Researchers have discovered that captive-bred Egyptian Vultures are able to match the performance of wild birds by their second migration.
A young bird's environment shapes its behavioural skills, as does the individual's experience built up over time. Researchers at Ben-Gurion University of the Negev set out to find out to compare the migration and flight skills of released Egyptian Vultures with those of wild-hatched birds.
Egyptian Vulture migrates between Europe and central Africa each year. Wild-hatched birds have an advantage in their early development, but new research shows released individuals learn fast (Alan Jack).
In the Western Palearctic, Egyptian Vulture is mostly a long-distance migrant, with birds breeding in southern Europe, North Africa and the Middle East migrating to wintering grounds south of the Sahara.
GPS transmitters were fitted to two groups of Egyptian Vultures, one of captive-bred birds and the other from the wild. In total, 65 individuals were tracked, giving information on 127 individual autumn migrations.
The results showed that both groups honed their migration efficiency and flight skills with time, as they gained experience of their surroundings and their migration route. Birds raised in captivity showed the most marked improvement. During their first migration, these birds were noticeably inefficient compared to their wild congeners but they had effectively 'caught up' with their skills by the second autumn migration.
Vultures released at a later stage appeared to take longer to become proficient, with those set free at a younger age apparently improving their behavioural skills sooner. However, even the late releases made the same improvements to daily progress, efficient soaring behaviour and migration duration.
Professor Oded Berger-Tal, from the Jacob Blaustein Institutes for Desert Research at the university, said: "It seems that birds, like humans, are also affected by their life experience."
Reference
Efrat, R, Hatzofe, O, Mueller, T, Sapir, N, & Berger-Tal, O. 2023. Early and accumulated experience shape migration and flight in Egyptian vultures. Current Biology, 33(24): 5526-5532. DOI: 10.1016/j.cub.2023.11.012
