You would be surprised at how little light will add to their total "daylight" hours. With my quail set up, one of my aviaries is set up along the side of a greenhouse, the greenhouse being one wall of the aviary. Well, right now I have a sick chicken in a hospital cage in the greenhouse with a 75 watt infra-red heat lamp on her at night only. This lamp is not pointed in the direction of the aviary, and is about 20 feet away from where the quail sleep at night. But as you might imagine, this red light just glows, lighting the greenhouse up like christmas! There are things blocking the light from entering the aviary, but still what little light gets into the aviary, has got the already "quieting down for the season Bob's" all in a breeding frenzy again so I have had to move some of them out and back into the breeding aviary! So it doesn't take much light to make longer day light hours.