| Titre : | Age-related timing of Short-toed Snake Eagle Circaetus gallicus migration along detoured and direct flyways (2017) |
| Auteurs : | Nicolantonio Agostini, Auteur ; Luca Baghino, Auteur ; Wouter M.G. Vansteelant, Auteur ; Michele Panuccio, Auteur |
| Type de document : | Article |
| Dans : | Bird Study (64(1) janvier 2, 2017) |
| Article en page(s) : | 37-44 |
| Résumé : | Capsule: Juvenile Short-toed Snake Eagles Circaetus gallicus hatching in the peripheral populations of Greece and Italy have limited opportunities for social learning of migration routes compared to those hatched elsewhere.Aims: To test the prediction that there would be a higher degree of migration synchrony between adult and juvenile Short-toed Snake Eagles originating from peripheral populations and using an extremely detoured flyway, when compared to other populations using a direct overland flyway.Methods: We use linear regression models to compare seasonal changes in the age distribution of migrating Short-toed Snake Eagles counted at two migration watch-sites in Italy (Arenzano) and Georgia (Batumi), along a detoured and a direct flyway, respectively.Results: Juveniles migrated a few days later than adults at both sites and the age ratios recorded at these two sites was similar. The daily proportion of juveniles increased along a similar slope during the migration season, thus showing a similar degree of synchrony between the age classes on both flyways.Conclusions: Contrary to our hypothesis, juvenile and adult migration is not more synchronized in peripheral populations using a detoured flyway compared to a core population using a direct migration flyway. Our results suggest that juveniles do not learn detours to complete trans-Mediterranean migration from their parents, but from other elders. |
| En ligne : | http://www.tandfonline.com/doi/full/10.1080/00063657.2016.1264362 |



