Found a dead Tawny Owl in our garden this morning, no sign of any injury apart from a mark on its back. we live on rodborough common near Stroud, down a fairly quiet country lane, we do have 2 cats but never have caught anything like this size bird before.

 I don’t know about the mark on its back  but maybe you could send a photo of the mark. For the death Even though Robrough common is a AONB site (protected area. )I  don’t think it’s related to  a Wildlife crime.

There’s lots of  causes of death even natural ones. It Could of been a cat or it could of been something else.  Weather the death is related to the mark or not I don’t know.

 But whatever the cause of death is it’s still recommended to report a bird of prey if you find a dead bird of prey.

 With dead birds of prey the BTO recommends reporting it to these guys

https://pbms.ceh.ac.uk/content/send-us-birds

Otherwise the Wildlife trust recommends phoneing someone like the RSPCA or local Wildlife Rescue Centre 

this link will show you If there’s any near you and then you can contact them 

https://helpwildlife.co.uk/map/

https://www.wildlifetrusts.org/wildlife-advice/found-dead-animal