What is the importance of pneumatic bones and air sacs in Aves ?

Explanation

### Step-by-Step Solution:

1. **Definition of Pneumatic Bones**:
- Pneumatic bones are lightweight bones found in birds (Aves) that contain internal air spaces. These bones are not solid but have cavities filled with air, which reduces their overall weight.

2. **Importance of Pneumatic Bones**:
- The primary importance of pneumatic bones is that they help in reducing the body weight of birds. This reduction in weight is crucial for flight, as lighter bones make it easier for birds to take off, fly, and maneuver in the air.

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