"Parabolic" mikes look like little satellite dishes--and they work under the same basic principle. That is, the parabola collects and concentrates a weak signal. So when the goal is to hear something that's very far away, a parabolic mike would be in order. Examples include a quarterback barking plays, or the chirping of the rare yellowbelly sapsucker.
Good parabolic mikes are a lot of fun--for example, you could hear a private conversation from across the park. This is why spies use parabolic mikes all the time. While the gear is legal, poking into people's private affairs could land you in jail!