Osprey sighted

Hi Today I was indoors and the dogs went crazy. They usually do this if a fox is attacking my hens. we rushed outside and in the 150' Beach tree there was a huge bird, it looked like a giant Sea Gull. I thought it must be an Eagle, as it was bigger than the local Buzzards, and bigger than the Kites that were in the sky as it took off. No chickens to be seen, all were hiding under brambles. Now I know very little about Ospreys, but looking on this website it would seem unusual to see one this time of year? If it wasn't an Osprey I can't think what it would be. I see buzzards here everyday. Fantastic looking bird what ever it was. Definitely had a white body and dark wings.