Coimbatore, Nov 29 (ANI): Butterfly observers and lovers got to experience a colorful spectacle as large swarms of butterflies migrating with the change of season descended upon the hills of Western Ghats near India's southern Coimbatore city. Butterfly migration is mostly due to change in season which also coincides with the flowering of trees. These trees then play hosts to these butterflies. Some of the varieties of migrant butterflies coloring the hills are Common Blue Bottle, Peacock Pansy, Plain Tiger, Angled Castor, Common Castor, Common Grass Yellow, Common Fouring, Common Laster, Painted Lady, Crimson Rose, Yellow Pansy, Blue Mormon, Chocolate Pansy, Common Crow and Forget me not amongst many other beautiful ones. The dense forest covers, green vegetation and the mineral- rich soil of the hills provide the butterflies with the perfect conditions for reproduction.