Regional bird accents
As someone who has travelled worldwide, I have noticed chickens and owls have distinctive regional calls.
Some owls in, at least, Western Greece making a 'bopping' cry as opposed to the 'twit-twoooo' of the English owl.
The 'morning call' of cockerels, which seem to have no or little relationship to sun-rise are even more distinctly more varied, even to the untrained ear. Having listened to such calls for years in Buckinghamshire, the damn multiple cocks within earshot of my small place on the Greek isle of Kithnos are extremely different both in timing and tone, and seem to start around 04.00H and carry on throughout the day!
My favourite bird call is the plaintiff call of the Canadian Loon < http://www.junglewalk.com/sound/loon-sounds.htm >.
P.S. When travelling, take time to study the night-sky filled with stars - and how it changes from place to place.