Conservation - Condrocs shot with tranq fly away

[nonsensemonster]

When I get into the Plains, I usually check the tree straight ahead for any kuaka or condrocs that I can shoot for easy standing/conservation tags. When there's kuaka, I shoot them, they pass out, I call for collection, no problem. When there's condrocs, I shoot, hit, and they fly away regardless. Is this expected behavior?

This has happened several times. Most recent was more upsetting since there were three emperor condrocs sitting under the tree when I loaded in for a bounty. I hit two (saw the little zero pop up next to it that means you hit it), and they all flew away.