# CE; # CON; # RES

Project Name: SOS STORK Croatia

Partners: SOS Storch – Storchenzug im Wandel, Lonjsko Polje Nature Park, Euronatur

Project Start Year: 2015

Status: Active

Species: White Stork (Ciconia ciconia)

IUCN Red List Status: Least Concern (LC)

Species Status in Croatia (Red Book): Least Concern (LC)

Project Details:

White storks are among the most well-known migratory birds in Croatia. Their large white wings, which can span up to 1.5 meters, easily capture attention. They can be seen nesting on rooftops, telephone poles, streetlights, chimneys, and the walls of abandoned houses, as well as on artificial platforms designed to facilitate stork nesting. Although they can thrive in various habitats, ranging from African savannas and steppes to European meadows, farmlands, and wetland areas, storks also frequent urban environments where they can find safe nesting sites. In some cases, these urban areas also provide food sources.

In 2000, the Swiss NGO “Stork Switzerland” launched the “SOS Stork” project to track storks via satellite telemetry, aiming to identify and mitigate threats to storks along the western migration route. Data collected from 45 tagged individuals indicated that the behavior of storks in Western Europe has changed—many spend their first winters in landfills in Andalusia, Spain, which has significantly impacted their migration. Due to legal regulations established in 1999, the amount of organic waste in landfills had to be reduced to 3% by 2016, meaning this food source would no longer be available to storks in the same quantities.

The goal of tagging and monitoring storks is to map their migration routes along the eastern flyway, where storks from Croatia travel south. The project seeks to identify key stopover points and determine whether they are urban areas, meadows, wetlands, or landfills, as well as how far into Africa Croatian storks migrate. Additionally, the project aims to identify major dangers storks encounter, such as high-voltage power lines and open water towers. Small transmitters are attached to the storks, which send location data at regular intervals. This data is transmitted via mobile networks to a central system for processing and analysis.

The collaboration between the Zagreb Zoo and “Stork Switzerland” officially began in 2015 when we tagged a young stork in its nest in the village of Čigoč (named Maksi) and another rehabilitated stork (Lonja) with a satellite transmitter. The collaboration continued in 2016 with two adult storks (Leta and Tesla) being tagged. In 2017, we tagged three more: two adults in Čigoč (Pomona and Tesla II) and one young stork in Osekovo (Nikola). In 2018, eight more storks were tagged, followed by seven in 2019. Unfortunately, no storks were tagged in 2020 due to the SARS-CoV-2 pandemic. However, in 2021, four young storks were tagged, and in 2022 and 2023, eight storks were tagged in each year. In 2024, three more young storks were tagged.

The project received the Euronatur grant for Wet Meadows and Pastures in 2015/2016. EuroNatur and partner organizations launched the wet meadow conservation project, with the European Stork Villages (ESVN) designated as flagship projects. The project aims to increase the area and quality of wet meadows and pastures within the ESVN network and promotes the exchange of ideas and expertise among Stork Villages across Europe.

Summary:

The project for monitoring white storks is conducted by tagging individuals with satellite transmitters to track their movements. The goal is to collect detailed information about migration routes and wintering grounds, as well as to identify and reduce threats such as illegal hunting and collisions with power lines, thereby contributing to the conservation of white storks and other migratory birds along the eastern migration route. The data collected over the years provides better insight into their behaviour and helps implement more effective conservation measures.