My Greyface ewes routinely stand on the third or fourth rail of a hurdle as a means to get first bite at haylage as I take it into the pen! Pretty clever really, hooves on a very small rail, but they seem to have no trouble. Haven't seen one trying it on stock fence outside yet, but it wouldn't surprise me. And despite their heavy fleece they seem quite capable of launching themselves vertically into the air at least 2-3 feet when the mood takes them.
Nothing surprises me anymore. I was always led to believe chickens didn't fly, but my lot have clearly never read that book! They aren't pretty or graceful, but they can clear 6-8 feet without too much trouble!