スミソニアン国立動物園さんのインスタグラム写真 - (スミソニアン国立動物園Instagram)「Egyptian vultures from Eastern Europe migrate twice as far as vultures in Western Europe to their wintering grounds in Northern Africa largely to avoid crossing large waterways, which do not have as many reliable thermal currents as routes over land. The largest study of the vultures' migrations tracked Egyptian vultures across approximately 70% of their range through 44 countries. Since the species is endangered, it is important for scientists to understand what kinds of obstacles the vultures encounter during their migrations to better protect them and the areas where they are spending time. “This study is an excellent example of scientific collaboration, with input from 11 research projects and 31 organizations,” said Evan Buechley, co-author of the paper and postdoctoral fellow with the Smithsonian Migratory Bird Center. “This enabled us to investigate the ecology of this endangered species across 70% of its global distribution. Our findings illuminate great variation in migratory behavior, including timing, duration, speed, and efficiency of migration, as well as the major overwintering destinations for the species in Africa. This information is vital for understanding potential drivers of population declines, as well as for targeting conservation actions.” Scientists tracked 94 Egyptian vultures from four different subpopulations over 11 years with lightweight transmitters that weighed less than 3% of their body masses. The vultures traveling to Northern Africa from Eastern Europe had longer migration routes and encountered four different bottlenecks, or areas where geography constricted their migrations routes. In addition to revealing differences between the subpopulations, the study also illuminated differences within the subpopulations. When Egyptian vultures made it to their wintering grounds, the Western and Eastern subpopulations’ ranges did not overlap. However, the wintering grounds of birds from the same breeding subpopulations could be spread over distances of as much as 4,000 kilometers. #EgyptianVulture #Ornithology #Migration #Vultures #Birds #Raptors #WeSaveSpecies」11月23日 7時10分