I raised a few cots with my Bobwhites just as teasers for my dogs. Setting them loose to free range and lay down scent was the primary objective and I gave them 2 weeks to adjust to the wild. While they were pen raised birds, they were in the flight pen but rarely did they ever take advantage of the openess and excercise thier wings as to build any flight muscles.
That is to say they are a ground bird and rarely fly, unlike the Bobwhite which is also a ground bird but are strong flyers by nature. From what I have seen, heard and read, the majority of cot/Japs/Egypt/paroha species are known for not flying and/or not flying well, not flying any long distances, or at great heights, less any landings are usually crash landings.
The ones I turned loose (somewhat 2 weeks wild) only made one slow uncoordinated flight (under the pressure of the dogs) they raised up into the air about 3 feet and crash landed 25 feet away and were cought by the dogs. Some never landed before my dogs cought them.
2 weeks is bare minimum and hardly time for any bird to learn flight or build muscles, but it does prove they can fly. Theoretically Most birds with any good amount of wing, muscle and feathers can fly, just some better than others. It depends more on the circumstances of Threat in this case though! If there is no threat, then many of them will never (or rarely) take flight as to build the needed muscle and coordinations. As 007Sean and TwoCrow stated..... we all 3 seem to concur.