30 Million Migratory Birds Depend on the Greek Islands

Greece Is | May 13th, 2022

In their attempt to cross this great ecological barrier, many migratory birds arriving on the Mediterranean coast lose a large part of their body mass and depend on a stopover in order to refuel and survive.

© Tasos Sakoulis

In celebrating World Migratory Bird Day on May 14, experts emphasize the importance of preserving ecological balance to ensure the safety of around 30 million birds.

A new study conducted by the Department of Biological Applications & Technologies of the University of Ioannina in collaboration with the Antikythera Ornithological Station (OSA) , confirms the major role of the small islands of southern Greece for migratory birds, and estimates over tens of millions of birds would be at risk if these precious sites were to become inhospitable due to climate change.

Every spring, millions of migratory birds return to breed in parts of Europe. To do so, they must first cross the Sahara Desert and then the Mediterranean Sea, a stretch of land that can be up to 2,800 kilometres, along which they encounter almost no opportunities to eat and increase their energy reserves.

According to the study, of the approximately 185 million birds migrating over Greece, almost 30 million must refuel at the first available island, and even small changes in environmental conditions along the way could lead to increased mortality for these species.

This is the first time that experts have been able to make a quantitative assessment of the birds that are likely to face future changes in their migratory journeys due to climate change. The researchers used – among other things – empirical data combined with aerodynamic models and focused their study on three small Greek islands: Gavdos (south of Crete), Antikythera (south of the Peloponnese) and Strophadia (in the southern Ionian Sea).

Measurements showed that, upon arrival on one of the three islands, the energy reserves of many migratory birds were close to zero, while, correspondingly, body mass values for many species were the lowest ever reported. The findings underlined the vital importance of long-term monitoring programmes for migratory birds in Greece and the Mediterranean region.

In other words, an extremely large number of migratory birds would not be able to cross the Sahara and the Mediterranean successfully if it were not for the small and large islands of southern Greece. These islands are not just a stopover but a vital stopover, critical to their survival.