This will be a brief post.
I have been reading about nutrient deficiencies in ungulates that mainly refer to sodium and calcium necessary to maintain, e.g., bone and antler growth.
These micronutrients are sometimes supplemented to wild ungulates via salt licks because it appears that they struggle to derive it from natural sources.
This is also why sometimes ungulates can become scavengers gnawing on bones of dead animals (see, e.g., this Voyageurs Wolf Project video of ‘deer eating wolves’ or, to be more exact, a deer regularly gnawing on a dead wolf’s bones).
I was wondering if lethal removal of ungulates (and also predators and other game species; I am mainly referring to animals that are hunted in substantial numbers) might result in a gradual decrease of micronutrients (that are ordinarily contained in bones and antlers but also in guts because some offal can be very high in specific mitronutrients) in the wild ecosystem.
In some places, hunters leave heads or even the skeletal parts and offal only carrying off choice tissue.
But mostly (at least in the country where I live) the entire carcass is brought home and processed there.
This probably depends on the size of the game (e.g., bison vs. roe deer) and national or regional legislation.
Micronutrients are contained in all tissue but some animal parts might bear higher concentrations of specific nutrients than others (e.g., bones, antlers, kidneys, liver etc.).
If these body parts are not returned to the soil (directly or through consumption and deposition by scavengers which is a faster and more efficient process that can also make some nutrients more readily available for plants), the micronutrient circulation in the ecosystem might become disrupted leading to overall poorer fitness in many species.
Urine and feces might not suffice as deposits to return nutrients uptaken from vegetation back to soil (on secondary consumer level) because most wild animals do not consume diets overabundant with micronutrients and these micronutrients are therefore incorporated into living tissue rather than excreted.
Urine and fecal matter might mainly contribute to macronutrient cycling. Micronutrients might be locked up in living tissue… until it becomes dead and decomposing tissue.
The consequences of these high micronutrient concentration biomass removals might be complex resulting in poorer health of many trophic levels and many functional groups (plants, herbivores, predators, scavengers, fungi invested in decomposition processes etc.).
I believe this is a part of the trophic cascade (only, in a non-beneficial way) that occurs where natural mortality is replaced by human-caused mortality (including instances where road-kills are displaced from wild ecosystems).
Notes by Ieva 