So, personally, I dont think collecting remains of animals (assuming its roadkill or scavanged bones) is unethical. Wild animals dont really get a say in what happens to their bodies after death with or without human intervention and dont really have any of the long term rituals reguarding death that humans do. Unless youre talking animals like Elephants, which i super doubt youre going to find just on the side of the road anywhere. I dont think it unfairly impacts the animal in any way and theyre incapable of consenting to anything about death, be that being naturally eaten by magots out by the road, buried, or turned into an articulated skeleton. Maybe its just because Im a morbid and death positive person and would let people turn my skull into a drinking cup for all I care after I die, but I dont see the harm in it.
And most of the animals you find on the road or on a hike will have either have been gotten to by insects and scavengers by the time you find them so theyve probably already begun to give back to the food chain. If youre concerned about that, you can possibly do what some hunters do and make a little uh...mesh bone cage, so that smaller scavangers like insects and rodents can eat it and return the nutrients to the soil, but not larger scavengers that might scatter the bones. Plus its like a free dermestid beetle treatment for free!
Speaking of morbid roadkill stuff! You should check out Paul Koudounaris on
instagram! They do roadkill funerals and theyre very sweet.