A slight ripple in the wind behind me, the briefest graze of my hair and, within a split second, the ice-cream cone had been snatched from my hand. One second I was holding a mint choc chip, the next I wasn’t. It was so fast, and the raid so precise, I didn’t really see it happen – just a vision of the gull’s tail feathers as it took to the sky.

I share my south-coast town with the gulls and you learn to be wary of them. Once, one landed on our table outside a fish and chip shop and made off with half our dinner. They nest noisily on our roof and like to wake us up at 5am every morning; they rip open the rubbish sacks people leave on the streets and creep close on the beach, looking for snacks.

On Sunday, a gull snatched a chihuahua, Gizmo, from a garden in Devon. “My partner was in the garden putting the washing out at the time and suddenly, he saw it swoop down,” the dog’s distraught owner told Devon Live. “It carried Gizmo a fair way as we couldn’t see him any more. I have no idea if he was dropped or where he is now.”

In 2015, in Cornwall, a yorkshire terrier had to be put down after gulls attacked him, leaving him with serious head wounds. His owner said “it was like a murder scene”. The same year, again in Cornwall, a pet tortoise died after being attacked by gulls.

Last month, the Royal Mail told some Cardiff residents that post deliveries could be affected by gull attacks on postal workers. “Our postmen and women can experience difficulties out when delivering or collecting mail due to swooping attacks by seagulls,” residents were told. In Lancashire, a couple reported being kept hostage in their house for days because a pair of gulls – whose chicks had slipped and fallen on to the porch above the front door – would dive-bomb them every time they tried to leave. In 2013, a woman had to have hospital treatment for cuts to her head sustained during an attack by a gull and, in 2002, a man died of a heart attack after being swooped at by the birds in his garden.

A gull eating a chip. Photograph: winhorse/Getty/iStockphoto

This time of year is when seagulls – the herring gulls and lesser black-backed gulls that have made towns and cities their home – are at their most aggressive. “Nestlings are becoming fledglings and when they take their first flight, they don’t necessarily fly very well,” says Peter Rock, who has spent years researching urban gull populations. “Often, the adult birds will hit them and drive them to the ground. It’s a bizarre spectacle, but the reason is, when they fly a bit too early, the likelihood is they’ll crash into something and really damage themselves.” The nestlings may end up being pushed down into a garden, to protect them, and if there are lots of shrubs or not enough room “for a run-up and a takeoff, they may be there for a day or two. The parents know their nestling is there and they will look after it.”

A lot of effort has gone into raising that chick. “They’re sitting on eggs for a month, and the fledgling period is about six weeks. Then after that, for a week or two, they look after them while they get used to flying. There is an investment of maybe 12 weeks. At this time of year, if something happens to their offspring, they won’t try again, so that means they won’t breed until next year. So the birds are quite fearless in protecting their young.” This will include trying to scare off anything they think may harm it, including people and dogs. “Incidents of gulls attacking dogs are not unknown, but it is rare,” says Rock. “The one thing we need to differentiate between is a real attack and a low pass – a threatening swoop. They will swoop at you, but won’t come any closer than 8-10ft. What they’re trying to do is drive you away from their territory. An attack will always come from behind, they will keep swooping at you until they get the opening to attack.” He recommends anyone being terrorised by gulls to carry a golf umbrella.

At any other time of year, he says, “gulls are not the slightest bit aggressive, unless it’s about competition for food”. It felt pretty aggressive when the gull snatched my ice-cream – a kilo of bird, swooping at 45mph with a wingspan of about 1.5 metres – but Rock says that is merely a question of ownership. “You may have paid the money for it, but that doesn’t mean it’s yours – that’s how the gulls work.” He has seen a gull partly swallow a sardine, only for another to pull it out of its mouth. “You may think it’s your house and you have all the paperwork to prove it, but the fact is, the gulls have settled on your roof, so therefore it’s theirs.”

‘Gulls are not the slightest bit aggressive, unless it’s about competition for food.’ Photograph: Posed by model/Getty/EyeEm

Are gulls becoming more aggressive? Steve Portugal, an ecophysiologist at Royal Holloway, University of London, doesn’t think so. “I think it’s more they’re coming into contact with us more,” he says – and when these very rare occurrences do happen, they’re publicised in newspapers and on social media. “Gulls have shifted their distribution and behaviours away from traditional nesting sites, which would have been cliffs and quite isolated areas, and started living in more urban areas because we make it easy for them. It only happens when there are babies involved – they are not randomly attacking people in November, it’s only ever to protect their young.” But does this proximity to people mean they are becoming bolder? “I guess it’s possible,” he says, although he adds that there hasn’t been any research done on this. “What would stop animals attacking us normally is fear, so it’s possible that any animal encountering people more often – urban foxes, for example – would become bolder. It would make sense that, over time, they gradually become more used to people.”

We don’t know what the current population of gulls is, although there is a survey being done this year, says Tony Whitehead at the RSPB. At the last count, in 2004, there were 130,000 herring gull pairs in summer, swelling to 730,000 individual birds in winter. “What we do know, on the censuses that have been carried out over the past 30 years, is there has been a decline in the number of herring gulls overall,” says Whitehead. As a result, the birds are protected and on the red list of threatened species. “We also know birds in towns and cities are producing more young successfully than those away from towns and cities, so it is quite possible the [urban] population is going up, but what we don’t know is whether that’s offsetting the overall decline.”

In the 19th century, there were no gulls in London, says Tim Dee, the wildlife writer and author of Landfill. “Only in the 20th century did gulls begin to come up the Thames. Some people began to feed them – people would come to the riverbank and share their lunch with them.” The Clean Air Act 1956 meant councils stopped burning rubbish, and so landfill sites started to fill up with waste food – this was also the end of rationing and the beginning of our convenient, throwaway culture. The gulls, drawn by easy food, started to move inland. “The two crucial sources of food are the stuff people chuck away in the street, but more substantially, the landfill sites, which peaked in the early 1990s,” says Dee. “This was before we began recycling our food waste. In the 1980s and 1990s, the first gulls in substantial numbers started breeding on rooftops, first of all in seaside towns, but increasingly moving inland.”

They discovered that towns and cities made more hospitable homes than clifftops on islands. “There is mostly not much disturbance,” says Rock. “It’s 4-6C warmer, which means gulls are capable of starting their breeding season earlier than those who breed on islands. We provide them with street lighting, which means they can forage at night as well as during the day.” He has seen birds take a “steam bath” using the emissions from heating flues. “Then, after that, they will find extractor fans blowing out warm air, so they’ll get a blow-dry as well.”

They are clever, resilient birds. “Many admire them for their adaptive skills,” says Dee. “Some people hate them and think they’re the new urban pigeons.” Are they a problem? “A lot of people see it that way,” says Rock. “My personal opinion is I wish people would see the decline of some species as a problem.” There is a view that other bird species are being pushed out by gulls, but Rock doesn’t believe this is the case.

Flock of seagulls. Photograph: Getty

Still, cash-strapped councils are spending hundreds of thousands of pounds on trying to control the birds. In her research, Sarah Trotter, an assistant professor of law at the London School of Economics, found Dumfries and Galloway in Scotland spent £263,000 between 2009 and 2016; Aberdeen spent £27,000 in 2015-16. The people doing well out of our growing antagonistic relationship with gulls, points out Rock, are the pest control companies – who use plastic owls in an attempt to scare them away, fly birds of prey, erect netting and swap eggs in nests for fake ones – even though he says there is no evidence any of it works.

And, says Whitehead: “If you don’t know what the overall population is, you don’t know at what point controls become damaging. You can apply to Natural England for a licence to cull gulls, but you’ve got to come up with some good reasons to do this.” This could include gulls nesting at airports, for instance. “Nicking a chip is not a good reason to kill whole populations of animals.”

A better solution, he says, would be to change our own behaviour. “You can walk down the seafront and you will see people throwing the odd chip, or a bit of sandwich, for a gull. Gulls are quite long-lived birds – up to 30 years – and as soon as they associate humans with food, they won’t distinguish between food that is given and food that is there for the taking. They also learn pretty quickly that if bin bags are left out or aren’t collected, that our streets are pretty good sources of food. If there is a conflict, it’s in the way we deal with food.”

Noise and nuisance is one thing, but actual, direct aggression is still very rare, says Portugal. “If you know there’s a gull nest then it’s probably good to avoid being around it too much to avoid any direct confrontation. But I don’t think it’s got to The Birds stage, where we should all be worried.”