AVIAN DIVERSITY AND ABUNDANCE IN RELATION TO SEASON, LIVESTOCK PRESENCE AND VEGETATION COVER IN A MEDITERRANEAN COASTAL WETLAND

Coastal wetlands are considered as systems of high avian diversity and are usually used for livestock production throughout the world. In this study, the diversity and seasonal abundance of avian species were monitored for two years on a monthly basis in a coastal grazing land in Evros Delta (Greece). The effects of livestock (cattle) presence and different classes of vegetation cover on the number of bird species were also investigated. A total of 96 bird species belonging to 29 families were recorded. The most commonly encountered species was the Eurasian skylark Alauda arvensis. The cattle presence was not significantly correlated (p>0.05) with the abundance of recorded bird species. On the contrary, patches with vegetation cover 25.1 - 50.0% and 50.1 - 75.0 % were used by more bird species in relation to patches with cover ≤25.0% or >75.0%. We concluded that the use of livestock grazing to preserve the desired vegetation cover (25 – 75%) is a promising management tool

Host dispersal shapes the population structure of a tick-borne bacterial pathogen

Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies "Candidatus Borrelia aligera" was also detected. Multilocus sequence typing (MLST) analysis of B. garinii isolates together with the global collection of B. garinii genotypes obtained from the Borrelia MLST public database revealed that: (a) there was little overlap among genotypes from different continents, (b) there was no geographical structuring within Europe, and (c) there was no evident association pattern detectable among B. garinii genotypes from ticks feeding on birds, questing ticks or human isolates. These findings strengthen the hypothesis that the population structure and evolutionary biology of tick-borne pathogens are shaped by their host associations and the movement patterns of these hosts.Peer reviewe

BREEDING ECOLOGY OF THE LITTLE EGRET (EGRETTA GARZETTA GARZETTA (L.,1766)) AT THE AXIOS DELTA, MACEDONIA, GREECE

Ο ΛΕΥΚΟΤΣΙΚΝΙΑΣ (EGRETTA G. GARZETTA), ΓΝΩΣΤΟΣ ΣΤΗΝ ΕΛΛΑΔΑ ΑΠΟ ΤΗΝ ΑΡΧΑΙΟΤΗΤΑ, ΣΗΜΕΡΑ ΑΝΑΠΑΡΑΓΕΤΑΙ ΣΕ ΤΟΥΛΑΧΙΣΤΟΝ 7 ΥΓΡΟΤΟΠΟΥΣ ΜΕΤΑΞΥ ΤΩΝ ΟΠΟΙΩΝ ΚΑΙ ΤΟ ΔΕΛΤΑ ΤΟΥ ΑΞΙΟΥ. ΣΤΟΧΟΣ ΤΗΣ ΜΕΛΕΤΗΣ ΗΤΑΝ Η ΔΙΕΡΕΥΝΗΣΗ: Α) ΤΩΝ ΠΑΡΑΜΕΤΡΩΝ ΤΗΣ ΑΝΑΠΑΡΑΓΩΓΗΣ, Β) ΤΗΣ ΣΧΕΣΗΣ ΤΟΥ ΕΙΔΟΥΣ ΜΕ ΤΑ ΕΝΔΙΑΙΗΜΑΤΑ ΤΟΥ ΔΕΛΤΑ ΑΞΙΟΥ ΚΑΙ Γ)ΤΗΣ ΔΙΑΣΠΟΡΑΣ ΤΩΝ ΑΝΗΛΙΚΩΝ ΑΤΟΜΩΝ. ΣΤΑ ΠΛΑΙΣΙΑ ΤΗΣ ΜΕΛΕΤΗΣ ΤΗΣ ΑΝΑΠΑΡΑΓΩΓΗΣ ΜΕΛΕΤΗΘΗΚΕ Η ΟΩΤΟΚΙΑ, Η ΕΚΚΟΛΑΨΗ ΚΑΙ Η ΠΤΕΡΩΣΗ ΤΩΝ ΝΕΟΣΣΩΝ, ΟΙ ΑΠΩΛΕΙΕΣ ΣΤΑ ΣΤΑΔΙΑ ΑΒΓΩΝ ΚΑΙ ΝΕΟΣΣΩΝ, Η ΔΙΑΙΤΑ ΤΩΝ ΝΕΟΣΣΩΝ ΚΑΘΩ Σ ΚΑΙ Η ΑΥΞΗΣΗ ΟΡΙΣΜΕΝΩΝ ΣΩΜΑΤΙΚΩΝ ΤΟΥΣ ΠΑΡΑΜΕΤΡΩΝ. Η ΣΧΕΣΗ ΤΟΥ ΕΙΔΟΥΣ ΜΕΤΑ ΕΝΔΙΑΙΤΗΜΑΤΑ ΔΙΕΡΕΥΝΗΘΗΚΕ ΜΕ ΤΗ ΜΕΛΕΤΗ ΤΗΣ ΚΑΤΑΝΟΜΗΣ, ΤΗΝ ΤΡΟΦΟΛΗΠΤΙΚΗ ΕΠΙΤΥΧΙΑ, ΤΗ ΔΙΑΤΡΟΦΗ ΚΑΙ ΤΗ ΔΙΑΤΡΟΦΙΚΗ ΤΗΣ ΑΞΙΑ. ΟΙ ΛΕΥΚΟΤΣΙΚΝΙΑΔΕΣ ΕΦΘΑΝΑΝ ΣΤΟ ΔΕΛΤΑ ΑΞΙΟΥ ΚΑΤΑ ΤΑ ΤΕΛΗ ΜΑΡ ΤΙΟΥ ΚΑΙ ΑΡΧΙΖΑΝ ΝΑ ΩΟΤΟΚΟΥΝ ΤΟ 2Ο ΔΕΚΑΗΜΕΡΟ ΤΟΥ ΑΠΡΙΛΙΟΥ. ΦΩΛΙΑΖΑΝ ΚΥΡΙΩΣ ΣΕ ΑΡΜΥΡΙΚΙΑ ΜΑΖΙ ΜΕ ΑΛΛΑ ΕΙΔΗ ΕΡΩΔΙΩΝ. Ο ΜΕΣΟΣ ΑΡΙΘΜΟΣ ΑΒΓΩΝ ΠΟΥ ΑΠΕΘΕΤΑΝ ΑΝΑ ΦΩΛΙΑ ΗΤΑΝ 4,3 ΑΠΟ ΤΑ ΟΠΟΙΑ ΕΚΚΟΛΑΠΤΟΝΤΑΝ 3,3 ΝΕΟΣΣΟΙ, ΑΠΟ ΤΟΥΣ ΟΠΟΙΟΥΣ ΕΠΙΒΙΩΝΑΝ ΩΣ ΤΗΝ 30Η ΜΕΡΑ ΤΗΣ ΖΩΗΣ ΤΟΥΣ 2,5 ΝΕΟΣΣΟΙ ΑΝΑ ΦΩΛΙΑ. ΟΙ ΠΡΩΤΟΙ ΣΕ ΣΕΙΡΑ ΕΚΚΟΛΑΨΗΣ ΝΕΟΣΣΟΙ ΑΥΞΑΝΟΝΤΑΝ ΚΑΛΥΤΕΡΑ ΑΠΟ ΤΟΥΣ ΥΠΟΛΟΙΠΟΥΣ. ΟΙ ΝΕΟΣΣΟΙ ΤΡΕΦΟΝΤΑΙ ΜΕ ΕΝΤΟΜΑ, ΨΑΡΙΑ ΚΑΙ ΑΜΦΙΒΙΑ. ΟΙ ΛΕΥΚΟΤΣΙΚΝΙΑΔΕΣ ΧΡΗΣΙΜΟΠΟΙΟΥΣΑΝ ΩΣ ΕΝΔΙΑΙΤΗΜΑΤΑ ΔΙΑΤΡΟΦΗΣ ΤΑ ΑΠΟΕΛΗ , ΤΑ ΓΛΥΚΑ ΝΕΡΑ ΚΑΙ ΤΟΥ Σ ΟΡΥΖΩΝΕΣ. Η ΤΡΟΦΟΛΗΠΤΙΚΗΕΠΙΤΥΧΙΑ ΗΤΑΝ ΜΕΓΑΛΥΤΕΡΗ ΣΤΟΥΣ ΟΡΥΖΩΝΕΣ.THE LITTLE EGRET (EGRETTA G. GARZETTA) KNOWN IN GREECE FROM ANCIENT TIMES, MOWDAYS REEDS AT 7 WETLANDS AT LEAST. THE AIM OF THE STUDY WAS THE RESEARCH OF A) THE BREEDING PARAMETRES, B) THE RELATION BETWEEN THE SPECIES AND THE HABITATS OF AXIOS RIVER DELTA AND C) THE DISPERSION OF THE IMMATURE BIRDS. CONCERNINGTHE BREEDING ECOLOGY THE FOLLOWING WERE STUDIED: EGG LAYING, HATCHING AND FLEDGING SUCCESS, LOSSES DURING THE EGG AND NESTLING STAGE, NESTLINGS DIET AS WELL AS GROWTH OF CERTAIN NESTLINGS BODY PARAMET RES. THE RELATIONSHIP BETWEEN THE SPECIES AND THE HABITATS WAS STUDIED BY THE DISTRIBUTION STUDY, THE FEEDING SUCCESS, THE DIET AND ITS VALUE FOR THE SPECIES. THE LITTLE EGRETS ARRIVEDAT THE STUDY AREA AT THE END OF MARCH AND STARTED BREEDING AT THE 2ND T HIRDOF APRIL. THEY NESTED ON TAMARISKS WITH OTHER HERON SPECIES. THE MEAN NUMBEROF EGGS PER NEST WAS 4.3 OF WHICH 3.3 NESTLINGS HATCHED AND 2.5 NESTLINGS FLEDGEG PER NEST. THE GROWTH OF THE NESTLINGS THAT HATCHED FIRST WAS BETTER THAN THE REST. THE NESTL INGS DIET WAS MAINLY FISH, INSECTS AND AMPHIBIANS. THELITTEL EGRETS USED FOR FEEDING THE SALTMARSHES, THE FRESHWATER HABITATS AND THE RICEFIELDS. THE FEEDING SUCCESS WAS HIGHER IN RICEFIELDS

Comparative breeding ecology of the Little Egret (Egretta g. garzetta) in the Axios delta (Greece) and the Camargue (France)

Data on the breeding biology of Little Egrets (Egretta garzetta) are compared between two internationally important Mediterranean wetlands for waterbirds : the Camargue in southern France and the Axios Delta, Macedonia, Greece. During the incubation and chick-rearing periods, Camargue Little Egrets fed mainly in freswhater marshes and secondarily in brackish and saltwater lagoons. In the Axios Delta, ricefields were particularly important, followed by brackish and saltwater habitat. These differences in feeding habitat use are reflected in chicks diet. Freshwater fish predominated (by number) in the Camargue while Axios chicks regurgitated mostly invertebrates and tadpoles from ricefields and saltwater fish. Clutches in the Axios were significantly greater than in the Camargue. This may be attributable to favourable feeding conditions offered by the coastal saltmarshes. These are heavily exploited during the pre-breeding season, before the ricefields become available. Brood sizes were significantly greater in the Camargue than in the Axios due to a greater proportion of four-chick broods. Furthermore, Camargue chicks at age 14 days, when the demand of food is highest, were fatter than the Axios chicks of the same age. Thus, after having laid fewer eggs than the egrets in the Axios, the Camargue birds were finally able to produce more youngDes données sur la biologie de reproduction de l’Aigrette garzette (Egretta garzetta) sont comparées entre deux zones humides méditerranéennes d’importance internationale pour les oiseaux d’eau : la Camargue en France et le delta de l'Axios en Grèce. Pendant l’incubation et l’élevage des poussins, les aigrettes de Camargue s’alimentent principalement dans les marais d’eau douce et, dans une moindre mesure, dans les lagunes d’eau saumâtre et salée. Dans l’Axios, les rizières constituent des lieux d’alimentation particulièrement importants, les milieux d’eau saumâtre et salée se plaçant en deuxième position. Les différences dans l’exploitation des divers types de milieux d’alimentation apparaissent dans le régime des poussins. En Camargue, les poissons d’eau douce constituent l’essentiel (en nombre) de leur alimentation alors qu’en Grèce, le régime est surtout composé d’invertébrés et de têtards provenant des rizières ainsi que de poissons d’eau salée. La taille des pontes est significativement plus élevée dans l’Axios qu’en Camargue. Ce résultat pourrait refléter une situation trophique favorable offerte par les marais salants côtiers de l’Axios, principaux milieux exploités par les aigrettes pendant la saison pré-nuptiale, avant la mise en eau des rizières. En Camargue, les nichées sont significativement plus élevées que dans l’Axios, une proportion plus élevée de nichées de quatre poussins ayant été enregistrée en France. De plus, à l’époque où les poussins ont besoin d’un maximum de nourriture pour survivre, vers deux semaines, ceux de Camargue sont en meilleure condition que ceux de Grèce. Par conséquent, à partir d’une ponte moins élevée que celle enregistrée dans l’Axios, les aigrettes de Camargue élèvent plus de jeunes qui sont en meilleure condition à l’époque cruciale de l’élevage. Ces différences dans le succès de la reproduction sont liées à une situation trophique très favorable en Camargue en période d’élevage. Dans l’Axios, il est essentiel que les rizières soient intégrées dans les programmes futurs de conservation de cette importante zone humide.Kazantzidis Savas, Hafner Heinz, Gourner Vassilis. Comparative breeding ecology of the Little Egret (Egretta g. garzetta) in the Axios delta (Greece) and the Camargue (France). In: Revue d'Écologie (La Terre et La Vie), tome 51, n°4, 1996. pp. 313-327

Winter diet of the Marsh Harrier Circus aeruginosus (Aves, Accipitriformes) in the Evros Delta (Greece)

The diet of the Marsh Harrier (Circus aeruginosus) was studied with the analysis of pellets collected in the Evros Delta. In total, 141 prey items were identified in 86 pellets. In terms of numbers, the diet consisted of 66.7% mammals, 27.7% birds and 5.7% insects. Considering biomass, birds were the most important prey, while mammals made up 36.6% of the diet. The most important species, in terms of biomass, were Sibling Vole (Microtus levis) -31.1%-,Teal (Anas crecca) -17.7%-, Moorhen (Gallinula chloropus) and Black-headed Gull (Chroicocephalus ridibundus) -11.8% each-. The mean estimated prey weight was 36 g., ranging from 1 to 300 g

Acoustic Monitoring Confirms Significant Poaching Pressure of European Turtle Doves (<i>Streptopelia turtur</i>) during Spring Migration across the Ionian Islands, Greece

The European turtle dove (Streptopelia turtur) is an Afro-Palearctic migrant whose populations have declined by 79% from 1980 to 2014. In 2018, the International Single Species Action Plan for the Turtle Dove (ISSAP) was developed with the goal of enabling, by 2028, an increase in turtle dove numbers along each of the three migration flyways (western, central, eastern). To achieve this, the illegal killing of turtle doves, a critical threat to the species, has to be eradicated. The Ionian Islands off the west coast of Greece lie on the eastern flyway and are considered a major turtle dove poaching hot-spot during spring migration. Quantifying wildlife crime, however, is challenging. In the absence of a reliable protocol for monitoring spring poaching levels, the agencies tasked with tackling the problem have no means of assessing the effectiveness of the anti-poaching measures and adapting them if required. Using passive acoustic monitoring (PAM) methods, we recorded gun hunting intensity at known turtle dove poaching sites during the 2019–2022 spring migrations (2–10 sites/season) with unprecedented spatial and temporal resolution. Based on published gunshot to killed/injured bird ratio for similar species (corroborated with discussions with local hunters) and an estimate of the proportion of hunting sites monitored by our PAM grid (using gunshot detection range estimates from control gunshots), we estimated that in 2021, up to 57,095 turtle doves were killed or injured across five Ionian Islands (Zakynthos, Paxi, Antipaxi, Othoni, and Mathraki). The 2022 estimate was almost half, but it is unclear as to whether the change is due to a decline in poachers or turtle doves. We propose ways of improving confidence in future estimates, and call for a temporary moratorium of autumn turtle dove hunting in Greece—as per ISSAP recommendation—until spring poaching is eradicated and the eastern flyway population shows signs of a full recovery. Finally, we hope our findings will pave the way for the development of PAM grids at turtle dove poaching hot-spots across all migration flyways, contributing to the global conservation of the species

Two distinct flyways with different population trends of Bewick's Swan Cygnus columbianus bewickii in East Asia

Two of the most fundamental ecological questions about any species relate to where they occur and in what abundance. Here, we combine GPS telemetry data, survey data and expert knowledge for the first time to define two distinct flyways (the East Asian Continental and West Pacific flyways), migration routes and abundance for the Eastern population of Bewick’s Swan Cygnus columbianus bewickii. The Eastern population is the largest flyway population, supporting c. 77% of Bewick’s Swan numbers globally. GPS telemetry data showed that birds breeding in the Russian arctic from the Yamal Peninsula to c. 140°E (including the Lena and Yana Deltas), winter in the middle and lower reaches of the Yangtze River in China (which we label the “East Asian Continental flyway”). Bewick’s Swans breeding from the Indigirka River east to the Koluchin Bay winter in Japan, mostly in Niigata, Yamagata and Ishikawa Prefectures (the “West Pacific flyway”). There was no overlap in migration routes used by tagged individuals from the two flyways. Counts of Bewick’s Swans in the East Asian Continental flyway during the 21st century have shown wide between-year variations, reflecting incomplete coverage in earlier years. Bewick’s Swans in this flyway currently numbers c. 65,000 birds based on extensive wintering survey coverage, compared to c. 81,000 in the early 2000s, based on less complete coverage. Chinese-wintering swans now concentrate mainly (c. 80%) at Poyang Lake in Jiangxi Province and Hubei Lakes (mostly in Longgan Lake), compared to a more widespread distribution both within Poyang and throughout the Auhui Lakes in 2004 and 2005. In contrast, Bewick’s Swans of the West Pacific flyway now numbers c. 40,000, compared to just 542 in 1970. This population has shown no significant overall change since 2004, when it numbered c. 45,000 birds. Small numbers within this population probably also winter in South Korea. These results provide our first basic understanding of the winter distribution of Chinese- and Japanese-wintering Bewick’s Swans in relation to their breeding areas, confirming the need to coordinate future research and monitoring in the two flyways, as well as the need for more information on swans wintering in South Korea

Host dispersal shapes the population structure of a tick-borne bacterial pathogen

Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies “Candidatus Borrelia aligera” was also detected. Multilocus sequence typing (MLST) analysis of B. garinii isolates together with the global collection of B. garinii genotypes obtained from the Borrelia MLST public database revealed that: (a) there was little overlap among genotypes from different continents, (b) there was no geographical structuring within Europe, and (c) there was no evident association pattern detectable among B. garinii genotypes from ticks feeding on birds, questing ticks or human isolates. These findings strengthen the hypothesis that the population structure and evolutionary biology of tick-borne pathogens are shaped by their host associations and the movement patterns of these hosts.This study received financial support from Fundação para a Ciência e a Tecnologia by the strategic program of MARE (MARE ‐ UID/MAR/04292/2013) and the fellowship to Ana Cláudia Norte (SFRH/BPD/108197/2015), and the Portuguese National Institute of Health. Raivo Mänd, Tomi Trilar, Tapio Eeva, Tomas Grim and Dieter Heylen were supported by the Estonian Research Council (research grant # IUT34‐8), the Slovenian Research Agency ‐programme “Communities, relations and communications in the ecosystems” (No. P1‐0255), the Academy of Finland (project 265859), the Internal Grant Agency of Palacky University (PrF_2014_018, PrF_2015_018, PrF_2013_018) and the Marie Sklodowska‐Curie Actions (EU‐Horizon 2020, Individual Global Fellowship, project no 799609), respectively