Rome has been invaded by thousands of gulls - the birds boldly steal food, make a mess on statues and have even attacked the Pope's doves of peace.
I was on the bus the other morning, drowsily heading for work, but through the window I spotted something that woke me up - a rather gruesome scene.
On the pavement a big, powerful gull was standing over a pigeon it had killed. Then the gull grabbed the carcass in its beak, launched himself over the top of my bus, dropped into a piazza and starting to tear the pigeon apart.
I suppose I still expect gulls to do the sort of things they're supposed to, like ride the wind on lonely shorelines, follow trawlers, live off scraps of fish - not devour pigeons on city streets.
But in many places these birds are giving up on the sea, and moving to town. Rome is no exception.
For thousands of years it had no nesting gulls. They only began coming in the 1980s, lured by bins and dumps groaning with food chucked away by modern Romans. Now there are tens of thousands of gulls here and this latest invasion of the Eternal City can be a bit barbaric.
Earlier this year Pope Francis was at his window, high above the masses in St Peter's Square. Beside him two children held two, pure white doves of peace. They released them, and the crowd cheered.
Horrifyingly one bird was almost immediately attacked in mid-air by a gull. He got the dove up against a wall of the Pope's palace, but he only had his prey by the tail.
The pigeon got away, leaving the gull with just a beak-full of feathers. Still, it was hard to imagine a more disturbing omen for peace. And things didn't get any better when a vicious looking crow savaged the other hapless dove.
But Rome's gulls surely love the autumn most, when millions of starlings come to the city. They swarm at dusk. It's one of nature's great air shows.
The flocks make vast, dark, swirling smudges in the sky. Hundreds of thousands of birds moving, almost as one, twisting and turning through the fading light. Then they roost in a screeching mass in the trees along the Tiber.
In ancient Rome the shapes the starlings made in the heavens were watched for signs - a way of knowing the mood of the gods. But these days, the swarms are hunted by the gulls. For them, it must be a sort of banqueting season.
The gulls aren't only bothering the local wildlife. I was at a rooftop bar the other evening. A posh place with white table cloths and a sweeping panorama of the city skyline.
But the gulls were making trouble. They'd perch on the edge of the balcony, almost within touching distance and fix you with a hungry glare. They wanted your snacks.
I watched a big gull make his move. As soon as a table was abandoned he was on it - ravenously gulping down the leftovers on a plate.
Next to us another gull was threatening an assault on a table that was still occupied. A smartly-dressed lady with blonde hair piled high on her head didn't like this, and her male companion was struggling to calm her down.
But it wasn't so much a scene from Hitchcock's The Birds - more of a pantomime really. A gull chick was slithering around on the tiles demanding food from his mother, screeching and screeching.
The restaurant's pianist was doing his best, tinkling away. But the place still sounded like Aberdeen when the trawlers come home.
As soon as we stood up from our table a gull was on it, pecking at the peanuts. A chubby waiter trotted over, and wearily flapped a menu at the big bird.
Those lucky enough to have rooftop apartments must loathe the gulls who become their rowdy neighbours in the nesting season.
The birds can be aggressive if they think you're threatening their chicks. You can be subjected to much squawking, and dive-bombing assaults or even be the target of a well-aimed streak of gull droppings. That'll spoil your morning on your terrace.
But as it happens I don't live up at the top of a palazzo and I don't mind the gulls. In fact, I reckon these latest arrivals add something to the ancient city.
I like to see flocks of them cooling off in the river when I cross the Tiber on a summer evening. I like to watch them go drifting, wings out-stretched across the red rooftops, gliding gracefully between the domes of the churches in the setting sun.
And they're here to stay. The gulls have become Romans.
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