Although I didn't see as much of the bird's behavior yesterday afternoon as I'd have liked (due to inclement weather), I didn't see anything that was inconsistent with general wild ani behavior that I've encountered in my travels in tropical locales.
To illustrate the sociality of anis (genus Crotophaga), GBAN is one of the few bird species in the world that are communal nesters, meaning that sometimes multiple females will share a single joint nest with as many as 20 eggs contained therein. Also, the Groove-billeds I've seen in Costa Rica would hang out around hotels, and afforded several photo opportunities. I've photographed Smooth-billeds in a few tropical locales along roadsides too, in Puerto Rico, Ecuador, and Brazil.
Over the several months I spent in southeastern Brazil I also became fairly familiar with its congener the Greater Ani (Crotophaga major). Greater Ani is also highly social, and although not necessarily fearless of humans nor is it terribly shy, and Greater Ani sometimes even engages in lengthy group chorus episodes where 3-6 individuals in a group will make a continuous gurgling cackle that can go on uninterrupted for several minutes. I actually got to see this a couple times, and it was quite a treat.
The point being, this bird's casual behavior around people doesn't seem to me to be an argument for prior captivity. It seemed like a typical ani to me. And I've never even heard of anis as being desired cage birds.
Eric
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Eric DeFonso
near Lyons, Boulder County, CO