Trip reports

Indoor meeting - Return of Ospreys to Wales

Friday, 8 February 2013

Ospreys (Pandion haliaetus) have a long history in Wales with fossil records having been found and it also appears on the West Glamorgan coat of arms sporting a fish in its beak. They became extinct in Wales as breeding birds in 1916.
Alex gave an interesting overview of the associated Greek mythology as well as alerting us to references in Shakespeare's Coriolanus before concentrating on its natural history.
One species is recognised and has a wide distribution. Its success can be attributed to its powerful wings and specialised talons along with excellent eyesight which allows precise localisation in both air and water.

Males and females arrive in the UK from Africa in late March and nest on tall structures that offer a good vantage point. Pairs are loyal to their previous nest sites and on their return will spend time making repairs. The previous year's chicks will return to an area approximately an hour away from where they were raised. The male will catch 500 fish, typically weighing 2-3 pounds each, per breeding season whilst the female performs 80% of the brooding duties.

The osprey decline was due to a combination of collectors seeking stuffed birds for display, the Victorian's desire to shoot trophy birds, egg collecting and DDT insecticide use. The latter didn't kill birds directly but resulted in thin shelled eggs that the adults weren't able to brood without the shells breaking.

Ospreys naturally recolonised Scotland in the 1950s although this was more likely to have been accidental as a result of taking a mistaken route rather than a deliberate plan to return to the UK! Ospreys were also translocated to Rutland water in 1996 and 2005 and these birds are gradually moving west towards Wales. The BTO estimate that 180 UK breeding pairs were present in 2012.
There are 2 osprey projects in Wales; the Dyfi osprey project run by the Montgomeryshire Wildlife Trust and the Glaslyn project in Gwynedd which has recently been handed over to the local community from the RSPB team.

Ospreys remain under threat from the perils of entrapment in fishing nets, deforestation and pollution effects in particular the impact of mass fish deaths and plastic swallowed by the fish they eat. Ceulan, one of the Dyfi osprey project birds sadly perished in Senegal in 2012 when he became tangled in fishing nets and drowned.

The talk stimulated lots of questions and we hope to see ospreys staying in Wales for many years to come.

Laura Moss