This morning while inspecting my P.Nigra's new shoots I discovered a nest in the bamboo. My P.Nigra is quite dense so I suppose this why the birds chose to build a nest in it.
The legal issues that will arise when the undead walk the earth are legion, and addressing them all is well beyond what could reasonably be accomplished in this brief Essay. Indeed, a complete treatment of the tax issues alone would require several volumes.
If you don't like the idea of a bird nest in your bamboo (although I can't understand why you wouldn't), then if there are no eggs in the nest or if it has been abandoned you can remove it.
I keep birds close if possible. Most of them help you removing small crop eating vermin in your garden, they eat mosquitos and other blood sucking creatures... You should be happy. Besides, they will drop fertilizer directly towards the roots of your bamboo.