Just to clarify:

The distribution maps in Kazmierczak show very few occurances of Buteo rufinus in Karnataka. The Upland Buzzard, as its name implies, Buteo bemilasius has very few occurances in India, and at that mostly in Nepal. The Common Buzzard Buteo buteohas very few occurances in Karnataka, but winters in Kerala. The last of Kazmierczak's buzzards, the White-eyed Buzzard Butastur teesa has distinctive facial markings and the white eye.

Ali-Ripley list the Shikra as having a golden or orange-yellow iris.

One could also compare the images on orientalbirdimages.org. I would have done it but I am travelling tomorrow and thus a bit pressed for time.

Apana