Well, somewhere in there is a Jack Russell Terrier who is stoically refusing to hear or, as is more likely, completely ignoring the dog whistle having heard quite clearly. You stand as much chance of spotting her and marking the spot with an 'x' as you did of winning the £250 jackpot in the 1960's 'Spot-the-Ball' competition using the same technique.
Going into the orchard to hunt her out is a possibilty but by the time you are at the far side of the orchard Minnow will have stealthily made her way to where you were, and this is how the to-and -fro search goes on until you are apoplectic with rage. Even the rustling of a bag of training treats has no effect so it must be good smell trail for a terrier when you can't even bribe her out.
Meanwhile Barney stays within sight, just a little to my right, and he's being as good as gold.
Now that really is an oxymoron and that's up there with 'military intelligence'.