Pigeon update
The pigeon survived the night but didn't eat anything. An attempt to release it failed. So, I called my boss, who has rehabbed pigeons in the past, and asked for help. As a result the pigeon has now been hand fed a mixture of millet seed, milk and bread and even drank a bit of water on its own. The color of its plumage indicates it is a juvenile blue bar (wild-type) racing homer. My boss is bringing me seed and I'll pick up some grit on the way home and see what I can do about a bigger cage. So far, so good. :)