Quill feathers at the base of quill wings are called

Options

A. down feathers
B. filoplumes
C. coverts
D. barbules

Answer

To answer the question "Quill feathers at the base of quill wings are called," we need to analyze the options provided: down feathers, philopellums, coverts, and barbiums.

### Step-by-Step Solution:

1. **Understanding Quill Feathers**: Quill feathers are the stiff, long feathers that form the wings of birds. They are essential for flight and aerodynamics.

2. **Identifying the Options**:
- **Down Feathers**: These are soft, fluffy feathers that provide insulation but are not quill feathers.
- **Philopellums**: This term is not commonly used in the context of bird feathers.
- **Coverts**: These are the feathers that cover the bases of the larger flight feathers (quill feathers) and help streamline the bird's body for better airflow.
- **Barbiums**: This term is not recognized in standard ornithology.

3. **Analyzing the Function of Coverts**: Coverts serve to cover the quill feathers and help in the smooth airflow around the wings and tail, which is crucial for flight.

4. **Conclusion**: Based on the definitions and functions of the feathers, the quill feathers at the base of quill wings are called **Coverts**.

### Final Answer:
The correct answer is **Coverts**.

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