Migration routes and differences in migration strategies of Whooper Swans between spring and autumn

Long-distance migratory birds travel more rapidly in spring than in autumn,as they face temporal breeding constraints.However,several species travel slower in spring owing to environmental influences,such as food availability and wind conditions.GPS trackers were attached to 17 Whooper Swans(Cygnus cygnus) inhabiting northeastern Mongolia,to determine their migration routes and stopover sites in spring and autumn.Differences between spring and autumn migrations,migration-influencing parameters,and the effect of spring stopover site temperatures were analyzed.Six swans completed perfect tours between their wintering and breeding sites,and these data were used for analysis.Spring migration lasted 57 days,with 49.2 days spent at 3.7 stopover sites.Autumn migration lasted 21.5 days,with 17.5 days spent at 1.0 stopover sites.Thus,the swans traveled more rapidly in autumn than in spring.Migration distance,number of stopovers,migration speed,and straightness were important migration determinants in both spring and autumn.Migration distance,stopover duration,number of stopovers,daily travel speed,travel duration,and migration speed differed significantly between spring and autumn.During spring migration,the temperature at the current stopover sites and that at the future stopover sites displayed significant variations(t=1585.8,df=631.6,p <0.001).These findings are critical for the conservation and management of Whooper Swans and their key habitats in East Asian regions,and the data are anticipated to make a particularly significant contribution toward developing detailed management plans for the conservation of their key habitats.

Comparing vocal structures of the parasitic and nonparasitic groups in Cuculinae

Background: Avian brood parasitism is a breeding strategy in which brood parasites lay their eggs in the nest of other species.This behavior is closely related to aspects of the biological evolution of the parasitic species such as reduced female body size and plumage color polymorphism.However,not much is known whether it is associated with the evolution of vocalization.Methods: We collected samples of the typical male calls of 67 species belonging to the sub?family Cuculinae.Using the calls,we measured five acoustic parameters for each samples to test the differences in vocal structures between parasitic and nonparasitic species.To control for potential phylogenetic effects,we also performed phylogenetic independent contrast analyses.Results: We found that vocal structures were relatively similar among the parasitic species with a tendency to simple and low?frequency calls.In addition,harmonic structures were observed more frequently in the nonparasitic group.Conclusions: Overall,these results support the idea that brood parasitic behavior with associated ecological condi?tions may play a role in vocal evolution,a better understanding of which may greatly improve our knowledge of vocal diversification in non?oscine birds.

Geolocator study reveals east African migration route of Central European Common Terns

Background: The majority of European Common Terns(Sterna hirundo) migrate south along the western coast of Europe and Africa, while birds from eastern regions are known to cross the Mediterranean Sea from east to west or migrate along the eastern African coast. The migration route of north European terns wintering along the coast of western Africa was already described using geolocator data, while knowledge about movements of the European inland populations is based only on relatively scarce recoveries of ringed birds.Methods: We used light-level geolocators in inland Common Tern colonies in Hungary and Croatia to study their migration route and to identify wintering areas along with stopover sites. Results revealed by geolocators were compared with recoveries of ringed birds.Results: All tracked birds used the east African migration route with autumn stopovers at Lower Nile and in the southern part of the Red Sea, and short spring stopover in Israel. Terns wintered along Kenyan coasts and in the southern Mozambique Channel. Autumn migration lasted four times longer than spring migration.Conclusions: This is the first geolocator study that describes the east African migration route of the Common Tern. Important stopover sites were identified. More studies of inland populations are needed to better elucidate tern winter movements.

A novel method to collect sperm from brood parasitic cuckoos:Urodeum stimulation(UroS)method

Sperm competition has been studied in numerous species as a representative example of postcopulatory sexual selection,where sampling sperm from male is the most basic and important step.Sperm collection can be tricky in birds,however,because unlike mammals,the genitals of birds are generally latent in the cloacal region and their characteristics vary among species.Various methods to collect sperm from different birds have been tested,such as cloacal massage,feces collection,and electro-stimulation,but their applicability varies depending on species.In this study,we introduced the urodeum stimulation method(UroS method)to collect sperm from Cuculus cuckoos,such as the Common Cuckoo(C.canorus).These species are expected to have interesting patterns of pair bonding and sperm competition because of their unique breeding strategy called brood parasitism;however,it remains unexplored.In this study,we described the application of our new method to expel semen from male common cuckoos,measured the volume of semen collected,checked the presence of sperm in the semen sample,and finally estimated its success rate among 82 males.Samples were successfully collected from 76 cuckoos(approximately 93%)and the colors and volumes of the samples were very diverse.Sperm was present in 43 of these samples(57%),showing a sperm observation rate approximately twice as high as that of the conventional cloacal massage method.We believe that this novel method will contribute to a better understanding of postcopulatory sexual selection in avian brood parasites and facilitate the process of sperm collection and artificial insemination in other medium-sized birds.

Linking individual attributes and host specialization in brood parasitic cuckoos

Generalist avian brood parasites vary considerably in their degree of host specialization(e.g.,number of hosts);some parasitize the nests of just a few host species,whereas others exploit more than 100 species.Several factors,including habitat range,habitat type,and geographic location,have been suggested to account for these variations.However,inter-specific differences in individual attributes,such as personality and plasticity,have rarely been considered as potential factors of such variation,despite their potential relationship to,for example,range expansion.Using cage experiments,we tested the hypothesis that parasitic species exploiting more host species may be more active and exploratory.To this end,we quantified behaviors exhibited by two Cuculus cuckoos(Common Cuckoo C.canorus and Oriental Cuckoo C.optatus)that vary greatly in their number of host species.Specifically,we evaluated exploratory behavior displayed by birds in the cage,such as the number of movements,head-turning,wing-flapping,and stepping.The Common Cuckoo,which has a higher number of host species,tended to exhibit higher levels of exploratory behaviors than the Oriental Cuckoo.Our study showed that the two cuckoo species exhibited different exploratory levels,as predicted by the differences in their number of hosts.Further studies regarding the causality between individual attributes and host specialization with improved experimental methodology would greatly enhance our understanding of the role of individual characteristics in the coevolution of avian brood parasites and their hosts.

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.

Dispersal patterns of exotic forest pests in South Korea

Invasive species have potentially devastating effects on ecological communi- ties and ecosystems. To understand the invasion process of exotic forest pests in South Korea, we reviewed four major species of exotic forest pests： the pine needle gall midge （Thecodiplosis japonensis）, pine wilt disease caused by the pine wood nematode （Bur- saphelenchus xylophilus）, the fall webworm （Hyphantria cunea） and the black pine bast scale （Matsucoccus thunbergianae）. We consider their biology, ecology, invasion history, dispersal patterns and related traits, and management as exotic species. Among these species, the dispersal process of fall webworm was linear, showing a constant range expan- sion as a function of time, whereas the other three species showed biphasic patterns, rapidly increasing dispersal speed after slow dispersal at the early invasion stage. Moreover, human activities accelerated their expansion, suggesting that prevention of the artificial movement of damaged trees would be useful to slow expansion of exotic species. We believe that this information would be useful to establish management strategies for invasion species.

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.