Policy on returning Herring Gulls to original site

Hi

Last year a fledging herring gull had to be removed from the area to have an operation (it had swallowed a hook and several feet of fishing line). The vet advised those who took it to him/her against returning it to its original location as the adults would attack and kill it, so it was taken to a bird sanctuary.

This year an adultHerring Gull was taken ill. The RSPCA were called and said it was suffering from botulism poisoning. They took it away for treatment. Apparently with treatment involving plenty of fluids it would be fine in a couple of days. However he said it wasn't RSPCA policy to return herring gulls to their original location. I am wondering why this is the case? Even where there are volunteers willing to arrange this?

There was research by a Jasper Parsons into Cannibalism in Herring Gulls where he ringed herring gull chicks and counted discarded rings for proof of cannibalism. However if removal/handling of gull chicks results in them being attacked - then obviously his research at gull sites was both pointless and damaging?

www.britishbirds.co.uk/.../V64_N12_P528_537_A094.pdf