birds of paradice leaves

Not sure but could be that the air is dry round the plant...try standing the pot on gravel with water in...

Have you fed it recently? Is it in a suitably sized pot? Is it in a draught?

Strelitzias grow in very dry places and drought is rarely a problem. They flower best when in a very large pot but just about bursting out of it. So it can be difficult keeping them fed and watered. Have you put it outside for the summer? It's natural for the old leaves to go brown and die when you can cut them off, but the new leaves and shoots should remain green. Without information on the size of your plant and the pot, it's hard to say what is causing the problem.