Increased occurrence of Egyptian vultures in Crete: exploring movement patterns and potential for wintering

Migration is an integral part of the annual cycle of many bird species that have evolved to take advantage of spatially segregated, seasonally abundant food resources while avoiding harsh winter conditions. Increasing evidence suggests that long-distance migrants are shortening their migration routes and wintering at higher latitudes closer to their breeding grounds. One potential example of this process are the observations of Egyptian vultures during the winter on the island of Crete. In this study we provide an overview of wintering Egyptian vulture occurrences on the island of Crete, seeking to shed additional light on the species’ wintering ecology. To this aim we collated extensive field observations spanning 28 winters from 1995 to 2023 and analysed telemetry data from three tracked vultures. Our results revealed a change in the wintering frequency of Egyptian vultures in the island with an increasing trend since 2015, especially regarding the presence of subadult and adult birds. We found an increased habitat use intensity for open landscapes and agricultural areas compared to other habitat types within Crete, emphasizing the influence of food availability on space utilization. We suggest that the interplay between climate changes, lack of experienced conspecifics and local food availability could have triggered the increasing number of wintering Egyptian vultures in Crete. The implications of this short-stopping behaviour extend to conservation strategies, highlighting the need for the consideration of new wintering sites and the potential threats faced by vultures during this period. We recommend the operation of supplementary feeding stations and actions to reduce the risk of electrocution to be considered as valuable conservation actions in the species’ wintering sites in Crete. Monitoring and further research are recommended to assess the long-term impact and viability of this new migration tactic, providing insights into adaptive responses to environmental change.