Australian here, who had a kelpie for 17 years. He was a red kelpie who passed away last year. And is greatly missed.
They are working dogs with the energy and intelligence that goes with it.
Ours used to work cattle and sheep- in yards and paddocks and still had energy to bounce around like a nutter when he came home for the day.
I saw him leap onto the back on a cow once, when he was running out of space in the yard and run across the backs of all of them to get clear and jump over the fence.
Bored, they dig and destroy.They will become obsessive with fetch games if lacking in activity. They can jump very high fences , leap onto utes with ease, charge around paddocks from dawn till dusk. Males with their bits intact are very dominant over other dogs.
We have since moved, to smaller premises and did not even consider getting another kelpie. For a start our 4ft fencing was far too low and 8 hectares was not , in my husbands view- large enough.
They are the most wonnderful dogs but need space, and I don't mean a regular yard.