International Osprey Data Project

The International Osprey Data Project is a long-term research project of Dr Mary Ann Steggles and Claudio Eduardo.  Volunteer observers assist the pair.  More than one hundred osprey nests from around the world are being observed.  In 2023, this included more than 158 chicks.

There has yet to be any significant research on siblicide in Western and Eastern Ospreys.  This project aims to establish a more accurate percentage of siblicide compared with fledges at the nests.  Through careful observation, the researchers hope to establish why many nests have died.  Is this strictly due to a lack of fish deliveries?  Or might there be other mitigating causes? In addition, information will be gathered on the number of chicks hatched, fledged, and predated. 

The project began in 2018 and will run for at least twenty years.  Initially, only a small number of nests were observed. This has expanded to include more than five times that number due to the use of a project template. The data will be analysed at the end of each breeding season, and the results will be published.  We hope to understand better Ospreys’ challenges in the 21st century and what drives the siblings to kill one another in the nest.  

For more information, please contact

Dr Mary Ann Steggles,