During a short period of sunshine, while I was pruning some dead branches in the backyard, I kept hearing a very loud chirp. I looked up and saw this Anna's hummingbird sitting on a branch.
Until now I have only observed hummingbirds singing or chirping, but never heard anything like this.
Whenever I looked up the same hummingbird still sat on the branch singing the usual song with which I'm familiar. But when I looked away I heard that same extremely loud chirp.
Finally I saw what was going on.
Apparently the hummingbird sitting on the branch is a female.
Meanwhile a male hummingbird was courting the female by flying straight up in the air until it looked like a tiny dot, and its bright red chest glowed in the sunshine. Then it swooped down, near the female, making the very loud chirp. According to what researchers conclude, the sound is made by the male's tail feathers.
Once I realized what was going on, I watched the male, fascinated.
After about 10 minutes the male flew away.
The show was over.