Complex sentence: In India, where swarms were common at one time, there have not been any swarms since 1927; it is thought this is due to a change of land use, with the areas of grassland in which it used to breed now being largely under cultivation.
Split into simpler sentences: In India, where it was abundant at one time, there have not been any swarms since 1927. It is thought this is due to a change of land use, with the areas of grassland in which it used to breed now being largely under cultivation.