About 320 bird species live in the wooded valleys of the sanctuary attracting bird watchers from various parts of the country and abroad. They come armed with long lenses and binoculars to get a glimpse of the amazing varieties here including the Malabar Hornbill, Racket-Tailed Drongos, Kingfishers, Darters and Cormorants.
About 160 species of butterflies have been reported from the sanctuary. While some are endemic to the region, while some others are on the verge of extinction, like the Travancore Evening Brown. Other species found include Paris Peacock, Common Tiger, Plain Tiger, Striped Tiger, Common Rose, Malabar Rose, Southern Bird Wing, Common Mormon, Blue Bottle, Common Albatross, Great Eggfly, Evening Brown, Jezebel, Clipper, Grey Pancy, Common Palmfly, Nilgiri Tiger, Malabar Tree Nymph, Lime Butterfly and Red Helen.