Which of the following characteristics is not associated with flight requirements in birds ?

Options

A. Feet with claws
B. Light hollow bones
C. A light horny beak with no teeth
D. An enlarged breastbone with strong muscles attached

Explanation

To determine which characteristic is not associated with flight requirements in birds, we will analyze the given options one by one.

### Step-by-Step Solution:

1. **Identify the Options**: We need to look at the characteristics provided in the question. The options include:
- Feet with claws
- Light hollow bones
- Light horny beak with no teeth
- Presence of a breast bone with strong muscles

2. **Analyze Each Option**:
- **Feet with claws**: These are primarily used for grasping and movement on the ground. While they are essential for hunting and perching, they do not contribute to the ability to fly.
- **Light hollow bones**: Birds have pneumatic (hollow) bones that reduce their overall weight, which is crucial for flight. This characteristic is definitely associated with flight.
- **Light horny beak with no teeth**: The beak, made of keratin, is lightweight and helps reduce the bird's weight. The absence of teeth also contributes to this. This characteristic is associated with flight as well.
- **Presence of a breast bone with strong muscles**: The breast bone (sternum) is where the flight muscles attach. Strong muscles connected to the breast bone are essential for the flapping motion required for flight.

3. **Conclusion**: After analyzing all the options, we find that the only characteristic that is not associated with flight is **feet with claws**. Therefore, this is the correct answer to the question.

### Final Answer:
**Feet with claws** is not associated with flight requirements in birds.