If you're a golfer, you probably have a pretty good understanding of what happens when a ball hits a cart path. If you're a bird, however, you probably don't know what a golf ball OR a carth path even is (and for that measure, you're probably not able to read this story. But stay with me regardless).
Here's a video of a seriema, a sort of ostrich-meets-swan species that is found in South America, happening upon a bunch of golf balls on a golf course, then testing how the balls react when bounced against the pavement. It appears that the bird is very amused, although there's the remote chance that it was also quietly terrified.
The bird was unavailable for comment.