Yesterday, I witnessed a crow mobbing two kites, trying to drive them away. One kite took the hint and flew off but the other was determined not to be deterred and the two of them wheeled and tumbled through the sky, the kite trying to shake off the pursuing crow. In the end the crow triumphed and flew back to its perch on the biggest oak tree, from which it cawed and... well, crowed! It was if it was proclaiming, "Aren't I the brave, clever boy!"
These photos aren't very good as the birds were way up in the sky, but they give some idea of the crow's tenacity and persistence.