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Xiangjiang Zhan - One of the best experts on this subject based on the ideXlab platform.
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Evidence for deleterious effects of harness-mounted satellite transmitters on Saker Falcons Falco cherrug
Bird Study, 2016Co-Authors: Andrew Dixon, Gankhuyag Purev-ochir, Nyambayar Batbayar, Lutfor Rahman, Dimitar Ragyov, Michael W. Bruford, Xiangjiang ZhanAbstract:Capsule This study identifies lethal and sub-lethal effects associated with the deployment of harness-mounted satellite transmitters on a large Falcon species.Aims We examined the effect of harness-mounted satellite transmitters and patagial tags on survival, behaviour and physical health of adult Saker Falcons.Methods We compared breeding turnover of Saker Falcons deployed with harness-mounted satellite transmitters or patagial tags with unmarked birds identified by using genetic markers. In addition, observational data were recorded on the breeding behaviour and physical condition of birds with satellite transmitters.Results This study found evidence of decreased survival, together with sub-lethal behavioural and physical effects, associated with the deployment of harness-mounted satellite transmitters on Saker Falcons. We found no effect of fitting patagial tags on breeding turnover, although the removal of patagial tags by several birds may have indicated they caused some degree of discomfort.Conclusi...
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Evidence for deleterious effects of harness-mounted satellite transmitters on Saker Falcons Falco cherrug
2016Co-Authors: Andrew Dixon, Gankhuyag Purev-ochir, Nyambayar Batbayar, Dimitar Ragyov, Md. Lutfor Rahman, Michael W. Bruford, Xiangjiang ZhanAbstract:Capsule This study identifies lethal and sub-lethal effects associated with the deployment of harness-mounted satellite transmitters on a large Falcon species. Aims We examined the effect of harness-mounted satellite transmitters and patagial tags on survival, behaviour and physical health of adult Saker Falcons. Methods We compared breeding turnover of Saker Falcons deployed with harness-mounted satellite transmitters or patagial tags with unmarked birds identified by using genetic markers. In addition, observational data were recorded on the breeding behaviour and physical condition of birds with satellite transmitters. Results This study found evidence of decreased survival, together with sub-lethal behavioural and physical effects, associated with the deployment of harness-mounted satellite transmitters on Saker Falcons. We found no effect of fitting patagial tags on breeding turnover, although the removal of patagial tags by several birds may have indicated they caused some degree of discomfort. Conclusion Researchers using harness-mounted transmitters on this, and similar, Falcon species need to assess how these deleterious effects may impact on species conservation, the welfare of individual birds and the interpretation of their studies.
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Peregrine and saker Falcon genome sequences provide insights into evolution of a predatory lifestyle
Nature Genetics, 2013Co-Authors: Xiangjiang Zhan, Andrew Dixon, Shengkai Pan, Margit G. Muller, Yuan Liu, Junyi Wang, Haolong HouAbstract:As top predators, Falcons possess unique morphological, physiological and behavioral adaptations that allow them to be successful hunters: for example, the peregrine is renowned as the world's fastest animal. To examine the evolutionary basis of predatory adaptations, we sequenced the genomes of both the peregrine (Falco peregrinus) and saker Falcon (Falco cherrug), and we present parallel, genome-wide evidence for evolutionary innovation and selection for a predatory lifestyle. The genomes, assembled using Illumina deep sequencing with greater than 100-fold coverage, are both approximately 1.2 Gb in length, with transcriptome-assisted prediction of approximately 16,200 genes for both species. Analysis of 8,424 orthologs in both Falcons, chicken, zebra finch and turkey identified consistent evidence for genome-wide rapid evolution in these raptors. SNP-based inference showed contrasting recent demographic trajectories for the two Falcons, and gene-based analysis highlighted Falcon-specific evolutionary novelties for beak development and olfaction and specifically for homeostasis-related genes in the arid environment–adapted saker.
Andrew Dixon - One of the best experts on this subject based on the ideXlab platform.
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seasonal variation in gonad physiology indicates juvenile breeding in the saker Falcon falco cherrug
Avian Biology Research, 2020Co-Authors: Andrew Dixon, Janelle Ward, Sarangerel Ichinkhorloo, Tuvshinjargal Erdenechimeg, Batbayar Galtbalt, Batmunkh Davaasuren, Batbayar Bold, Nyambayar BatbayarAbstract:We describe seasonal changes in the physiology of reproductive organs of Saker Falcons electrocuted on an electricity power line in Mongolia. Macroscopic examination of the gonads revealed asymmetr...
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Evidence for deleterious effects of harness-mounted satellite transmitters on Saker Falcons Falco cherrug
Bird Study, 2016Co-Authors: Andrew Dixon, Gankhuyag Purev-ochir, Nyambayar Batbayar, Lutfor Rahman, Dimitar Ragyov, Michael W. Bruford, Xiangjiang ZhanAbstract:Capsule This study identifies lethal and sub-lethal effects associated with the deployment of harness-mounted satellite transmitters on a large Falcon species.Aims We examined the effect of harness-mounted satellite transmitters and patagial tags on survival, behaviour and physical health of adult Saker Falcons.Methods We compared breeding turnover of Saker Falcons deployed with harness-mounted satellite transmitters or patagial tags with unmarked birds identified by using genetic markers. In addition, observational data were recorded on the breeding behaviour and physical condition of birds with satellite transmitters.Results This study found evidence of decreased survival, together with sub-lethal behavioural and physical effects, associated with the deployment of harness-mounted satellite transmitters on Saker Falcons. We found no effect of fitting patagial tags on breeding turnover, although the removal of patagial tags by several birds may have indicated they caused some degree of discomfort.Conclusi...
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Evidence for deleterious effects of harness-mounted satellite transmitters on Saker Falcons Falco cherrug
2016Co-Authors: Andrew Dixon, Gankhuyag Purev-ochir, Nyambayar Batbayar, Dimitar Ragyov, Md. Lutfor Rahman, Michael W. Bruford, Xiangjiang ZhanAbstract:Capsule This study identifies lethal and sub-lethal effects associated with the deployment of harness-mounted satellite transmitters on a large Falcon species. Aims We examined the effect of harness-mounted satellite transmitters and patagial tags on survival, behaviour and physical health of adult Saker Falcons. Methods We compared breeding turnover of Saker Falcons deployed with harness-mounted satellite transmitters or patagial tags with unmarked birds identified by using genetic markers. In addition, observational data were recorded on the breeding behaviour and physical condition of birds with satellite transmitters. Results This study found evidence of decreased survival, together with sub-lethal behavioural and physical effects, associated with the deployment of harness-mounted satellite transmitters on Saker Falcons. We found no effect of fitting patagial tags on breeding turnover, although the removal of patagial tags by several birds may have indicated they caused some degree of discomfort. Conclusion Researchers using harness-mounted transmitters on this, and similar, Falcon species need to assess how these deleterious effects may impact on species conservation, the welfare of individual birds and the interpretation of their studies.
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Influence of nest box design on occupancy and breeding success of predatory birds utilizing artificial nests in the Mongolian steppe
2016Co-Authors: Lutfor Rahman, Nyambayar Batbayar, Gankhuyag Purev-ochir, Andrew DixonAbstract:SUMMARY We monitored 100 artificial nests of four different designs to examine the occupancy and breeding success of predatory birds in nest site limited, steppe habitat of central Mongolia. Three species, upland buzzard Buteo hemilasius, common raven Corvus corax and saker Falcon Falco cherrug, occupied artificial nests in all years and their number increased over the five-year study period, when the number of breeding predatory birds rose from 0 to 64 pairs in our 324 km 2 study area. The number of breeding pairs of saker Falcons increased at a faster rate than ravens, reflecting their social dominance. Saker Falcons and common ravens preferred to breed inside closed-box artificial nests with a roof, whereas upland buzzards preferred open-top nests. For saker Falcons nest survival was higher in closed nests than open nests but there was no significant difference in laying date, clutch size and brood size in relation to nest design. This study demonstrates that whilst nest boxes can increase breeding populations in nest site limited habitats, nest design may also influence occupancy rates and breeding productivity of the species utilizing them. Careful consideration is needed in designing nests to maximize occupancy rates and productivity.
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Peregrine and saker Falcon genome sequences provide insights into evolution of a predatory lifestyle
Nature Genetics, 2013Co-Authors: Xiangjiang Zhan, Andrew Dixon, Shengkai Pan, Margit G. Muller, Yuan Liu, Junyi Wang, Haolong HouAbstract:As top predators, Falcons possess unique morphological, physiological and behavioral adaptations that allow them to be successful hunters: for example, the peregrine is renowned as the world's fastest animal. To examine the evolutionary basis of predatory adaptations, we sequenced the genomes of both the peregrine (Falco peregrinus) and saker Falcon (Falco cherrug), and we present parallel, genome-wide evidence for evolutionary innovation and selection for a predatory lifestyle. The genomes, assembled using Illumina deep sequencing with greater than 100-fold coverage, are both approximately 1.2 Gb in length, with transcriptome-assisted prediction of approximately 16,200 genes for both species. Analysis of 8,424 orthologs in both Falcons, chicken, zebra finch and turkey identified consistent evidence for genome-wide rapid evolution in these raptors. SNP-based inference showed contrasting recent demographic trajectories for the two Falcons, and gene-based analysis highlighted Falcon-specific evolutionary novelties for beak development and olfaction and specifically for homeostasis-related genes in the arid environment–adapted saker.
Vicente Urios - One of the best experts on this subject based on the ideXlab platform.
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wintering habitats of eleonora s Falcons falco eleonorae in madagascar
Bird Study, 2012Co-Authors: Ugo Mellone, Pascual Lopezlopez, Ruben Liminana, Vicente UriosAbstract:Capsule Eleonora’s Falcons wintering in Madagascar selected degraded humid forests and cultivated areas close to pristine humid forest. Aims To identify the habitat preferences of Eleonora’s Falcon Falco eleonorae on their wintering grounds in Madagascar, and to use this information to gain insights into the conservation priorities of this species. Methods A total of 11 Eleonora’s Falcons were captured in Spain in 2007 and 2008 and equipped with solar-powered satellite transmitters. We obtained information on five complete wintering events for three birds, two of them tracked for two consecutive years. Data were analyzed using geographic information system-based cartography. Results The analyses showed a preference for degraded humid forests and cultivated lands within areas where pristine humid forests were the most abundant habitat type. Conclusions Eleonora’s Falcons could be taking advantage from a spill-over edge effect of their insect prey into cultivated and more open areas close to humid forests. However, the importance of humid forests for Eleonora’s Falcons seems to be high. The current loss of this habitat in Madagascar is a cause for concern with respect to the conservation of this long-distance migratory Falcon species.
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from the mediterranean sea to madagascar are there ecological barriers for the long distance migrant eleonora s Falcon
Landscape Ecology, 2010Co-Authors: Pascual Lopezlopez, Ruben Liminana, Ugo Mellone, Vicente UriosAbstract:We examined the connection between landscape characteristics and behaviour of a long-distance migratory raptor. Our main goal was to test whether long-distance migratory birds adjust their migration programme according to the different characteristics of the habitats crossed during the journey with special emphasis in the so-called “ecological barriers”, inhospitable environments such as deserts, ice fields, seas and mountain ranges, where the opportunities to fulfil energy requirements are low or absent and environmental factors could be extremely severe. To this end, 11 Eleonora’s Falcons were tracked by satellite telemetry in their ca. 9000 km autumn migration route from colonies located in Western Mediterranean to their wintering grounds in Madagascar during 2007 and 2008. Our results show that Eleonora’s Falcons migrated during day and night-time, adjusting migration speed and daily distance in relation to the crossed region. Unlike other migrant species, Eleonora’s Falcons did not avoid ecological barriers by making unnecessary detours around them or converging on narrow corridors. Nocturnal migration and higher daily distances were observed when flying across the Sahara Desert and the Mozambique Channel. The circadian pattern of activity budget shows that Eleonora’s Falcon relies on an internal navigation mechanism that works during both day and night. Finally, our results suggest that the Sahara is an ecological barrier not only for passerines but also for raptors migrating within the Palaearctic-African flyway.
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autumn migration of eleonora s Falcon falco eleonorae tracked by satellite telemetry
Zoological Studies, 2009Co-Authors: Pascual Lopezlopez, Ruben Liminana, Vicente UriosAbstract:Terra Natura Foundation. P. Lopez-Lopez was supported by a FPU grant (reference AP2005-0874) of the Spanish Ministry of Science and Innovation.
Pascual Lopezlopez - One of the best experts on this subject based on the ideXlab platform.
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wintering habitats of eleonora s Falcons falco eleonorae in madagascar
Bird Study, 2012Co-Authors: Ugo Mellone, Pascual Lopezlopez, Ruben Liminana, Vicente UriosAbstract:Capsule Eleonora’s Falcons wintering in Madagascar selected degraded humid forests and cultivated areas close to pristine humid forest. Aims To identify the habitat preferences of Eleonora’s Falcon Falco eleonorae on their wintering grounds in Madagascar, and to use this information to gain insights into the conservation priorities of this species. Methods A total of 11 Eleonora’s Falcons were captured in Spain in 2007 and 2008 and equipped with solar-powered satellite transmitters. We obtained information on five complete wintering events for three birds, two of them tracked for two consecutive years. Data were analyzed using geographic information system-based cartography. Results The analyses showed a preference for degraded humid forests and cultivated lands within areas where pristine humid forests were the most abundant habitat type. Conclusions Eleonora’s Falcons could be taking advantage from a spill-over edge effect of their insect prey into cultivated and more open areas close to humid forests. However, the importance of humid forests for Eleonora’s Falcons seems to be high. The current loss of this habitat in Madagascar is a cause for concern with respect to the conservation of this long-distance migratory Falcon species.
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from the mediterranean sea to madagascar are there ecological barriers for the long distance migrant eleonora s Falcon
Landscape Ecology, 2010Co-Authors: Pascual Lopezlopez, Ruben Liminana, Ugo Mellone, Vicente UriosAbstract:We examined the connection between landscape characteristics and behaviour of a long-distance migratory raptor. Our main goal was to test whether long-distance migratory birds adjust their migration programme according to the different characteristics of the habitats crossed during the journey with special emphasis in the so-called “ecological barriers”, inhospitable environments such as deserts, ice fields, seas and mountain ranges, where the opportunities to fulfil energy requirements are low or absent and environmental factors could be extremely severe. To this end, 11 Eleonora’s Falcons were tracked by satellite telemetry in their ca. 9000 km autumn migration route from colonies located in Western Mediterranean to their wintering grounds in Madagascar during 2007 and 2008. Our results show that Eleonora’s Falcons migrated during day and night-time, adjusting migration speed and daily distance in relation to the crossed region. Unlike other migrant species, Eleonora’s Falcons did not avoid ecological barriers by making unnecessary detours around them or converging on narrow corridors. Nocturnal migration and higher daily distances were observed when flying across the Sahara Desert and the Mozambique Channel. The circadian pattern of activity budget shows that Eleonora’s Falcon relies on an internal navigation mechanism that works during both day and night. Finally, our results suggest that the Sahara is an ecological barrier not only for passerines but also for raptors migrating within the Palaearctic-African flyway.
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autumn migration of eleonora s Falcon falco eleonorae tracked by satellite telemetry
Zoological Studies, 2009Co-Authors: Pascual Lopezlopez, Ruben Liminana, Vicente UriosAbstract:Terra Natura Foundation. P. Lopez-Lopez was supported by a FPU grant (reference AP2005-0874) of the Spanish Ministry of Science and Innovation.
Jacqueline M Doyle - One of the best experts on this subject based on the ideXlab platform.
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new insights into the phylogenetics and population structure of the prairie Falcon falco mexicanus
BMC Genomics, 2018Co-Authors: Jacqueline M Doyle, Douglas A Bell, Peter H Bloom, Gavin Emmons, Amy Fesnock, Todd E Katzner, Larry Lapre, Kolbe Leonard, Phillip SanmiguelAbstract:Management requires a robust understanding of between- and within-species genetic variability, however such data are still lacking in many species. For example, although multiple population genetics studies of the peregrine Falcon (Falco peregrinus) have been conducted, no similar studies have been done of the closely-related prairie Falcon (F. mexicanus) and it is unclear how much genetic variation and population structure exists across the species’ range. Furthermore, the phylogenetic relationship of F. mexicanus relative to other Falcon species is contested. We utilized a genomics approach (i.e., genome sequencing and assembly followed by single nucleotide polymorphism genotyping) to rapidly address these gaps in knowledge. We sequenced the genome of a single female prairie Falcon and generated a 1.17 Gb (gigabases) draft genome assembly. We generated maximum likelihood phylogenetic trees using complete mitochondrial genomes as well as nuclear protein-coding genes. This process provided evidence that F. mexicanus is an outgroup to the clade that includes the peregrine Falcon and members of the subgenus Hierofalco. We annotated > 16,000 genes and almost 600,000 high-quality single nucleotide polymorphisms (SNPs) in the nuclear genome, providing the raw material for a SNP assay design featuring > 140 gene-associated markers and a molecular-sexing marker. We subsequently genotyped ~ 100 individuals from California (including the San Francisco East Bay Area, Pinnacles National Park and the Mojave Desert) and Idaho (Snake River Birds of Prey National Conservation Area). We tested for population structure and found evidence that individuals sampled in California and Idaho represent a single panmictic population. Our study illustrates how genomic resources can rapidly shed light on genetic variability in understudied species and resolve phylogenetic relationships. Furthermore, we found evidence of a single, randomly mating population of prairie Falcons across our sampling locations. Prairie Falcons are highly mobile and relatively rare long-distance dispersal events may promote gene flow throughout the range. As such, California’s prairie Falcons might be managed as a single population, indicating that management actions undertaken to benefit the species at the local level have the potential to influence the species as a whole.