9 pair
Explanation
Pigeons have 9 pairs of air sacs, which are thin-walled extensions of the respiratory system that help to make birds lighter and more efficient at flying. The air sacs are connected to the lungs and bronchi, and they allow air to flow through the respiratory system in a one-way direction. This makes it easier for birds to take in oxygen and release carbon dioxide, which is essential for their high-energy lifestyle.
Here are the names of the 9 pairs of air sacs in pigeons:
- Cervical air sacs (2 pairs)
- Clavicular air sac (1 unpaired sac)
- Cranial thoracic air sacs (2 pairs)
- Caudal thoracic air sacs (2 pairs)
- Abdominal air sacs (2 pairs)
