I often see smaller birds chasing bigger birds out of their territory. For instance, crows seem to love to chase hawks. But this was the first time I had ever seen a hummingbird chasing a bigger bird. You can't see the hummingbird, but that swatch of white is the Belted Kingfisher being chased across the lake.
The kingfisher perched on one of the birdbox poles near the lake.
This kingfisher is a male.
In the Fall of 2019, the nesting boxes were still up, and this kingfisher was more than happy to use them as perches. It's hard to see in this photo, but this bird is a female. Female Belted Kingfishers have an additional 'belt' that is rust-colored. See next photos.