You won't find it there. Chukars and pigeons are not game birds, therefore game laws do not apply to them, there is no season or bag limit. If you go to the PGC home pge, click on laws, then click on regulations, go to regulations on game lands you should be able to find the period when you can't do it on game lands, it is prior and duing the youth hunts for pheasants.
The DNR won't be able to help you. The PGC would have all of the requirements.
However, go by what John S has recommended in his posts. He provides you will all the requirements and best places to find them.
There are no requirements for their use except at certain times on state gamelands. The WPRA is helping to confuse the issue and are areas set aside to try and re-establish wild pheasant in the state. It is unlikely that you intended to use any of these areas for training and unless you do intend to be working on these grounds, you have no issues.
If you are using them on private or state gamelands with the exception of WPRA areas or gamelands at a limited time in the fall, there are no regulations.
These gentlemen are giving you good advise, remember if you plan on using any Pa legal game birds for gun dog training in the future, all PGC season & limits are enforced as you train, unless you are on a Pa licensed regulated shooting grounds.
Good luck with your training