The dataset includes the population of ringing, province of recapture/resighting and individual i... more The dataset includes the population of ringing, province of recapture/resighting and individual identity of the records for which the distance of movements was calculated (n = 9862)
Microsatellite genotypes of all individuals (n=590) separeted by locality (n=25). Genepop format ... more Microsatellite genotypes of all individuals (n=590) separeted by locality (n=25). Genepop format was selected to create the dataset
Social barriers have been shown to reduce gene flow and contribute to genetic structure among pop... more Social barriers have been shown to reduce gene flow and contribute to genetic structure among populations in species with high cognitive capacity and complex societies, such as cetaceans, apes and humans. In birds, high dispersal capacity is thought to prevent population divergence unless major geographic or habitat barriers induce isolation patterns by dispersal, colonization or adaptation limitation. We report that Iberian populations of the red-billed chough, a social, gregarious corvid with high dispersal capacity, show a striking degree of genetic structure composed of at least 15 distinct genetic units. Monitoring of marked individuals over 30 years revealed that long-distance movements over hundreds of kilometres are common, yet recruitment into breeding populations is infrequent and highly philopatric. Genetic differentiation is weakly related to geographic distance and habitat types used are overall qualitatively similar among regions and regularly shared by individuals of different populations, so that genetic structure is unlikely to be due solely to isolation by distance or isolation by adaptation. Moreover, most population nuclei showed relatively high levels of genetic diversity, suggesting a limited role for genetic drift in significantly differentiating populations. We propose that social mechanisms may underlie this unprecedented level of genetic structure in birds through a pattern of isolation by social barriers not yet described, which may have driven this remarkable population divergence in the absence of geographic and environmental barriers
Natal dispersal, the movement between the birth and the first breeding site, has been rarely stud... more Natal dispersal, the movement between the birth and the first breeding site, has been rarely studied in long-lived territorial birds with a long-lasting pre-breeding stage. Here we benefited from the long-term monitoring programs of six populations of Egyptian vultures (Neophron percnopterus) from Spain and France to study how the rearing environment determines dispersal. For 124 vultures, we recorded a median dispersal distance of 48 km (range 0–656 km). Linear models were used to assess the effect of population and individual traits on dispersal distance at two spatial scales. Dispersal distances were inversely related to vulture density in the natal population, suggesting that birds perceive the abundance of conspecifics as a signal of habitat quality. This was particularly true for declining populations, so increasing levels of opportunistic philopatry seemed to arise in high density contexts as a consequence of vacancies created by human-induced adult mortality. Females dispers...
Knowledge about the population size and trends of common bird species is crucial for setting cons... more Knowledge about the population size and trends of common bird species is crucial for setting conservation priorities and management actions. Multi-species large-scale monitoring schemes have often provided such estimates relying on extrapolation of relative abundances in particular habitats to large-scale areas. Here we show an alternative to inference-rich predictive models, proposing methods to deal with caveats of population size estimations in habitat-specialist species, reed warblers (Acrocephalus scirpaceus and Acrocephalus arundinaceus). Reed warblers were only found in pure reedbeds within riparian woodlands or in riparian vegetation scattered within or around reedbed patches, as expected according to their habitat specialization. The proportion of individuals located in reedbed associated with lotic and lentic waters differed between species, and no reed warbler was recorded in reedbed located along dry streams. This indicates that microhabitat features or their effects on ...
Determining the exposure and magnitude at which various pollutants are differentially assimilated... more Determining the exposure and magnitude at which various pollutants are differentially assimilated at the breeding and non-breeding grounds of migratory wildlife is challenging. Here, the possibility of applying the migratory connectivity framework to understanding contamination in birds is illustrated by considering flame retardants in inviable eggs of a migratory raptor, the black kite (Milvus migrans). The occurrence and concentration of legacy and emerging compounds in eggs from the southeastern peri-urban area of Madrid city, central Spain, were compared with those from Doñana National Park in southern Spain. A much higher occurrence and concentration of multiple polybrominated diphenyl ethers and Dechlorane 602 were found in Madrid than Doñana, but the opposite patterns were found for Dechlorane Plus. Individuals from these and other breeding areas in western Europe showed a strong intermixing pattern over widespread wintering areas in Africa, as assessed by ringing recoveries ...
Social barriers have been shown to reduce gene flow and contribute to genetic structure among pop... more Social barriers have been shown to reduce gene flow and contribute to genetic structure among populations in species with high cognitive capacity and complex societies, such as cetaceans, apes and humans. In birds, high dispersal capacity is thought to prevent population divergence unless major geographic or habitat barriers induce isolation patterns by dispersal, colonization or adaptation limitation. We report that Iberian populations of the red-billed chough, a social, gregarious corvid with high dispersal capacity, show a striking degree of genetic structure composed of at least 15 distinct genetic units. Monitoring of marked individuals over 30 years revealed that long-distance movements over hundreds of kilometres are common, yet recruitment into breeding populations is infrequent and highly philopatric. Genetic differentiation is weakly related to geographic distance and habitat types used are overall qualitatively similar among regions and regularly shared by individuals of ...
Capsule The hypothesized regional population size of a common species in Spain was found to be un... more Capsule The hypothesized regional population size of a common species in Spain was found to be unreliable when compared with a complete and simultaneous single-species direct census. Aims To provide a regional census of Eurasian Jackdaws Corvus monedula as an example to highlight the crucial importance of baseline knowledge of actual population size of common species for validation and calibration of population size predictions derived from extrapolation. Methods Population size was measured by means of simultaneous counts of winter communal roosts after determining the best census date and other relevant information on flock routines, foraging areas and potential sources of count variability. Results A large discrepancy between hypothesized (∼330 000 individuals) and directly censused population size (∼15 000 individuals) was recorded. Conclusion Programmes aimed at establishing population size of wildlife by statistical inference should attempt to explicitly test their predictions by comparison with directly censused population sizes of particular species in control areas.
... Between 23 May and 15 October 1997 several thousand hirundines were trapped in Laguna de San ... more ... Between 23 May and 15 October 1997 several thousand hirundines were trapped in Laguna de San Juan, central Spain (40° 08'N 3°26'W). Twenty-one Red-rumped Swallows were ... King (1994) states that this occurs in Great Reed Warblers(Acrocephalus arundinaceus). ...
Proceedings of the Royal Society B: Biological Sciences, 2005
Several avian species show a bright carotenoid-based coloration during spring and following a per... more Several avian species show a bright carotenoid-based coloration during spring and following a period of duller coloration during the previous winter, despite carotenoids presumably being fully deposited in feathers during the autumn moult. Carotenoid-based breast feathers of male linnets ( Carduelis cannabina ) increased in hue (redness), saturation and brightness after exposing them to outdoor conditions from winter to spring. This represents the first experimental evidence showing that carotenoid-based plumage coloration may increase towards a colourful expression due to biotic or abiotic environmental factors acting directly on full-grown feathers when carotenoids may be fully functional. Sunlight ultraviolet (UV) irradiation was hypothesized to denature keratin and other proteins that might protect pigments from degradation by this and other environmental factors, suggesting that sunlight UV irradiation is a major factor in the colour increase from winter to spring. Feather prot...
We report a field study of the haematocrit of pied flycatcher (Ficedula hypoleuca) nestlings when... more We report a field study of the haematocrit of pied flycatcher (Ficedula hypoleuca) nestlings when close to fledging. First a descriptive study was conducted of both fledgling and adult haematocrit over 2 years to analyse correlates of variation in this trait. Then a swapping experiment was performed to see whether variation among fledglings had a measurable genetic component. Average fledgling haematocrits were lower than those of their male and female parents. Intraclass correlations among sibships in fledgling haematocrit were high in both years, indicating that the estimates of resemblance were inflated, probably by common environmental effects. Fledgling haematocrits were unrelated to date and number of young in the nest. Fledglings with a high haematocrit were heavy and had thick breast muscles. There were no significant relationships between the average fledgling haematocrit and those of the adults caring for them. Nest mite ectoparasites negatively affected fledgling haematocrit. The haematocrits of adults did not differ between sexes or years and in both sexes were unrelated to breeding date, body mass, age, clutch size or number of young reared. Females, but not males, caring for fledglings in nests infested by mites had a lower haematocrit than those rearing young in mite-free nests. The cross-fostering experiment indicated that almost all measured variation in haematocrit was explained by the nest where the bird was reared (67.2% of the explained variance), not by their nest of origin (7.8%), meaning that there was a very small, non-significant resemblance in the haematocrit of genetically related sibs when reared in different environments while unrelated nestlings reared in the same nestbox had similar haematocrits. The low proportion of variance explained by the familial component may be due to the high connection of haematocrit to fitness.
The dataset includes the population of ringing, province of recapture/resighting and individual i... more The dataset includes the population of ringing, province of recapture/resighting and individual identity of the records for which the distance of movements was calculated (n = 9862)
Microsatellite genotypes of all individuals (n=590) separeted by locality (n=25). Genepop format ... more Microsatellite genotypes of all individuals (n=590) separeted by locality (n=25). Genepop format was selected to create the dataset
Social barriers have been shown to reduce gene flow and contribute to genetic structure among pop... more Social barriers have been shown to reduce gene flow and contribute to genetic structure among populations in species with high cognitive capacity and complex societies, such as cetaceans, apes and humans. In birds, high dispersal capacity is thought to prevent population divergence unless major geographic or habitat barriers induce isolation patterns by dispersal, colonization or adaptation limitation. We report that Iberian populations of the red-billed chough, a social, gregarious corvid with high dispersal capacity, show a striking degree of genetic structure composed of at least 15 distinct genetic units. Monitoring of marked individuals over 30 years revealed that long-distance movements over hundreds of kilometres are common, yet recruitment into breeding populations is infrequent and highly philopatric. Genetic differentiation is weakly related to geographic distance and habitat types used are overall qualitatively similar among regions and regularly shared by individuals of different populations, so that genetic structure is unlikely to be due solely to isolation by distance or isolation by adaptation. Moreover, most population nuclei showed relatively high levels of genetic diversity, suggesting a limited role for genetic drift in significantly differentiating populations. We propose that social mechanisms may underlie this unprecedented level of genetic structure in birds through a pattern of isolation by social barriers not yet described, which may have driven this remarkable population divergence in the absence of geographic and environmental barriers
Natal dispersal, the movement between the birth and the first breeding site, has been rarely stud... more Natal dispersal, the movement between the birth and the first breeding site, has been rarely studied in long-lived territorial birds with a long-lasting pre-breeding stage. Here we benefited from the long-term monitoring programs of six populations of Egyptian vultures (Neophron percnopterus) from Spain and France to study how the rearing environment determines dispersal. For 124 vultures, we recorded a median dispersal distance of 48 km (range 0–656 km). Linear models were used to assess the effect of population and individual traits on dispersal distance at two spatial scales. Dispersal distances were inversely related to vulture density in the natal population, suggesting that birds perceive the abundance of conspecifics as a signal of habitat quality. This was particularly true for declining populations, so increasing levels of opportunistic philopatry seemed to arise in high density contexts as a consequence of vacancies created by human-induced adult mortality. Females dispers...
Knowledge about the population size and trends of common bird species is crucial for setting cons... more Knowledge about the population size and trends of common bird species is crucial for setting conservation priorities and management actions. Multi-species large-scale monitoring schemes have often provided such estimates relying on extrapolation of relative abundances in particular habitats to large-scale areas. Here we show an alternative to inference-rich predictive models, proposing methods to deal with caveats of population size estimations in habitat-specialist species, reed warblers (Acrocephalus scirpaceus and Acrocephalus arundinaceus). Reed warblers were only found in pure reedbeds within riparian woodlands or in riparian vegetation scattered within or around reedbed patches, as expected according to their habitat specialization. The proportion of individuals located in reedbed associated with lotic and lentic waters differed between species, and no reed warbler was recorded in reedbed located along dry streams. This indicates that microhabitat features or their effects on ...
Determining the exposure and magnitude at which various pollutants are differentially assimilated... more Determining the exposure and magnitude at which various pollutants are differentially assimilated at the breeding and non-breeding grounds of migratory wildlife is challenging. Here, the possibility of applying the migratory connectivity framework to understanding contamination in birds is illustrated by considering flame retardants in inviable eggs of a migratory raptor, the black kite (Milvus migrans). The occurrence and concentration of legacy and emerging compounds in eggs from the southeastern peri-urban area of Madrid city, central Spain, were compared with those from Doñana National Park in southern Spain. A much higher occurrence and concentration of multiple polybrominated diphenyl ethers and Dechlorane 602 were found in Madrid than Doñana, but the opposite patterns were found for Dechlorane Plus. Individuals from these and other breeding areas in western Europe showed a strong intermixing pattern over widespread wintering areas in Africa, as assessed by ringing recoveries ...
Social barriers have been shown to reduce gene flow and contribute to genetic structure among pop... more Social barriers have been shown to reduce gene flow and contribute to genetic structure among populations in species with high cognitive capacity and complex societies, such as cetaceans, apes and humans. In birds, high dispersal capacity is thought to prevent population divergence unless major geographic or habitat barriers induce isolation patterns by dispersal, colonization or adaptation limitation. We report that Iberian populations of the red-billed chough, a social, gregarious corvid with high dispersal capacity, show a striking degree of genetic structure composed of at least 15 distinct genetic units. Monitoring of marked individuals over 30 years revealed that long-distance movements over hundreds of kilometres are common, yet recruitment into breeding populations is infrequent and highly philopatric. Genetic differentiation is weakly related to geographic distance and habitat types used are overall qualitatively similar among regions and regularly shared by individuals of ...
Capsule The hypothesized regional population size of a common species in Spain was found to be un... more Capsule The hypothesized regional population size of a common species in Spain was found to be unreliable when compared with a complete and simultaneous single-species direct census. Aims To provide a regional census of Eurasian Jackdaws Corvus monedula as an example to highlight the crucial importance of baseline knowledge of actual population size of common species for validation and calibration of population size predictions derived from extrapolation. Methods Population size was measured by means of simultaneous counts of winter communal roosts after determining the best census date and other relevant information on flock routines, foraging areas and potential sources of count variability. Results A large discrepancy between hypothesized (∼330 000 individuals) and directly censused population size (∼15 000 individuals) was recorded. Conclusion Programmes aimed at establishing population size of wildlife by statistical inference should attempt to explicitly test their predictions by comparison with directly censused population sizes of particular species in control areas.
... Between 23 May and 15 October 1997 several thousand hirundines were trapped in Laguna de San ... more ... Between 23 May and 15 October 1997 several thousand hirundines were trapped in Laguna de San Juan, central Spain (40° 08'N 3°26'W). Twenty-one Red-rumped Swallows were ... King (1994) states that this occurs in Great Reed Warblers(Acrocephalus arundinaceus). ...
Proceedings of the Royal Society B: Biological Sciences, 2005
Several avian species show a bright carotenoid-based coloration during spring and following a per... more Several avian species show a bright carotenoid-based coloration during spring and following a period of duller coloration during the previous winter, despite carotenoids presumably being fully deposited in feathers during the autumn moult. Carotenoid-based breast feathers of male linnets ( Carduelis cannabina ) increased in hue (redness), saturation and brightness after exposing them to outdoor conditions from winter to spring. This represents the first experimental evidence showing that carotenoid-based plumage coloration may increase towards a colourful expression due to biotic or abiotic environmental factors acting directly on full-grown feathers when carotenoids may be fully functional. Sunlight ultraviolet (UV) irradiation was hypothesized to denature keratin and other proteins that might protect pigments from degradation by this and other environmental factors, suggesting that sunlight UV irradiation is a major factor in the colour increase from winter to spring. Feather prot...
We report a field study of the haematocrit of pied flycatcher (Ficedula hypoleuca) nestlings when... more We report a field study of the haematocrit of pied flycatcher (Ficedula hypoleuca) nestlings when close to fledging. First a descriptive study was conducted of both fledgling and adult haematocrit over 2 years to analyse correlates of variation in this trait. Then a swapping experiment was performed to see whether variation among fledglings had a measurable genetic component. Average fledgling haematocrits were lower than those of their male and female parents. Intraclass correlations among sibships in fledgling haematocrit were high in both years, indicating that the estimates of resemblance were inflated, probably by common environmental effects. Fledgling haematocrits were unrelated to date and number of young in the nest. Fledglings with a high haematocrit were heavy and had thick breast muscles. There were no significant relationships between the average fledgling haematocrit and those of the adults caring for them. Nest mite ectoparasites negatively affected fledgling haematocrit. The haematocrits of adults did not differ between sexes or years and in both sexes were unrelated to breeding date, body mass, age, clutch size or number of young reared. Females, but not males, caring for fledglings in nests infested by mites had a lower haematocrit than those rearing young in mite-free nests. The cross-fostering experiment indicated that almost all measured variation in haematocrit was explained by the nest where the bird was reared (67.2% of the explained variance), not by their nest of origin (7.8%), meaning that there was a very small, non-significant resemblance in the haematocrit of genetically related sibs when reared in different environments while unrelated nestlings reared in the same nestbox had similar haematocrits. The low proportion of variance explained by the familial component may be due to the high connection of haematocrit to fitness.
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