Ecologists estimate that the clearance of deer carcasses prevents hundreds of thousands of kilos of vital minerals from re-entering the environment every year.
This loss could undermine the long-term success of habitat recovery efforts, experts say.
Environmental benefits
In Scotland, deer populations have been actively managed since 1959, primarily to control over-browsing – eating shoots and leaves of trees and shrubs.
Researchers at the University of Edinburgh and Yale University used nationwide cull data on red, roe, fallow, and sika deer between 2010 and 2022 to calculate annual nutrient losses. They estimated levels of phosphorus, nitrogen and calcium for each deer species based on their average body and antler size.
They calculated that 251,188kg of calcium, 195,652kg of nitrogen and 152,834kg of phosphorus are lost across Scotland each year.
The research team says that the loss of calcium has a bigger environmental impact than loss of nitrogen or phosphorus. Low-calcium soils can hinder commercial and native woodland regeneration, and can have knock-on effects for birds, which experience declines in shell thickness in low-calcium environments.
Carcasses also bring other ecosystem benefits, such as being a food source for small predators including pine martens. Carcasses have also been shown to distract predators from ground-nesting birds, such as capercaillies, during the breeding season.