Question

people catch bird and keep them in cages why

Answer 1

just to satisfy their desires of having a bird as a pet

Answer 2

All caged birds are either captured or captive-bred. In the wild, these beautiful beings are never alone, and if separated even for just a moment, they call wildly to their flockmates. Flock-oriented, they preen each other, fly together, play, and share egg-incubation duties. Many species of birds mate for life and share parenting tasks. Most birds will not take a second mate in the wild if their first is lost.

Life in captivity is often a death sentence for birds, who may suffer from malnutrition, an improper environment, loneliness, and the stress of confinement. Birds are meant to fly and be with others of their own kind in a natural environment. Confinement causes birds to have temper tantrums and mood swings.

hope it helps you.