The Breeding colonies, population growth and breeding success of the Dalmatian pelican Pelecanus crispus in Greece: a country-wide perspective, 1967-2021

Greece holds the third larger breeding population of Dalmatian Pelican in the world. We present data about the establishment and growth, breeding performance and conservation status for all six colonies of the species in Greece for 40 years. Main features of wetlands and colonies are described. We discuss the local, regional and global natural and anthropogenic factors that may have affected colony growth. After 1982 colony surveys were carried out with various methods, adapted to the particularities of each wetland and availability of resources, and targeted estimating number of nests and number of near-fledged young via direct counting either during on-site visits or from vantage points, and recently, counts on photos taken by drones flown one or more times during breeding. Number of nests in Lake Mikri Prespa rose from ca. 100 to 1200-1500 and levelled-off. DPs from Prespa started breeding successfully in Kerkini in 2004 after placement of artificial nesting rafts. The Karla Reservoir was colonised in 2011, just two years after it started filling with water. The DP colony on Lake Chimaditis, an important stop over and feeding site, probably initiated around 2016 and continues growing. The two colonies at the western coastline have limited exchanges with those in the eastern part of the country. Amvrakikos increased and levelled off recently as conservation and management measures restricted disturbance, whilst emigrants re-established the old colony at Messolonghi in 2011 which continues to grow. The overall breeding population in Greece grew from ca 100 to over 2000 br pairs showing an annual growth rate of 7.9%. Younger colonies show high annual growth rates clearly attributed to immigration, while older colonies have growth rates less than 10%. Interacting natural and anthropogenic factors are assumed to have contributed to pelican increase in Greece the last 40 years: better legal protection status, increasingly effective protection, patrolling and conservation measures; public awareness campaigns; provision of artificial nesting structures; increased winter survival due to higher temperatures owed to climate change; less disturbance and persecution due to decline of fisheries; increasing abundance and availability of fish due to eutrophication and climate change; increasing numbers of sympatric great cormorants rendering pelican fishing more efficient; appearance of new wetlands and change of wetlands due to human intervention works.