Storks nesting in Slovenia early and in record numbers

"During the census we visit all white stork nests in Slovenia and we check the breeding success. We do this from late June to early July when the baby storks are big enough to be easily counted," said Urška Gajšek from DOPPS.

Talking with locals about the nesting process, fights for the nest and arrivals of storks is a very important part of the census, allowing them to learn the information that cannot be obtained otherwise, Gajšek said. The census takers also inspect the nest for stability and security.

The association has been performing the census since 1999 using an internationally established method. The data is included in the international white stork census, Gajšek said.

This year the first storks returned to their nests in Slovenia already in early February, while they usually return in the second half of March. Many pairs were able to start nesting early and saw their chicks fly two to four weeks earlier than usual.

According to DOPPS head Damijan Denac, the white stork likes a warm and dry climate, meaning it can adapt to climate change well. "It populates new areas and it apparently has enough food sources, which is what makes it so successful," Denac said.

The number of stork pairs nesting in Slovenia has increased only slightly from last year but the number of chicks was significantly lower in 2023 when only 437 fledglings learned how to fly. This was largely due to the cold and rainy weather in May when the chicks are at a stage when they cannot yet regulate their body temperature and many pass away.

In rainy weather storks can also struggle to find enough food and will sometimes abandon one chick to increase the odds of survival for the others.

Until this year the highest number of stork pairs nesting in Slovenia was 300, recorded in 2023, and the most baby storks made it out of their nests in 2020 when there were 596 chicks.