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Aivar Leito - One of the best experts on this subject based on the ideXlab platform.
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Shallow genetic population structure in an expanding migratory bird with high breeding site fidelity, the Western Eurasian Crane Grus Grus Grus
Journal of Ornithology, 2019Co-Authors: Martin Haase, Henriette Höltje, Beate Blahy, Damon Bridge, Eberhard Henne, Ulf S. Johansson, Katrin Kaldma, Ekaterina A. Khudyakova, Amy King, Aivar LeitoAbstract:Geringe genetische Populationsstruktur eines sich ausbreitenden Zugvogels mit hoher Brutortreue, des Westlichen Eurasischen Kranichs, Grus Grus Grus Seit mehr als einem halben Jahrhundert breitet sich der Eurasische Kranich ( Grus Grus Grus ) wieder nach Westeuropa bis hin nach Großbritannien, den Niederlanden und Dänemark aus, wo er ausgerottet war. Der Eurasische Kranich ist einerseits eine sehr mobile, ziehende Art. Andererseits ist er territorial und zeichnet sich durch eine hohe Brutplatztreue aus. Die genetische Populationsstruktur ist somit von gegensätzlichen Kräften mit unterschiedlichen Konsequenzen geprägt. Wir ermittelten die Populationsstruktur der Westeuropäischen Population (WEP) des Eurasischen Kranichs basierend auf sechs hochvariablen Mikrosatelliten-Loci und Samples aus acht Regionen. Wir kombinierten klassische F-Statistik einschließlich molekularer Varianzanzanalysen mit a priori festgelegter Struktur mit divisiven Clusteranalysen—einer Bayes’schen Methode (STRUCTURE) und einer Diskriminanzanalyse von Hauptkomponenten (DAPC)–, die die Struktur a posteriori schätzen. Die F-Statistik zeigte, dass die Populationen nur gering differenziert waren. Der Großteil der genetischen Varianz (> 90%) lag auf Ebene der Individuen. Auf den ersten Blick schienen die divisiven Ansätze ein übereinstimmendes Bild zu zeichnen. Beide fanden vier Cluster. Allerdings gab es keinerlei Übereinstimmung in der Zusammensetzung der Cluster und keines der Resultate war biologisch sinnvoll. STRUCTURE wies allerdings die höchste Wahrscheinlichkeit einem Szenario ohne Populationsunterteilung zu und lieferte somit eine alternative Interpretation, die mit der F-Statistik übereinstimmte. Daher schließen wir, dass die WEP des Eurasischen Kranichs weitestgehend homogen ist. For more than half a century, the Western Eurasian Crane ( Grus Grus Grus ) has been expanding its range toward western Europe, recolonizing areas where it had been previously driven to extinction, including the UK, the Netherlands and Denmark. The Western Eurasian Crane is, on the one hand, a very mobile, migratory species, but on the other, is territorial and shows high breeding site fidelity. Hence, its genetic population structure is subject to antagonizing forces, which have different consequences. Based on the genotyping of six highly variable microsatellite loci, we inferred the population structure of the Western Eurasian Crane from samples from eight regions. We integrated classic F -statistics including analyses of molecular variance with a priori designation of structure and divisive clustering approaches, i.e. a Bayesian procedure (STRUCTURE) and discriminant analysis of principal components, which infer structure a posteriori. According to the F -statistics, populations were only weakly differentiated, and the majority of the genetic variance (> 90%) was attributed to individuals. At first glance, the divisive approaches appeared to agree in finding four clusters. Yet, there was no correspondence regarding the composition of the clusters and none of the results were biologically meaningful. However, STRUCTURE delivered an alternative interpretation, designating the highest likelihood to a scenario without subdivision, in clear agreement with the findings based on the F -statistics. In conclusion, the Western Eurasian Crane is genetically largely homogeneous, probably as a consequence of the rapid growth and range expansion of its population.
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Shallow genetic population structure in an expanding migratory bird with high breeding site fidelity, the Western Eurasian Crane Grus Grus Grus
Journal of Ornithology, 2019Co-Authors: Martin Haase, Henriette Höltje, Beate Blahy, Damon Bridge, Eberhard Henne, Ulf S. Johansson, Katrin Kaldma, Ekaterina A. Khudyakova, Amy King, Aivar LeitoAbstract:Geringe genetische Populationsstruktur eines sich ausbreitenden Zugvogels mit hoher Brutortreue, des Westlichen Eurasischen Kranichs, Grus Grus Grus Seit mehr als einem halben Jahrhundert breitet sich der Eurasische Kranich ( Grus Grus Grus ) wieder nach Westeuropa bis hin nach Großbritannien, den Niederlanden und Dänemark aus, wo er ausgerottet war. Der Eurasische Kranich ist einerseits eine sehr mobile, ziehende Art. Andererseits ist er territorial und zeichnet sich durch eine hohe Brutplatztreue aus. Die genetische Populationsstruktur ist somit von gegensätzlichen Kräften mit unterschiedlichen Konsequenzen geprägt. Wir ermittelten die Populationsstruktur der Westeuropäischen Population (WEP) des Eurasischen Kranichs basierend auf sechs hochvariablen Mikrosatelliten-Loci und Samples aus acht Regionen. Wir kombinierten klassische F-Statistik einschließlich molekularer Varianzanzanalysen mit a priori festgelegter Struktur mit divisiven Clusteranalysen—einer Bayes’schen Methode (STRUCTURE) und einer Diskriminanzanalyse von Hauptkomponenten (DAPC)–, die die Struktur a posteriori schätzen. Die F-Statistik zeigte, dass die Populationen nur gering differenziert waren. Der Großteil der genetischen Varianz (> 90%) lag auf Ebene der Individuen. Auf den ersten Blick schienen die divisiven Ansätze ein übereinstimmendes Bild zu zeichnen. Beide fanden vier Cluster. Allerdings gab es keinerlei Übereinstimmung in der Zusammensetzung der Cluster und keines der Resultate war biologisch sinnvoll. STRUCTURE wies allerdings die höchste Wahrscheinlichkeit einem Szenario ohne Populationsunterteilung zu und lieferte somit eine alternative Interpretation, die mit der F-Statistik übereinstimmte. Daher schließen wir, dass die WEP des Eurasischen Kranichs weitestgehend homogen ist. For more than half a century, the Western Eurasian Crane ( Grus Grus Grus ) has been expanding its range toward western Europe, recolonizing areas where it had been previously driven to extinction, including the UK, the Netherlands and Denmark. The Western Eurasian Crane is, on the one hand, a very mobile, migratory species, but on the other, is territorial and shows high breeding site fidelity. Hence, its genetic population structure is subject to antagonizing forces, which have different consequences. Based on the genotyping of six highly variable microsatellite loci, we inferred the population structure of the Western Eurasian Crane from samples from eight regions. We integrated classic F -statistics including analyses of molecular variance with a priori designation of structure and divisive clustering approaches, i.e. a Bayesian procedure (STRUCTURE) and discriminant analysis of principal components, which infer structure a posteriori. According to the F -statistics, populations were only weakly differentiated, and the majority of the genetic variance (> 90%) was attributed to individuals. At first glance, the divisive approaches appeared to agree in finding four clusters. Yet, there was no correspondence regarding the composition of the clusters and none of the results were biologically meaningful. However, STRUCTURE delivered an alternative interpretation, designating the highest likelihood to a scenario without subdivision, in clear agreement with the findings based on the F -statistics. In conclusion, the Western Eurasian Crane is genetically largely homogeneous, probably as a consequence of the rapid growth and range expansion of its population.
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Shallow genetic population structure in an expanding migratory bird with high breeding site fidelity, the Western Eurasian Crane Grus Grus Grus
Journal of Ornithology, 2019Co-Authors: Martin Haase, Henriette Höltje, Beate Blahy, Damon Bridge, Eberhard Henne, Ulf S. Johansson, Katrin Kaldma, Ekaterina A. Khudyakova, Amy King, Aivar LeitoAbstract:For more than half a century, the Western Eurasian Crane (Grus Grus Grus) has been expanding its range toward western Europe, recolonizing areas where it had been previously driven to extinction, including the UK, the Netherlands and Denmark. The Western Eurasian Crane is, on the one hand, a very mobile, migratory species, but on the other, is territorial and shows high breeding site fidelity. Hence, its genetic population structure is subject to antagonizing forces, which have different consequences. Based on the genotyping of six highly variable microsatellite loci, we inferred the population structure of the Western Eurasian Crane from samples from eight regions. We integrated classic F-statistics including analyses of molecular variance with a priori designation of structure and divisive clustering approaches, i.e. a Bayesian procedure (STRUCTURE) and discriminant analysis of principal components, which infer structure a posteriori. According to the F-statistics, populations were only weakly differentiated, and the majority of the genetic variance (> 90%) was attributed to individuals. At first glance, the divisive approaches appeared to agree in finding four clusters. Yet, there was no correspondence regarding the composition of the clusters and none of the results were biologically meaningful. However, STRUCTURE delivered an alternative interpretation, designating the highest likelihood to a scenario without subdivision, in clear agreement with the findings based on the F-statistics. In conclusion, the Western Eurasian Crane is genetically largely homogeneous, probably as a consequence of the rapid growth and range expansion of its population.
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The potential impacts of changes in ecological networks, land use and climate on the Eurasian crane population in Estonia
Landscape Ecology, 2015Co-Authors: Aivar Leito, Robert G.h. Bunce, Mart Külvik, Ivar Ojaste, Janar Raet, Miguel Villoslada, Meelis Leivits, Anne Kull, Valdo Kuusemets, Tiiu KullAbstract:Context The Eurasian crane ( Grus Grus ) is an iconic and sensitive species. It is therefore necessary to understand its landscape ecology in order to determine threats. Objectives (1) To map the distribution of cranes and then model their habitat requirements in Estonia, linked to the current level of protection. (2) To determine the environmental characteristics of, and the habitats present in, sites utilized by the birds, and their sensitivity to change. Methods (1) The distribution of cranes was recorded by observation and by tracking individuals. A model of potential breeding sites was compared with the occurrence of the bird in Estonia and then linked to protected sites. (2) The seasonal distribution of the bird was overlaid with a European environmental classification and the CORINE land cover map. A model of climate change was also utilized. Results (1) A new map of European migration routes, wintering and stopover sites is presented. (2) The bird requires a habitat network, with wetlands being essential for nesting and roosting. The composition of habitats used for feeding varies according to geographical location. (3) In Estonia not all potential breeding sites are occupied and many existing sites are not protected. (4) Climate change could threaten populations in the south but could be beneficial in Estonia. Conclusions (1) The existing ecological network in Estonia is adequate to maintain a viable breeding population of the Eurasian crane. (2) Climate change could support the breeding of cranes but complicate their migration and wintering.
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The potential impacts of changes in ecological networks, land use and climate on the Eurasian crane population in Estonia
Landscape Ecology, 2015Co-Authors: Aivar Leito, Robert G.h. Bunce, Mart Külvik, Ivar Ojaste, Janar Raet, Miguel Villoslada, Meelis Leivits, Anne Kull, Valdo Kuusemets, Tiiu KullAbstract:Context The Eurasian crane (Grus Grus) is an iconic and sensitive species. It is therefore necessary to understand its landscape ecology in order to determine threats.
Juan C. Alonso - One of the best experts on this subject based on the ideXlab platform.
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A simple strategy for improving bird sexing from highly degraded DNA samples
Conservation Genetics Resources, 2019Co-Authors: Francisco Morinha, Luis M. Bautista, Marlene Monteiro, Juan C. AlonsoAbstract:A simple methodology was developed to select new sex-specific primers for bird sexing from degraded and low-quantity DNA sources. The strategy was validated using highly degraded DNA extracted from Giemsa-stained blood smears of common cranes ( Grus Grus ). The new primers allowed the accurate molecular sexing using (i) a classic approach of PCR followed by agarose gel electrophoresis and (ii) an advanced real-time PCR method. The simplicity, speed and low cost make this methodology a versatile molecular tool for selection of novel markers/primers for bird sex differentiation from complex DNA sources, which can be used as basis or complement in several fields of ornithological research.
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FACTORS INFLUENCING DAILY FOOD-INTAKE PATTERNS IN BIRDS: A CASE STUDY WITH WINTERING COMMON CRANES
The Condor, 2013Co-Authors: Luis M. Bautista, Juan C. AlonsoAbstract:Abstract. Avian foraging activity during daytime peaks after dawn and before dusk. The relative importance of each period of intensive foraging on the accumulated intake varies by species, individual, and day. We studied the relative importance of each period from direct observation of radio-tagged Common Cranes (Grus Grus) during winter at a site of stopover and wintering in Spain. After a mathematical model was fitted, accumulated intake showed a typical anti-sigmoid shape, with greatest increases of intake after dawn and before dusk. The rise of accumulated intake decelerated until 50% of the day length, when the trajectory inflected and accelerated according to the fitted model. The trajectory of accumulated intake in territorial families that foraged in small home ranges with food predictably available but the cost of vigilance high decelerated until 20% of the day length, then accelerated for the rest of the day. In flocking nonterritorial cranes the inflection point was delayed until 60% of the day...
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Migration and wintering patterns of a central European population of Common Cranes Grus Grus
Bird Study, 2008Co-Authors: Javier A. Alonso, Juan C. Alonso, Gunter NowaldAbstract:Capsule German breeding birds wintered mainly in southwest Spain and some in France. Aims To describe migration routes and phenology, and the interannual fidelity to staging and wintering sites. Methods A total of 93 cranes were colour-banded, and 67 of them radiotagged, at their breeding territories in northern Germany and later located at their wintering areas in Spain. Results After a migratory trip lasting 3‐28 days, most cranes arrived at Gallocanta in northeastern Spain, where they staged for 1‐44 days. Some families stayed there the whole winter, but most continued to southwestern Iberia, where they dispersed over at least 13 wintering areas. Site fidelity was more marked in adult pairs than immatures, half of which used different areas in their second and third winters from those used by their parents. Conclusions Most German cranes wintered in southwestern Spain, with smaller numbers in France. Some immatures remained in France as second- or third-year birds, after having spent their first winter in Spain with their parents, whereas none of them shifted southwards. This suggests that immatures have probably contributed more than adult pairs to the northward shift in the winter range observed during the last decades.
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Family-based territoriality vs flocking in wintering common cranes Grus Grus
Journal of Avian Biology, 2004Co-Authors: Juan C. Alonso, Luis M. Bautista, Javier A. AlonsoAbstract:is a contribution to project PB91-0081 of the Direccion General de Investigacion Cientifica y Tecnica.
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Modelling state-dependent interference in common cranes
Journal of Animal Ecology, 2002Co-Authors: Richard A. Stillman, Luis M. Bautista, Juan C. Alonso, Javier A. AlonsoAbstract:Summary 1. Interference is a key component of food competition, but is difficult to measure in natural animal populations. Using data from a long-term study, we show that interference between common cranes Grus Grus L., feeding on patches of cereal seeds, reduces intake rates at high competitor densities, and that the strength of interference is unrelated to food abundance. 2. An alternative to measuring interference directly is to predict its strength using behaviour-based models. We test an interference model, originally developed for shorebirds feeding on invertebrate prey, for cranes. We compare the predictions of a rate-maximizing model, in which animals steal food if this increases intake rate, and a state-dependent model, in which they only rate-maximize if their intake rate is below a target value, otherwise they minimize injury risk by not stealing food. State-dependent aggression occurs in cranes. 3. The state-dependent model predicts more accurately the relative aggression rates of cranes of different dominance. However, both models predict accurately the observed strength of interference, that the strength of interference is unrelated to food abundance, at least within the observed range of crane and seed densities, and that cranes of a higher dominance have a higher intake rate than those of lower dominance. 4. This paper shows how state-dependent behaviour can be incorporated into an interference model, and that the model can produce accurate predictions for a system quite different to that for which it was developed.
Martin Haase - One of the best experts on this subject based on the ideXlab platform.
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Shallow genetic population structure in an expanding migratory bird with high breeding site fidelity, the Western Eurasian Crane Grus Grus Grus
Journal of Ornithology, 2019Co-Authors: Martin Haase, Henriette Höltje, Beate Blahy, Damon Bridge, Eberhard Henne, Ulf S. Johansson, Katrin Kaldma, Ekaterina A. Khudyakova, Amy King, Aivar LeitoAbstract:Geringe genetische Populationsstruktur eines sich ausbreitenden Zugvogels mit hoher Brutortreue, des Westlichen Eurasischen Kranichs, Grus Grus Grus Seit mehr als einem halben Jahrhundert breitet sich der Eurasische Kranich ( Grus Grus Grus ) wieder nach Westeuropa bis hin nach Großbritannien, den Niederlanden und Dänemark aus, wo er ausgerottet war. Der Eurasische Kranich ist einerseits eine sehr mobile, ziehende Art. Andererseits ist er territorial und zeichnet sich durch eine hohe Brutplatztreue aus. Die genetische Populationsstruktur ist somit von gegensätzlichen Kräften mit unterschiedlichen Konsequenzen geprägt. Wir ermittelten die Populationsstruktur der Westeuropäischen Population (WEP) des Eurasischen Kranichs basierend auf sechs hochvariablen Mikrosatelliten-Loci und Samples aus acht Regionen. Wir kombinierten klassische F-Statistik einschließlich molekularer Varianzanzanalysen mit a priori festgelegter Struktur mit divisiven Clusteranalysen—einer Bayes’schen Methode (STRUCTURE) und einer Diskriminanzanalyse von Hauptkomponenten (DAPC)–, die die Struktur a posteriori schätzen. Die F-Statistik zeigte, dass die Populationen nur gering differenziert waren. Der Großteil der genetischen Varianz (> 90%) lag auf Ebene der Individuen. Auf den ersten Blick schienen die divisiven Ansätze ein übereinstimmendes Bild zu zeichnen. Beide fanden vier Cluster. Allerdings gab es keinerlei Übereinstimmung in der Zusammensetzung der Cluster und keines der Resultate war biologisch sinnvoll. STRUCTURE wies allerdings die höchste Wahrscheinlichkeit einem Szenario ohne Populationsunterteilung zu und lieferte somit eine alternative Interpretation, die mit der F-Statistik übereinstimmte. Daher schließen wir, dass die WEP des Eurasischen Kranichs weitestgehend homogen ist. For more than half a century, the Western Eurasian Crane ( Grus Grus Grus ) has been expanding its range toward western Europe, recolonizing areas where it had been previously driven to extinction, including the UK, the Netherlands and Denmark. The Western Eurasian Crane is, on the one hand, a very mobile, migratory species, but on the other, is territorial and shows high breeding site fidelity. Hence, its genetic population structure is subject to antagonizing forces, which have different consequences. Based on the genotyping of six highly variable microsatellite loci, we inferred the population structure of the Western Eurasian Crane from samples from eight regions. We integrated classic F -statistics including analyses of molecular variance with a priori designation of structure and divisive clustering approaches, i.e. a Bayesian procedure (STRUCTURE) and discriminant analysis of principal components, which infer structure a posteriori. According to the F -statistics, populations were only weakly differentiated, and the majority of the genetic variance (> 90%) was attributed to individuals. At first glance, the divisive approaches appeared to agree in finding four clusters. Yet, there was no correspondence regarding the composition of the clusters and none of the results were biologically meaningful. However, STRUCTURE delivered an alternative interpretation, designating the highest likelihood to a scenario without subdivision, in clear agreement with the findings based on the F -statistics. In conclusion, the Western Eurasian Crane is genetically largely homogeneous, probably as a consequence of the rapid growth and range expansion of its population.
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Shallow genetic population structure in an expanding migratory bird with high breeding site fidelity, the Western Eurasian Crane Grus Grus Grus
Journal of Ornithology, 2019Co-Authors: Martin Haase, Henriette Höltje, Beate Blahy, Damon Bridge, Eberhard Henne, Ulf S. Johansson, Katrin Kaldma, Ekaterina A. Khudyakova, Amy King, Aivar LeitoAbstract:Geringe genetische Populationsstruktur eines sich ausbreitenden Zugvogels mit hoher Brutortreue, des Westlichen Eurasischen Kranichs, Grus Grus Grus Seit mehr als einem halben Jahrhundert breitet sich der Eurasische Kranich ( Grus Grus Grus ) wieder nach Westeuropa bis hin nach Großbritannien, den Niederlanden und Dänemark aus, wo er ausgerottet war. Der Eurasische Kranich ist einerseits eine sehr mobile, ziehende Art. Andererseits ist er territorial und zeichnet sich durch eine hohe Brutplatztreue aus. Die genetische Populationsstruktur ist somit von gegensätzlichen Kräften mit unterschiedlichen Konsequenzen geprägt. Wir ermittelten die Populationsstruktur der Westeuropäischen Population (WEP) des Eurasischen Kranichs basierend auf sechs hochvariablen Mikrosatelliten-Loci und Samples aus acht Regionen. Wir kombinierten klassische F-Statistik einschließlich molekularer Varianzanzanalysen mit a priori festgelegter Struktur mit divisiven Clusteranalysen—einer Bayes’schen Methode (STRUCTURE) und einer Diskriminanzanalyse von Hauptkomponenten (DAPC)–, die die Struktur a posteriori schätzen. Die F-Statistik zeigte, dass die Populationen nur gering differenziert waren. Der Großteil der genetischen Varianz (> 90%) lag auf Ebene der Individuen. Auf den ersten Blick schienen die divisiven Ansätze ein übereinstimmendes Bild zu zeichnen. Beide fanden vier Cluster. Allerdings gab es keinerlei Übereinstimmung in der Zusammensetzung der Cluster und keines der Resultate war biologisch sinnvoll. STRUCTURE wies allerdings die höchste Wahrscheinlichkeit einem Szenario ohne Populationsunterteilung zu und lieferte somit eine alternative Interpretation, die mit der F-Statistik übereinstimmte. Daher schließen wir, dass die WEP des Eurasischen Kranichs weitestgehend homogen ist. For more than half a century, the Western Eurasian Crane ( Grus Grus Grus ) has been expanding its range toward western Europe, recolonizing areas where it had been previously driven to extinction, including the UK, the Netherlands and Denmark. The Western Eurasian Crane is, on the one hand, a very mobile, migratory species, but on the other, is territorial and shows high breeding site fidelity. Hence, its genetic population structure is subject to antagonizing forces, which have different consequences. Based on the genotyping of six highly variable microsatellite loci, we inferred the population structure of the Western Eurasian Crane from samples from eight regions. We integrated classic F -statistics including analyses of molecular variance with a priori designation of structure and divisive clustering approaches, i.e. a Bayesian procedure (STRUCTURE) and discriminant analysis of principal components, which infer structure a posteriori. According to the F -statistics, populations were only weakly differentiated, and the majority of the genetic variance (> 90%) was attributed to individuals. At first glance, the divisive approaches appeared to agree in finding four clusters. Yet, there was no correspondence regarding the composition of the clusters and none of the results were biologically meaningful. However, STRUCTURE delivered an alternative interpretation, designating the highest likelihood to a scenario without subdivision, in clear agreement with the findings based on the F -statistics. In conclusion, the Western Eurasian Crane is genetically largely homogeneous, probably as a consequence of the rapid growth and range expansion of its population.
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Shallow genetic population structure in an expanding migratory bird with high breeding site fidelity, the Western Eurasian Crane Grus Grus Grus
Journal of Ornithology, 2019Co-Authors: Martin Haase, Henriette Höltje, Beate Blahy, Damon Bridge, Eberhard Henne, Ulf S. Johansson, Katrin Kaldma, Ekaterina A. Khudyakova, Amy King, Aivar LeitoAbstract:For more than half a century, the Western Eurasian Crane (Grus Grus Grus) has been expanding its range toward western Europe, recolonizing areas where it had been previously driven to extinction, including the UK, the Netherlands and Denmark. The Western Eurasian Crane is, on the one hand, a very mobile, migratory species, but on the other, is territorial and shows high breeding site fidelity. Hence, its genetic population structure is subject to antagonizing forces, which have different consequences. Based on the genotyping of six highly variable microsatellite loci, we inferred the population structure of the Western Eurasian Crane from samples from eight regions. We integrated classic F-statistics including analyses of molecular variance with a priori designation of structure and divisive clustering approaches, i.e. a Bayesian procedure (STRUCTURE) and discriminant analysis of principal components, which infer structure a posteriori. According to the F-statistics, populations were only weakly differentiated, and the majority of the genetic variance (> 90%) was attributed to individuals. At first glance, the divisive approaches appeared to agree in finding four clusters. Yet, there was no correspondence regarding the composition of the clusters and none of the results were biologically meaningful. However, STRUCTURE delivered an alternative interpretation, designating the highest likelihood to a scenario without subdivision, in clear agreement with the findings based on the F-statistics. In conclusion, the Western Eurasian Crane is genetically largely homogeneous, probably as a consequence of the rapid growth and range expansion of its population.
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Genetic evidence of female specific eggshell colouration in the Common Crane (Grus Grus)
Journal of Ornithology, 2016Co-Authors: Henriette Höltje, Martin Haase, Wolfgang Mewes, Angela Schmitz OrnésAbstract:The large variation in colouration and patterning of bird eggs suggests a variety of functions. For instance, in cases of intra- and inter-specific brood parasitism, the recognition of own eggs by the parents could be essential for their reproductive success. However, individual specific signatures may also be of interest from an applied point of view, as it would be possible to monitor individual females across breeding seasons by identifying their eggs. This would be of particular importance for species that are difficult to catch and ring such as the Common Crane ( Grus Grus ). Since 2004, nest monitoring of this species has been conducted by one of us (W.M.) in north-east Germany, which led to the development of a semi-quantitative method to identify female cranes by diagnostic egg features including ground colour and spots of eggshells. In order to verify this approach, we quantitatively determined the spot patterns on eggshells from eggs of 19 females identified by this method. We used standardised photographs of the eggs laid across three seasons and the computer program “Egg Shell Pattern ANAlysis” (ESPANA). The resulting data were statistically analysed by conducting principal coordinate analyses and analyses of similarity. To prove the identity of the putative females, we extracted DNA for microsatellite analyses from eggshell pieces collected after hatching from up to seven breeding seasons. Our analyses confirmed that Common Cranes lay eggs with individual specific patterns and confirmed the reliability of the semi-quantitative method of identification. Microsatellite genotypes based on nine loci were identical for all samples from each particular, putative female. Therefore, the semi-quantitative approach of identifying females based on their clutches is indeed an innovative monitoring tool that will make many species accessible for addressing important issues in population biology, ecology and conservation. Genetischer Nachweis für individuelle Eierschalenfärbung von Kranichweibchen ( Grus Grus ) Die Vielfalt in der Färbung und Zeichnung von Vogeleiern legt eine Reihe an möglichen Funktionen nahe. So könnte im Fall von intra- oder interspezifischem Brutparasitismus das Erkennen der eigenen Eier eine wichtige Rolle für den Fortpflanzungserfolg der Eltern spielen. Individuell spezifische Signaturen könnten zu dem von Interesse sein, wenn dadurch ein Monitoring von Weibchen währende der Brutzeit ermöglicht würde. Dies wäre von besonderer Bedeutung für die Arten, die nur schwer individuell unterschieden oder markiert werden können, wie beispielsweise den Grauen Kranich ( Grus Grus ). Ein in Norddeutschland laufendes Brutmonitoring führte 2004 zur Entwicklung einer semi-quantitativen Methode, die die Identifizierung von Kranichweibchen anhand von Eiermerkmalen, wie der Eischalengrundfarbe und der Fleckenzeichung ermöglichte. Zur Verifizierung der Methode wurde die Eischalenmusterung von 19 durch sie individuell identifizierten Kranichweibchen quantitativ bestimmt. Grundlage waren standardisierte Fotografien von Eiern aus drei Brutperioden, die mit dem Computerprogramm „Egg Shell Pattern ANAlysis” (ESPANA) analysiert wurden. Die gewonnenen Daten wurden mittels einer Hauptkoordinatenanalyse (PCoA) und einer Ähnlichkeitsanalyse (ANOSIM) statistisch ausgewertet. Um die Identität der angenommen Kranichweibchen zu beweisen, extrahierten wir aus Eierschalenstücken, die nach dem Schlupf der Küken über mehrere Brutperioden gesammelt wurden, DNA für Mikrosatellitenanalysen. Unsere Analysen bestätigten, dass Kranichweibchen Eier mit individuell spezifischen Mustern legen, und damit auch die semi-quantitative Identifizierungsmethode. Die mittels neun Loci bestimmten Genotypen waren für die angenommenen Kranichweibchen über alle Proben identisch. Somit ist die semi-quantitative Methode zur Identifizierung von Kranichweibchen anhand ihrer Gelege ein innovatives Werkzeug zum Monitoring, um auch andere Arten für Fragen der Populationsbiologie, der Ökologie und des Naturschutzes zugänglich zu machen.
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Genetic evidence of female specific eggshell colouration in the Common Crane ( Grus Grus )
Journal of Ornithology, 2015Co-Authors: Henriette Höltje, Martin Haase, Wolfgang Mewes, Angela Schmitz OrnésAbstract:The large variation in colouration and patterning of bird eggs suggests a variety of functions. For instance, in cases of intra- and inter-specific brood parasitism, the recognition of own eggs by the parents could be essential for their reproductive success. However, individual specific signatures may also be of interest from an applied point of view, as it would be possible to monitor individual females across breeding seasons by identifying their eggs. This would be of particular importance for species that are difficult to catch and ring such as the Common Crane (Grus Grus). Since 2004, nest monitoring of this species has been conducted by one of us (W.M.) in north-east Germany, which led to the development of a semi-quantitative method to identify female cranes by diagnostic egg features including ground colour and spots of eggshells. In order to verify this approach, we quantitatively determined the spot patterns on eggshells from eggs of 19 females identified by this method. We used standardised photographs of the eggs laid across three seasons and the computer program “Egg Shell Pattern ANAlysis” (ESPANA). The resulting data were statistically analysed by conducting principal coordinate analyses and analyses of similarity. To prove the identity of the putative females, we extracted DNA for microsatellite analyses from eggshell pieces collected after hatching from up to seven breeding seasons. Our analyses confirmed that Common Cranes lay eggs with individual specific patterns and confirmed the reliability of the semi-quantitative method of identification. Microsatellite genotypes based on nine loci were identical for all samples from each particular, putative female. Therefore, the semi-quantitative approach of identifying females based on their clutches is indeed an innovative monitoring tool that will make many species accessible for addressing important issues in population biology, ecology and conservation.
Jesús M. Avilés - One of the best experts on this subject based on the ideXlab platform.
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How do vigilance and feeding by common cranes Grus Grus depend on age, habitat, and flock size?
Journal of Avian Biology, 2007Co-Authors: Jesús M. Avilés, Peter A. BednekoffAbstract:Animals often spend less time vigilant and more time feeding when foraging in larger groups. This group-size effect does not, however, consider if larger groups differ systematically from smaller ones: Large groups could form in different habitats than small groups or be composed of a different mix of ages or classes than small groups. We examined how habitat differences and flock size and composition explain feeding and vigilance rates in common cranes Grus Grus, wintering in holm oak Quercus ilex dehesas of Spain. Flock size and composition were related to habitat type in cranes: flocks formed in areas sown with cereal crops were larger than flocks formed in set aside areas. Vigilance rate depended on habitat but decreased with increasing flock size in a similar way across all habitats. Juveniles were less vigilant than adults and showed little change in vigilance with flock size. Vigilance increased and feeding time decreased over months from November through February. Our results show that vigilance is affected by habitat but that the group size effect on vigilance is not the product of differences between habitats in group size or composition.
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Food selection of wintering common cranes (Grus Grus) in holm oak (Quercus ilex) dehesas in south-west Spain in a rainy season
Journal of Zoology, 2006Co-Authors: Jesús M. Avilés, J.m. Sánchez, Deseada ParejoAbstract:In the holm oak Quercus ilex dehesas of the Iberian Peninsula, several food types occur that can be selected by birds through the winter. In this framework, diet composition and diet selection of common cranes Grus Grus was studied during a rainy wintering season. The winter diet of the common crane is mostly herbivorous in the holm oak dehesas of south-west Spain with
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Common cranesGrus Grus and habitat management in holm oak dehesas of Spain
Biodiversity & Conservation, 2004Co-Authors: Jesús M. AvilésAbstract:Changes in agricultural policies have favored tree clearing and removal of shrubs to favor intensive farming in the holm oak Quercus ilex dehesas of Iberia. The effect of these changes for bird species wintering in this agricultural landscape has been rarely analyzed. Here the effects are studied of farming changes in traditional holm oak dehesas on population size, social structure and time budget of common cranes Grus Grus in eight traditional wintering sites in Spain. The role of acorn availability, the principal winter food of the species, in relation to management is also assessed. The number of cranes in each wintering area was not related to degree of agricultural intensification, nor to the availability of acorns. However, crane flock size decreased, and the relative occurrence of isolated family groups increased in less intensively transformed wintering areas characterized by the predominance of fallow lands. The age composition of crane flocks varied with acorn availability since more juveniles were reported in areas with relatively lower acorn availability. Time budget was also related to acorn availability, since cranes spent relatively more time preening in those wintering areas with higher availability of acorns. Globally evidence suggests the need to maintain the fallow land (posíos) to sustain the wintering populations of cranes in Iberia, since this agro-grazing system maintains most of the juvenile cranes using the western migratory route.
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Common cranes Grus Grus and habitat management in holm oak dehesas of Spain
Biodiversity and Conservation, 2004Co-Authors: Jesús M. AvilésAbstract:Changes in agricultural policies have favored tree clearing and removal of shrubs to favor intensive farming in the holm oakQuercus ilex dehesas of Iberia. The effect of these changes for bird species wintering in this agricultural landscape has been rarely analyzed. Here the effects are studied of farming changes in traditional holm oak dehesas on population size, social structure and time budget of common cranesGrus Grus in eight traditional wintering sites in Spain. The role of acorn availability, the principal winter food of the species, in relation to management is also assessed. The number of cranes in each wintering area was not related to degree of agricultural intensification, nor to the availability of acorns. However, crane flock size decreased, and the relative occurrence of isolated family groups increased in less intensively transformed wintering areas characterized by the predominance of fallow lands. The age composition of crane flocks varied with acorn availability since more juveniles were reported in areas with relatively lower acorn availability. Time budget was also related to acorn availability, since cranes spent relatively more time preening in those wintering areas with higher availability of acorns. Globally evidence suggests the need to maintain the fallow land (posios) to sustain the wintering populations of cranes in Iberia, since this agro-grazing system maintains most of the juvenile cranes using the western migratory route.
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Time budget and habitat use of the Common Crane wintering in dehesas of southwestern Spain
Canadian Journal of Zoology, 2003Co-Authors: Jesús M. AvilésAbstract:In many bird species juvenile inexperience drastically reduces their survival, and parents must provide for them. I tested whether time budget and habitat use in adult wintering Common Cranes (Grus Grus) in dehesas (pastoral woodland) of western Spain were affected by the presence of juveniles. Juvenile cranes devote less time to vigilance and spend more time feeding than adults in dehesas. Likewise, juveniles are involved in fewer aggressive encounters than adult cranes. Contrary to expectation, adults accompanied by juveniles devoted the same amount of time to vigilance and feeding and had the same intake rate than adults without juveniles in attendance. However, adult cranes with offspring in attendance were involved in more aggressive encounters than adults without juveniles in attendance when both adult groups were involved in large flocks. In contrast, when adults accompanied by juveniles were in small flocks they were involved in fewer aggressive encounters than adults without juveniles. I also det...
Javier A. Alonso - One of the best experts on this subject based on the ideXlab platform.
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Migration and wintering patterns of a central European population of Common Cranes Grus Grus
Bird Study, 2008Co-Authors: Javier A. Alonso, Juan C. Alonso, Gunter NowaldAbstract:Capsule German breeding birds wintered mainly in southwest Spain and some in France. Aims To describe migration routes and phenology, and the interannual fidelity to staging and wintering sites. Methods A total of 93 cranes were colour-banded, and 67 of them radiotagged, at their breeding territories in northern Germany and later located at their wintering areas in Spain. Results After a migratory trip lasting 3‐28 days, most cranes arrived at Gallocanta in northeastern Spain, where they staged for 1‐44 days. Some families stayed there the whole winter, but most continued to southwestern Iberia, where they dispersed over at least 13 wintering areas. Site fidelity was more marked in adult pairs than immatures, half of which used different areas in their second and third winters from those used by their parents. Conclusions Most German cranes wintered in southwestern Spain, with smaller numbers in France. Some immatures remained in France as second- or third-year birds, after having spent their first winter in Spain with their parents, whereas none of them shifted southwards. This suggests that immatures have probably contributed more than adult pairs to the northward shift in the winter range observed during the last decades.
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Family-based territoriality vs flocking in wintering common cranes Grus Grus
Journal of Avian Biology, 2004Co-Authors: Juan C. Alonso, Luis M. Bautista, Javier A. AlonsoAbstract:is a contribution to project PB91-0081 of the Direccion General de Investigacion Cientifica y Tecnica.
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Modelling state-dependent interference in common cranes
Journal of Animal Ecology, 2002Co-Authors: Richard A. Stillman, Luis M. Bautista, Juan C. Alonso, Javier A. AlonsoAbstract:Summary 1. Interference is a key component of food competition, but is difficult to measure in natural animal populations. Using data from a long-term study, we show that interference between common cranes Grus Grus L., feeding on patches of cereal seeds, reduces intake rates at high competitor densities, and that the strength of interference is unrelated to food abundance. 2. An alternative to measuring interference directly is to predict its strength using behaviour-based models. We test an interference model, originally developed for shorebirds feeding on invertebrate prey, for cranes. We compare the predictions of a rate-maximizing model, in which animals steal food if this increases intake rate, and a state-dependent model, in which they only rate-maximize if their intake rate is below a target value, otherwise they minimize injury risk by not stealing food. State-dependent aggression occurs in cranes. 3. The state-dependent model predicts more accurately the relative aggression rates of cranes of different dominance. However, both models predict accurately the observed strength of interference, that the strength of interference is unrelated to food abundance, at least within the observed range of crane and seed densities, and that cranes of a higher dominance have a higher intake rate than those of lower dominance. 4. This paper shows how state-dependent behaviour can be incorporated into an interference model, and that the model can produce accurate predictions for a system quite different to that for which it was developed.
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Patch use in cranes: a field test of optimal foraging predictions
Animal Behaviour, 1995Co-Authors: Juan C. Alonso, Luis M. Bautista, Javier A. Alonso, Rodrigo Muñoz-pulidoAbstract:Abstract The marginal value theorem states that foragers should leave patches when the instantaneous capture rate has fallen to the average capture rate for the habitat. This predicts that patch residence time should increase with increasing patch quality and decrease with increasing habitat quality. These and other predictions from prescient, Bayesian and fixed-time models were tested using observations on 14 radio-tagged free-living common cranes,Grus Grus, foraging in cereal farmland. Cranes behaved as Bayesian foragers. Their intake rates on leaving patches changed with patch and habitat quality. The behaviour of cranes was consistent with marginal value theorem predictions only in patches where energy return was lower than required to meet daily food requirements. In contrast, birds left richer patches earlier than expected and at higher intake rates than poor patches. In addition, cranes stayed longer in larger flocks. These results suggest that cranes changed their foraging rules according to their expected energy balance.
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Blood values of common cranes (Grus Grus) by age and season
Comparative Biochemistry and Physiology Part A: Physiology, 1993Co-Authors: M. Abelenda, Luis M. Bautista, Maria Paz Nava, Alfonso Fernández, Javier A. Alonso, Juan C. Alonso, Rodrigo Muñoz-pulido, Marisa PuertaAbstract:Abstract 1. 1. We studied the blood composition of common cranes (Grus Grus) along the wintering period (October–March). 2. 2. Plasma proteins decreased along the winter period whereas plasma urea increased. Both parameters were highly correlated. 3. 3. Plasma levels of uric acid, triglycerides and cholesterol did not change during the winter. Young birds showed higher levels of plasma triglycerides. 4. 4. Red blood cell number, hematocrit and blood hemoglobin content were similar in young and adult birds. Lower values of hematocrit and red cell number were recorded in early autumn. 5. 5. Total white blood cell number did not change during the winter, young birds showing higher numbers than adults. Lymphocyte number decreased from November to March while heterophil counts increased.
