Context dependent song-flight performance and timing in the Black-headed Bunting(Emberiza melanocephala)

Many songbirds produce song-flights;however,the function,vocal and motor characteristics,as well as the diel and seasonal variation of song-flight in songbirds remain not well understood.Here,we studied two types of song-flight in male Black-headed Buntings(Emberiza melanocephala),the Moth—a standard,i.e.,perch song produced during a horizontal flight,and the Towering—a specifically structured song produced during a complex ascending and descending flight.While perch song,used during Moth flight,has already been described,here we provide the first description and sonogram representation of the more elaborate and less stereotyped Towering song.While males started to perform Moth song-flights as soon as they arrived at the breeding site,Towering did not start before the female arrival.Males usually delivered spontaneous Moth song-flights before chasing rivals or undertaking aerial fights,suggesting Moth is directed towards conspecific males and serves as a threat display.Furthermore,playback of conspecific perch songs triggered males to approach the loudspeaker with Moth song-flights.The Towering started after females arrived at the breeding site,suggesting the Towering is directed towards conspecific females.We detected a seasonal difference in the peak Towering rate between forenoon and afternoon,suggesting that Towerings performed at different times of the day have different functions.Forenoon Towerings were strongly positively related to the number of fertile females at the breeding site,while afternoon Towerings peaked very early in the breeding season and coincided with the number of females at the breeding site before the onset of nest-building.These results provide evidence that birds can direct different types of song-flight towards different receivers and suggest the possibility that time of the day determines the context of the display,namely to attract social mates or solicit copulation.Further work is needed to account for the effect of between male variability in song-flight rate,as well as in height/steepness of flight or song quality.

Mining citizen science data to explore stopover sites and spatiotemporal variation in migration patterns of the red-footed falcon

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.

Breeding phase and outcome determine space use in European rollers Coracias garrulus prior to migration

The breeding period is a demanding and time-constrained phase for migratory bird species.Breeding outcome and duration can interact with the extent and duration of post-breeding movements,resulting in individual differences in space use ultimately influencing later stages of the annual cycle.We present space-use and home range estimates during the breeding season for 21 European rollers Coracias garrulus tracked between 2018 and 2022,in Italy and Croatia.Using high-resolution spatial GPS data coupled with regular nest-box monitoring,we analyzed dif-ferences in space use during the incubation/nestling period versus post-breeding period prior to migration,accounting for the breeding outcome(successful vs.failure).We found that adult movements were strongly reduced during the first phase,whereas increased in the post-breeding phase,especially for failed breeders.Successful breeders remained in the surroundings of the nest site,whereas unsuccessful ones tended to abandon the nest and visit distant areas(up to 500 km)for long periods(60.5±6.2 days).Breeding outcome did not influence the departure date of autumn migration,suggesting that failed breeders used this period for exploratory movements but not for advancing the onset of migra-tion.Such exploratory movements may be functional to prospect and inform settlement decisions in failed breeders in search of new breeding opportunities and may be particularly important in migratory species,which generally have a limited period to gather information prior to autumn migration.The study demonstrates the need to investigate seasonal movements in different populations and the potential importance of pros-pectingpost-breeding movements for long-distance migratory species.