Valentine's Day is just around the corner, and some birds, like the great horned owl, are already busy wooing potential mates. In a lighthearted celebration of all the love in the air, we've put together a slideshow of avian duos. TIP: To enhance your viewing pleasure, we recommend watching it in full-screen mode (click the 'play' icon and then click the icon with arrows in the bottom right corner of the video screen).