Last year we made bone sauce and applied it to every single tree and bush that could not hold a collar. They're all eaten now. Why is that? We made it correctly. It looked correct, smelled correct, etc.
Well, I think Sepp lives in an area of great diversity and food sources. I don't. We have what feels like a million rabbits trying to survive off commercialized winter wheat and what little else grows on our windswept plains. They are so hungry I don't think bone sauce is a deterrent. It's probably not enjoyable for them but between that and starving, well they eat.
Anyway, my observed opinion is all.
In his book "The Spear of Destiny" Trevor Ravenscroft relates a story of how Rudolf Steiner prepared a homeopathic solution made from the body of a rabbit to repelled all the rabbits on the estate of Count Keyseylingk in 1924. Steiner went on to develop Bio-dynamic farming. Perhaps Holzers bone salve has it's origin in homeopathy.
I have not tried bone salve. But it seems worth some investigation whether bone salve made from ungulates such as cattle will repel ungulates such as deer but not rabbits. If that works maybe it's a different kind of bone salve for other pests.
Right, here our serious browsing problem comes from yak-like dzos that people release to fend for themselves all year except the few weeks when they are used for farmwork. There's precious little for them to eat in the desert here, so sometimes they may be somewhat starving, and they'll push through barbed wire and I expect they might eat things that have bone-sauce. An animal that is seriously hungry may eat it anyway.
In environment that has other things to browse and no population explosion of browsing animals, bone sauce may work perfectly.
Works at a residential alternative high school in the Himalayas SECMOL.org . "Back home" is Cape Cod, E Coast USA.
I think it might also be that bunnies just aren't as smart as deer. I've noticed that the bone sauce works quite well on my deer. I've applied it for two years now, and this year they ate only one nibble off of the 14 or so fruittrees I applied it too. They've even avoided my raspberries, and I don't see them in my front lawn at all any more. My wetland paths, though, have had the salmonberry mowed down by the deer.
But, the bunnies don't seem to care about it. I applied the sauce right next to my strawberries and peas--they keep eating them. I have LOTS of other native plants and not too many bunnies, but they don't care. Now, surrounding the plants with chives and pieces of onions HAS worked at keeping the bunnies at bay. My bunnies do not like alliums, much to my delight!
Edited to add: My bonesauce was made from almost all chicken bones (with maybe a bone or two from lamb &/or cow).
Ah, I may try onions and chives around my trees and shrubs then.
I think rabbits (like pheasants) stay in one area whereas deer roam a much larger area. Those that stay in a smaller area learn to know no fear. I almost tread on the pheasants in my field before I notice them and yesterday I cut myself a path through the long grass. A couple of peasants, like Lord and Lady Pheasant just strolled down my newly cut avenue right behind me. It was quite funny to see but the birds have learnt not to be afraid anymore. I'm afraid it's time to start feeding the fox cubs on rabbit stew.
I wonder if Sepp Holzer might be employing a rabbit trapping program in addition to using his bone sauce. A few years ago, I tried relying solely on spray deterrents and tree guards with the end result being numerous girdled trees. By trapping during the winter my rabbit problem has almost completely disappeared, plus the rabbit stew dinners are a nice plus.
On the flip side, I didn't get someone to hunt the deer on my property last year, and boy am I paying for it now...