*WARNING* Some of the footage may be considered graphic as the story involves… exploding toads
In 2005, a small pond in Hamburg, Germany became the focus of international attention as roughly 1,000 toads were discovered dead, having seemingly exploded. Dubbed the Pond of Death, the culprit, originally believed to be some kind of virus, would turn out to be a highly intelligent bird.
Corvids are a family of birds that includes crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs and nutcrackers. They are considered the most intelligent of the birds, and among the most intelligent of all animals—having demonstrated self-awareness in mirror tests (European Magpies) and tool making ability (crows, rooks)—skills until recently regarded as solely the province of humans and a few other higher mammals.
Their total brain-to-body mass ratio is equal to that of great apes and cetaceans, and only slightly lower than in humans. [Source]