Residents of San Francisco, Chicago, Miami, and other cities have been tracking flocks of non-native parrots in their midst since at least the 1970s. The tropical birds, usually escapees from the pet trade, variously incite excitement, wonder, and irritation among a human populace that generally regards them as either welcome additions to a neighborhood (to wit, the 2003 documentary Wild Parrots of Telegraph Hill) or as noisy pests prone to causing fires and power outages when they nest on power lines and transfer stations.
These same love-'em-or-hate-'em urbanites have been helping researchers get a bead on just how many parrots and parrot species US cities are hosting and whether the birds have naturalized—that is, bred to create self-sustaining populations. | 
