Genuine question - imagine they are both out in the garden free ranging supervised and a fox comes along...Rupert runs one way, Tia runs the other, or both freeze with fear in different places. Which one are you going to get safe from the fox first? Or are you going to leave the rabbits and concentrate on chasing the fox, hoping that you can chase it away for long enough to then get the rabbits safe. I just don't see how it's possible to guarantee their safety in that scenario where there is more than one rabbit, as it's a simple fact that you can't be in two places at once.
To be honest, it wouldn't happen, but if it did happen, the fox comes in the bottom - we have a two (actually three) tiered garden - the lawn is raised about 10 (maybe more) ft from the ground level, which is decking - then from the deckin the garden has a steep slope (of at least 10ft) down to a stream.... there are wooden steps from the decking to the top level (around a well pond). The patio is to the side of the lawn (in front of pond) from the patio doors, which lead into dining room / sitting room.
Rupert and Tia have the lawn area, and the side of the house where their shed is... I don't allow them to be round the side of the house if the lawn is 'open' (its not open all the time as its been muddy, and they're not allowed on the lawn in summer when its just been cut).
The reason they're not allowed round the side is incase a fox (or more likely next doors cat!) comes.... The fox has never been seen round the front, only ever the back. we would hear it before seeing it, if we didn't hear it first, rupert would, and rupert ALWAYS runs to me, whatever scares him, he runs to me. tia doesn't run she never runs, and when she does, she follows rupert.
TBH if im home alone, i don't let them in the garden, unless its only on the patio, and i close the fence off round the patio so they're close. the only time they're allowed to properly free range on the whole lawn is when the weather is nice, and we're both out.
Whats the alternative for rupert and tia exactly??! They live in their shed, shut in, all day and all night!? im not prepared to do that. I won't give them a run BECAUSE I know we have foxes, and where the shed is, is poured concrete, so i couldn't fix it to the ground (its a rented house and we've already used their shed!) and i would never ever risk leaving them with the risk of a fox lifting the run up (I won't ever move their shed becasue it is sheltered where it is and i can see in from the window on the stairs).
I am confident that my rabbits have the absolute safety they need.
The OP has already said she's ordered a fence and sonic thingy. I cannot have a sonic thingy because at the back of our house is a nature reserve / dog walking area.
The only danger that has ever been an issue for ME and MY rabbits is next doors cat (but its dead now) and a magpie - yes, a magpie, which landed by the side of the house and tried to peck rupert!
Also, the mesh door on our shed has got three padlocks, this is because I KNOW foxes can open anything (they're not stupid, theyre really clever) like latches etc.
I KNOW that foxes get bored of trying to get in somewhere if they fail - as I already said, my shed has scratches on the door from the first couple of nights we got rupert and tia - the fox has never been back since.