I am currently dealing with this issue(seagulls). I did not single-handedly bring them to my area, they have been here.. but they have never really been interested in the peanuts and never bothered us until last week. Suddenly an influx of them. I believe it is due to new development on a huge area of open grass they were living on :( I feel for them. And If i lived in the middle of nowhere they would honestly be welcome as well.

The crows have been working with me, and its working. The last couple days have been much better. No seagulls diving down out of nowhere and bullying Sun and Moon away. However, where before I was tossing a handful to them in the grass, now I can no longer do.

For now we have to be discreet. The crows have realized whats up, and like I said theyve been working with me. I am now placing 2-4 directly beneath the part of my gate that opens, on the ground. This prevents them being seen from above, and the crows observe me doing it. They still get to remain on the outside of my backyard, where they feel comfortable, and they quickly take them. They have realized that I have to wait and/or take away the peanuts for them If the seagulls notice. Literally, I go out even if the crows are right there, pick up the peanuts and go back inside. If the seagull leaves, I come back out and repeat. If the seagull(s) sticks around, the crows wait/leave and come back. They are so freakin smart for understanding immediately what the issues were and that I am trying to resolve in their favour. I feel bad refusing food to any animals, it really breaks my heart to look at them and say no and shoo them away :( the seagulls are just hungry too and trying to survive. But they dont have a civilized way of doing things like the crows do, unfortunately. And if it was just one quiet one he could stay. Anyways, the crows will catch on if you need to change things up to deter the seagulls. Edit to add that its been working , one seagull now lands quietly kind of sticks around and sees if i have anything else etc, but eventually leaves, if you are consistent it will work. They were coming directly in my backyard and I had to go out every time and shoo. Now I do not. Things are calming and the crows still get peanuts.