Where do Palaearctic Great White Pelicans (Pelecanus onocrotalus) presently overwinter?

The population of Great White pelicans Pelecanus onocrotalus breeding in the Palaearctic (from Greece to the USSR) is estimated at more than 10 000 pairs. This species has, however, been very little studied and the restricted amount of ringing carried out on this bird has not greatly improved our knowledge of its migration routes and wintering areas. Counts have been carried out during the autumn migration period over several years at three different sites (Greece, Bulgaria and Israel) and the migration routes, the stopover sites and the numbers of birds can now be described with precision. By using a motorized glider, migrating pelicans could be followed from the north to the south of Israel in a single day, the average speed could be estimated and further information on the flight capabilities could be obtained. After the discovery of very high numbers during the migration period, the hypothesis has been advanced that non-breeding Great White pelicans do not remain on their wintering grounds, but return each spring to oversummer in the Palaearctic. The majority of the population of Great White pelicans breeding in the Palaearctic used to winter in the Nile delta (Egypt) at the start of this century. Because of the numerous developments carried out in the delta, however, they no longer winter there and they have been forced to find another wintering area further south. Unfortunately, this new site is still unknown and several hypotheses are proposed. Finally we recommend that movements be monitored by satellite in the future in order to discover the new wintering site(s) of this species and to confirm the correctness of the migration routes described in this study.La population de pélicans blancs, Pelecanus onocrotalus, nicheuse dans le Paléarctique (de la Grèce à l’URSS) est estimée à plus de 10 000 couples. Pourtant cette espèce a été très peu étudiée et le baguage restreint de ces oiseaux n’a guère contribué à améliorer nos connaissances sur les routes de migration et sur l’hivernage de cette espèce. Nous avons effectué des dénombrements pendant la période migratoire automnale, sur plusieurs années et en trois sites différents (Grèce, Bulgarie et Israël) et nous pouvons maintenant décrire avec précision les voies de migration, les sites d’escale et les effectifs de cette espèce. L’utilisation d’un planeur motorisé nous a permis de suivre les pélicans blancs en migration, du nord au sud d’Israël en une seule journée, d’estimer leur vitesse moyenne et d’approfondir nos connaissances sur les possibilités de vol de cette espèce. La découverte d’effectifs très importants en période migratoire nous a amenés à émettre l’hypothèse que les pélicans blancs non nicheurs ne restent pas sur leurs lieux d’hivernage, mais reviennent chaque printemps en zone paléarctique pour estiver. En effet la majorité de la population de pélicans blancs nicheuse dans le Paléarctique hivernaient au début du siècle dans le delta du Nil (Egypte). Actuellement, à cause des nombreux aménagements réalisés dans ce delta, les pélicans blancs n’y hivernent plus et ils ont été contraints de trouver un nouveau site d’hivernage plus au sud. Malheureusement ce nouveau site est encore inconnu et plusieurs hypothèses sont proposées. Nous recommandons à l’avenir le suivi par satellite afin de découvrir le ou les nouveaux sites d’hivernage de cette espèce et de confirmer l’exactitude des voies migratoires proposées dans cette étude.Crivelli Alain Jean, Leshem Yossi, Mitchev Taniu, Jerrentrup Hans. Where do Palaearctic Great White Pelicans (Pelecanus onocrotalus) presently overwinter?. In: Revue d'Écologie (La Terre et La Vie), tome 46, n°2, 1991. pp. 145-171

First Nationwide Monitoring Program for the Detection of Potentially Invasive Mosquito Species in Austria

In Austria, only fragmented information on the occurrence of alien and potentially invasive mosquito species exists. The aim of this study is a nationwide overview on the situation of those mosquitoes in Austria. Using a nationwide uniform protocol for the first time, mosquito eggs were sampled with ovitraps at 45 locations in Austria at weekly intervals from May to October 2020. The sampled eggs were counted and the species were identified by genetic analysis. The Asian tiger mosquito Aedes albopictus was found at two sites, once in Tyrol, where this species has been reported before, and for the first time in the province of Lower Austria, at a motorway rest stop. The Asian bush mosquito Aedes japonicus was widespread in Austria. It was found in all provinces and was the most abundant species in the ovitraps by far. Aedes japonicus was more abundant in the South than in the North and more eggs were found in habitats with artificial surfaces than in (semi-) natural areas. Further, the number of Ae. japonicus eggs increased with higher ambient temperature and decreased with higher wind speed. The results of this study will contribute to a better estimation of the risk of mosquito-borne disease in Austria and will be a useful baseline for a future documentation of changes in the distribution of those species

Long-term size and range changes of the Griffon Vulture Gyps fulvus population in the Balkans: a review

The Eurasian Griffon Vulture Gyps fulvus is a large Palearctic, Indohimalayan and Afrotropical Old-World vulture. The species' range is vast, encompassing territories from the Pyrenees to the Himalayas. We reviewed and analysed a long-term data set for Griffon Vulture in the Balkans to estimate the change in its population size and range between 1980 and 2019. After a large historical decline, the Griffon Vulture population slightly increased in the last 39 years (lambda = 1.02) and reached 445-565 pairs in 2019. We recorded a gradual increase of Griffon Vulture subpopulations in Serbia (lambda = 1.08 +/- 0.003), Bulgaria (lambda = 1.08 +/- 0.003) and Croatia (lambda = 1.05 +/- 0.005) and steep to a moderate decline of the species subpopulations in Greece (lambda = 0.88 +/- 0.005) and North Macedonia (lambda = 0.94 +/- 0.01). However, species range contracted to half of its former range in the same period. It occurred in 42 UTM squares in the 1980-1990 period and only 20 UTM squares between 2011 and 2019 and concentrated into three source subpopulations in Bulgaria, Serbia, and Croatia. Following reintroductions of the Griffon Vulture in Bulgaria, new colonies were formed at three novel localities after 2010. Regular movements of individuals between the different subpopulations exist nowadays. Therefore, preservation of both current and former core areas used for breeding and roosting is essential for species conservation in the region. However, the Griffon Vulture still faces severe threats and risk of local extinction. Various hazards such as poisoning, collision with energy infrastructure, disturbance and habitat alteration are depleting the status of the Balkan population and its full recovery. Further studies should analyse age-specific survival and mortality, recruitment, genetic relatedness, spatial use to inform the viability of this population in the future