About 40km from Udaipur there is a township called Gogunda. On the outskirts of this township, near the bus stand, there is a slight slope on the road that is followed by 200m of straight road, on both sides of which there are big trees.

From this vantage point near the bus stand I was watching a Crested Hawk Eagle (Spizaetus cirrhatus) circling clockwise in the sky. As it neared the tree-tops around 35 Blue Rock Pigeons got frightened and flew away. Then the flock turned and started circling anti-clockwise on the same plane as that of Crested Hawk Eagle.

The eagle widened its circles and started gaining height. The pigeons followed suit. When they crossed each other, some pigeons brushed past the eagle and sometimes they flew so threateningly that the eagle had to change its course to avoid headlong collision.

This went on for about 10 minutes during which the birds reached very high altitudes and their circles widened further. At this point when the eagle and pigeons were farthest apart in the circle, the pigeons dropped vertically towards the ground and within no time settled on the trees having eluded the predator.

Published in Journal of Bombay Natural History Society:

Tehsin, R. H. (1982) Collective Defensive Strategy in Blue Rock Pigeon (Columba livia). J.Bom. Nat. Hist. Soc. 79: 414