I don't do my own fecals, not sure I would be able to ID different kinds. That's not in my current skill set. If you can find a vet that will do a fecal for you, that is what I would do. Even your vet, if you have one for other animals, may be willing. Just explain that you want to ID the actual type so you can work on reducing the possible hosts. You can also just look a the general lists of hosts and see which of those you seem to have a lot of, and go from there. You probably can't get rid of them all (hosts), but can try to reduce numbers to much less. Just depends on too many variables. If that's not doable, then you may just need to worm on a regular schedule to keep the birds healthy. Without fecal testing, that will be by trial and observation. Keep a log of when you worm (it is very easy to forget when you actually did it) and whom, when you see signs of reinfestation, log that and worm again, over time you will figure out how often you should be doing it to keep them healthy. I worm every 3 months for roundworm in my flock, and occasionally I have to worm someone in between that. And I log it every single time, because I can never remember exactly when I did it.