Are Mockingbirds the Bird Police?

They protect more than their own.

Opinion page by Duane Alan Hahn.

Since around 1995, I started to notice that the Northern Mockingbird isn't the territorial monster that attacks everything and everyone as some people might say, at least where I live. I spent many years watching birds and the Mockingbirds in my area only seemed to attack 'bad' birds such as Crows, Grackles, Cowbirds, and Blue Jays. Mockingbirds often act like the 'bird police' and even seemed to protect other good birds when they were at our feeders.

A couple of times over the years, a huge bird swooped down, trying to capture the small birds at our feeders, and one of those times a couple of Mockingbirds flew in and chased that bird off. They didn't just chase it off, they flew with it over the trees and escorted it out of the area. As large as that bird was, those Mockingbirds could have been in big trouble, but they did their duty and the other birds were safe.

All of the things I've seen seems to add up to more than a territorial bird looking out for its own. I have no proof, but it's obvious to me that Mockingbirds are the police of birds. They may be able to copy so many different sounds because they need to communicate with as many birds as possible in the same way that it benefits a police officer to know at least a few important words from another language such as Spanish. I doubt that Mockingbirds only learn those sounds to attract females.