Bonal Bird Sanctuary is the second largest bird sanctuary in the state, after Ranganthittu Bird Sanctuary in Mysore, and around 21 species of birds have been recorded here, including purple heron, white-necked stork, white ibis, black ibis, brahminy duck, and bar-headed goose.
Bonal Bird Sanctuary has its origins in the Bonal tank, a water conservation tank built by the 17th century medieval ruler of Shorapur, Pam Naik. Later, during the regime of British colonial rulers, Meadows Taylor, the British administrator at Shorapur, extended it to 1,600 acres with 12 feet average depth. This is mentioned in his autobiography, "The Story of My Life".
Bonal Bird Sanctuary was one of largest amongst the twelve such water tanks built in the drought prone region, and gradually started attracting migratory birds in this region. Most of these tanks were used for fishing, and numerous families were dependent on it. This tank is the economical pillar of this region. In 1998, heeding to calls by conservationists, the state government of Karnataka transferred the area to the Forest Department of Karnataka from the Fisheries Department of Karnataka.
Subsequently the fishing was banned in the tank, but it took many more years before it was formally declared a bird sanctuary of Bonal.