Of all Britain’s predatory birds, grey herons are among the most successful. They have been the subject of the second longest-running survey for any species, with detailed records going back almost a century. In 1928 there were 4,000 pairs in England and Wales, while in 2015 the figure for all Britain was 11,124.
Herons have more than doubled their population partly as a result of remarkable versatility. Fish are the obvious dietary staple but mammals – rats, voles and moles included – are more than routine, as are snakes, lizards, frogs and birds’ eggs. Adult birds have been seen to eat anything from robins and starlings to wood pigeons and mallards. There was correspondence in last January’s edition of Birdwatch describing a heron at Rainham Marshes, in Essex, attacking and killing a member of its own species. The same letter referred to them recently killing and trying to devour little grebes and coots.
I’ve seen a good cross-section of this adaptability but never, until this day, had I witnessed the following technique. At Rockland Staithe there are a couple of tall metal posts at least 2m above the high-tide waterline. A heron is a habitual occupant of the tiny village quay, where the posts serve as a strategic perch to watch for possible titbits from local fishermen.
I noticed this individual heron hop and raise its wings, with knees bent low to the post, as if it felt itself threatened. Instead of flying off, however, it angled its dagger-bill at the water below the perch and then, as an oarsman might shove off a boat, it pressed forward and down, hitting the water like a huge kingfisher. There was a split second when it sat at the surface riding its own brief swell. Then the heron, with a nice-sized roach in its beak, rose once more. The long hackles at its neck swayed with the force of the action. Diamond drops cascaded everywhere from the black-fringed cloak of its wings, which now rose and fell like bellows and, with long legs trailing way below, the heron regained its iron post to feed. I timed it all at under 15 seconds.
