The monitoring study on the Osprey

The monitoring study project on Ospreys is a convincing example of the work for the Finnish environment that ringers do. People became aware of the world-wide decline of Osprey populations in the late 1960's. In 1971, the Finnish ringers made the Osprey a target for a special monitoring study, after which almost all Osprey nest sites reported to the Zoological Museum (an estimated 90 % of them) are checked on a yearly basis. In 2005, 1,541 nest sites were checked, and 923 territories proved to be occupied.

In addition to checking nest sites and ringing nestlings ringers have made observations on fishing grounds and prey fish of the Ospreys. Ringers have also collected unhatched eggs and dead nestlings found in the nests for toxicology analyses.

As early as in the early days of the Osprey project the lack of nest trees - in addition to environmental pollutants and persecution - was found to be a serious threat to the Osprey population of Finland. The only means of trying to ward off this threat factor brought by our intense forestry is to build artificial nests, a project to which Osprey ringers have devoted a lot of time and money. Today, nearly half of the known Finnish Osprey pairs nest in artificial nests! Due to an effective building of artificial nests, a decline in persecution during migration and a lightening of the toxic load the development of the Finnish Osprey population has been favourable: the average breeding success has been good and the population has increased slightly year by year.

Osprey nest trees included in the monitoring study have been marked with a glass fibre protection board. If you find an Osprey nest tree not marked with a protection board, send a message with as exact data as possible on the location of the nest (preferably a copy of the base map, scale 1:20,000) to the Ringing Centre.

Migration and wintering of Finnish Ospreys have also been mapped with the help of satellite tracking. Read more about this at the Satellite ospreys site.

Publications

• Saurola, P. 1998: Suomen sääkset 1998 (Summary: Finnish Ospreys Pandion haliaetus in 1998). - Linnut-vuosikirja 1998: 31-37.
• Saurola, P. 1999: Suomen sääkset 1999 (Summary: Finnish Ospreys Pandion haliaetus in 1999). - Linnut-vuosikirja 1999: 8-12.
• Saurola, P. 2001: Suomen sääkset 2000 (Summary: Finnish Ospreys Pandion haliaetus in 2000). - Linnut-vuosikirja 2000: 29-33.
• Saurola, P. 2002: Suomen sääkset 2001: reviirien tarkastusta ja satelliittiseurantaa (Summary: Finnish Ospreys Pandion haliaetus in 2001). - Linnut-vuosikirja 2001: 4-9.
• Saurola, P. 2003: Suomen sääkset – tarkastustyö jatkui tehokkaana (Summary: Finnish Ospreys Pandion haliaetus in 2002). - Linnut-vuosikirja 2002: 20-23.
• Saurola, P. 2004: Suomen sääkset 2003 - seuranta jatkui ja siirtoistutus alkoi (Summary: Finnish Ospreys Pandion haliaetus 2003). - Linnut-vuosikirja 2003: 8-13.
• Saurola, P. 2005: Suomen sääkset 2004 (Summary: Finnish Ospreys Pandion haliaetus 2004). - Linnut-vuosikirja 2004: 20-27.
• Saurola, P. 2006: Suomen sääkset 2005 (Summary: Finnish Ospreys Pandion haliaetus 2005). - Linnut-vuosikirja 2005: 23-26.