As I stood by the field surveying upcoming tasks, a sleek little bird swooped by my hat like some diminutive fighter aircraft. They don't normally do that.
Looking up, I noticed it was the type for which I had provided nesting gourds. The nests were a few feet away, way up on a pole. Seconds later, the aerial combatant buzzed down inches from my hat once again. I looked up and saw another such bird entering one of the gourds.
They are a potential nesting pair. Presumably, the male was trying to discourage my presence while the female set about home making. I obliged. The task could easily wait.