But inside the room, light filters weakly through the windows, muted illumination offset by bright patches which move across the floor as the day progresses. No direct light ever falls upon the cage. The day draws to a close, and darkness surrounds the house. Occasionally lights are turned on, spilling pools of xanthic light about them, to be as suddenly and unpredictably turned off. The unnatural flickering glow of the television casts a ghostly pallor on everything in the room.
Shadows appear and shift with chaotic frenzy.
Finally, all are extinguished. Darkness is the only consistent factor. Consider these three scenarios. The first one of course, is the natural environment that most tropical birds experience. This is what their biological programming is tuned to make peak use of.