Potential importance of wind patterns and guidance opportunities for the conservation of the Egyptian Vulture Neophron percnopterus in Italy

Abstract

Summary Movement ecology and environmental factors are topics of paramount importance to consider when planning conservation programmes for target species. Here we discuss this topic by reviewing the available information related to the Egyptian Vulture Neophron percnopterus, with reference to the remnant breeding population of Southern Italy, of high conservation concern and subject of a long-term captive-breeding re-stocking programme. We describe how adverse wind conditions over the Central Mediterranean Sea make the sea-crossing challenging with detrimental effects on the survival of inexperienced birds, and coupled this information with count data of migrating Egyptian Vultures. Furthermore, we indicate how low population size and scarce opportunities in meeting migrating conspecifics could potentially lead juvenile Egyptian Vultures to follow unfavourable migratory routes, with possible repercussions on survival. We postulate how these concomitant factors could be indirectly influencing the long-term survival of this small population, principally affected by anthropogenic threats. We also discuss how the same factors could actually be affecting captive-bred young individuals released in late summer in southern continental Italy, in the framework of the restocking programme. An integrative approach with tailor-made release methods, which also takes into account the age of released birds and geographical and environmental factors, would likely be useful for a more goal-oriented and long-lasting conservation outcome, for the preservation of this endangered scavenger.

Differential Flight Strategies of Western Marsh Harrier Circus aeruginosus in Relation to Sex and Age Class during Spring Migration in the Central Mediterranean

“…Satellite studies showed that WMHs leave a drift effect when flying in stronger crosswinds, exploiting their tail support to migrate faster especially during spring migration (Mellone et al 2012, Vansteelant et al 2020). Moreover, visual observations made at the Cap Bon Promontory (NE Tunisia), showed that WMHs facing the open sea undertake the crossing even in strong side winds (Agostini & Duchi 1994), prevailing in early spring over the Channel of Sicily (see also Agostini et al 2022). In this picture, it is reasonable to assume that during strong winds, having with higher frequency a side component in the study area in early spring, WMHs would tend to fly more dispersed in space, thus forming even smaller flocks.…”

First Results of Tracking of the Juvenile Egyptian Vultures from Karatau, Kazakhstan

“…23). Тем не менее, прослеживание Боралдая показало, что лётная активность в ночное время -с 19:00 до 05:00 LMT занимает 3,12% от общего вре- (Agostini et al, 2015), in Asia the Pamir-Alai mountains are the barrier that Kazakhstan EVs and eagles , fly around from the west, crossing only the Hindu Kush at maximum altitudes. It is known that unfavorable wind conditions over the central Mediterranean Sea make it difficult for EVs to fly across the sea and have a detrimental effect on the survival of inexperienced juvenile birds (Agostini et al, 2023).…”

“…В то же время, треки казахстанских птиц не прямолинейны, близки к таковым балканских стервятников, что связано с тем, что птицам из обеих популяций приходится огибать ландшафтные барьеры. И если в Европе такими барьерами являются преимущественно моря, которые парящие хищники обычно не хотят пересекать из-за ограниченного теплового подъема (Agostini et al, 2015), то в Азии -это горы Памиро-Алая, которые казахстанские стервятники, также как и орлы (Карякин и др., 2019; 2021), обходят с запада, пересекая на максимальных высотах только Гиндукуш. То, что неблагоприятные ветровые условия над центральной частью Средиземного моря усложняют перелёт стервятников через море и пагубно влияют на выживание неопытных ювенильных птиц, известно (Agostini et al, 2023).…”

Against the flow: unexpected migration movements over the open sea by inexperienced ospreys

“…The morphology and body mass of these birds prevent them to use a constant flapping (powered) flight for long distances (Newton 2008;Agostini et al 2015), especially over the open water, where thermal updrafts are generally much weaker than over land (Duriez et al 2018;Nourani et al 2021). This is the reason for which heavier and broad winged raptors are obligate soarers congregating at strategic points (bottlenecks) to reduce the distance to be covered over water (Agostini et al 2016(Agostini et al , 2022Panuccio et al 2016;Premuda et al 2015). For instance, short-toed snake eagles Circaetus gallicus breeding in southern Italy and Greece have evolved a peculiar migration strategy which entails long detours across southern Europe for crossing the Mediterranean Sea at its narrower points (ca 14 km), the Strait of Gibraltar and the Bosphorus, respectively (Panuccio et al 2012).…”