From: Helen Krummenacker avona@jps.net
Well, 1stly, Xena isn't filmed in America, so it wouldn't have our songbrds.
Xena might not be, but an awful lot of other things are. But then I've heard European birds singing in the background on Dr Who, when they're all supposed to be on another planet. Maybe producers or sound editors just don't notice such things, or maybe they're too hard to edit out.
More importantly, you mean Neil, the Great Birder, doesn't know that you British colonialists imported your birds who have been more or less taking over from the native songbirds?
Only House Sparrows, Starlings and Rock Doves in any great quantity, and Pheasant (which was introduced to Britain in the first place by the Romans). Aside from Pheasant, these are largely human-commensal species that can only move in when the native songbirds have been driven out by urbanisation and agriculture.
One of the biggest threats to an indigenous species is from a North American bird to a European one - the Ruddy Duck has extended its range into Spain, where it readily hybridises with the native White-Headed Duck. Admittedly it was Brits who let the Ruddy fly free in the first place. A cull is now underway.
Neil