From time to time we would have doves (or pigeons) roost in the traffic signal lights, always on the upper red light. It took me a while to figure it out. This would be in the early winter months when they were looking for a little warmth. Now, we have energy efficient LED lights which do not generate extra heat. Poor birdies.
In the winter, the ravens in Whitehorse would sit on the street lights. They were activated by a light sense on the top of the housing holding the light, which pointed down. The ravens would sit on the sensor, which would turn on the light and warm up the cold raven.