"Sweet" singing and "pretty" behaviour can be attributed to humans but not to animals and especially not wild animals. The magpie kills so that it may thrive, a basic instinct. Songbirds' voices, however sweet, are an evolutionary device, not something created for the benefit of human sensibilities. They also kill other animals that aren't cute and fluffy but are garden pests, so we don't care. Indeed, we welcome their killer instincts because it benefits us.
It is the massive loss of habitat, both rural and urban, that has led to the decline of small birds. However, if we really dislike successful breeders who don't make a nice noise and do cause destruction perhaps we can lift the ban on killing humans, who are demonstrably responsible for the killing of species of all kinds, including our own, and the ruination of innumerable habitats?
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