Citizen scienee data have already been used to effectively address questions regarding migration,a fun dame ntal stage in the life history of birds.In this study,we use data from eBird and from 3 additional regional c...Citizen scienee data have already been used to effectively address questions regarding migration,a fun dame ntal stage in the life history of birds.In this study,we use data from eBird and from 3 additional regional citizen scienee databases to describe the migration routes and timing of the red-footed falcon Falco vespertinus in the Mediterranean region across 8years(2010-2017).We further examine the seasonal and yearly variation in migration patterns and explore sites used during the species migration.Our results suggest that the autumn passage is spatially less variable and temporally more consistent among years than in spring and that birds migrate faster in spring than in autumn.The species seems to be more prevalent along the Central Mediterranean during spring migration,probably as a result of the clockwise loop migration that red-footed falcons perform.There was a high variation in annual median migration dates for both seasons as well as in migration routes across years and seasons.Higher variation was exhibited in the longitudinal component thus indicating flexibility in migration routes.In additi on,our results showed the species'preference for I owl a nds covered with cropla nd and mosaics of cropland and natural vegetation as stopover sites during migration.Stopover areas predicted from our distribution modeling highlight the importance of the Mediterranean islands as stopover sites for sea-crossing raptors,such as the red-footed falcon.This study is the first to provide a broad-scale spatiotemporal perspective on the species migration across seasons,years and flyways and dem on strates how citize n science data can inform future monitori ng and conservation strategies.展开更多
The analysis of bird ringing data often comes with some potential sources of error and bias,as ring wear and/or loss could affect mark-recapture analyses and produce erroneous estimates of survival.Furthermore,ring we...The analysis of bird ringing data often comes with some potential sources of error and bias,as ring wear and/or loss could affect mark-recapture analyses and produce erroneous estimates of survival.Furthermore,ring wear and loss rates may differ between and within species based on the habitat they use or the species’ life-history traits and behaviour as well as the type of the ring.In this study we use resighting data from a long-term double marking experiment to directly estimate the rate of colour-ring loss among different Dalmatian Pelican colonies over time,evaluate any possible factors that could contribute to differential ring loss and assess how it may bias the results of mark-resighting analyses.Based on 14,849 resightings from 1275 individuals and using multi-state continuous-time hidden Markov models(HMMs) we showed that probability of ring loss was markedly different among colonies,ranging from 0.10 to 0.42 within the first year of marking,whereas the cumulative probability of losing a ring after ten years ranged 0.64 to 0.99.These rates are among the highest estimated when compared to previous studies in waterbirds.Our approach assessing the intra-specific variance in ring loss provided several factors potentially involved,such as the use of glue and the fledgling age accuracy and we could further hypothesise the effect of environmental factors.Finally,our results showed that ring loss can be a significant challenge for the assessment of the species’ population dynamics using mark-recapture methods as survival was consistently underestimated when not accounting for ring loss and varied significantly among different colonies.展开更多
Background:Conservation of small and isolated populations can be challenging since they are prone to loss of genetic diversity due to random genetic drift and inbreeding.Therefore,information from the assessment of ge...Background:Conservation of small and isolated populations can be challenging since they are prone to loss of genetic diversity due to random genetic drift and inbreeding.Therefore,information from the assessment of genetic diversity and structure are needed for conservation programs to determine the appropriate management strategy for the populations.We investigated the levels of genetic variability in a resident Greylag Goose(Anser anser) population,the southernmost breeding population of the species in Europe and the sole viable population of any goose species in Greece.Methods:A fragment of mtDNA Control Region and a panel of 11 microsatellite markers were used to search for any signs of genetic impoverishment and population substructure and to reveal the underlying processes through the identification of possible past demographic events.Results:The population was found to be monomorphic in the amplified fragment of the mitochondrial Control Region,with all individuals sharing a single private haplotype.Analyses showed a lack of any population substructure indicating a panmictic population.Although the population seems to have experienced a strong and recent genetic bottleneck and exhibits a small effective population size,we did not find evidence of either extremely low levels of genetic diversity or inbreeding depression.Conclusions:The recent demographic decline we detected and the combined influence of residency and anthropogenic factors have probably shaped the current genetic status.Our study population does not need emergency conservation actions but should be regarded as a discrete management unit.Future management strategies should focus on population and genetic monitoring and preventing further abundance declines that would increase the risk of genetic impoverishment.展开更多
基金This article is in memoriam of our beloved friend and colleague Michele Panuccio and his passion for raptor migration.We are thankful to Triantafyllos Akriotis,Vasileios Bontzorlos,Thord Fransson,Giannis Gasteratos,Nikolaos Katsimanis,Elli Navarette,Diego Rubolini,Victoria Saravia,and Nikos Tsiopelas for helping with data collection.Peter Palatitz and 3 anonymous reviewers provided valuable comments on a previous draft of this manuscript.We acknowledge the Cornell Lab of Ornithology for hosting eBird and providing free access to researchers as well as the thousands of birders that contribute their sightings to eBird and other citizen science platforms.
文摘Citizen scienee data have already been used to effectively address questions regarding migration,a fun dame ntal stage in the life history of birds.In this study,we use data from eBird and from 3 additional regional citizen scienee databases to describe the migration routes and timing of the red-footed falcon Falco vespertinus in the Mediterranean region across 8years(2010-2017).We further examine the seasonal and yearly variation in migration patterns and explore sites used during the species migration.Our results suggest that the autumn passage is spatially less variable and temporally more consistent among years than in spring and that birds migrate faster in spring than in autumn.The species seems to be more prevalent along the Central Mediterranean during spring migration,probably as a result of the clockwise loop migration that red-footed falcons perform.There was a high variation in annual median migration dates for both seasons as well as in migration routes across years and seasons.Higher variation was exhibited in the longitudinal component thus indicating flexibility in migration routes.In additi on,our results showed the species'preference for I owl a nds covered with cropla nd and mosaics of cropland and natural vegetation as stopover sites during migration.Stopover areas predicted from our distribution modeling highlight the importance of the Mediterranean islands as stopover sites for sea-crossing raptors,such as the red-footed falcon.This study is the first to provide a broad-scale spatiotemporal perspective on the species migration across seasons,years and flyways and dem on strates how citize n science data can inform future monitori ng and conservation strategies.
基金supported by MAVA Foundation and Tour du Valatsupported financially by the MAVA Foundationby the Prespa Ohrid Nature Trust (PONT)。
文摘The analysis of bird ringing data often comes with some potential sources of error and bias,as ring wear and/or loss could affect mark-recapture analyses and produce erroneous estimates of survival.Furthermore,ring wear and loss rates may differ between and within species based on the habitat they use or the species’ life-history traits and behaviour as well as the type of the ring.In this study we use resighting data from a long-term double marking experiment to directly estimate the rate of colour-ring loss among different Dalmatian Pelican colonies over time,evaluate any possible factors that could contribute to differential ring loss and assess how it may bias the results of mark-resighting analyses.Based on 14,849 resightings from 1275 individuals and using multi-state continuous-time hidden Markov models(HMMs) we showed that probability of ring loss was markedly different among colonies,ranging from 0.10 to 0.42 within the first year of marking,whereas the cumulative probability of losing a ring after ten years ranged 0.64 to 0.99.These rates are among the highest estimated when compared to previous studies in waterbirds.Our approach assessing the intra-specific variance in ring loss provided several factors potentially involved,such as the use of glue and the fledgling age accuracy and we could further hypothesise the effect of environmental factors.Finally,our results showed that ring loss can be a significant challenge for the assessment of the species’ population dynamics using mark-recapture methods as survival was consistently underestimated when not accounting for ring loss and varied significantly among different colonies.
基金supported financially by the MAVA Foundationpartly funded through a grant by the Green Fund of the Hellenic Ministry of Environment and Energy+2 种基金a grant by the Bodosaki Foundationtwo grants by two groups of Dutch naturalistsled by the biologist Gerrit Jansen("Nature Workshops Gerrit Jansen")
文摘Background:Conservation of small and isolated populations can be challenging since they are prone to loss of genetic diversity due to random genetic drift and inbreeding.Therefore,information from the assessment of genetic diversity and structure are needed for conservation programs to determine the appropriate management strategy for the populations.We investigated the levels of genetic variability in a resident Greylag Goose(Anser anser) population,the southernmost breeding population of the species in Europe and the sole viable population of any goose species in Greece.Methods:A fragment of mtDNA Control Region and a panel of 11 microsatellite markers were used to search for any signs of genetic impoverishment and population substructure and to reveal the underlying processes through the identification of possible past demographic events.Results:The population was found to be monomorphic in the amplified fragment of the mitochondrial Control Region,with all individuals sharing a single private haplotype.Analyses showed a lack of any population substructure indicating a panmictic population.Although the population seems to have experienced a strong and recent genetic bottleneck and exhibits a small effective population size,we did not find evidence of either extremely low levels of genetic diversity or inbreeding depression.Conclusions:The recent demographic decline we detected and the combined influence of residency and anthropogenic factors have probably shaped the current genetic status.Our study population does not need emergency conservation actions but should be regarded as a discrete management unit.Future management strategies should focus on population and genetic monitoring and preventing further abundance declines that would increase the risk of genetic impoverishment.
