbionts from the environment during the development of the uropygium, which could be a selective advantage if strains with higher antimicrobial capacity are incorporated into the gland and could aid hosts in fighting against pathogenic and disease-causing microbes.
Martín-Vivaldi, M., Ruiz-Rodríguez, M., Méndez, M. and Soler, J. J. 2006. Relative importance of ... more Martín-Vivaldi, M., Ruiz-Rodríguez, M., Méndez, M. and Soler, J. J. 2006. Relative importance of factors affecting nestling immune response differs between junior and senior nestlings within broods of hoopoes Upupa epops. Á J. Avian Biol. 37: 467 Á476. Animals should invest in the immune system to protect themselves from parasites, but the cost of immune responses may limit investment depending on resource availability. In birds' broods, senior and junior chicks in size hierarchies face different rearing conditions, and thus we predicted that factors affecting immune response should differ between them. In asynchronously hatched hoopoe Upupa epops broods, we found that the immune response of senior nestlings was not related to their body condition, but positively related to risk of parasitism (which was indirectly estimated by laying date). This suggests that their immunocompetence is not limited by access to resources, and they can differentially invest in immune response with increasing risk of parasitism. On the other hand, immune response of junior nestlings was related to their body condition, but secondarily also to risk of parasitism. Our results agree with previous studies that have found significant influence of nutritional status and risk of parasitism on nestlings immune defence, but show that the effects of these environmental factors on nestling immunocompetence differ between nestlings occupying high and low rank positions in size hierarchies. The possible influence of maternal effects on the results found is also discussed. M. Martín-Vivaldi (correspondence)
Symbiotic microorganisms may be directly transferred from parents to offspring or acquired from a... more Symbiotic microorganisms may be directly transferred from parents to offspring or acquired from a particular environment that animals may be able to select. If benefits for hosts vary among microbial strains, natural selection may favour hosts holding the most beneficial one. Enterococci symbionts living in the hoopoe (Upupa epops) uropygial gland are able to synthesise bacteriocins (antimicrobial peptides that inhibit the growth of competitor bacteria). We explored variability in genetic profile (through RAPD-PCR analyses) and antimicrobial properties (by performing antagonistic tests against ten bacterial indicator strains) of the different isolates obtained from the uropygial glands of hoopoe females and nestlings. We found that the genetic profile of bacterial isolates was related to antimicrobial activity, as well as to individual host identity and the nest from which samples were obtained. This association suggest that variation in the inhibitory capacity of Enterococci symbionts should be under selection. Citation: Ruiz-Rodríguez M, Valdivia E, Martín-Vivaldi M, Martín-Platero AM, Martínez-Bueno M, et al. (2012) Antimicrobial Activity and Genetic Profile of Enteroccoci Isolated from Hoopoes Uropygial Gland. PLoS ONE 7(7): e41843.
We developed twenty microsatellite markers for the Dupont 0 s lark (Chersophilus duponti), one of... more We developed twenty microsatellite markers for the Dupont 0 s lark (Chersophilus duponti), one of the most endangered European bird species, and tested in two related, more widely distributed species: crested lark (Galerida cristata) and thekla lark (Galerida theklae). 14 markers amplified and were polymorphic in Dupont 0 s lark, 11 in crested lark and 6 in thekla lark. Microsatellite variability analyses were carried out on Dupont 0 s lark (N = 23-28 individuals), crested lark (N = 9-10) and thekla lark (N = 14) populations in NE Spain showing moderate/high diversity, ranging from 1 to 13 alleles per locus. The mean allelic richness in Dupont's lark was 6.21 and expected and observed heterozygosities ranged from 0.195 to 0.848 and from 0.071 to 0.889, respectively. Crested and thekla larks showed moderate/high diversity with a mean allelic richness of 4.36 and 4.67, respectively. This microsatellite set could be useful for population genetic studies of lark species widely differing in population fragmentation and conservation status across the Old World.
The uropygial glands of birds serve multiple functions, and there is great interspecific variabil... more The uropygial glands of birds serve multiple functions, and there is great interspecific variability in the composition and properties of their secretions. A special case is the secretion in the hoopoes Upupa epops, and green woodhoopoes Phoeniculus purpureus, which, contrary to the commonly white and odourless secretions, are dark with pungent odour. Recently, bacteria have been isolated from glands of both woodhoopoes and hoopoes and here we test the hypothesis that bacteria are responsible of some of the special properties of glands and secretions of this group of birds. We explore natural seasonal changes and intersexual differences in the properties of hoopoe glands and secretions, check the natural occurrence of bacteria within secretions, and analyse the effect of experimental injection of antibiotics on uropygial gland properties. Male glands underwent no seasonal changes, and their secretions were invariably white and odourless, very similar to female glands outside the breeding season. However, in comparison to the uropygial gland of non-breeding females, those of incubating females showed a marked increase in size and volume of secretion produced, which became dark and pungent. All these parameters increased until the hatching date and returned to values similar to those in the prelaying phase towards the end of the nestling period. Nestling glands produced secretions similar to those of females in colour and odour. Gland size of both females and nestlings predicted the amount of secretion produced. Microscopic techniques confirmed the presence of bacteria at high density and in active division in all dark secretions examined. The antibiotic treatment significantly reduced the load of enterococci in nestling glands, did not affect size of glands, but diminished the volume of secretion, which was lighter in colour than that of control nestlings. In nesting females, the experimental injection of antibiotic affected some measurements of gland size and secretion colour. Because the experiment did not affect general health estimates (immunocompetence, body condition or growing) of nestlings, our results suggest that some of the special properties of hoopoe glands are mediated by the presence of symbiotic bacteria.
Individual variability influences the demographic and evolutionary dynamics of spatially structur... more Individual variability influences the demographic and evolutionary dynamics of spatially structured populations, and conversely ecological and evolutionary dynamics provide the context under which variations at the individual level occur. Therefore, it is essential to identify and characterize the importance of the different factors that may promote or hinder individual variability. Animal signaling is a prime example of a type of behavior that is largely dependent on both the features of individuals and the characteristics of the population to which they belong. After 10 years studying the dynamics of a population of a long-lived species, the eagle owl (Bubo bubo), we investigated the emergence and maintenance of traits that reveal individual identity by focusing on vocal features. We found that individuals inhabiting a high density population characterized by a relative lack of heterogeneity (in terms of prey availability and breeding success) among breeding sites might be selected for reducing the levels of identity. Two non-mutually exclusive hypotheses may explain the structural call patterns we detected: (1) similarity in calls may be principally a consequence of the particular characteristics of the population; and (2) high density may encourage individuals to mimic each other's vocalizations in a cascade effect, leading to a widespread and unique communication network.
Size and isolation of local populations are main parameters of interest when assessing the geneti... more Size and isolation of local populations are main parameters of interest when assessing the genetic consequences of habitat fragmentation. However, their relative influence on the genetic erosion of local populations remains unclear. In this study, we first analysed how size and isolation of habitat patches influence the genetic variation of local populations of the Dupont's lark (Chersophilus duponti), an endangered songbird. An information-theoretic approach to model selection allowed us to address the importance of interactions between habitat variables, an aspect seldom considered in fragmentation studies, but which explained up to 65% of the variance in genetic parameters. Genetic diversity and inbreeding were influenced by the size of local populations depending on their degree of isolation, and genetic differentiation was positively related to isolation. We then identified a minimum local population of 19 male territories and a maximum distance of 30 km to the nearest population as thresholds from which genetic erosion becomes apparent. Our results alert on possibly misleading conclusions and sub-optimal management recommendations when only additive effects are taken into account and encourage the use of most explanatory but easy-to-measure variables for the evaluation of genetic risks in conservation programmes.
Host identification from mosquito blood meals has been routinely used to identify the feeding pre... more Host identification from mosquito blood meals has been routinely used to identify the feeding preferences of insects in studies on transmission of vector-borne pathogens. Here, we identified for the first time the susceptibility of the endangered Iberian lynx (Lynx pardinus) to the attack of a wild mosquito female, the mosquito Anopheles atroparvus. Furthermore , we used 11 microsatellite markers to test for the utility of vertebrate DNA isolated from insect blood meals for individual identification of wildlife. Only the three smallest markers were successfully amplified; however, this genotype did not match with any of the previously genotyped individuals in southern Spain. These results support the use of DNA from mosquito blood meals as a non-invasive source of DNA and a powerful tool on epidemiological and conservation biology studies. However, as may be the case of other non-invasive sampling methods, the utility of this technique is probably limited by the quantity and quality of vertebrate DNA.
Intraspecific geographic variation in morphology is common in animals along geographic or climati... more Intraspecific geographic variation in morphology is common in animals along geographic or climatic clines. Local ecological factors are likely to act simultaneously at smaller spatial scales, but have hardly been contrasted with wide-ranging predictors. We tested here whether the morphological variation of Dupont's Larks (Chersophilus duponti) responded to ecological parameters at two different spatial scales. First, we investigated the effects of geographic and climatic gradients over its breeding range. Second, we focussed at a smaller spatial scale on a fragmented population and tested additionally several fine-grained ecological factors related to key components in the species' habitat. Contrary to Bergmann's rule, wing length and cranium size decreased with rainfall and increased with aridity and maximum temperature at the large scale, so birds tend to be larger at lower latitudes. At the same time, wing and tarsus length increased at high elevations where minimum temperatures are lower, providing some support to Bergmann's rule. At the small spatial scale we failed to detect any relationship between body size and positional or climatic variables, nor did food availability, intra-and inter-specific competition and predation pressure produce any significant effect on morphology. Nevertheless, cranium size and wing length differed between habitats as measured by soil and vegetation types, and wing length decreased with patch size. This later result could be explained in the context of strong habitat fragmentation if larger individuals have a higher propensity of dispersing or a higher probability of surviving dispersal events. Our study indicates that several geographic and environmental sources may occur simultaneously at different spatial scales. Further, even at the same scale, intraspecific morphological variation may show contrasting patterns for climatic, latitudinal, and elevational gradients that make their interpretation difficult in the context of ecogeo-graphical rules. The effects elicited by aridity, habitat loss, and fragmentation on body size should be considered in future studies of global change, as they may have serious consequences for the distribution, abundance, and ultimately the persistence of birds in arid environments.
1. It has been recently showed that one bacterial strain isolated from the uropygial gland of a n... more 1. It has been recently showed that one bacterial strain isolated from the uropygial gland of a nestling hoopoe Upupa epops produced antimicrobial peptides active against a broad spectrum of pathogenic bacteria. These bacteria might thus mediate antimicrobial properties of the uropygial secretions as a consequence of the symbiotic association with hoopoes. 2. We study antimicrobial properties of white (from males and non-breeding females) and brown (from nestlings and breeding females) uropygial gland secretions of hoopoes Upupa epops , as well as the association with the presence of bacteria living inside their uropygial gland. 3. We found that brown, but not white secretions contained bacteria and showed antimicrobial activity against the feather degrading bacterium Bacillus licheniformis. The antagonistic activity of bacterial colonies was mediated by antimicrobial peptides because protease inhibited antimicrobial properties. 4. All except one identified bacterium in aerobic cultures were of the genus Enterococcus , and the microscopic study of uropygial secretions and glands confirmed a high density of bacteria within the gland. 5. Furthermore, we studied potential benefits of antimicrobial peptides produced by symbiotic bacteria of hoopoes by adding protease to incubating nests. 6. The experiment increased bacterial growth and hatching failures in hoopoes but not in spotless starlings Sturnus unicolor , a species that does not harbour bacteria in its uropygial gland. 7. Thus, microbiological, anatomical and ecological results suggest a tight symbiotic interaction between bacteria that produce antibiotic substances and the hoopoes.
Identifying the genetic processes derived from habitat fragmentation is critical for the conserva... more Identifying the genetic processes derived from habitat fragmentation is critical for the conservation of endangered species. We conducted an integrated analysis of genetic patterns in the endangered Dupont's lark (Chersophilus duponti), a circum-Mediterranean songbird threatened by the loss and fragmentation of natural steppes in recent decades. After sampling all the remaining Spanish populations and the two closest North African ones, we found that the Mediterranean Sea acts as a major barrier against gene flow and that recent habitat fragmentation is isolating Spanish populations at different spatial scales. While we found a historical signal of gene flow among Spanish regions, a coalescent model supported that the ancestral panmictic population is evolving into several different units in the absence of current gene flow, genetic drift being more intense in the smaller and more isolated populations. Moreover, small-scale spatial autocorrelation analyses showed that genetic differentiation is also acting within populations. The spatial genetic structure, significant levels of inbreeding and high relatedness within patches raise concerns on the viability of most of the extant populations. We highlight the urgency for steppe patches to be protected, expanded and reconnected, considering the genetic clusters identified here rather than the previously considered eco-geographic regions occupied by the species. Meanwhile, translocations could be considered as a complementary, faster management action to attenuate the crowding and genetic effects of population fragmentation and the extinction risk of small populations without compromising the current local adaptations, culture diversity and genetic clusters already known for the species.
Sex determination of Dupont's lark Chersophilus duponti using molecular sexing and dis-criminant ... more Sex determination of Dupont's lark Chersophilus duponti using molecular sexing and dis-criminant functions. Aims: To test for sexual size dimorphism in external measurements of the Dupont's lark Cher-sophilus duponti, using a sample of live birds previously sexed by molecular techniques, and to obtain dis-criminant functions to easily sex birds in hand. Location: Birds were captured in different populations throughout Spain and Morocco. Most birds were trapped in the Ebro Valley (north-eastern Spain). Methods: A total of 317 adult and 42 yearlings were captured, banded, weighted and measured. A drop of blood was extracted for molecular sexing. After testing for sex differences in body size, discriminant function analyses were performed to identify the best traits for sexing both juveniles and adults. Results: All the measured parameters differed significantly between sexes in adult Dupont's larks. The best discriminant function accurately assigned sex to 99.0 % of the adults. The parameter which gave the best single factor correlation with sex was wing length, and the discriminant function with only this variable classified correctly 97.5 % of all the adults. An adult would be a male if wing length > 97 mm and a female if wing length < 97 mm. Sex had a significant effect on all parameters of juvenile individuals as well, except for bill depth. The best discriminant function, using wing length and cranium size, predicted correctly the sex of 97.6 % of the juveniles. Conclusions: Dupont's lark showed clear size dimorphism, males being heavier and larger than females in nearly all measured traits. From an evolutionary perspective, this difference could be explained by processes of intra-and inter-sexual competition, and even by potential costs linked to song flight in males. In any case, the discriminant functions produced using morphometry of individuals previously sexed by molecular procedures provided a highly accurate, inexpensive and fast method for sexing this threatened species in hand, which can help to interpret and understand many questions about its behav-ioural and population ecology. RESUMEN.-Determinación del sexo en la alondra de Dupont Chersophilus duponti utilizando técni-cas moleculares y funciones discriminantes. Objetivos: Examinar el dimorfismo sexual en medidas corporales de la alondra de Dupont Cherso-philus duponti, utilizando una muestra de aves vivas cuyo sexo se determinó con técnicas moleculares, y obtener funciones discriminantes para sexar las aves fácilmente en mano. Localidad: Las aves se capturaron en varias poblaciones tanto en España como en Marruecos. La mayoría de las aves fue capturada en el Valle
Exploring processes of coevolution of microorganisms and their hosts is a new imperative for life... more Exploring processes of coevolution of microorganisms and their hosts is a new imperative for life sciences. If bacteria protect hosts against pathogens, mechanisms facilitating the intergenerational transmission of such bacteria will be strongly selected by evolution. By disentangling the diversity of bacterial strains from the uropygium of hoopoes (Upupa epops) due to genetic relat-edness or to a common environment, we explored the importance of horizontal (from the environment) and vertical (from parents) acquisition of antimicrobial-producing symbionts in this species. For this purpose, we compared bacterial communities among individuals in nonmanipulated nests; we also performed a cross-fostering experiment using recently hatched nestlings before uropygial gland development and some nestlings that were reared outside hoopoe nests. The capacity of individuals to acquire microbial symbionts horizontally during their development was supported by our results, since cross-fostered nestlings share bacterial strains with foster siblings and nestlings that were not in contact with hoopoe adults or nests also developed the symbiosis. Moreover, nestlings could change some bacterial strains over the course of their stay in the nest, and adult females changed their bacterial community in different years. However, a low rate of vertical transmission was inferred, since genetic siblings reared in different nests shared more bacterial strains than they shared with unrelated nestlings raised in different nests. In conclusion, hoopoes are able to incorporate new symbionts from the environment during the development of the uropygium, which could be a selective advantage if strains with higher antimicrobial capacity are incorporated into the gland and could aid hosts in fighting against pathogenic and disease-causing microbes.
Martín-Vivaldi, M., Ruiz-Rodríguez, M., Méndez, M. and Soler, J. J. 2006. Relative importance of ... more Martín-Vivaldi, M., Ruiz-Rodríguez, M., Méndez, M. and Soler, J. J. 2006. Relative importance of factors affecting nestling immune response differs between junior and senior nestlings within broods of hoopoes Upupa epops. Á J. Avian Biol. 37: 467 Á476. Animals should invest in the immune system to protect themselves from parasites, but the cost of immune responses may limit investment depending on resource availability. In birds' broods, senior and junior chicks in size hierarchies face different rearing conditions, and thus we predicted that factors affecting immune response should differ between them. In asynchronously hatched hoopoe Upupa epops broods, we found that the immune response of senior nestlings was not related to their body condition, but positively related to risk of parasitism (which was indirectly estimated by laying date). This suggests that their immunocompetence is not limited by access to resources, and they can differentially invest in immune response with increasing risk of parasitism. On the other hand, immune response of junior nestlings was related to their body condition, but secondarily also to risk of parasitism. Our results agree with previous studies that have found significant influence of nutritional status and risk of parasitism on nestlings immune defence, but show that the effects of these environmental factors on nestling immunocompetence differ between nestlings occupying high and low rank positions in size hierarchies. The possible influence of maternal effects on the results found is also discussed. M. Martín-Vivaldi (correspondence)
Symbiotic microorganisms may be directly transferred from parents to offspring or acquired from a... more Symbiotic microorganisms may be directly transferred from parents to offspring or acquired from a particular environment that animals may be able to select. If benefits for hosts vary among microbial strains, natural selection may favour hosts holding the most beneficial one. Enterococci symbionts living in the hoopoe (Upupa epops) uropygial gland are able to synthesise bacteriocins (antimicrobial peptides that inhibit the growth of competitor bacteria). We explored variability in genetic profile (through RAPD-PCR analyses) and antimicrobial properties (by performing antagonistic tests against ten bacterial indicator strains) of the different isolates obtained from the uropygial glands of hoopoe females and nestlings. We found that the genetic profile of bacterial isolates was related to antimicrobial activity, as well as to individual host identity and the nest from which samples were obtained. This association suggest that variation in the inhibitory capacity of Enterococci symbionts should be under selection. Citation: Ruiz-Rodríguez M, Valdivia E, Martín-Vivaldi M, Martín-Platero AM, Martínez-Bueno M, et al. (2012) Antimicrobial Activity and Genetic Profile of Enteroccoci Isolated from Hoopoes Uropygial Gland. PLoS ONE 7(7): e41843.
We developed twenty microsatellite markers for the Dupont 0 s lark (Chersophilus duponti), one of... more We developed twenty microsatellite markers for the Dupont 0 s lark (Chersophilus duponti), one of the most endangered European bird species, and tested in two related, more widely distributed species: crested lark (Galerida cristata) and thekla lark (Galerida theklae). 14 markers amplified and were polymorphic in Dupont 0 s lark, 11 in crested lark and 6 in thekla lark. Microsatellite variability analyses were carried out on Dupont 0 s lark (N = 23-28 individuals), crested lark (N = 9-10) and thekla lark (N = 14) populations in NE Spain showing moderate/high diversity, ranging from 1 to 13 alleles per locus. The mean allelic richness in Dupont's lark was 6.21 and expected and observed heterozygosities ranged from 0.195 to 0.848 and from 0.071 to 0.889, respectively. Crested and thekla larks showed moderate/high diversity with a mean allelic richness of 4.36 and 4.67, respectively. This microsatellite set could be useful for population genetic studies of lark species widely differing in population fragmentation and conservation status across the Old World.
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