It depends upon the species you are interested in adopting. Please go to our Related Links section and check to see if we have a bird rescue organization near you listed. If we do not, please contact your local Avian Vet, Humane Society or Animal Care and Control to see if they know of a bird rescue organization near you. You should definitely try to capture the Cockatiel. You can try to set out a cage with some seed treats, millet spray, etc.
Some birds are tamer than others.
Some may actually respond if you try to talk to them. Set the empty cage next to this one with treats inside and a bird mirror and see if the tiel will go into it to be close to his friends. If these things don't work and the bird appears weak, ill or in danger of being attacked by cats or other predators, you can try more extreme measures. You can get a large net and try catching the bird off guard. The problem with this is, if you miss you may never see the bird again since he will likely become fearful after that.