Sea and gulls are they associated anymore?

Someone dropped a quiche in London street and as I am watching 10 black headed gulls and 7 herring gulls not to mention several magpies and crows appeared. Possibly so many as street busy so it has taken some time for it to be finished off.
Street nowhere near river, sea, McDonalds or even rubbish dump so it is remarkable how so many managed to find this item, like a scene from ‘The Birds’ as a toddler pulled back from approaching too close.

I vaguely remember a paper (in British Birds probably) charting the changing habits of ‘sea’ gulls. They were virtually unknown inland in the 19th Century. Now they appear in their thousands at inland lakes and even just farmland. (I’ve seen 2,000 black-headed gulls on the farm across the road from us.)
There was a mention on a TV programme about how the gulls that appear at the top of Cairngorm (near the ski lift) are a threat to native species. I don’t know, but I imagine that a young mountain hare would be easy pickings for a herring gull, for example. One of the problems is that people discard half-eaten sandwiches which then attract scavangers.

But it is a bit odd given that kites were common in London on rubbish in the past, why were gulls not common there at that time too?

Don’t know about the comparison with Red Kites. Regards Gulls, fewer fish in the sea combined with readily available food sources inland and safer nesting sites are part of the answer. This bbc article is quite informative about gulls moving away from the sea and forming colonies inland: Why seagulls are making their homes in our cities - BBC Future

I don’t know the answer to that one! Perhaps the kites out-scavenged the gulls?!
Birds can learn and forget new habits surprisingly quickly as with the well known example of blue tits going for milk-bottle tops, which was common when I was a boy. The current generation of blue tits no longer do this as there was a period when they ‘forgot’ due to lack of opportunity.

If they have changed their habits so much then I wonder if they might change other aspects such as their colour. Don’t know why the plumage is white, at least on underside, could see that darker plumage above might have some ‘blending in with rock’ advantage when nesting. But if there are no predators, other than perhaps foxes, then is there any selective advantage in changing colour.

The Seabird’s Cry by Adam Nicolson has an interesting few pages about urban gulls. They have greater body weight, suggesting they are ‘doing better’ in cities, but poorer breeding success. He concludes junk food makes junk gulls.

… and also junk people??

The white underside of gulls is said to be to camouflage them against the sky (so the fish that they are hunting don’t spot them).

Countershading - Wikipedia

An excellent read!
An excellent read!

Perhaps that also works when they are dancing around tapping their feet on the football pitches encouraging the worms to come to surface. Although not sure if the worms would notice whatever colour the bird was.

Nice, everyone should read that
Look through your old observations and see if you have captured it

This photo illustrates the point nicely - a very evocative photo, IMO.

I’m about 4 miles from the sea as the crow/seagull flies. At dusk in the winter months I get hundreds of gulls flying towards the coast from further inland. They apparently roost at sea overnight but forage inland during the day. I presume they go in the other direction in the morning but I’ve never seen that.

origionaly we were talking about habits so i thought i would join in aswell but now its about things about the colour thing which may play a role in survival while I understand the interest I dont see what it has to do with gulls and rubbish so im not really interested but im interested in the hsbit thing. habit wise Blue tits arnt the only ones that learn habits so do crows and gulls. the topic about blue tots and habits wasnt random.

if Blue tits can learn how to open a milk bottle why not gulls learn tricks too. can they forget also and if so can they re learn behaviors. they hsvr learned to asdociate people with food just as othrt birds have including garden birds and learned how to find them and where and can even be quiet clever. gulls know how to get into rubbish bins I even seen one open one once. and have learned other ways to find food and how to find them aswell

also gulls arnt strictly seabirds anymore since they can be found land and sea. nowadays the term gulls is more acurate since sea gulls and sea birds implys they can only be found at sea. that might used to of been the case before the factors that caused them to come inland and before they learned to asdociate people with food and how to get them or even how to get into them but evet since they have spread inland there not considered strictly seabirds anymore unlike may of been the case when first termed seagulls but its not the case anymore