The clamour for magpie culls is like the baying of a crowd at a witch trial. There’s no basis in fact for the claim that magpies are threatening British songbirds, only entrenched irrational ideas about corvids.
Organisations like the Songbird Survival Trust have in the past made badly misjudged calls for such culls. The real cause of population declines of species such as the bullfinch and yellowhammer is human activity: unsustainable land management, unecological farming practices and rampant urbanisation. A new large-scale study published in the Journal of Applied Ecology has confirmed this.
Anyone reaching for their airgun when they see a magpie in the garden is just gratifying a deep-seated superstitious instinct, which equates corvids with death. Or exhibiting a highly selective appreciation of nature, which would like to see the predators of its favourite species wiped off the face of the earth.
for more information, see article by Mark Whittingham Does predator control alter bird populations?