What a load of crap your saying about the strays being sick, utter crap, i had a bird from the stray centre last week, it was there for around a week to ten days, got the bird back, isolated her, next morning checked her droppings they were perfect, so what are you slavering about the birds being sick birds,
How many a bird had came back from the stray centre, and the following year turned out to be one of the best guys bird in his loft as a yearling, i no a few, so talk sence IB.