Kestrels are a small falcon raptor similar in size to a mourning dove. Preferring open country with few trees, you’ll usually see them perched on telephone wires, fence posts, or in this case an irrigation pipe. They are also known for hovering. This is different than the thermal floating/gliding that hawks and crows do. The Kestrel will use an advanced flapping motion to hold in place high in the air, and then dive bomb on their prey. Here is a very rapid sequence of still photos that show this flapping motion.