When we bring in new birds we do the following. 1) Vaccinate even if they have been done. 2) swab test to check for usual problems. 3) These then will join once got the all clear from vets,I only just introduced 4 birds into the stock loft. Which I got in at Blackpool. 4) Forgot to say birds are on there own in aviary. 5) once in with other birds,I put Avidress in to water for a fortnight as well.