Ice thick on the river this morning, and gulls thick on the ice. Gulls are interesting: fiercely hierarchical but not territorial. This means that unlike, say, robins, who establish radii around their nests (I think it's about 60', but I could be wrong) and chase away any other robin who comes near, gulls don't particularly care where they perch and have no instinct to return to the same spot to hang out. The instinct they DO have is to perch on whatever spot the gull who got there first is sitting on, I guess on the theory that he found the best spot. (Because if you get there first why would you sit on the second-best spot?) So they spend a lot of time and energy kicking each other off pilings, roofs and ice floes. And then settling their wings and looking around to see what was so fabulous about that spot. Meanwhile, the gull who got evicted flaps around looking for some other sucker to evict. I guess evolutionarily it works for them, but it seems like a lot of effort for not much payoff to me.