As long as he's running, he thinks that he might win this one. Once he's cornered and there is no victory in sight for him, he displays his uncertainty and fear in this manner. Unless necessary to handle him during daylight hours, you might simply go into the coop at night to pick him up in a nice, calm fashion; might as well give him a thorough exam while you've got him, checking under his wings, around his vent, the scales of his legs and feet and the bottoms of his feet (wellness checkup). If you perform one of these wellness checkups on a weekly basis, and quit chasing him all over God's little creation, he may warm up to being handled by you. If you offer him treats in the daytime, while you're seated comfortably and have fifteen minutes or so (when you're not in a rush) You can possibly build more trust with him. In the beginning, your 'building a bond with treats' exercise may require that you toss the treats out to him, but as the weeks or months progress, you should eventually have him eating out of your hand.