Of the 58 hen harriers tagged by the nature regulator, 72% are thought to have been illegally killed over the study’s ten-year duration. While the species, one of the UK’s rarest birds, enjoys legal protection, there have been multiple reports of hen harriers disappearing near land managed for driven grouse shooting.
Only four birds were found with direct evidence of illegal killing, with 38 simply disappearing, the study notes. “Despite the lack of physical evidence, this strongly suggests destruction of the tag and removal of the carcass,” the authors say. “We conclude that illegal killing is the most parsimonious explanation for the fate of these birds.”