Behold…the eastern bluebird.
Bluebirds apparently are hunters…birds of prey. As far as I can see, they are only intimidating to very small things. They hunt for insects, spiders, little bits of fruit and other creatures from whatever perch seems promising, they watch the ground, and then swoop down, pouncing on their prey.
I have seen this pouncing. At the time that I first observed this, I didn’t know what they were doing, but after long minutes of observation, I believed and still do, that they are actually addicted to eating dirt.