First lets see here,Human bones have been used before in ancient times as ritual knives..
As for the harvesting of animal parts...We cannot any longer use African elephant ivory due to poaching and thus it is no longer available.
The mastodon ivory has been extinct for a few million years and thus cannot be poached.They are found and used..
The Walrus "oosic is fossilized and found by the eskimos and not taken from the walrus unless legally taken which they are the only ones that can sell the parts and so no poaching the walrus Ivory is also the same way..
As for the Stag,India stag was legally harvested sheds in there country and thus no poaching,now there government has stopped the export of the stag and we are running out.As for domestic game,some parts are legal and some arent,Most of what you see being used are traded from legal hunters or found sheds..
As for the cow bones these are farm raised for food and the bones are completely legal to use.
The giraffe bones are legally picked up and sold from africa and not poached,the certificate that comes with it says that it is from animals that had been killed by other animals and then the bones picked up and used and thus not wasted at all.
So as for the comment that not using natural materials would stop the poaching and unjustified killing of animals,I don't think this is the problem and wouldn't stop nothing..It is the greedy people that think they have to brag about how many or how big and don't hunt for the meat and kill anything in site.There is no reason not to hunt a trophy as long as you use what you kill.Like a couple of deer will last a family most all winter or a elk or moose will feed a family all winter,things like thatbut as for the handle material we are using no it won't stop poaching or over killing to get our handles because 99% of it is found or legally harvested and not hurting iur environment..
Guess I should get off my soap box
Bruce