About two weeks ago the the owner of a parking garage where a large flock of pigeons used to roost got rid of the door that they used to roost on. There were three babies running around on the ground of the garage after bieng dumped out of thier nests on the door. A fourth had been run over by a car before I got there. Anyway I have been raising the remaining three babies by myself and they are eating and drinking on thier own and starting to fly but about three days ago I noticed one of the babies seemed sick. He has become very sluggish and barley moves. He will walk over to the food when the others are eating and tries to eat but he dosent seem to be eating much. His feathers are always fluffed up and he's always resting his eyes. He also seemed abut cold. I dont know what to do. I have isolated him from the rest of the babies and gave him a reptile heat pad to keep warm and I hand feed him peas and make sure he drinks enough each day. What else should I do? What is wrong with him?