Wednesday, June 14, 2023

Head start for southern dunlins

For the first time in Sweden, "head-started" birds have been released into the wild. Four litters of the critically endangered subspecies southern dunlin have been bred at Ottenby on Öland in an attempt to increase the number of individuals in the wild.

After months of preparation and hard work, we were able to release a total of 14 individuals of the threatened southern dunlin on Öland during the first two weeks of June. The method used is called headstarting and is an effective and proven method to stop population decline for wading birds. It involves collecting eggs from wild birds to hatch and raise young during their first critical weeks, and then releasing them when they have grown.

The releases have taken place in two rounds where the first 7 chicks were released in early June and the remaining 7 were released 10 days later. It is the birds' ability to fly that determines when they can be released. Once they’ve learned to fly, they can more easily escape predators. Headstarting has proven to have many benefits.

In the wild, 60–90% of eggs and young risk being eaten by predators. Food shortages or bad weather are also a risk. Through the protection that headstarting brings, more individuals can survive to flight-ready age.

Collecting eggs early also means that the wild birds often lay a second brood, something they do naturally if they fail to breed at the beginning of the season. This increased productivity is certainly crucial at a time when the Swedish population of southern dunlin is close to extinction with fewer than 60 pairs throughout the country.

From the moment they hatch the chicks cope on their own, parents only help to show where to find food while keeping an eye out for predators. A trait that makes them easier to raise without parents. Once released, the chicks are ready to fly, and have thus gained a head start with better chances of survival.

The project is a collaboration between Nordens Ark and BirdLife Sweden and makes several other efforts for the southern dunlins and its important habitats, such as various measures in the field, information to the public in collaboration with universities and county administrative boards.

We are grateful for the support of wwand the lottery ticket buyers who made this possible.