Thank you for your care and concern over this pigeon.
The bird doesn't necessarily have to be older, just 100 percent healthy and healed.
The best time is when weather is warm and easier for the bird to acclimate.
The bird should have access to bathing several times, so that its feathers are weather proofed for rain and such.
If you can release it in an area that is "pigeon friendly" where they have access to good food and water and protection that would be ideal. Also, if you know anyone who rehabs pigeons, and if they have birds to release, it would be best to release them as a group, if possible.
There are several threads on when to release and how, here is one:
http://www.pigeons.biz/forums/showthread.php?t=10874
The bird doesn't necessarily have to be older, just 100 percent healthy and healed.
The best time is when weather is warm and easier for the bird to acclimate.
The bird should have access to bathing several times, so that its feathers are weather proofed for rain and such.
If you can release it in an area that is "pigeon friendly" where they have access to good food and water and protection that would be ideal. Also, if you know anyone who rehabs pigeons, and if they have birds to release, it would be best to release them as a group, if possible.
There are several threads on when to release and how, here is one:
http://www.pigeons.biz/forums/showthread.php?t=10874