Primera cita de menjamosques balear Muscicapa striata balearica (Jordans, 1913) a l’illa d’anticítera (Illes Jòniques, Grècia)

Es presenta la primera captura per anellament d’un exemplar de menjamosques gris de la subespècie balear a l’illa d’Anticítera (grècia), i la seva recuperació a la seva zona de cria a Menorca (Illes Balears). Aquesta dada pot indicar una estratègia migratòria primaveral diferenciada de la subespècie nominal striata.The first instance is presented of a Balearic spotted Flycatcher ringed on Antikythera island (Ionian Islands, greece) and recovered in its breeding area in Menorca (Balearic Islands). The results may indicate a different spring migration strategy of this subspecies to the nominate striata

Remarkably similar migration patterns between different red-backed shrike populations suggest that migration rather than breeding area phenology determines the annual cycle

The regular fluctuation of resources across the Globe guides movements of migratory animals. To ensure sufficient reproductive output and maintain viable population sizes, migratory animals should match arrival at breeding areas with local peaks in resource availability. It is generally assumed that breeding phenology dictates the timing of the annual cycle, but this is poorly studied. Here, we use light-level geolocator tracking data to compare the annual spatiotemporal migration patterns of a long-distance migratory songbird, the red-backed shrike, Lanius collurio, breeding at widely different latitudes within Europe. We find that populations use remarkably similar migration routes and are highly synchronized in time. Additional tracks from populations breeding at the edges of the European range support these similar migration patterns. When comparing timing of breeding and vegetation phenology, as a measure of resource availability across populations, we find that arrival and timing of breeding corresponds to the peak in vegetation greenness at northern latitudes. At lower latitudes birds arrive simultaneously with the more northerly breeding populations, but after the local greenness peak, suggesting that breeding area phenology does not determine the migratory schedule. Rather, timing of migration in red-backed shrikes may be constrained by events in other parts of the annual cycle.</p

The great tit HapMap project: a continental‐scale analysis of genomic variation in a songbird

A major aim of evolutionary biology is to understand why patterns of genomic diversity vary within taxa and space. Large-scale genomic studies of widespread species are useful for studying how environment and demography shape patterns of genomic divergence. Here, we describe one of the most geographically comprehensive surveys of genomic variation in a wild vertebrate to date; the great tit (Parus major) HapMap project. We screened ca 500,000 SNP markers across 647 individuals from 29 populations, spanning ~30 degrees of latitude and 40 degrees of longitude – almost the entire geographical range of the European subspecies. Genome-wide variation was consistent with a recent colonisation across Europe from a South-East European refugium, with bottlenecks and reduced genetic diversity in island populations. Differentiation across the genome was highly heterogeneous, with clear ‘islands of differentiation’, even among populations with very low levels of genome-wide differentiation. Low local recombination rates were a strong predictor of high local genomic differentiation (FST), especially in island and peripheral mainland populations, suggesting that the interplay between genetic drift and recombination causes highly heterogeneous differentiation landscapes. We also detected genomic outlier regions that were confined to one or more peripheral great tit populations, probably as a result of recent directional selection at the species' range edges. Haplotype-based measures of selection were related to recombination rate, albeit less strongly, and highlighted population-specific sweeps that likely resulted from positive selection. Our study highlights how comprehensive screens of genomic variation in wild organisms can provide unique insights into spatio-temporal evolutionary dynamics

Tracking data highlight the importance of human-induced mortality for large migratory birds at a flyway scale

Human-induced direct mortality affects huge numbers of birds each year, threatening hundreds of species worldwide. Tracking technologies can be an important tool to investigate temporal and spatial patterns of bird mortality as well as their drivers. We compiled 1704 mortality records from tracking studies across the African-Eurasian flyway for 45 species, including raptors, storks, and cranes, covering the period from 2003 to 2021. Our results show a higher frequency of human-induced causes of mortality than natural causes across taxonomic groups, geographical areas, and age classes. Moreover, we found that the frequency of human-induced mortality remained stable over the study period. From the human-induced mortality events with a known cause (n = 637), three main causes were identified: electrocution (40.5 %), illegal killing (21.7 %), and poisoning (16.3 %). Additionally, combined energy infrastructure-related mortality (i.e., electrocution, power line collision, and wind-farm collision) represented 49 % of all human-induced mortality events. Using a random forest model, the main predictors of human-induced mortality were found to be taxonomic group, geographic location (latitude and longitude), and human footprint index value at the location of mortality. Despite conservation efforts, human drivers of bird mortality in the African-Eurasian flyway do not appear to have declined over the last 15 years for the studied group of species. Results suggest that stronger conservation actions to address these threats across the flyway can reduce their impacts on species. In particular, projected future development of energy infrastructure is a representative example where application of planning, operation, and mitigation measures can enhance bird conservation

The meaning of the 'local' : a study of production and audiences in local radio broadcasting in Crete

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Stopover ecology before and after crossing big ecological barriers in the eastern mediterranean: The case of garden warbler Sylvia borin (BODDAERT 1783)

The garden warbler Sylvia borin, one of the most common migrants, are used to study thestopover ecology of small birds before and after crossing ecological barriers in the EasternMediterranean. The median passage of the species was calculated as 16th of September and5th of May for the autumn and spring period respectively, based on data from Antikythira. To look into the preparation of the species just before the Sahara desert and the Mediterranean Sea crossing in autumn, inexperienced in previous migration garden warblers were studied on Crete using radio-transmitters. The results shows that the species stays on Crete for 13-20 days and depart with an average fuel load of about 100%. The migration over the ecological barrier of the dessert and the sea was simulated and showed that the barrier crossing during spring is more demanding comparing to the crossing during autumn. The necessary body mass that the garden warbler need, prior the crossing was calculated to be 30 g and 35 g for autumn and spring period respectively. Comparing the data from east Mediterranean islands to the findings from central and western Mediterranean locations it seems that that the arriving body mass is lower in eastern Mediterranean. The lower body mass found for garden warbler in eastern Mediterranean is caused partially due to a high percentage of burned protein during migration as showed through the study of breast muscle variation before and after the barrier crossing. Depleted garden warblers that arrive at a stopover site after the crossing of the seas and the dessert on spring is capable of achieving high refuelling rates as shown though a caging experiment hold at Antikythira.Για τη μελέτη της οικολογίας των ενδιάμεσων μεταναστευτικών σταθμών πριν και μετά τη διάσχιση μεγάλων οικολογικών φραγμάτων στα πλαίσια αυτής της διατριβής χρησιμοποιήθηκε ένα πολυάριθμο, στρουθιόμορφο είδος ο Κηποτσιροβάκος Sylvia borin. Η ενδιάμεση ημερομηνία μετανάστευσης του είδους υπολογίστηκε με δεδομένα που συλλέχτηκαν στα Αντικύθηρα την περίοδο του 2007 με 2009, είναι η 16η Σεπτεμβρίου και 5η Μαΐου για την ανοιξιάτικη και την φθινοπωρινή περίοδο αντίστοιχα. Η προετοιμασία για την διάσχιση της Μεσόγειου και της Σαχάρας μελετήθηκε σε ανήλικους Κηποτσιροβάκους στην Κρήτη με την χρήση μικροπομπών. Το είδος παραμένει στην Κρήτη για 13-20 ημέρες και εναποθέτει σε αυτήν την πλειοψηφία του απαιτητού για την διάσχιση του οικολογικού φράγματος ενεργειακό απόθεμα. Η προσομοίωση της διάσχισης του οικολογικού φράγματος έδειξε ότι η διάσχιση του φράγματος κατά την άνοιξη είναι πιο απαιτητική σε σχέση με την διάσχιση του φθινοπώρου. Η απαραίτητη σωματική μάζα για την επιτυχημένη μετανάστευση πάνω από τη Μεσόγειο και την Σαχάρα υπολογίστηκε στα 30 g και 35 g για το φθινόπωρο και την άνοιξη αντίστοιχα. Η σωματική μάζα κατά την άφιξη του είδους σε νησιά της ανατολικής Μεσόγειου είναι μικρότερη σε σχέση με τις τιμές που παρατηρούνται στην δυτική και ανατολική Μεσόγειο. Η μειωμένες τιμές της σωματικής μάζας στα πουλιά που φτάνουν στην ανατολική Μεσόγειο οφείλεται εν μέρει στον καταβολισμό μεγάλου πόσου πρωτεϊνών όπως έδειξε η μελέτη της διακύμανσης του θωρακικού μυϊκού ιστού που βασίστηκε σε δεδομένα από το είδος στην Κρήτη και τα Αντικύθηρα. Τα καταπονημένα από την μετανάστευση Κηποτσιροβάκοι είναι σε θέση να αναπληρώσουν την απολεσθέντα από την διάσχιση του φράγματος, σωματική τους μάζας, όπως προκύπτει από πείραμα εγκλωβισμού βασισμένο σε είκοσι εννιά (29) άτομα

Οικολογία ανοιξιάτικης μετανάστευσης ειδών του γένους sylvia στη Γαύδο

Long distance migrating birds face two big ecological barriers, the Sahara desert and the Mediterranean sea during their biannual journey to and from their breeding and wintering sites. Gavdos, a small island south of Crete, is the first land the migrating birds reach after the African coast during the spring migrating period. Stopover ecology of the genus Sylvia in Gavdos was studied for tree consecutive years (2002-2004) during the spring migration period. Migration phenology, the overall arrival condition of the birds as well as the orientation of migration were also studied. Further more, the importance of the wind direction on the stopover decision in Gavdos was also elaborated. The mean timing of migration of the genus showed a little variation between years. The maximum migration intensity was recorded in the last ten days of April, while the passage lasted throughout the mist-netting period, namely, the first week of April until the 20 of May. The fat fuel reserves of the birds at first capture were depleted, and it also seems likely that a big proportion of the protein reserves were a burnted too during the flight across the Mediterranean Sea. The minimum average stopover for the species studied varied from 3 to 4 days, while all the species expressed a positive fuel deposition rate during their stopover. The orientation of migration varied from 297 ο to 313ο, depending on the species. Finally, the wind direction proved to be an important factor influencing the stopover decision of birds in Gavdos.Τα μεταναστευτικά είδη πουλιών που διανύουν μεγάλες αποστάσεις, έχουν να αντιμετωπίσουν δύο μεγάλα οικολογικά φράγματα, την έρημο της Σαχάρας και την θάλασσα της Μεσογείου. Κατά την ανοιξιάτικη μεταναστευτική περίοδο, η Γαύδος αποτελεί την πρώτη στεριά που αντικρίζουν τα μεταναστευτικά πουλιά, μετά τις ακτές της Αφρικής. Για τρία συναπτά έτη στο νησί της Γαύδου μελετήθηκε η μετανάστευση του γένους Sylvia (τρία είδη) κατά την ανοιξιάτικη μεταναστευτική περίοδο. Πιο συγκεκριμένα εξετάστηκε η φαινολογία της μετανάστευσης του γένους και η φυσιολογική κατάσταση των πουλιών κατά την άφιξή τους στη Γαύδο. Επίσης μελετήθηκε η οικολογία μεταναστευτικών σταθμών (stopover ecology), ο προσανατολισμός μετανάστευσης (migration orientation) των υπό εξέταση ειδών στη Γαύδο, και τέλος εξετάστηκε η απόκριση των μεταναστευτικών πουλιών στην διεύθυνση των ανέμων όσον αφορά την απόφαση προσγείωσης στη Γαύδο. Το μέγιστο της μεταναστευτικής ροής του γένους τοποθετείται στο τελευταίο δεκαήμερο του Απριλίου, ενώ τα πρώτα άτομα κάνουν την εμφάνισή τους στην Γαύδο κατά το δεύτερο πενθήμερο του Απριλίου. Τα άτομα του γένους κατά την αύξηση τους στη Γαύδο έχουν χρησιμοποιήσει το μεγαλύτερο μέρος του υποδερμικού λίπους, που αποτελεί το βασικό ενεργειακό νόμισμα της μετανάστευσης. Έκτος από την καύση του λιπώδη ιστού, τα πουλιά που χρησιμοποιούν τη Γαύδο ως ενδιάμεσο μεταναστευτικό σταθμό, πιθανότατα χρησιμοποιούν και μεγάλο μέρος μυϊκού ιστού. Ο μέσος ελάχιστος χρόνος παραμονής του γένους στη Γαύδο υπολογίστηκε 3 με 4 ημέρες ενώ όλα τα υπό εξέταση είδη εμφανίζουν θετικό ρυθμό ενεργειακού ανεφοδιασμού κατά την παραμονή τους στο νησί. Η κατεύθυνση των υπό εξέταση ειδών ήταν βορειοδυτική. Τέλος φαίνεται ότι η απόφαση για την προσγείωση σε ένα μεταναστευτικό σταθμό επηρεάζεται από τη διεύθυνση των ανέμων

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During long-distance flights, birds catabolize not only fat but also protein, which results in structural or functional loss as protein is stored in organs. In this study we investigated breast muscle size in relation to body mass in garden warblers Sylvia borin before and after crossing the Sahara desert and the Mediterranean Sea in autumn and spring migration, respectively. Breast muscle size was measured by moulding the shape of the muscles of live birds. Samples were collected on the Greek island of Antikythira during spring after the barrier crossing and on Crete during autumn, where garden warblers prepare for barrier crossing on their southward migration. Breast muscle size on Antikythira was significantly smaller than the equivalent size measured on Crete. Breast muscle size followed the changes in total body mass when garden warblers had a low body mass while this relationship disappeared when body mass is above 17.5 g. The combination of low body masses and small breast muscle size of birds that have just crossed the Sahara desert and the Mediterranean Sea and landed on Antikythira indicates a severe protein break down. During extended flights, when fat reserves are insufficient, the use of protein can also be a lifeline to reach the destination. The weak association between body mass and breast muscle size during autumn implies that the increase of breast muscle, as a preparation for the barrier crossing, does not take place en route from breeding sites to the Mediterranean area