It is one thing to drive hours to see a rare bird. That, in and of itself, is funny and strange, not to mention frowned upon in some circles. However, it is something else to actually break into a sprint in order to see a rarity. The person disappearing behind the tree line is clearly in good shape from running after many rare birds; that is why he is in front of the pack.
Billowing, puffy jackets add a sense of drama to any photograph. Also note the Chacos: an unusual choice for locomoting at such high speeds.
In fact, it is a good thing the jacket has such wind resistance...at the speed this birder was moving, if not for the jacket acting as an air brake, he would have been unable to make the turn in time and ran straight into the fence. Being impaled on a fence, like some overgrown shrike victim, is not a good way to see a Common Cuckoo.