Why do some birds sit on the back of other animals?

Many birds have been observed sitting on the back of other animals, such as cattle, elephants, and even humans. This behavior is known as "riding" or "perching" and serves multiple purposes for the birds. The correct answer to the question is option 'A' - for food. Let's explore this answer in detail.

1. Mutualistic Relationship:
- Birds that sit on the backs of other animals often have a mutualistic relationship with them.
- These birds, known as "cattle egrets" or "cattle birds," for example, are commonly found perched on the backs of grazing animals like cows or buffaloes.
- The birds benefit from this association as it provides them with easy access to food.

2. Food Availability:
- Grazing animals like cows disturb insects and other small creatures as they move through the grass.
- This disturbance causes insects to fly up into the air, making them easily visible to the birds sitting on the animals' backs.
- The birds take advantage of this opportunity and snatch the insects in mid-air, securing a readily available food source.

3. Easier Hunting:
- By perching on the back of another animal, birds have a higher vantage point.
- This elevated position allows them to spot prey more easily than if they were on the ground or in the air.
- It gives them a clear view of the surrounding area, making it easier to locate and catch insects or small animals.

4. Safety and Protection:
- Perching on the back of another animal also provides the birds with some level of safety and protection.
- The larger animal acts as a shield, making it harder for predators to reach the birds.
- Additionally, the presence of the larger animal may disturb or discourage potential threats, increasing the safety of the perching birds.

Conclusion:
In summary, birds sit on the backs of other animals, such as cattle, for food. This behavior allows them to take advantage of the insects and small creatures disturbed by the grazing animals. It also provides them with an elevated vantage point for easier hunting and offers some level of safety and protection from predators.