How birds mate?

Spring is the breeding season for most birds, but how do birds mate? Coming together in sexual copulation is essential to fertilize eggs to raise young birds, but the sex act is only a brief part of birds' courtship and pair bonds.

The Reproductive Anatomy of Birds

Most birds do not have the same reproductive body parts as mammals. Instead, both male and female birds have a cloaca – one opening (also called the vent) that serves as the bodily exit for their digestive, urinary and reproductive systems.

This means that the same opening that excretes feces and urine is where eggs are laid. During the breeding season, the cloaca swells and protrudes slightly outside the body, while during the rest of the year it is much less prominent.