Yes they can but the emus will chase the chickens. This has not been a problem until recently when two juvenile chicks ventured out into the yard. The emus gave chase, stomping and tossing the two chicks. One now has an injured leg and I am deciding how to proceed. Totally my fault. The emus have to get very familiar with any living thing coming into their territory then they are fine with it. But if something new is introduced suddenly, the chasing and stomping is seriously bad. So if you house them together, you have to make sure that new arrivals are in a penned area, in sight of the emus but out of their reach until they are completely familiar with them or a tragedy can occur as did here. They are just doing what comes natural. Mine are good watch guards and chase off hawks, cats, etc. I just have to find a way to fence off new birds until safe. Be careful.