Explanation:

Indian Rollers live around open grounds, cultivated fields and in local parks in cities. They usually do not migrate, although they do make seasonal movements in search of food. They are also popularly known as ‘friends of farmers,’ as these birds are known to help in pest control by feeding on insects, arachnids, small reptiles, and amphibians.
There is a very popular superstition that sighting a Neelkanth on Dussehra day will help absolve people of their sins. It is also believed that if a person sees a Neelkanth and makes a wish, the bird will take the wish to the similarly blue-throated Lord Shiva on Mt Kailash who will fulfil the wish.
To cater to these superstitious beliefs, bird catchers start trapping these vivid birds almost a month before the festival.  The birds are caged, their legs tied, their wings trimmed and even glued, so that they cannot fly. This is endangering the population of these birds.