NEW STUDY
Billions of migratory birds travel each year between their breeding grounds in Eurasia and their wintering areas in sub-Saharan Africa. During migration, the majority of these birds must cross the ecological barrier formed by the Sahara Desert and the Mediterranean Sea, an exceptionally perilous undertaking.
According to recent studies, the barrier crossing accounts for the highest mortality rates throughout their annual cycle. Oases in the Sahara, areas of dense vegetation in North Africa, and Mediterranean islands are utilised by the birds for energy refuelling and rest, known as stopover sites, which are crucial for the successful outcome of their migration journey.
A new study reveals that climate change could drastically reshape the migratory patterns of trans-Saharan birds, posing unique challenges for their survival. Researchers found that as the Sahara and Mediterranean barriers grow harsher, crucial stopover sites in North Africa will decrease, leaving birds with fewer places to rest and refuel. This change will lead to depleted energy reserves upon reaching the north Mediterranean, threatening their migration success.
Key Findings:
- Critical North African refueling spots will vanish, affecting birds' fuel loads more than the desert-crossing distances
- Birds arriving lean and late at insular stopovers in the Mediterranean may face survival risks and reduced breeding success, given the increasing aridity locally
- Climate-induced aridity is predicted to delay migration timings and reduce arrival fuel loads
The Icterine Warbler (Hippolais icterina) is among the migratory birds that are ringed in Antikythera Bird Observatory and cross the Sahara - Mediterranean barrier
The study is available:
The present study was conducted using data from the Antikythera Bird Observatory (ABO), run by the Hellenic Ornithological Society / BirdLife Greece.
The study was part of the ROUTES Project supported by the Hellenic Foundation for Research and Innovation (H.F.R.I). ROUTES is hosted by the Department of Biological Applications and Technology at University of Ioannina and runs in collaboration with the Hellenic Ornithological Society / BirdLife Greece.
Common Reed Warbler (Acrocephalus scirpaceus) | Photo: Giorgos Alexandris / HOS