Some direct sunlight is beneficial for pet birds as it helps in the process of Vitamin D synthesis and calcium absorption in their bodies. Calcium is important during the breeding season while egg laying and it also helps to strengthen their bones. But how much direct sunlight you should expose your pet birds to during the day time depends on a number of factors.
Firstly, the amount of sunlight you should give your pet birds during the day depends on your geographical location. In those locations where the summer season is excessively long and the weather is too much hot during the day time, birds do not need any direct sunlight at all during the entire summer season. In Lahore, where I live, pet birds do not need any direct sunlight from April to September.
Direct Sunlight During the Winter Season
During the winter season, from November to February pet birds should be exposed to some direct sunlight but no more than couple of hours a day. Also direct sunlight should not cover the entire cage or aviary. Direct sunlight should be made available only to a portion of a cage so that birds should have a choice to move away from direct sunlight and sit into a shaded area of the cage if they feel over heated.
Any extra direct sunlight which your birds cannot tolerate can be extremely dangerous to the health of your pet birds. This can cause your birds to get a heat stroke which results in dysfunctioning of organs and can lead to the death of a bird. Only a modest amount of direct sunlight which gives them a pleasant sensation is required. Make sure you expose your pet birds to direct sunlight in your personal supervision.
Direct Sunlight During the Summer Season
To construct an outdoor bird aviary, you should take into consideration the climate of your particular region. If you live in a region where there is a very hot summer season then you should consider protecting your birds from excessive high temperature and place you cage in an area where your birds can get some relief from excess heat during the day time. In this case your priority is to protect your birds from direct sunlight, not providing them the sunlight.
I have carefully constructed my birds aviaries with a special consideration to the direct sunlight. I placed them into a location where there is very little direct sunlight that can enter my aviaries during the summer. I have covered my aviaries with a cloth from those parts of the cage where my birds do not need any direct sunlight. In the winter I uncover the cages so that my birds can enjoy the benefits of some direct sunlight.
Special Dietary Needs
Secondly, it depends on the diet of your pet birds. If your pet birds are well fed with all the essential nutrients and vitamins which fulfills all their energy and dietary requirements then your pet birds will not need much direct sunlight to breed properly and remain healthy and happy during their lifetime. If you live in a region where there is an elongated winter season, then your birds may need some extra food supplements like cod liver oil and more sunflower seeds in their diet.