Environmental monitoring and assessment, Feb 14, 2024
The increasing impact of human activities on ecosystems is provoking a profound and dangerous eff... more The increasing impact of human activities on ecosystems is provoking a profound and dangerous effect, particularly in wildlife. Examining the historical migration patterns of quail (Coturnix coturnix) offers a compelling case study to demonstrate the repercussions of human actions on biodiversity. Urbanization trends, where people gravitate toward mega-urban areas, amplify this effect. The proliferation of artificial urban ecosystems extends its influence across every biome, as human reliance on infrastructure and food sources alters ecological dynamics extensively. We examine European quail migrations pre-and post-World War II and in the present day. Our study concentrates on the Italian peninsula, investigating the historical and contemporary recovery of ringed quail populations. To comprehend changes in quail migration, we utilize trajectory analysis, open statistical data, and linear generalized models. We found that while human population and economic growth have shown a linear increase, quail recovery rates exhibit a U-shaped trajectory, and cereal and legume production displays an inverse U-shaped pattern. Generalized linear models have unveiled the significant influence of several key factors-time periods, cereal and legume production, and human demographicson quail recovery rates. These factors closely correlate with the levels of urbanization observed across these timeframes. These insights underscore the profound impact of expanding human populations and the rise of mega-urbanization on ecosystem dynamics and services. As our planet becomes more urbanized, the pressure on ecosystems intensifies, highlighting the urgent need for concerted efforts directed toward conserving and revitalizing ecosystem integrity. Simultaneously,
bioRxiv (Cold Spring Harbor Laboratory), Jan 25, 2024
The red-legged partridge (Alectoris rufa) is a popular game bird species that is in decline in se... more The red-legged partridge (Alectoris rufa) is a popular game bird species that is in decline in several regions of southwestern Europe. The introduction of farm-reared individuals of a distinct genetic make-up in hunting reserves can result in genetic swamping of wild populations. Here we present a de novo genome assembly for the red-legged partridge based on long-read sequencing technology. The assembled genome size is 1.14 Gb, with scaffold N50 of 37.6 Mb and contig N50 of 29.5 Mb. Our genome is highly contiguous and contains 97.06% of complete avian core genes. Overall, quality of this genome assembly is equivalent to those available for other close relatives such as the Japanese quail or the chicken. This genome assembly will contribute to the understanding of genetic dynamics of wild populations of red-legged partridges with releases of farm-reared reinforcements and to appropriate management decisions of such populations.
The aim of this paper was to use geometric morphometrics to study the skull sexual dimorphism of ... more The aim of this paper was to use geometric morphometrics to study the skull sexual dimorphism of toy rabbits, which present paedomorphic (babyness) traits comparing data with those from agriotype (ancestor), Oryctolagus cuniculus. For this purpose, we examined 43 post-weaned corpses belonging to wild rabbit (n=22, 7 ♂ and 15 ♀, 1295.6 ± 333.8 kg of body weight and 88.0 ± 1.12 cm of ear length) and toy type (n=21, 4 ♂ and 17 ♀, short and upright ears, 1031.3 ± 644.13 kg of body weight and 6.2 ± 1.08 cm of ear length). Heads were radiographed using a Potro® machine on a latero-lateral projection and 7 landmarks were located on the skull and studied by means of geometric morphometric procedures. Size and shape between genders appeared statistically different only for toys, mainly focused on splanchnocranium (face) for shape. Detected sexual dimorphism could be attributed to selection arising from differential mating success, or sexual selection, due to human management. Moreover, the i...
Global warming affects ecosystem services, communities and populations, influencing the physiolog... more Global warming affects ecosystem services, communities and populations, influencing the physiology, behaviour or environment of living beings, and hence impacts its survival or breeding. Identifying species susceptibility to warming is relevant in assessing risks to animal populations and ecological processes. The progressive increase in ambient temperature as a result of global warming might have an effect on the timing of primary moult. This could affect a bird's annual cycle, influencing reproductive success and population dynamics. We describe a method to examine the potential effects of global warming on the primary moult process in a sedentary population of Red-legged Partridges (Alectoris rufa). We organised the factors that might influence the timing of moult end into a network and distinguished between environmental and intrinsic factors. We sorted the factors according to their contribution to quantitative moult models and constructed a diagrammatic scheme showing their interactions and effect on the end of primary moult over the annual cycle. In Red-legged Partridges, the timing of the end of moult varies according to age-sex class. We found no timing differences by age, but found significant timing differences by adult sex. More females overlap their moult with juveniles than males because female parental effort is higher, more females incubate and brood chicks. The timing of the end of moult varies by year due to conspecific interactions that change according to influences of the weather, habitat, and social and flock conditions. Parent birds synchronize their primary moult with the chick's growth, degree of cover and food resources. From the time of hatching to the following year, the date (day-length), social factors (conspecific interactions), and weather (resources) affect the timing of moult and the birds' annual cycle. Global warming affects the timing of the end of moult and that of the annual cycle. If the extent of the breeding period is shortened, there could be a negative effect on population outcomes. Middle size prey species are key in trophic chains. Our results suggest that the timing of the end of moult could be used as a proxy measure of warming impacts on wildlife and ecosystems and also as a tool for the management of game birds.
The Science of the total environment, Jan 20, 2018
Two methodological criticisms of our paper "Synchronizing biological cycles as key to surviv... more Two methodological criticisms of our paper "Synchronizing biological cycles as key to survival under a scenario of global change: The Common quail (Coturnix coturnix) strategy" (Nadal et al., 2018) were proposed in the comment by Rodriguez-Teijeiro et al. (2018) regarding: 1) our estimates of the mean date of arrival, duration of stay and departure stages in the different regions studied; and 2) the analyses carried out to correlate the phenology of the species with changes in the climate variables. The conceptual model that we presented relates the dynamics of this quail population, which moves between short periods of stays, and the spatio-temporal structure of their geographic distribution data, in order to understand the ecology of these birds and to link their movement and residency patterns with geographical area and climate conditions. The probability that quail are resident in a region on any particular date is a result of their overall ecological strategy. We beli...
Wild birds differ in size according to their age and sex, adult birds being larger than juveniles... more Wild birds differ in size according to their age and sex, adult birds being larger than juveniles. In the galliforms, males are larger than females, in contrast to some groups, such as the raptors, in which the females are larger. Size generally influences the rank hierarchy within a group of birds, although the age, sex, temperament and behaviour of an individual may override its size related rank order. The scaled size of birds according to age and sex affects their physiology and behaviour. Precise details of body-size differences by age and sex are poorly known in most partridge species. We measured 13,814 wild partridges in a homogenous population over 14 years of study to evaluate size differences within a uniform habitat and population management regime. We show that wild Red-legged Partridges have scaled mass, and body- and wing-lengths consistent with age/sex classes. Power functions between mass and body-length (as a proxy for walking efficiency), and between mass and wing...
Countries share responsibility for the management and conservation of migratory bird species. How... more Countries share responsibility for the management and conservation of migratory bird species. However, a limited understanding of population dynamics hampers the implementation of harvest and transboundary management. Age-ratios and population density can be useful indicators to assess population dynamics to improve management and conservation actions. Here, the dynamics of an Atlantic population of Common quail Coturnix coturnix, using 32,508 quail samples and 4814 hunter questionnaires over a 20-year period (1996-2016) served as a comparative study for examining age-ratio patterns related to different geographic zones, population density and weather parameters. Results show that age-ratios varied over zones and years, specifically age-ratio 1 (AR1), used as an index of late breeding attempts, varied from 0.1 to 0.21. Age-ratio 2 (AR2), a surrogate of central recruitment, varied from 0.16 to 0.66. Finally, age-ratio 3 (AR3), used as an indicator of the population's annual breeding success, varied from 3.69 to 6.68. Age-ratio is linked to internal and external factors (i.e. effect of rainfall, variations over time and density-dependent relationships) depicting how quail age groups make segregated migration in time and space. Quail age groups perform a complex pattern of migration because of entwined changes in abundance, migration routes and timing, influencing population connectivity and dynamics. Our findings highlight the relevance of citizen science and transboundary agreements to improve management and conservation measures of migrant species. Administrations and policy-makers in developed and developing countries must coordinate efforts to engage hunters in a participatory management systems to achieve sustainability.
Quality breeding areas are vital for the management and conservation of migratory bird species, e... more Quality breeding areas are vital for the management and conservation of migratory bird species, especially those under pressure from climate warming effects. The Common quail Coturnix coturnix is a migratory species characterized by its itinerant breeding (several breeding attempts in different places) and exposure to high mortality rates, and it is a case in point. The identification and management of high quality nesting areas is essential to conserve this and other migratory species. Here, we use a Spanish long-term quail ringing dataset (1961-2014) to correlate population age structure with temporal and geographical variables. We show that northern Mediterranean regions provide optimal breeding sites and have balanced population age structures (young:adult males). The proportion of young:adult males provides an indicator of the relative quality of various breeding areas. Records of ringed quail provide data on the overlap between young and adult males temporarily resident in different geographic areas and may provide a useful tool to evaluate habitat quality. We found that the timing of sequential breeding attempts and temporary residency of quail are associated with latitude, altitude, and geographic location of quail ringing records. In southern regions, young males arrive at the breeding area later than adults, while in northern regions young birds and adults arrive at same time. Optimal breeding areas are characterized by high quality habitat, have high quail densities, and a mixture of young and adult males, factors that favour sexual selection, heterozygosity and population viability. However, not all high quality habitat areas are suitable for reproduction, being necessary enough quail density and the adequate proportion of young:adult males.
Background: Predation is one of the most important natural selection forces. Prey species can opt... more Background: Predation is one of the most important natural selection forces. Prey species can optimize feeding behavior and escape from predators based on mobility conditioned by body proportions. With age, mobility capacity increases and individuals are more efficient in finding resources and safety (e.g., food and refuge). Birds' mobility is driven by the dimensions, of the head and torso, as well as the extremities and flight feathers. To assess the relationship between body traits and to understand how body proportions are organized in wild Red-legged partridges (Alectoris rufa), we used biometric data from nearly 14,000 individuals, obtained during a long-term study (1988-2011) on a wild population. Results: We used GLMs and regressions to model the relationship between body mass and the size of body parts. We found that wing length was the morphological part best explained by other body trait measures. Wing length models were better predictors in juveniles than in adults and in females than in males. Wing length and feather length, mass and total length are the most strongly related parts; mass and wing length, total length and feather length are moderately related. The association between mass and wing length is intermediated by feather length and total length. Conclusions: Social inclusion, feeding and predator evasion may be affected by body structure intermediated by mobility and health. Our results suggest that proportions of the body, extremities and flight feathers drive mobility which is intimately associated with ecology, biological efficiency, health and physical optimization. Our findings showed that wing size was strongly allied to other body part measurements, enhancing the importance of body structure conformation for flight. Our study highlights the scaled relationship of body structure among age-sex classes and its relevance to social cohesion, flock movement and the balance between predation and starvation.
Almost all birds use their fight feathers as a means of escaping predators, and their specific de... more Almost all birds use their fight feathers as a means of escaping predators, and their specific design is adapted to their individual circumstances. For example, Galliform birds use a fast, explosive, noisy takeoff to startle a predator. Their legs, wings and feathers must work together to create a strong propulsive force and loud, rhythmic sound. Partridges in a group initiate escape simultaneously, even though individuals in the flock differ in size and experience, as well as in age and sex resulting in feathers that differ in length and shape. In a long-term study, we measured 13 814 wild red-legged partridges (Alectoris rufa) to understand how variation in feather proportions and morphometrics between the age-sex classes relate to their escape abilities. We devised two new indexes to quantify the aerodynamic differences between age-sex classes. Our approach synthesizes the understanding of bird take-flight mechanics, feather proportions and the aerodynamic properties of wing tips to show how differences in feather length and tip shape characterize age-sex classes. Our findings suggest that the density, stiffness, permeability, size and shape of the distal primary feathers and wing tips can explain aerodynamic differences between individuals and the efficiency of groups in escape situations. ADDITIONAL KEYWORDS: distal primary feathers-feather tip-flock coordination-predator escape-takeoff-wing tip.
Farmland and migratory bird populations are in decline. The Common quail (Coturnix coturnix) prov... more Farmland and migratory bird populations are in decline. The Common quail (Coturnix coturnix) provides an exception to this trend and its populations have remained stable over the last two decades. However, some basic facts regarding quail biology and ecology, such as the geographic distribution of age and sex classes during the summer, remain poorly understood. We analyzed 43,194 Spanish quail ringing records from 1961 to 2014 to assess the effects of geography and weather conditions on the probability that individuals will be ringed during the various stages of their annual cycle (arrival -spring migration-, stationary breeding period, departure -autumn migration- and winter) for the different quail age-sex classes over time. We found that spatial distribution of the age and sex classes can be explained by date, latitude, longitude, altitude, rainfall, and temperature. Our results suggest that date accounts for most of the variation in the distribution of quail age classes, followe...
The Science of the total environment, Jan 27, 2017
Breeding grounds are key areas for sustaining Common quail (Coturnix coturnix) populations as thi... more Breeding grounds are key areas for sustaining Common quail (Coturnix coturnix) populations as this species is characterised by short life expectancy that requires high offspring production. Annually, breeding quails make up to three breeding attempts in different places. However, the impact of climate warming on quail phenology is unknown. Here, we use a long-term study (1961-2014) of quail-ringing in Spain and data on variation in rainfall and temperature over the past 86years to evaluate how quails have responded to climate change in recent years. Our aim was to understand how this species is adapting to new farming practices and climate change. Our results suggest that increases in temperature and decreases in precipitation modify quail phenology. In hot years, an advance in mean arrival dates and stay stages but a delay in departure dates was found. However, in rainy years a delay in the mean start of the stay stage occurred. In cloudy areas, our findings show that quails advanc...
The dynamics of a wild red-legged partridge population were examined over a 14-year period in Spa... more The dynamics of a wild red-legged partridge population were examined over a 14-year period in Spain to identify patterns in age and sex ratios in relation to weather parameters, and to assess the importance of these parameters in population dynamics and management. The results gave age ratios of 1.07 (but 2.13 in July counts), juvenile sex ratios of 1.01 and adult sex ratios of 1.47. Overall, 12% more females were hatched and female juvenile mortality was 7.3% higher than in males. Sex differential mortality explains the 19.2% deficit in adult females, which are more heavily predated than males during the breeding period. Accordingly, age ratios are dependent on sex ratios and both are density dependent. Over time, ratios and density changes appear to be influenced by weather and management. When the habitat is well conserved, partridge population dynamics can be explained by a causal chain: weather operates on net primary production, thereby affecting partridge reproduction and pre...
Quality breeding areas are vital for the management and conservation of migratory bird species, e... more Quality breeding areas are vital for the management and conservation of migratory bird species, especially those under pressure from climate warming effects. The Common quail Coturnix coturnix is a migratory species characterized by its itinerant breeding (several breeding attempts in different places) and exposure to high mortality rates, and it is a case in point. The identification and management of high quality nesting areas is essential to conserve this and other migratory species. Here, we use a Spanish long-term quail ringing dataset (1961-2014) to correlate population age structure with temporal and geographical variables. We show that northern Mediterranean regions provide optimal breeding sites and have balanced population age structures (young:adult males). The proportion of young:adult males provides an indicator of the relative quality of various breeding areas. Records of ringed quail provide data on the overlap between young and adult males temporarily resident in different geographic areas and may provide a useful tool to evaluate habitat quality. We found that the timing of sequential breeding attempts and temporary residency of quail are associated with latitude, altitude, and geographic location of quail ringing records. In southern regions, young males arrive at the breeding area later than adults, while in northern regions young birds and adults arrive at same time. Optimal breeding areas are characterized by high quality habitat, have high quail densities, and a mixture of young and adult males, factors that favour sexual selection, heterozygosity and population viability. However, not all high quality habitat areas are suitable for reproduction, being necessary enough quail density and the adequate proportion of young:adult males.
Afro-paleartic migratory birds can subsist to global change effects. • Migration and nomadism tim... more Afro-paleartic migratory birds can subsist to global change effects. • Migration and nomadism timely distribute groups of age and sex in suitable habitats. • The distribution of quail age and sex class follows variations in weather and habitat suitability. • The migration added to nomadism is consistent with success in finding optimal habitats. • Temporal, spatial, age and sex distributions facilitate offset mortality.
Environmental monitoring and assessment, Feb 14, 2024
The increasing impact of human activities on ecosystems is provoking a profound and dangerous eff... more The increasing impact of human activities on ecosystems is provoking a profound and dangerous effect, particularly in wildlife. Examining the historical migration patterns of quail (Coturnix coturnix) offers a compelling case study to demonstrate the repercussions of human actions on biodiversity. Urbanization trends, where people gravitate toward mega-urban areas, amplify this effect. The proliferation of artificial urban ecosystems extends its influence across every biome, as human reliance on infrastructure and food sources alters ecological dynamics extensively. We examine European quail migrations pre-and post-World War II and in the present day. Our study concentrates on the Italian peninsula, investigating the historical and contemporary recovery of ringed quail populations. To comprehend changes in quail migration, we utilize trajectory analysis, open statistical data, and linear generalized models. We found that while human population and economic growth have shown a linear increase, quail recovery rates exhibit a U-shaped trajectory, and cereal and legume production displays an inverse U-shaped pattern. Generalized linear models have unveiled the significant influence of several key factors-time periods, cereal and legume production, and human demographicson quail recovery rates. These factors closely correlate with the levels of urbanization observed across these timeframes. These insights underscore the profound impact of expanding human populations and the rise of mega-urbanization on ecosystem dynamics and services. As our planet becomes more urbanized, the pressure on ecosystems intensifies, highlighting the urgent need for concerted efforts directed toward conserving and revitalizing ecosystem integrity. Simultaneously,
bioRxiv (Cold Spring Harbor Laboratory), Jan 25, 2024
The red-legged partridge (Alectoris rufa) is a popular game bird species that is in decline in se... more The red-legged partridge (Alectoris rufa) is a popular game bird species that is in decline in several regions of southwestern Europe. The introduction of farm-reared individuals of a distinct genetic make-up in hunting reserves can result in genetic swamping of wild populations. Here we present a de novo genome assembly for the red-legged partridge based on long-read sequencing technology. The assembled genome size is 1.14 Gb, with scaffold N50 of 37.6 Mb and contig N50 of 29.5 Mb. Our genome is highly contiguous and contains 97.06% of complete avian core genes. Overall, quality of this genome assembly is equivalent to those available for other close relatives such as the Japanese quail or the chicken. This genome assembly will contribute to the understanding of genetic dynamics of wild populations of red-legged partridges with releases of farm-reared reinforcements and to appropriate management decisions of such populations.
The aim of this paper was to use geometric morphometrics to study the skull sexual dimorphism of ... more The aim of this paper was to use geometric morphometrics to study the skull sexual dimorphism of toy rabbits, which present paedomorphic (babyness) traits comparing data with those from agriotype (ancestor), Oryctolagus cuniculus. For this purpose, we examined 43 post-weaned corpses belonging to wild rabbit (n=22, 7 ♂ and 15 ♀, 1295.6 ± 333.8 kg of body weight and 88.0 ± 1.12 cm of ear length) and toy type (n=21, 4 ♂ and 17 ♀, short and upright ears, 1031.3 ± 644.13 kg of body weight and 6.2 ± 1.08 cm of ear length). Heads were radiographed using a Potro® machine on a latero-lateral projection and 7 landmarks were located on the skull and studied by means of geometric morphometric procedures. Size and shape between genders appeared statistically different only for toys, mainly focused on splanchnocranium (face) for shape. Detected sexual dimorphism could be attributed to selection arising from differential mating success, or sexual selection, due to human management. Moreover, the i...
Global warming affects ecosystem services, communities and populations, influencing the physiolog... more Global warming affects ecosystem services, communities and populations, influencing the physiology, behaviour or environment of living beings, and hence impacts its survival or breeding. Identifying species susceptibility to warming is relevant in assessing risks to animal populations and ecological processes. The progressive increase in ambient temperature as a result of global warming might have an effect on the timing of primary moult. This could affect a bird's annual cycle, influencing reproductive success and population dynamics. We describe a method to examine the potential effects of global warming on the primary moult process in a sedentary population of Red-legged Partridges (Alectoris rufa). We organised the factors that might influence the timing of moult end into a network and distinguished between environmental and intrinsic factors. We sorted the factors according to their contribution to quantitative moult models and constructed a diagrammatic scheme showing their interactions and effect on the end of primary moult over the annual cycle. In Red-legged Partridges, the timing of the end of moult varies according to age-sex class. We found no timing differences by age, but found significant timing differences by adult sex. More females overlap their moult with juveniles than males because female parental effort is higher, more females incubate and brood chicks. The timing of the end of moult varies by year due to conspecific interactions that change according to influences of the weather, habitat, and social and flock conditions. Parent birds synchronize their primary moult with the chick's growth, degree of cover and food resources. From the time of hatching to the following year, the date (day-length), social factors (conspecific interactions), and weather (resources) affect the timing of moult and the birds' annual cycle. Global warming affects the timing of the end of moult and that of the annual cycle. If the extent of the breeding period is shortened, there could be a negative effect on population outcomes. Middle size prey species are key in trophic chains. Our results suggest that the timing of the end of moult could be used as a proxy measure of warming impacts on wildlife and ecosystems and also as a tool for the management of game birds.
The Science of the total environment, Jan 20, 2018
Two methodological criticisms of our paper "Synchronizing biological cycles as key to surviv... more Two methodological criticisms of our paper "Synchronizing biological cycles as key to survival under a scenario of global change: The Common quail (Coturnix coturnix) strategy" (Nadal et al., 2018) were proposed in the comment by Rodriguez-Teijeiro et al. (2018) regarding: 1) our estimates of the mean date of arrival, duration of stay and departure stages in the different regions studied; and 2) the analyses carried out to correlate the phenology of the species with changes in the climate variables. The conceptual model that we presented relates the dynamics of this quail population, which moves between short periods of stays, and the spatio-temporal structure of their geographic distribution data, in order to understand the ecology of these birds and to link their movement and residency patterns with geographical area and climate conditions. The probability that quail are resident in a region on any particular date is a result of their overall ecological strategy. We beli...
Wild birds differ in size according to their age and sex, adult birds being larger than juveniles... more Wild birds differ in size according to their age and sex, adult birds being larger than juveniles. In the galliforms, males are larger than females, in contrast to some groups, such as the raptors, in which the females are larger. Size generally influences the rank hierarchy within a group of birds, although the age, sex, temperament and behaviour of an individual may override its size related rank order. The scaled size of birds according to age and sex affects their physiology and behaviour. Precise details of body-size differences by age and sex are poorly known in most partridge species. We measured 13,814 wild partridges in a homogenous population over 14 years of study to evaluate size differences within a uniform habitat and population management regime. We show that wild Red-legged Partridges have scaled mass, and body- and wing-lengths consistent with age/sex classes. Power functions between mass and body-length (as a proxy for walking efficiency), and between mass and wing...
Countries share responsibility for the management and conservation of migratory bird species. How... more Countries share responsibility for the management and conservation of migratory bird species. However, a limited understanding of population dynamics hampers the implementation of harvest and transboundary management. Age-ratios and population density can be useful indicators to assess population dynamics to improve management and conservation actions. Here, the dynamics of an Atlantic population of Common quail Coturnix coturnix, using 32,508 quail samples and 4814 hunter questionnaires over a 20-year period (1996-2016) served as a comparative study for examining age-ratio patterns related to different geographic zones, population density and weather parameters. Results show that age-ratios varied over zones and years, specifically age-ratio 1 (AR1), used as an index of late breeding attempts, varied from 0.1 to 0.21. Age-ratio 2 (AR2), a surrogate of central recruitment, varied from 0.16 to 0.66. Finally, age-ratio 3 (AR3), used as an indicator of the population's annual breeding success, varied from 3.69 to 6.68. Age-ratio is linked to internal and external factors (i.e. effect of rainfall, variations over time and density-dependent relationships) depicting how quail age groups make segregated migration in time and space. Quail age groups perform a complex pattern of migration because of entwined changes in abundance, migration routes and timing, influencing population connectivity and dynamics. Our findings highlight the relevance of citizen science and transboundary agreements to improve management and conservation measures of migrant species. Administrations and policy-makers in developed and developing countries must coordinate efforts to engage hunters in a participatory management systems to achieve sustainability.
Quality breeding areas are vital for the management and conservation of migratory bird species, e... more Quality breeding areas are vital for the management and conservation of migratory bird species, especially those under pressure from climate warming effects. The Common quail Coturnix coturnix is a migratory species characterized by its itinerant breeding (several breeding attempts in different places) and exposure to high mortality rates, and it is a case in point. The identification and management of high quality nesting areas is essential to conserve this and other migratory species. Here, we use a Spanish long-term quail ringing dataset (1961-2014) to correlate population age structure with temporal and geographical variables. We show that northern Mediterranean regions provide optimal breeding sites and have balanced population age structures (young:adult males). The proportion of young:adult males provides an indicator of the relative quality of various breeding areas. Records of ringed quail provide data on the overlap between young and adult males temporarily resident in different geographic areas and may provide a useful tool to evaluate habitat quality. We found that the timing of sequential breeding attempts and temporary residency of quail are associated with latitude, altitude, and geographic location of quail ringing records. In southern regions, young males arrive at the breeding area later than adults, while in northern regions young birds and adults arrive at same time. Optimal breeding areas are characterized by high quality habitat, have high quail densities, and a mixture of young and adult males, factors that favour sexual selection, heterozygosity and population viability. However, not all high quality habitat areas are suitable for reproduction, being necessary enough quail density and the adequate proportion of young:adult males.
Background: Predation is one of the most important natural selection forces. Prey species can opt... more Background: Predation is one of the most important natural selection forces. Prey species can optimize feeding behavior and escape from predators based on mobility conditioned by body proportions. With age, mobility capacity increases and individuals are more efficient in finding resources and safety (e.g., food and refuge). Birds' mobility is driven by the dimensions, of the head and torso, as well as the extremities and flight feathers. To assess the relationship between body traits and to understand how body proportions are organized in wild Red-legged partridges (Alectoris rufa), we used biometric data from nearly 14,000 individuals, obtained during a long-term study (1988-2011) on a wild population. Results: We used GLMs and regressions to model the relationship between body mass and the size of body parts. We found that wing length was the morphological part best explained by other body trait measures. Wing length models were better predictors in juveniles than in adults and in females than in males. Wing length and feather length, mass and total length are the most strongly related parts; mass and wing length, total length and feather length are moderately related. The association between mass and wing length is intermediated by feather length and total length. Conclusions: Social inclusion, feeding and predator evasion may be affected by body structure intermediated by mobility and health. Our results suggest that proportions of the body, extremities and flight feathers drive mobility which is intimately associated with ecology, biological efficiency, health and physical optimization. Our findings showed that wing size was strongly allied to other body part measurements, enhancing the importance of body structure conformation for flight. Our study highlights the scaled relationship of body structure among age-sex classes and its relevance to social cohesion, flock movement and the balance between predation and starvation.
Almost all birds use their fight feathers as a means of escaping predators, and their specific de... more Almost all birds use their fight feathers as a means of escaping predators, and their specific design is adapted to their individual circumstances. For example, Galliform birds use a fast, explosive, noisy takeoff to startle a predator. Their legs, wings and feathers must work together to create a strong propulsive force and loud, rhythmic sound. Partridges in a group initiate escape simultaneously, even though individuals in the flock differ in size and experience, as well as in age and sex resulting in feathers that differ in length and shape. In a long-term study, we measured 13 814 wild red-legged partridges (Alectoris rufa) to understand how variation in feather proportions and morphometrics between the age-sex classes relate to their escape abilities. We devised two new indexes to quantify the aerodynamic differences between age-sex classes. Our approach synthesizes the understanding of bird take-flight mechanics, feather proportions and the aerodynamic properties of wing tips to show how differences in feather length and tip shape characterize age-sex classes. Our findings suggest that the density, stiffness, permeability, size and shape of the distal primary feathers and wing tips can explain aerodynamic differences between individuals and the efficiency of groups in escape situations. ADDITIONAL KEYWORDS: distal primary feathers-feather tip-flock coordination-predator escape-takeoff-wing tip.
Farmland and migratory bird populations are in decline. The Common quail (Coturnix coturnix) prov... more Farmland and migratory bird populations are in decline. The Common quail (Coturnix coturnix) provides an exception to this trend and its populations have remained stable over the last two decades. However, some basic facts regarding quail biology and ecology, such as the geographic distribution of age and sex classes during the summer, remain poorly understood. We analyzed 43,194 Spanish quail ringing records from 1961 to 2014 to assess the effects of geography and weather conditions on the probability that individuals will be ringed during the various stages of their annual cycle (arrival -spring migration-, stationary breeding period, departure -autumn migration- and winter) for the different quail age-sex classes over time. We found that spatial distribution of the age and sex classes can be explained by date, latitude, longitude, altitude, rainfall, and temperature. Our results suggest that date accounts for most of the variation in the distribution of quail age classes, followe...
The Science of the total environment, Jan 27, 2017
Breeding grounds are key areas for sustaining Common quail (Coturnix coturnix) populations as thi... more Breeding grounds are key areas for sustaining Common quail (Coturnix coturnix) populations as this species is characterised by short life expectancy that requires high offspring production. Annually, breeding quails make up to three breeding attempts in different places. However, the impact of climate warming on quail phenology is unknown. Here, we use a long-term study (1961-2014) of quail-ringing in Spain and data on variation in rainfall and temperature over the past 86years to evaluate how quails have responded to climate change in recent years. Our aim was to understand how this species is adapting to new farming practices and climate change. Our results suggest that increases in temperature and decreases in precipitation modify quail phenology. In hot years, an advance in mean arrival dates and stay stages but a delay in departure dates was found. However, in rainy years a delay in the mean start of the stay stage occurred. In cloudy areas, our findings show that quails advanc...
The dynamics of a wild red-legged partridge population were examined over a 14-year period in Spa... more The dynamics of a wild red-legged partridge population were examined over a 14-year period in Spain to identify patterns in age and sex ratios in relation to weather parameters, and to assess the importance of these parameters in population dynamics and management. The results gave age ratios of 1.07 (but 2.13 in July counts), juvenile sex ratios of 1.01 and adult sex ratios of 1.47. Overall, 12% more females were hatched and female juvenile mortality was 7.3% higher than in males. Sex differential mortality explains the 19.2% deficit in adult females, which are more heavily predated than males during the breeding period. Accordingly, age ratios are dependent on sex ratios and both are density dependent. Over time, ratios and density changes appear to be influenced by weather and management. When the habitat is well conserved, partridge population dynamics can be explained by a causal chain: weather operates on net primary production, thereby affecting partridge reproduction and pre...
Quality breeding areas are vital for the management and conservation of migratory bird species, e... more Quality breeding areas are vital for the management and conservation of migratory bird species, especially those under pressure from climate warming effects. The Common quail Coturnix coturnix is a migratory species characterized by its itinerant breeding (several breeding attempts in different places) and exposure to high mortality rates, and it is a case in point. The identification and management of high quality nesting areas is essential to conserve this and other migratory species. Here, we use a Spanish long-term quail ringing dataset (1961-2014) to correlate population age structure with temporal and geographical variables. We show that northern Mediterranean regions provide optimal breeding sites and have balanced population age structures (young:adult males). The proportion of young:adult males provides an indicator of the relative quality of various breeding areas. Records of ringed quail provide data on the overlap between young and adult males temporarily resident in different geographic areas and may provide a useful tool to evaluate habitat quality. We found that the timing of sequential breeding attempts and temporary residency of quail are associated with latitude, altitude, and geographic location of quail ringing records. In southern regions, young males arrive at the breeding area later than adults, while in northern regions young birds and adults arrive at same time. Optimal breeding areas are characterized by high quality habitat, have high quail densities, and a mixture of young and adult males, factors that favour sexual selection, heterozygosity and population viability. However, not all high quality habitat areas are suitable for reproduction, being necessary enough quail density and the adequate proportion of young:adult males.
Afro-paleartic migratory birds can subsist to global change effects. • Migration and nomadism tim... more Afro-paleartic migratory birds can subsist to global change effects. • Migration and nomadism timely distribute groups of age and sex in suitable habitats. • The distribution of quail age and sex class follows variations in weather and habitat suitability. • The migration added to nomadism is consistent with success in finding optimal habitats. • Temporal, spatial, age and sex distributions facilitate offset mortality.
Un reciente trabajo científico analiza por primera vez una de las pocas poblaciones de perdiz roj... more Un reciente trabajo científico analiza por primera vez una de las pocas poblaciones de perdiz roja silvestre de alta densidad que quedan en España. Se trata de la situada en el Campo de Montiel, en Castilla La Mancha. El artículo demuestra cómo una adecuada gestión de las condiciones de la población de las perdices rojas silvestres mejora la biodiversidad del territorio afectado, y aumenta la producción de riqueza natural. El artículo ha sido publicado por la revista Plos One, con sede en San Francisco (California) y en Cambridge (Reino Unido).
Uploads
Papers by Jesus Nadal