Anyway, there was an incredible racket as hordes of crows, I'd say up to 40, and I think a few magpies, were dive bombing something across the road in Silverdale. It was a heron, which seems to be in real trouble, being forced to flap around close to buildings and trees.
I couldn't imagine why all these crows were going for it - what possible benefit is there for a crow in a heron crash landing? Anyway, the most plausible suggestion I find from googling is that
Source hereCrows are very smart. They apparently watch herons feeding and mob herons who have recently eaten. Herons in such a state are loaded-down and cannot fly well. When mobbed, the heron will often disgorge its meal enabling it to escape, while the crows get an easy meal.
The explanation came from an old friend who was once nearly hit by a fish that fell out of the sky. He seemed to think that mobbing of herons by crows was not unusual.
